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  • American Meteorological Society  (124)
  • Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.  (81)
  • American Association for the Advancement of Science
  • Cell Press
  • Molecular Diversity Preservation International
  • PANGAEA
  • 2020-2023  (235)
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  • 1
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-05-04
    Description: Climate change can make extreme drought and flood events more frequent, while damming large rivers can alter the hydrological regime by making droughts more prolonged and floods less intense. Together, both factors can affect aquatic communities. Here, the variation of Chironomidae community attributes between extreme floods and droughts in a neotropical floodplain river was investigated. The hypothesis that the abundance, richness, diversity and variability attributes of the Chironomidae community are reduced after extreme events was tested. Sampling took place quarterly from 2000 to 2012, although only a few years were selected to investigate our predictions. Twelve sampling periods were selected, which were divided into years in which, El Niño (extreme flood) and La Niña (extreme drought) phenomena occurred. In the Paraná River, three points were determined for the collection of benthic material, in transect: right bank, center and left bank of the river. We recorded 75 morphospecies of Chironomidae. The most common taxa in periods of extreme flooding were Djalmabatista sp 2, Lopescladius sp 1 and Tanytarsus type E. For periods of extreme drought, the most common taxa were Polypedilum (Tripodura) sp 4, Polypedilum sp 3 and Lopescladius sp 1. A composition and attributes of the Chironomidae community in the Paraná River varied between before and after extreme flood and drought events. Attributes such as Shannon-Wiener abundance, richness and diversity were reduced after extreme floods and, in contrast, tended to increase after extreme drought events (except Shannon diversity). Thus, it can be stated that the evaluated flood and drought events, despite being extreme, have different consequences in the Chironomidae community of the Paraná River. Given the environmental and global conditions we experience today, including climate change and dams, extreme events could be even more frequent in aquatic ecosystems. Therefore, it is essential to understand the consequences of extreme flood and drought events on ecosystems with high biodiversity and that provide relevant ecosystem services such as floodplain rivers.
    Description: As mudanças climáticas podem tornar eventos de secas e cheias extremas mais frequentes, enquanto barramentos de grandes rios podem alterar o regime hidrológico por tornar as secas mais prolongadas e as cheias menos intensas. Em conjunto, ambos fatores podem afetar as comunidades aquáticas. Aqui, a variação dos atributos da comunidade de Chironomidae entre as cheias e secas extremas em um rio de planície de inundação neotropical. Testou-se a hipótese de que os atributos abundância, riqueza, diversidade e variabilidade da comunidade de Chironomidae são reduzidos após eventos extremos. As amostragens ocorreram trimestralmente 2000 a 2012, embora apenas alguns anos foram selecionados para investigar nossas predições. Selecionou-se 12 períodos de amostragem, que foram divididos em anos que ocorreram fenômenos de El Niño (cheia extrema) e La Niña (seca extrema). No rio Paraná foram determinados três pontos para coleta do material bentônico, em transecto: margem direita, centro e margem esquerda do rio. Registrou-se 75 morfoespécies de Chironomidae. Os táxos mais comuns nos períodos de cheia extrema foram Djalmabatista sp 2, Lopescladius sp 1 e Tanytarsus tipo E. Para os períodos de seca extrema, os táxons mais comuns foram Polypedilum (Tripodura) sp 4, Polypedilum sp 3 e Lopescladius sp 1. A composição e os atributos da comunidade de Chironomidae no rio Paraná variaram entre antes e depois de eventos de cheia e seca extremas. Os atributos, como abundância, riqueza e diversidade de Shannon-Wiener, foram reduzidos após cheias extremas e em contrapartida, tenderam a aumentar após eventos de seca extrema (exceto diversidade de Shannon). Pode-se afirmar que os eventos de cheias e secas avaliados, apesar de extremos, acarretam em diferentes consequências na comunidade de Chironomidae do rio Paraná. Considerando que as condições ambientais e globais que vivenciamos hoje, incluindo mudanças climáticas e barragens, os eventos extremos poderão ser ainda mais frequentes nos ecossistemas aquáticos. Portanto, é fundamental compreendermos as consequências dos eventos de cheia e seca extremas em ecossistemas com elevada biodiversidade e que fornecem relevantes serviços ecossistêmicos como rios de planícies de inundação.
    Description: Masters
    Keywords: Chironomidae (Diptera: Insecta) ; Zoobentos de água doce ; Comunidades, Ecologia de ; Pulso de inundação ; Mudanças climáticas ; ASFA_2015::Y::Zoobenthos ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::F::Floodplains ; ASFA_2015::C::Climatic changes
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 26pp.
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  • 2
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-05-04
    Description: Decomposition is a process of great importance to the ecosystem. Macroinvertebrates together with fungi and bacteria play a very important role in the cycling of organic matter. Through decomposition, nutrients that make up the organisms can be reused and macroinvertebrates act by fractionating the organic matter in this process. The exotic species Hydrilla verticillata (L.f) Royle usually causes problems in various regions of the globe such as economic damage in hydroelectric plants. This exotic species competes with native species and can facilitates new invasions. The objective of the present work is to evaluate how the colonization of macroinvertebrates occurs during the decomposition of H. verticillata and E. najas macrophytes, as well as other community attributes during the process such as density, richness, Shannon diversity and Pielou evenness. The experiment was carried out in Garças Lake and the macrophytes were collected in Paraná River. Macrophytes were dried at room temperature and 5 g of each species were added in two types of litterbags, one thin mesh (0.5 mm) and another with thick mesh (4 mm), totalling 100 litterbags. The litterbags were fixed at 5 points in the lake and removed each 4 days. In the laboratory the litterbags were washed with a 0.2 μm mesh sieve, the decomposing material was sorted and the remainder was oven dried for further decay calculation. There was no significant difference in community attributes, except when time was applied assigned to analysis. The decomposition was similar in both species because both had similar characteristics, including phylogenetic proximity. The most observed taxon during the process was Chironomidae. Thus, it is worth noting that more studies are needed to elucidate questions related to the colonization process and quantify the degradation of organic matter of exotic and native species in the Upper Paraná River floodplain.
    Description: A decomposição é um processo de grande importâcia para os ecossistemas, e os macroivertebrados juntamente com fungos e bactérias possuem um importante papel na ciclagem da matéria orgânica. Pela decomposição, os nutrientes que compõem os organismos podem ser novamente reutilizados, e os macroinvertebrados atuam fracionando essa matéria orgânica. A espécie exótica Hydrilla verticillata (L.f) Royle é uma espécie de macrófita submersas que atualmente tem causado problemas em diversas regiões do globo. Além de causar prejuízos econômicos em usinas hidroelétricas H. verticillata causa prejuízos para as espécies nativas devido a competição por recursos, o que pode facilitar novas invasões. Avaliou-se como ocorre a colonização de macroinvertebrados durante a decomposição das macrófitas H. verticillata e E. najas, além de avaliar outros atributos de comunidade durante o processo como, por exemplo, densidade, riqueza, diversidade de Shannon e equitabilidade de Pielou. O experimento foi realizado na Lagoa das Garças e as macrófitas foram coletadas no Rio Paraná. Após a coleta, as plantas foram secas em temperatura ambiente. Foram acondicionadas 5 g de material seco de cada espécie em dois tipos de litterbag, um com malha fina (0,5mm) e outro com malha grossa (4 mm), totalizando 100 litterbags. Os litterbags foram fixados em 5 pontos na lagoa e retirados em um intervalo de 4 em 4 dias. Em laboratório, os litterbags foram lavados com auxílio de peneira de malha de 0,2 μm. O material em decomposição foi triado e o restante foi seco em estufa para posterior cálculo de decaimento. Não houve diferença significativa nos atributos de comunidade, exceto quando o tempo foi aplicado como uma variável à análise. A decomposição foi similar nas duas espécies devido a ambas possuírem características semelhantes. Talvez, a proximidade filogenética entre as macrófitas possa ter gerado a similaridade dos resultados obtidos durante o experimento. O táxon mais observado durante o processo foi de Chironomidae e o processo de colonização ocorreu de forma muito semelhante para ambos os tratamentos. Os tipos de malhas mostraram resultados parecidos, pois podem não ter influenciado a colonização e a entrada dos macroinvertebrados durante o processo de decomposição. Desse modo, a colonização dos invertebrados não dependeu das espécies de macrófita e/ou tipo de malha. Por isso ressalta-se a importância de novos estudos para melhor direcionar questões voltadas para a colonização e quantificar a degradação da matéria orgânica relativa a espécies exóticas e nativas na planície de inundação do alto rio Paraná.
    Description: Masters
    Keywords: Macroinvertebrados de água doce ; Colonização ; Lagos rasos ; Indicadores biológicos ; Macrófitas aquáticas submersas ; Decomposição ; Ecologia de lagos rasos ; Processos ecossistêmicos ; ASFA_2015::M::Macrophytes ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::F::Floodplains ; ASFA_2015::D::Decomposition ; ASFA_2015::C::Colonization ; ASFA_2015::L::Lakes
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 25pp.
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  • 3
    Publication Date: 2022-05-25
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Sadai, S., Condron, A., DeConto, R., & Pollard, D. Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming. Science Advances, 6(39), (2020): eaaz1169, doi:10.1126/sciadv.aaz1169.
    Description: Meltwater and ice discharge from a retreating Antarctic Ice Sheet could have important impacts on future global climate. Here, we report on multi-century (present–2250) climate simulations performed using a coupled numerical model integrated under future greenhouse-gas emission scenarios IPCC RCP4.5 and RCP8.5, with meltwater and ice discharge provided by a dynamic-thermodynamic ice sheet model. Accounting for Antarctic discharge raises subsurface ocean temperatures by 〉1°C at the ice margin relative to simulations ignoring discharge. In contrast, expanded sea ice and 2° to 10°C cooler surface air and surface ocean temperatures in the Southern Ocean delay the increase of projected global mean anthropogenic warming through 2250. In addition, the projected loss of Arctic winter sea ice and weakening of the Atlantic Meridional Overturning Circulation are delayed by several decades. Our results demonstrate a need to accurately account for meltwater input from ice sheets in order to make confident climate predictions.
    Description: This research was supported by the NSF Office of Polar Programs through NSF grant 1443347, the Biological and Environmental Research (BER) division of the U.S. Department of Energy through grant DE-SC0019263, the NSF through ICER 1664013, and by a grant to the NASA Sea Level Science Team 80NSSC17K0698.
    Repository Name: Woods Hole Open Access Server
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  • 4
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 33(9), (2020): 3845-3862, doi:10.1175/JCLI-D-19-0215.1.
    Description: The latitudinal structure of the Atlantic meridional overturning circulation (AMOC) variability in the North Atlantic is investigated using numerical results from three ocean circulation simulations over the past four to five decades. We show that AMOC variability south of the Labrador Sea (53°N) to 25°N can be decomposed into a latitudinally coherent component and a gyre-opposing component. The latitudinally coherent component contains both decadal and interannual variabilities. The coherent decadal AMOC variability originates in the subpolar region and is reflected by the zonal density gradient in that basin. It is further shown to be linked to persistent North Atlantic Oscillation (NAO) conditions in all three models. The interannual AMOC variability contained in the latitudinally coherent component is shown to be driven by westerlies in the transition region between the subpolar and the subtropical gyre (40°–50°N), through significant responses in Ekman transport. Finally, the gyre-opposing component principally varies on interannual time scales and responds to local wind variability related to the annual NAO. The contribution of these components to the total AMOC variability is latitude-dependent: 1) in the subpolar region, all models show that the latitudinally coherent component dominates AMOC variability on interannual to decadal time scales, with little contribution from the gyre-opposing component, and 2) in the subtropical region, the gyre-opposing component explains a majority of the interannual AMOC variability in two models, while in the other model, the contributions from the coherent and the gyre-opposing components are comparable. These results provide a quantitative decomposition of AMOC variability across latitudes and shed light on the linkage between different AMOC variability components and atmospheric forcing mechanisms.
    Description: The authors gratefully acknowledge support from the Physical Oceanography Program of the U.S. National Science Foundation (Awards OCE-1756143 and OCE-1537136) and the Climate Program Office of the National Oceanic and Atmospheric Administration (Award NA15OAR4310088). Gratitude is extended to Claus Böning and Arne Biastoch who shared ORCA025 output. S. Zou thanks F. Li, M. Buckley, and L. Li for helpful discussions. We also thank three anonymous reviewers for helpful suggestions.
    Keywords: Deep convection ; Ocean circulation ; Thermocline circulation
    Repository Name: Woods Hole Open Access Server
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  • 5
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    American Association for the Advancement of Science
    Publication Date: 2022-05-25
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Foukal, N. P., Gelderloos, R., & Pickart, R. S. A continuous pathway for fresh water along the East Greenland shelf. Science Advances, 6(43), (2020): eabc4254, doi:10.1126/sciadv.abc4254.
    Description: Export from the Arctic and meltwater from the Greenland Ice Sheet together form a southward-flowing coastal current along the East Greenland shelf. This current transports enough fresh water to substantially alter the large-scale circulation of the North Atlantic, yet the coastal current’s origin and fate are poorly known due to our lack of knowledge concerning its north-south connectivity. Here, we demonstrate how the current negotiates the complex topography of Denmark Strait using in situ data and output from an ocean circulation model. We determine that the coastal current north of the strait supplies half of the transport to the coastal current south of the strait, while the other half is sourced from offshore via the shelfbreak jet, with little input from the Greenland Ice Sheet. These results indicate that there is a continuous pathway for Arctic-sourced fresh water along the entire East Greenland shelf from Fram Strait to Cape Farewell.
    Description: Funding for this work comes from the NSF under grant numbers OCE-1756361 and OCE-1558742 (N.P.F. and R.S.P.) and grant numbers OCE-1756863 and OAC-1835640 (R.G.).
    Repository Name: Woods Hole Open Access Server
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  • 6
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Hahn, L. C., Storelvmo, T., Hofer, S., Parfitt, R., & Ummenhofer, C. C. Importance of Orography for Greenland cloud and melt response to atmospheric blocking. Journal of Climate, 33(10), (2020): 4187-4206, doi:10.1175/JCLI-D-19-0527.1.
    Description: More frequent high pressure conditions associated with atmospheric blocking episodes over Greenland in recent decades have been suggested to enhance melt through large-scale subsidence and cloud dissipation, which allows more solar radiation to reach the ice sheet surface. Here we investigate mechanisms linking high pressure circulation anomalies to Greenland cloud changes and resulting cloud radiative effects, with a focus on the previously neglected role of topography. Using reanalysis and satellite data in addition to a regional climate model, we show that anticyclonic circulation anomalies over Greenland during recent extreme blocking summers produce cloud changes dependent on orographic lift and descent. The resulting increased cloud cover over northern Greenland promotes surface longwave warming, while reduced cloud cover in southern and marginal Greenland favors surface shortwave warming. Comparison with an idealized model simulation with flattened topography reveals that orographic effects were necessary to produce area-averaged decreasing cloud cover since the mid-1990s and the extreme melt observed in the summer of 2012. This demonstrates a key role for Greenland topography in mediating the cloud and melt response to large-scale circulation variability. These results suggest that future melt will depend on the pattern of circulation anomalies as well as the shape of the Greenland Ice Sheet.
    Description: This research was supported by the Woods Hole Oceanographic Institution Summer Student Fellow program, by the U.S. National Science Foundation under AGS-1355339 to C.C.U., and by the European Research Council through Grant 758005.
    Keywords: Ice sheets ; Blocking ; Cloud cover ; Topographic effects ; Climate change ; Climate variability
    Repository Name: Woods Hole Open Access Server
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  • 7
    Publication Date: 2022-03-01
    Description: To examine the atmospheric responses to Arctic sea ice variability in the Northern Hemisphere cold season (from October to the following March), this study uses a coordinated set of large-ensemble experiments of nine atmospheric general circulation models (AGCMs) forced with observed daily varying sea ice, sea surface temperature, and radiative forcings prescribed during the 1979–2014 period, together with a parallel set of experiments where Arctic sea ice is substituted by its climatology. The simulations of the former set reproduce the near-surface temperature trends in reanalysis data, with similar amplitude, and their multimodel ensemble mean (MMEM) shows decreasing sea level pressure over much of the polar cap and Eurasia in boreal autumn. The MMEM difference between the two experiments allows isolating the effects of Arctic sea ice loss, which explain a large portion of the Arctic warming trends in the lower troposphere and drive a small but statistically significant weakening of the wintertime Arctic Oscillation. The observed interannual covariability between sea ice extent in the Barents–Kara Seas and lagged atmospheric circulation is distinguished from the effects of confounding factors based on multiple regression, and quantitatively compared to the covariability in MMEMs. The interannual sea ice decline followed by a negative North Atlantic Oscillation–like anomaly found in observations is also seen in the MMEM differences, with consistent spatial structure but much smaller amplitude. This result suggests that the sea ice impacts on trends and interannual atmospheric variability simulated by AGCMs could be underestimated, but caution is needed because internal atmospheric variability may have affected the observed relationship.
    Description: Published
    Description: 8419–8443
    Description: 2A. Fisica dell'alta atmosfera
    Description: JCR Journal
    Keywords: Arctic ; Sea ice ; Atmospheric circulation ; Climate models ; 01.01. Atmosphere
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 8
    Publication Date: 2022-02-14
    Description: The influence of the Atlantic multidecadal variability (AMV) on the North Atlantic storm track and eddy-driven jet in the winter season is assessed via a coordinated analysis of idealized simulations with state-of-the-art coupled models. Data used are obtained from a multimodel ensemble of AMV± experiments conducted in the framework of the Decadal Climate Prediction Project component C. These experiments are performed by nudging the surface of the Atlantic Ocean to states defined by the superimposition of observed AMV± anomalies onto the model climatology. A robust extratropical response is found in the form of a wave train extending from the Pacific to the Nordic seas. In the warm phase of the AMV compared to the cold phase, the Atlantic storm track is typically contracted and less extended poleward and the low-level jet is shifted toward the equator in the eastern Atlantic. Despite some robust features, the picture of an uncertain and model-dependent response of the Atlantic jet emerges and we demonstrate a link between model bias and the character of the jet response.
    Description: Published
    Description: 347-360
    Description: 4A. Oceanografia e clima
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 9
    Publication Date: 2022-12-01
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 103(6), (2022): E1502-E1521, https://doi.org/10.1175/bams-d-21-0227.1.
    Description: Climate observations inform about the past and present state of the climate system. They underpin climate science, feed into policies for adaptation and mitigation, and increase awareness of the impacts of climate change. The Global Climate Observing System (GCOS), a body of the World Meteorological Organization (WMO), assesses the maturity of the required observing system and gives guidance for its development. The Essential Climate Variables (ECVs) are central to GCOS, and the global community must monitor them with the highest standards in the form of Climate Data Records (CDR). Today, a single ECV—the sea ice ECV—encapsulates all aspects of the sea ice environment. In the early 1990s it was a single variable (sea ice concentration) but is today an umbrella for four variables (adding thickness, edge/extent, and drift). In this contribution, we argue that GCOS should from now on consider a set of seven ECVs (sea ice concentration, thickness, snow depth, surface temperature, surface albedo, age, and drift). These seven ECVs are critical and cost effective to monitor with existing satellite Earth observation capability. We advise against placing these new variables under the umbrella of the single sea ice ECV. To start a set of distinct ECVs is indeed critical to avoid adding to the suboptimal situation we experience today and to reconcile the sea ice variables with the practice in other ECV domains.
    Description: PH’s contribution was funded under the Australian Government’s Antarctic Science Collaboration Initiative program, and contributes to Project 6 of the Australian Antarctic Program Partnership (ASCI000002). PH acknowledges support through the Australian Antarctic Science Projects 4496 and 4506, and the International Space Science Institute (Bern, Switzerland) project #405.
    Description: 2022-12-01
    Keywords: Sea ice ; Climate change ; Climatology ; Climate records
    Repository Name: Woods Hole Open Access Server
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  • 10
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-12-06
    Description: Aquatic environments have been anthropically influenced over the years, mainly with the construction of dams and hydroelectric plants. However, few studies evaluate how the parasitic fauna can be influenced in the long term by these environmental changes. Possible changes in the composition of endoparasites of the invasive fish Trachelyopterus galeatus in the upper Paraná River floodplain were investigated over a 27-year study period. 79 fish were analyzed in period 1 (1993) and 31 in period 2 (2019/2020). In the first period, the fish showed higher values in the variables weight (g) and standard length (cm), when compared to period 2. A total of five species of endoparasites were found, three per period. Although the richness was the same, the composition of endoparasites differed between the periods, as only one species of digenetic (Microrchis oligovitellum) parasitized the host in both periods of study. It was found that both the development of the fish and its endoparasites were affected over time. It is noteworthy that the beginning of operation of the Porto Primavera dam, located upstream of the plain, occurred between the two sampling periods (1999), and caused several environmental changes, possibly being the main responsible for these changes in the parasitofauna. Most endoparasites require intermediate hosts to complete their life cycles. Therefore, a modified environment may lose diversity and ecological interactions, as it affects the populations they use during the transmission process between hosts. This may explain the difference found in the infracommunities of T. galeatus parasites, emphasizing, through the results obtained, the importance of including these organisms in studies that evaluate environmental impacts caused by anthropic actions
    Description: Ambientes aquáticos têm sido influenciado antropicamente ao longo dos anos, principalmente com a construção de barragens e usinas hidrelétricas. Contudo, poucos estudos avaliam como a fauna parasitária pode ser influenciada a longo prazo por essas mudanças ambientais. Investigou-se possíveis alterações na composição de endoparasitas do peixe invasor Trachelyopterus galeatus na planície de inundação do alto rio Paraná, em um intervalo de 27 anos de estudo. Foram analisados 79 peixes no período 1 (1993) e 31 no período 2 (2019/2020). No primeiro período, os peixes apresentaram maiores valores nas variáveis peso (g) e comprimento padrão (cm), quando comparados com o período 2. Encontrou-se um total de cinco espécies de endoparasitas, sendo três por período. Apesar da riqueza ter sido igual, a composição de endoparasitas diferiu entre os períodos, pois apenas uma espécie de digenético (Microrchis oligovitellum) parasitou o hospedeiro nos dois períodos de estudo. Constatou-se que tanto o desenvolvimento do peixe quanto seus endoparasitas foram afetados ao longo do tempo. Destaca-se que o início do funcionamento da barragem de Porto Primavera, localizada à montante da planície, ocorreu entre os dois períodos de amostragem (1999), e provocou diversas alterações ambientais, sendo, possivelmente, a principal responsável por essas mudanças da parasitofauna. A maioria dos endoparasitas requer hospedeiros intermediários para completar seus ciclos de vida. Portanto, um ambiente modificado, pode perder diversidade e interações ecológicas, visto que afeta as populações que eles utilizam durante o processo de transmissão entre hospedeiros. Isso pode explicar a diferença encontrada nas infracomunidades de parasitas de T. galeatus, enfatizando, por meio dos resultados obtidos, a importância de incluir esses organismos nos estudos que avaliam impactos ambientais causados por ações antrópicas.
    Description: Masters
    Keywords: Fauna endoparasitária (Platyhelminthes). ; Trachelyopterus galeatus (Linnaeus, 1766) “cangati”. ; Peixes siluriformes. ; Parasitismo. ; Ecologia. ; Parasitismo em peixes de água doce. ; ASFA_2015::F::Freshwater fish ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::P::Parasitism ; ASFA_2015::P::Parasites
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
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  • 11
    Publication Date: 2022-11-27
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(6), (2022): 1233-1244, https://doi.org/10.1175/jpo-d-21-0223.1.
    Description: The Sverdrup relation is the backbone of wind-driven circulation theory; it is a simple relation between the meridional transport of the wind-driven circulation in the upper ocean and the wind stress curl. However, the relation is valid for steady circulation only. In this study, a time-dependent Sverdrup relation is postulated, in which the meridional transport in a time-dependent circulation is the sum of the local wind stress curl term and a time-delayed term representing the effect of the eastern boundary condition. As an example, this time-dependent Sverdrup relation is evaluated through its application to the equatorial circulation in the Indian Ocean, using reanalysis data and a reduced gravity model. Close examination reveals that the southward Somali Current occurring during boreal winter is due to the combination of the local wind stress curl in the Arabian Sea and delayed signals representing the time change of layer thickness at the eastern boundary.
    Description: This work is supported by NSFC (41822602, 41976016, 42005035, 42076021), the Strategic Priority Research Program of Chinese Academy of Sciences (XDB42000000, XDA 20060502), Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML2019ZD0306), Guangdong Basic and Applied Basic Research Foundation (2021A1515011534), Youth Innovation Promotion Association CAS, ISEE2021ZD01, and LTOZZ2002. The numerical simulation is supported by the High-Performance Computing Division in the South China Sea Institute of Oceanology.
    Description: 2022-11-27
    Keywords: Ocean circulation ; Ocean dynamics ; Rossby waves ; Wind stress curl
    Repository Name: Woods Hole Open Access Server
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  • 12
    Publication Date: 2022-11-18
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tian, Y., Liu, X., Li, J., Deng, Y., DeGiorgis, J. A., Zhou, S., Caratenuto, A., Minus, M. L., Wan, Y., Xiao, G., & Zheng, Y. Farm-waste-derived recyclable photothermal evaporator. Cell Reports Physical Science, 2(9), (2021): 100549, https://doi.org/10.1016./j.xcrp.2021.100549
    Description: Interfacial solar steam generation is emerging as a promising technique for efficient desalination. Although increasing efforts have been made, challenges exist for achieving a balance among a plethora of performance indicators—for example, rapid evaporation, durability, low-cost deployment, and salt rejection. Here, we demonstrate that carbonized manure can convert 98% of sunlight into heat, and the strong capillarity of porous carbon fibers networks pumps sufficient water to evaporation interfaces. Salt diffusion within microchannels enables quick salt drainage to the bulk seawater to prevent salt accumulation. With these advantages, this biomass-derived evaporator is demonstrated to feature a high evaporation rate of 2.81 kg m−2 h−1 under 1 sun with broad robustness to acidity and alkalinity. These advantages, together with facial deployment, offer an approach for converting farm waste to energy with high efficiency and easy implementation, which is particularly well suited for developing regions.
    Description: This project is supported by the National Science Foundation through grant no. CBET-1941743. This project is based upon work supported in part by the National Science Foundation under EPSCoR Cooperative Agreement no. OIA-1655221.
    Keywords: Biomass ; Recyclable ; Manure ; Farm waste ; Photothermal evaporation ; Desalination
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 13
    Publication Date: 2022-12-09
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(7), (2022): 1333-1350, https://doi.org/10.1175/jpo-d-21-0298.1.
    Description: Idealized numerical simulations were conducted to investigate the influence of channel curvature on estuarine stratification and mixing. Stratification is decreased and tidal energy dissipation is increased in sinuous estuaries compared to straight channel estuaries. We applied a vertical salinity variance budget to quantify the influence of straining and mixing on stratification. Secondary circulation due to the channel curvature is found to affect stratification in sinuous channels through both lateral straining and enhanced vertical mixing. Alternating negative and positive lateral straining occur in meanders upstream and downstream of the bend apex, respectively, corresponding to the normal and reversed secondary circulation with curvature. The vertical mixing is locally enhanced in curved channels with the maximum mixing located upstream of the bend apex. Bend-scale bottom salinity fronts are generated near the inner bank upstream of the bend apex as a result of interaction between the secondary flow and stratification. Shear mixing at bottom fronts, instead of overturning mixing by the secondary circulation, provides the dominant mechanism for destruction of stratification. Channel curvature can also lead to increased drag, and using a Simpson number with this increased drag coefficient can relate the decrease in stratification with curvature to the broader estuarine parameter space.
    Description: The research leading to these results was funded by NSF Awards OCE-1634481 and OCE-2123002.
    Description: 2022-12-09
    Keywords: Estuaries ; Mixing ; Secondary circulation ; Fronts ; Tides ; Numerical analysis/modeling
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 14
    Publication Date: 2022-12-16
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(7), (2022): 1415–1430. https://doi.org/10.1175/JPO-D-21-0147.1.
    Description: Strong subinertial variability near a seamount at the Xisha Islands in the South China Sea was revealed by mooring observations from January 2017 to January 2018. The intraseasonal deep flows presented two significant frequency bands, with periods of 9–20 and 30–120 days, corresponding to topographic Rossby waves (TRWs) and deep eddies, respectively. The TRW and deep eddy signals explained approximately 60% of the kinetic energy of the deep subinertial currents. The TRWs at the Ma, Mb, and Mc moorings had 297, 262, and 274 m vertical trapping lengths, and ∼43, 38, and 55 km wavelengths, respectively. Deep eddies were independent from the upper layer, with the largest temperature anomaly being 〉0.4°C. The generation of the TRWs was induced by mesoscale perturbations in the upper layer. The interaction between the cyclonic–anticyclonic eddy pair and the seamount topography contributed to the generation of deep eddies. Owing to the potential vorticity conservation, the westward-propagating tilted interface across the eddy pair squeezed the deep-water column, thereby giving rise to negative vorticity west of the seamount. The strong front between the eddy pair induced a northward deep flow, thereby generating a strong horizontal velocity shear because of lateral friction and enhanced negative vorticity. Approximately 4 years of observations further confirmed the high occurrence of TRWs and deep eddies. TRWs and deep eddies might be crucial for deep mixing near rough topographies by transferring mesoscale energy to small scales.
    Description: This work was supported by the National Natural Science Foundation of China (92158204, 91958202, 42076019, 41776036, 91858203), the Open Project Program of State Key Laboratory of Tropical Oceanography (project LTOZZ2001), and Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML2019ZD0304).
    Description: 2022-12-16
    Keywords: Abyssal circulation ; Ocean circulation ; Ocean dynamics ; Intraseasonal variability
    Repository Name: Woods Hole Open Access Server
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  • 15
    Publication Date: 2022-12-21
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(12), (2022): 2923–2933, https://doi.org/10.1175/jpo-d-22-0064.1.
    Description: The characteristics and dynamics of depth-average along-shelf currents at monthly and longer time scales are examined using 17 years of observations from the Martha’s Vineyard Coastal Observatory on the southern New England inner shelf. Monthly averages of the depth-averaged along-shelf current are almost always westward, with the largest interannual variability in winter. There is a consistent annual cycle with westward currents of 5 cm s−1 in summer decreasing to 1–2 cm s−1 in winter. Both the annual cycle and interannual variability in the depth-average along-shelf current are predominantly driven by the along-shelf wind stress. In the absence of wind forcing, there is a westward flow of ∼5 cm s−1 throughout the year. At monthly time scales, the depth-average along-shelf momentum balance is primarily between the wind stress, surface gravity wave–enhanced bottom stress, and an opposing pressure gradient that sets up along the southern New England shelf in response to the wind. Surface gravity wave enhancement of bottom stress is substantial over the inner shelf and is essential to accurately estimating the bottom stress variation across the inner shelf.
    Description: The National Science Foundation, Woods Hole Oceanographic Institution, the Massachusetts Technology Collaborative, and the Office of Naval Research have supported the construction and maintenance of MVCO. The analysis presented here was partially funded by the National Science Foundation under Grants OCE 1558874 and OCE 1655686.
    Keywords: Continental shelf/slope ; Coastal flows ; Momentum ; Ocean dynamics ; Wind stress
    Repository Name: Woods Hole Open Access Server
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  • 16
    Publication Date: 2022-12-21
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(12), (2022): 2909-2921, https://doi.org/10.1175/jpo-d-22-0063.1.
    Description: A remarkably consistent Lagrangian upwelling circulation at monthly and longer time scales is observed in a 17-yr time series of current profiles in 12 m of water on the southern New England inner shelf. The upwelling circulation is strongest in summer, with a current magnitude of ∼1 cm s−1, which flushes the inner shelf in ∼2.5 days. The average winter upwelling circulation is about one-half of the average summer upwelling circulation, but with larger month-to-month variations driven, in part, by cross-shelf wind stresses. The persistent upwelling circulation is not wind-driven; it is driven by a cross-shelf buoyancy force associated with less-dense water near the coast. The cross-shelf density gradient is primarily due to temperature in summer, when strong surface heating warms shallower nearshore water more than deeper offshore water, and to salinity in winter, caused by fresher water near the coast. In the absence of turbulent stresses, the cross-shelf density gradient would be in a geostrophic, thermal-wind balance with the vertical shear in the along-shelf current. However, turbulent stresses over the inner shelf attributable to strong tidal currents and wind stress cause a partial breakdown of the thermal-wind balance that releases the buoyancy force, which drives the observed upwelling circulation. The presence of a cross-shelf density gradient has a profound impact on exchange across this inner shelf. Many inner shelves are characterized by turbulent stresses and cross-shelf density gradients with lighter water near the coast, suggesting turbulent thermal-wind-driven coastal upwelling may be a broadly important cross-shelf exchange mechanism.
    Description: The National Science Foundation, Woods Hole Oceanographic Institution, the Massachusetts Technology Collaborative, and the Office of Naval Research have supported the construction and maintenance of MVCO. The analysis presented here was partially funded by the National Science Foundation under Grants OCE 1558874 and OCE 1655686.
    Keywords: Buoyancy ; Coastal flows ; Currents ; Dynamics ; Lagrangian circulation/transport ; Upwelling/downwelling
    Repository Name: Woods Hole Open Access Server
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  • 17
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    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-07
    Description: Freshwater ecosystems are changing their natural conditions, influenced and accelerated by human activities. These processes are capable of changing the hydrological regime and the composition of the communities, letting the future of aquatic biodiversity unknown. The construction of dams has been one of the main factors responsible for environmental changes, such as nutrients depletion, increased water transparency and loss of biodiversity in freshwater ecosystems. The aim of our study was to analyze the functional and taxonomic dissimilarity of the zooplankton community and its drivers in response to the effect of the hydrological cycle (drought and rainy), in two highly distinct floodplains, the Upper Paraná River (river with a cascade of dams) and the Amazon. A total of 72 samples were collected (16 AMA dry and 16 on rainy and 20 PAR dry and 20 on rainy) from zooplankton communities as the response variable, phytoplankton as a predictor of food, fish as a predictor of potential predators and limnological variables. Were calculated β-Total diversity and partitioned in the components β-Repl and β-Rich (taxonomic and functional approach). We expect that environmental heterogeneity is going to drive higher values of beta diversity. In sequence, distance-based redundancy analysis (db-RDA) was calculated using the distance matrices generated in the functional and taxonomic beta to assess which are the determinants of zooplankton beta diversity. Thus, we hypothesized that biotic interactions will have stronger relationships with zooplankton dissimilarity during the drought and, limnological variables and spatial component will be more important during rainy season. Greater environmental heterogeneity was found in the Amazon floodplain and also in the dry season. The beta functional and taxonomic diversity of zooplankton showed a similar relationship between the floodplains and between the hydrological periods, represented by the β-Repl component, except for the drought season in the Upper Paraná River, where the functional diversity showed the lowest values, undetected by the taxonomic approach. The factors that influenced the zooplankton beta functional and taxonomic diversity in the two floodplains were different depending on the hydrological period, reflecting once again the difference in environmental heterogeneity and the strength of hydrodynamics within each plain. The analysis of the species and functional traits distribution and, which are the variables structuring this distribution is extremely important to analyze ecosystem processes and services, especially in impacted environments such as the Upper Paraná River floodplain, and a floodplain so biodiverse as the Amazon, and even so, with the prediction of the construction of numerous dams in its hydrographic basin. We reinforce the importance of periodic flooding in these floodplains, for the maintenance of biodiversity and ecosystem services over time, and in this way, prevent biotic homogenization, and consequently, conserve these aquatic ecosystems.
    Description: Os ecossistemas de água doce estão passando por frequentes alterações nas suas condições naturais, influenciadas e aceleradas por atividades humanas. Esses processos são capazes de alterar o regime hidrológico e a composição das comunidades, deixando cada vez mais incerto o futuro da biodiversidade aquática. A construção de barramentos tem sido um dos principais responsáveis por modificações ambientais, como a redução de nutrientes, o aumento da transparência da água e a perda de biodiversidade em ecossistemas dulcícolas. O objetivo deste estudo foi analisar a dissimilaridade funcional e taxonômica da comunidade zooplanctônica e seus determinantes em resposta ao efeito do ciclo hidrológico (seca e chuva) em duas planícies de inundação altamente distintas, a planície do alto rio Paraná (rio com cascata de barramentos) e planície Amazônica. Foram coletadas 72 amostras (16 na seca e 16 na cheia na planície Amazônica e 20 na seca e 20 na cheia na palnície do alto rio Paraná) das comunidades de zooplâncton como variável resposta, de fitoplâncton como variável preditora de alimentação, de peixes como preditor de potenciais predadores e as variáveis limnológicas. Foram calculadas a diversidade β-Total e particionada nos componentes β-Repl e β-Rich em uma abordagem taxonômica e funcional, e espera-se que a heterogeneidade ambiental conduza a maiores valores de diversidade beta. Na sequência, foi calculada através das matrizes de distância geradas na beta funcional e taxonômica a análise de redundância baseada em distância (db-RDA) para avaliar quais os determinantes da diversidade beta. Assim, foi hipotetizado que as interações bióticas apresentarão relações mais fortes com a dissimilaridade zooplanctônica na seca e as variáveis limnológicas e o espaço na cheia. Foi encontrada uma maior heterogeneidade ambiental na planície Amazônica e também no período de seca. A diversidade beta funcional e taxonômica do zooplâncton apresentou uma relação semelhante entre as planícies e entre os períodoshidrológicos, representados pelo componente β-Repl, exceto pelo período de seca na planície do alto rio Paraná onde a diversidade funcional apresentou os menores valores, não detectado pela abordagem taxonômica. Os fatores que influenciaram a diversidade beta funcional e taxonômica zooplanctônica nas duas planícies de inundação foram bem distintos dependendo do período hidrológico, refletindo mais uma vez a diferença na heterogeneidade ambiental e na força da hidrodinâmica dentro de cada planície. A análise da distribuição das espécies e dos traços funcionais, e de quais variáveis estruturam essa distribuição é de extrema importância para analisar os processos e serviços ecossistêmicos, especialmente em ambientes impactados como a planície de inundação do alto rio Paraná, e uma planície tão biodiversa como a Amazônica e, mesmo assim, com previsão de construção de inúmeros barramentos em sua bacia hidrográfica. Reforça-se a importância da inundação periódica nessas planícies, para a manutenção da biodiversidade e dos serviços ecossistêmicos ao longo do tempo e, desta forma, prevenir a homogeneização biótica, e consequentemente, a conservação dos ecossistemas aquáticos.
    Description: PhD
    Keywords: Zooplâncton de água doce ; Comunidades, Ecologia de ; Diversidades beta taxonômica e funcional ; Planícies de inundação ; Floodplain ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::Y::Zooplankton ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::S::Species diversity
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 56pp.
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  • 18
    facet.materialart.
    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-05
    Description: Although several studies have dealt with the description of morphological characters in Cichlidae, usually aiming for phylogenetic inference, little attention has been given to their musculature. The complete striated musculature of a cichlid species, Geophagus sveni Lucinda, Lucena & Assis, was described for the first time, with illustrations of all muscles and a protocol for the dissection of specimens. The striated musculature of at least of species of each genus in tribe Geophagini, among other cichlids, was compared, and 98 characters were described with the purpose of analysing their relation with the group’s phylogeny. This character matrix was employed to produce two unconstrained phylogenetic analyses, one weighted and the other unweighted. The myological characters were mapped upon a pre-existing phylogenetic hypothesis, for understanding the correlation among the characters and trophic specialisations of each taxon. The conclusion is that Geophagini specialised in sifting substrate (winnowers) tend to present a few convergent adaptations, manifested in the shape and degree of development of muscles such as adductor mandibulae, levator arcus palatini, dilatator operculi, adductor branchialis 1 and obliqui ventrales 1–2. This study facilitates future investigations on the functions of the striated muscles in fishes and their role in the processes of adaptive radiation, i.e., functional diversification.
    Description: Apesar de diversos estudos terem tratado da descrição de caracteres morfológicos em Cichlidae, geralmente para fins de inferência filogenética, muito pouco se estudou sobre sua musculatura. Descreveu-se, pela primeira vez, a musculatura estriada completa de uma espécie de ciclídeo, Geophagus sveni Lucinda, Lucena & Assis, com ilustrações de todos os músculos e um protocolo para a dissecção de exemplares. Comparou-se a musculatura esquelética de pelo menos uma espécie de cada gênero da tribo Geophagini, dentre outros ciclídeos, e descreveram-se 98 caracteres com o propósito de analisar sua relação com a filogenia do grupo. Essa matriz de caracteres foi empregada para produzir duas análises filogenéticas sem restrição, uma com pesagem e outra sem pesagem. Mapearam-se os caracteres miológicos sobre uma hipótese filogenética pré-existente, para a compreensão da correlação entre os caracteres e as especializações tróficas de cada táxon. Conclui-se que os Geophagini especializados em peneirar o substrato (winnowers) tendem a apresentar algumas adaptações convergentes, manifestadas na forma e no grau de desenvolvimento de músculos como adductor mandibulae, levator arcus palatini, dilatator operculi, adductor branchialis 1 e obliqui ventrales 1–2. Este estudo possibilita futuras investigações acerca das funções dos músculos estriados em peixes e seu papel nos processos de irradiação adaptativa, i.e., diversificação funcional.
    Description: PhD
    Keywords: Geophagini (Acanthopterygii, Cichlidae) “cará” ; Peixes de água doce ; Filogenia ; Morfologia ; Musculatura esquelética ; ASFA_2015::F::Freshwater fish ; ASFA_2015::T::Taxonomy ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::M::Morphology (organisms) ; ASFA_2015::P::Phylogeny ; ASFA_2015::M::Musculoskeletal system
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 234pp.
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  • 19
    facet.materialart.
    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-05
    Description: The success of biological invasions depends on overcoming environmental filters. After the filters are transposed and subsequently established, invasive species can reach high densities and cause impacts, such as loss of biodiversity and damage to the functioning of ecosystems. The golden mussel (Limnoperna fortunei) is an invasive bivalve in South America and presents high densities in invaded environments. It has a planktonic larval stage, divided into five stages, and an encrusting adult. The larval stage is considered the main propagule of the species. It is known that abiotic factors act differently on larval stages, as these present morphological and physiological differences. Some works shown the ability of L. fortunei to select groups and functional traits of phytoplankton species, but these studies are experimental and with adult representatives. Considering that larvae are the main propagule of the species, therefore, abiotic filters act primarily on them, we sought to (i) evaluate the population structure of L. fortunei larvae and its relationship with environmental factors in lotic environments in the floodplain of the Upper Paraná River. In addition, considering that larvae can reach high density values, we also sought to (ii) identify the potential impacts of high larval densities on the taxonomic and functional diversity of phytoplankton, and their effects on ecosystem functioning. The results showed differences in the age pyramid between the evaluated environments, and found that most environmental filters act on the early larval stages. Among these filters, turbidity stands out. We also identified a negative effect of L. fortunei larval density on the functional and taxonomic diversity of the phytoplankton community. The effects of larval density on these facets of phytoplankton diversity resulted in indirect negative effects on the biomass stock of the community of these producers. It's expected that knowledge about the filters that control larval densities of L. fortunei can contribute to the control and management of the species, in order to avoid major impacts on the phytoplankton, and consequently, on the environment.
    Description: O sucesso das invasões biológicas depende da superação filtros ambientais. Após a transposição dos filtros e consequente estabelecimento, as espécies invasoras podem atingir altas densidades e ocasionar impactos, como perda de biodiversidade e prejuízos ao funcionamento dos ecossistemas. O mexilhão-dourado (Limnoperna fortunei) é um bivalve invasor na América do Sul e apresenta elevadas densidades nos ambientes invadidos. Apresenta fase larval planctônica, dividida em cinco estágios, e adulta incrustante. A fase larval é considerada o principal propágulo da espécie. É sabido que os fatores abióticos atuam diferentemente sobre os estágios larvais, dado que estes apresentam diferenças morfológicas e fisiológicas. Alguns trabalhos evidenciaram a capacidade de L. fortunei em selecionar grupos e traços funcionais das espécies de fitoplâncton, porém esses estudos são experimentais e com representantes adultos. Considerando que as larvas são o principal propágulo da espécie, logo, os filtros abióticos agem primariamente sobre elas e buscou-se (i) avaliar a estruturação populacional das larvas de L. fortunei e sua relação com os fatores ambientais em ambientes lóticos da planície de inundação do alto rio Paraná. Ainda, considerando que as larvas podem atingir elevados valores de densidade também buscou-se (ii) identificar os potenciais impactos das altas densidades larvais sobre a diversidade taxonômica e funcional de fitoplâncton, e seus reflexos sobre o funcionamento ecossitêmico. Os resultados evidenciaram diferenças na pirâmide etária entre os ambientes avaliados, e constatou-se que a maioria dos filtros ambientais age sobre os estágios larvais iniciais. Dentre esses filtros, destaca-se a turbidez. Também identificou-se o efeito negativo da densidade larval de L. fortunei sobre a diversidade funcional e taxonômica da comunidade de fitoplâncton. Os efeitos da densidade larval sobre essas facetas da diversidade do fitoplâncton resultaram em efeitos negativos indiretos sobre o estoque de biomassa da comunidade desses produtores. Espera-se que o conhecimento sobre os filtros que controlam as densidades larvais de L. fortunei possa contribuir para o controle e manejo da espécie, a fim de evitar maiores impactos sobre o fitoplancton, e consequentemente, sobre o ambiente.
    Description: PhD
    Keywords: Limnoperna fortunei (Dunker, 1857) (Bivalve) "mexilhão-dourado" ; Moluscos límnicos invasores ; Bivalves límnicos invasores ; Larvas ; Invasores biológicos ; Diversidade taxonômica e funcional ; Filtros ambientais ; ASFA_2015::P::Phytoplankton ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::I::Impacts ; ASFA_2015::A::Alien species ; ASFA_2015::M::Molluskan larvae ; ASFA_2015::F::Floodplains ; ASFA_2015::T::Taxonomy
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 75pp.
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  • 20
    facet.materialart.
    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-05
    Description: It is expected that the longitudinal limnological gradients described for reservoirs have great implications for the composition and yield of multispecific fisheries practiced in this type of environment, directly and indirectly affecting the operational strategies for the collection of the species. Recognition of patterns of spatial and temporal variation of stocks and their form of exploitation is fundamental to the rationalization of fishery management. It is, however, a complex task given the large number of variables and the physical, biological and socioeconomic interactions involved. Daily landing data from 12 fisheries along the Itaipu reservoir over a period of 11 years are analyzed in this study. Uni and multivariate analysis techniques are used to identify (i) spatial-temporal patterns in the composition of the fish and in the yield of the fishery and (ii) longitudinal gradients in the operational strategies used in fishing. The results are discussed in light of longitudinal and temporal limnological gradients, species life strategies and competitive uses of the basin upstream. Significant correlation was verified between sedimentation rates, considered a synthesis variable of the limnological conditions, and yield of the 10 main species (90% of the total catch). Of these species, eight showed significant longitudinal gradients in abundance. Three of them concentrated in the fluvial zone, one in the lacustrine, three in the fluvial-transitional and one in the lacustrine-transitional. Diet requirements (autochthonous and allochthonous resources) and migratory behavior were considered the most adequate terms to explain these patterns. The marked decline in the fishery yield was attributed to the fall in the CPUEs of the two most caught species, that were, perna-de-moça Hypophthalmus oremaculatus in the lacustrine zone (trophic state reduction in the reservoir, recruitment overfishing) and armado Pterodoras granulosus in the fluvial zone (regulation of the floods on the floodplain upstream from the operation of new reservoirs, growth overfishing). Three fishery strategies were observed: (I) cascudo-preto Rhinelepis aspera fisheries in the fluvial zone using casting nets and wooden boats propelled by a stationary (center) motor (10 to 12 HP), (II) Hypophthalmus oremaculatus fisheries in the transition and lacustrine zones with gillnets, wooden boats driven by oars or a rabeta motor (3.5 to 4 HP) and (III) Pterodoras granulosus and jaú Zungaro jahu fisheries in the fluvial zone carried out with fish-hooks, wooden boats and a stationary (center) motor (10 to 12 HP). It was verifield the importance of the fisheries in sustaining families marginalized from other sectors of the economy and their regulation and rationalization in the operation of the reservoirs upstream to insure the occurrence of floods on the floodplain upstream.
    Description: É esperado que os gradientes limnológicos longitudinais descritos para reservatórios, tenham grandes implicações sobre a composição e o rendimento de pescarias multiespecíficas, exercidas neste tipo de ambiente, afetando direta e indiretamente as estratégias operacionais para a captura das espécies. O reconhecimento dos padrões de variação espaciais e temporais dos estoques e de sua forma de exploração é fundamental para a racionalização do manejo da pesca, sendo, entretanto, uma tarefa complexa, dado o grande número de variáveis e interações físicas, biológicas e socioeconômicas envolvidas. Neste estudo, são analisados os dados diários de acompanhamento de desembarque em 12 áreas de pesca ao longo do reservatório de Itaipu, tomados durante 11 anos. Técnicas de análise uni e multivariadas são utilizadas para identificar (i) os padrões espaço-temporais na composição do pescado e no rendimento da pesca, (ii) os gradientes longitudinais nas estratégias operacionais empregadas na atividade pesqueira. Os resultados são discutidos à luz dos gradientes limnológicos longitudinais e temporais, as estratégias de vida das espécies e os usos concorrentes da bacia a montante. Correlações significativas foram constatadas entre as taxas de sedimentação, considerada variável síntese das condições limnológicas, e o rendimento das 10 principais espécies (90% das capturas totais). Destas espécies, oito mostraram gradientes longitudinais significativos na abundância, sendo três delas concentradas na zona fluvial, uma na lacustre, três na fluvial-transição, e uma na lacustre-transição. Requerimentos na dieta (recursos autóctones e alóctones) e o comportamento migratório foram considerados como a explicação mais adequada a estes padrões. O acentuado declínio no rendimento da pesca foi atribuído à queda nas CPUEs das duas espécies mais capturadas, ou seja, perna-de-moça Hypophthalmus oremaculatus, na zona lacustre (redução no estado trófico do reservatório, sobrepesca de recrutamento) e armado Pterodoras granulosus, na fluvial (regulação das cheias na planície a montante pela construção de novos reservatórios, e sobrepesca de crescimento). Três estratégias de pesca foram observadas: (I) pescaria de cascudo-preto Rhinelepis aspera na zona fluvial com uso de tarrafas, embarcações de madeira, com propulsão por motor de estacionário (centro), potência de 10 a 12,5 HP; (II) pescaria de Hypophthalmus oremaculatus nas zonas de transição e lacustre, com redes de espera, embarcações de madeira impulsionada por remo ou motor rabeta, com potência de 3,5 a 4 HP; (III) pescaria de Pterodoras granulosus e jaú Zungaro jahu, na zona fluvial realizada com anzóis, barcos de madeira e motor estacionário (centro), de 10 a 12,5 HP. Verifica-se a importância da pesca para o sustento de famílias marginalizadas de outros setores da economia e propõem-se ações de controle da atividade e a racionalização na operação dos reservatórios, a montante, visando assegurar a ocorrência de cheias na planície alagável a montante.
    Description: PhD
    Keywords: Pesca artesanal de água doce ; Gradientes horizontais ; Manejo ; Peixes de água doce ; Estratégias de pesca ; Reservatório de Itaipu ; Zonação ; Itaipu Binacional ; ASFA_2015::F::Freshwater fish ; ASFA_2015::F::Fisheries management ; ASFA_2015::G::Gradients ; ASFA_2015::R::Reservoir fisheries ; ASFA_2015::F::Fish stocks
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 64pp.
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-05
    Description: Neotropical aquatic environments are highly heterogeneous and present a broad light spectral variation. Photic conditions can be closely related to aquatic vertebrates’ visual system evolution, which can interfere with ecological factors, such as feeding. Therefore, due to the species’ biodiversity and ecological adaptations observed in continental aquatic environments, Neotropical cichlids represent an important model for evolutionary studies. Cichlinae shows several adaptations regarding their life cycle and may present and accumulate mutations resulting in specific amino acid changes of visual proteins. These proteins are encoded by visual opsins genes, which allow some “measurement” of natural selection on the protein using molecular tools. Thus, it is possible to verify whether the diet constitutes an important factor in the diversification of the gene responsible for the scotopic vision of these vertebrates. In this study, 40 species of Neotropical cichlids were categorized according to their diet and, using different codon selection analyses, different protein sites positively selected were observed in specialist and generalist species. The lineages of predatory fish showed evidence of a stronger evolution of the RH1 gene when compared to other groups, indicating the influence of the diet on this group's visual evolution.
    Description: Ambientes aquáticos neotropicais possuem grande heterogeneidade de habitats, apresentando diferenças na intensidade luminosa na coluna d’água. A luminosidade está diretamente relacionada com o sistema visual dos vertebrados aquáticos, o que pode interferir em fatores ecológicos, como a alimentação. Em consideração à biodiversidade de espécies e diversas adaptações ecológicas observadas em ambientes aquáticos continentais, os ciclídeos neotropicais representam um bom modelo para estudos evolutivos. Este grupo possui diversas adaptações ao seu modo de vida e pode apresentar e acumular mutações em sítios específicos das proteínas visuais que podem ser relacionadas com tais adaptações. As proteínas visuais são codificadas por genes opsins, o que permite o estudo da intensidade de atuação da seleção natural sobre a proteína utilizando ferramentas moleculares. Com o objetivo de verificar se a dieta constitui um importante fator na diversificação do gene responsável pela visão escotópica destes vertebrados, foram utilizadas 40 espécies de ciclídeos neotropicais categorizadas de acordo com sua dieta e, por meio de diferentes análises de seleção de códons, foram observados diferentes sítios da proteína positivamente selecionados em espécies especialistas e generalistas. As linhagens de peixes predadores apresentaram evidências de uma rápida seleção do gene RH1 quando comparadas a outros grupos, indicando a influência da dieta na evolução visual deste grupo.
    Description: Masters
    Keywords: Peixes ciclídeos (Cichlidae) ; Peixes de água doce ; Sistema visual ; Evolução molecular ; Proteínas ; ASFA_2015::F::Freshwater fish ; ASFA_2015::M::Molecular biology ; ASFA_2015::P::Proteins ; ASFA_2015::V::Vision ; ASFA_2015::R::Rhodopsin ; ASFA_2015::A::Aquatic environment ; ASFA_2015::P::Physiology (fish)
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 44pp.
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-05
    Description: We describe seven new species of Physocypria sensu latu from three of the main Brazilian floodplains: Gen. 1 spec. A gen. et spec. nov. and Gen. 1 spec. B gen. et spec. nov. from the Upper Paraná River floodplain and the South Matogrossense Pantanal, Gen. 2 spec. C gen. et spec. nov., Gen. 1 spec. D gen. et spec. nov. and Gen. 2 spec. E gen. et spec. nov. from the South Matogrossense Pantanal only and Gen. 1 spec. F gen. et spec. nov. and Gen. 1 spec. G gen. et spec. nov. only from the Amazon River floodplain. All new species here described were found in sexual populations. Generally, the new species have a short and suboval carapace, with the left valve overlapping the right valve on all sides, except for the dorsal side in some species. The morphology of hemipenis and prehensile palps, together with the shape of the valves, were most important to distinguish the species. However, several other morphological characters from limb chaetotaxy are discussed, e.g., the absence in all new species of the short accompanying seta of the five natatory setae on antenna; the presence in all new species of a long seta next to the two a-seta on the first thoracopod and the presence/absence or length of specific setae on second and third thoracopod. We discuss the taxonomic position of the seven new species by evaluating the validity of extant genera, especially of Keysercypria Karanovic, 2011, and foreshadow that our seven new species represent two new genera of Cyclocypridinae.
    Description: Sete novas espécies de Physocypria sensu latu foram descritas de três das principais planícies brasileiras: Gen. 1 spec. A gen. et spec. nov. e Gen. 1 spec. B gen. et spec. nov. da planície de inundação do alto rio Paraná e do Pantanal Sul Matogrossense, Gen. 2 spec. C gen. et spec. nov., Gen. 1 spec. D gen. et spec. nov. e Gen. 2 spec. E gen. et spec. nov. somente do Pantanal Sul Matogrossense e Gen. 1 spec. F gen. et spec. nov. e Gen. 1 spec. G gen. et spec. nov. somente da planície de inundação do rio Amazonas. Todas as novas espécies aqui descritas foram encontradas em populações sexuadas. Em geral, as novas espécies têm uma carapaça curta e suboval, com a valva esquerda sobrepondo a valva direita em todos os lados, com exceção do lado dorsal em algumas espécies. A morfologia do hemipênis e dos palpos preênseis, juntamente com a forma das valvas, foram as mais importantes para distinguir as espécies. A ausência em todas as novas espécies das cerdas curtas que acompanham as cinco cerdas natatórias nas antenas; a presença em todas as novas espécies de uma cerda longa ao lado das duas a-cerdas no primeiro toracópode e a presença/ausência ou comprimento de cerdas específicas no segundo e terceiro toracópodes são características presentes nos apêndices utilizadas para distinção dos novos gêneros e espécies. Discutiu-se a posição taxonômica das sete novas espécies avaliando a validade dos gêneros existentes, especialmente da Keysercypria Karanovic, 2011, e concluiu-se que nossas sete novas espécies representam dois novos gêneros de Cyclocypridinae.
    Description: Masters
    Keywords: Physocypria sensu latu (Crustacea, Ostracoda) ; Candonidae ; Microcrustáceos de água doce ; Taxonomia descritiva ; Morfologia descritiva ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::F::Freshwater crustaceans ; ASFA_2015::T::Taxonomy ; ASFA_2015::M::Morphology (animal) ; ASFA_2015::F::Floodplains
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 115pp.
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-05
    Description: Biological invasions have been occurring at a faster pace as a result of anthropic actions. At the same time, climate change can increase invasion rates, and also favor invading organisms. One of the predictions for climate change is the increase in periods of drought, in some regions of the planet. In this way, environments that suffer from these disorders become more susceptible to invasion by aquatic plants, especially those that are adapted to different types of habitats. Within this context, the objectives were: (i) to determine the response of a native species (Hymenachne pernambucensis) and another invasive species (Urochloa arrecta) to extreme drought, and (ii) to test whether the interspecific competition between them is affected by stress caused by drought. An in situ experiment was carried out, in which the biomass and the length of the species were different for different levels of drought, in which the invasive species was superior to the native species. However, the intensity of relative competition had only different aerial biomass between species, but in this case the invasive species showed a preference for growth in monoculture than in polyculture. It was concluded, then, that the invasive species U. arrecta has greater resilience to droughts than the native species H. pernambucensis. However, the native species showed greater competitive ability. These results may explain the high dominance of this invasive species in the invaded sites, due to its better resistance to disturbances. In the same way, it demonstrates that native species can reduce the invasion rates of this species, considering that it does not grow well in the presence of neighbors.
    Description: Invasões biológicas vêm ocorrendo em um ritmo mais acelerado como resultado de ações antrópicas. Simultaneamente, as mudanças climáticas podem potencializar as taxas de invasão, e ainda favorecer organismos invasores. Uma das previsões para as mudanças climáticas é o aumento dos períodos de seca, em algumas regiões do planeta. Desta forma, ambientes que sofrem esses distúrbios se tornam mais suscetíveis à invasão por plantas aquáticas, em especial por aquelas que estão adaptadas a diversos tipos de habitats. Dentro deste contexto, os objetivos foram de: (i) determinar a resposta de uma espécie nativa (Hymenachne pernambucensis) e outra invasora (Urochloa arrecta) a uma seca extrema, e (ii) testar se a competição interespecífica entre ambas é afetada pelo estresse provocado pela seca. Foi realizado um experimento in situ, no qual a biomassa e o comprimento das espécies foram diferentes para diferentes níveis de seca, em que a espécie invasora foi superior a espécie nativa. Porém, a intensidade de competição relativa teve apenas a biomassa aérea diferente entre as espécies, mas nesse caso a espécie invasora demonstrou preferência por crescimento em monocultura do que em policultura. Concluiu-se, então, que a espécie invasora U. arrecta apresenta maior resiliência a secas do que a espécie nativa H. pernambucensis. Porém, a espécie nativa demonstrou maior habilidade competitiva. Esses resultados podem explicar a alta dominância dessa espécie invasora nos locais invadidos, devido a esta resistir melhor aos distúrbios. De mesmo modo, demonstra que espécies nativas podem reduzir as taxas de invasão dessa espécie, tendo em vista que ela não cresce bem na presença de vizinhos.
    Description: Masters
    Keywords: Poaceae (Gramineae) ; Macrófitas aquáticas invasoras ; Espécies invasoras ; Resiliência ; Mudanças climáticas ; ASFA_2015::M::Macrophytes ; ASFA_2015::A::Aquatic plants ; ASFA_2015::C::Competition ; ASFA_2015::F::Freshwater plants ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::R::Resilience (ecosystem) ; ASFA_2015::C::Climatic changes ; ASFA_2015::A::Alien species
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 32pp.
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  • 24
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-07-05
    Description: Global climate change influences the precipitation patterns, which can have dramatic effects on aquatic and terrestrial ecology. In order to create mitigation strategies is required a deep understanding of the mechanisms and rates of climate change. Lakes and wetlands are sentinels of environmental changes because their sediments and water columns serve as sensitive records of the climate, hydrology, and anthropogenic (human-induced) processes. The Pantanal, located in the Upper Paraguay River, is considered the largest wetland on Earth, and it performs numerous ecosystem services, has an immense biodiversity and is fundamental to global biogeochemical cycles. The environmental changes that occurred on the western border of the Pantanal during the last 19 cal kyr BP were interpreted based on the paleolimnological analysis of sedimentary cores recovered in the Negra and Cáceres lakes. The cores, show variations in the abundance, diversity, and preservation of sponge spicules, phytoliths, and geochemistry of sediments over time. In the Late Pleistocene, the Lakes Negra and Cáceres were strongly influenced by the South American Monsoon System, with intense fluvial activity during a more humid climate. The accumulation of organic carbon in the Pantanal floodplain lakes varied throughout the Late Quaternary. In the Middle Holocene, however, there were drier periods when these lakes were disconnected from the Paraguay River. High levels of organic carbon have been recorded from ~ 7.3-6 cal kyr BP. The records of δ13Corg, δ15Norg and C/N revealed that the organic matter deposited during this phase in the Gaíva, Castelo, Cáceres, and Negra lakes are the source of aquatic macrophytes. It is suggested that the increase in carbon burial in these lakes occurred in a drier climate, in which there was a decrease in the pelagic area. However, the productive coastal areas remained flooded and without the influence of the flood pulses, which were colonized by extensive mats of aquatic macrophytes. The prolonged drier climate resulted in the desiccation and subaerially exposed lake floor, causing sedimentary gaps close to the transition to the Late Holocene. The data suggest that the lakes in the Pantanal floodplain respond in a complex and sometimes indirect way to global climate change. In this sense, the dynamics of the adjacent river system must be considered when interpreting paleohydrology and vegetation patterns. The results of this study allowed new interpretations about the hydroclimatic controls of the lacustrine carbon cycling in the Pantanal wetlands.
    Description: As mudanças climáticas globais resultam em alterações nos padrões de precipitação, que podem ter efeitos dramáticos na ecologia aquática e terrestre. Para criar estratégias de mitigação de impactos é necessário um profundo entendimento dos mecanismos e taxas das mudanças climáticas. Os lagos e as áreas úmidas são considerados sentinelas das mudanças ambientais, porque seus sedimentos e colunas de água servem como registros sensíveis dos processos climáticos, hidrológicos e antropogênicos (induzidos pelo homem) da região. O Pantanal, localizado no alto rio Paraguai, é considerada a maior área úmida do planeta e desempenha inúmeros serviços ecossistêmicos, abriga uma imensa biodiversidade e é fundamental para os ciclos biogeoquímicos globais. As mudanças ambientais ocorridas na borda oeste do Pantanal durante os últimos 19 k anos AP foram interpretadas com base na análise paleolimnológica de testemunhos sedimentares recuperados nas lagoas Negra e Cáceres. Os testemunhos mostram variações na abundância, diversidade e preservação de espículas de esponja, fitólitos e geoquímica dos sedimentos ao longo do tempo. No final do Pleistoceno, as lagoas Negra e Cáceres foram influenciadas fortemente pelo Sistema de Monção Sul-Americano, com atividade fluvial intensa durante um clima mais úmido que o atual. A acumulação de carbono orgânico nas lagoas da planície de inundação do Pantanal variou ao longo do Quaternário Tardio. No Holoceno Médio, entretanto, houve períodos mais secos que o atual, em que essas lagoas foram desconectadas do rio Paraguai. Altos teores de carbono orgânico foram registrados a partir de ~7,3-6 k anos AP. Os registros de δ13Corg, δ15Norg e C/N revelaram que a matéria orgânica depositada durante essa fase nas lagoas Gaíva, Castelo, Cáceres e Negra (direcionadas em um transecto Norte-Sul) tem como fonte as macrófitas aquáticas. Sugere-se que o aumento no enterro de carbono ocorreu em um clima mais seco, no qual houve a diminuição da área pelágica dessas lagoas. No entanto, as áreas litorâneas produtivas permaneceram alagadas e sem influência dos pulsos de inundação, as quais foram colonizadas por extensos bancos de macrófitas aquáticas. O clima mais seco prolongado resultou na dessecação e exposição do fundo de alguns dessas lagoas, ocasionando hiatos sedimentares próximo à transição para o Holoceno Tardio. Os dados sugerem que as lagoas da planície de inundação do Pantanal respondem de maneira complexa e, às vezes, indireta às mudanças climáticas. Nesse sentido, a dinâmica do sistema fluvial adjacente deve ser considerada na interpretação dos padrões de paleoidrologia e vegetação. Os resultados deste estudo permitiram novas interpretações sobre os controles hidroclimáticos da ciclagem de carbono lacustre nas zonas úmidas do Pantanal.
    Description: PhD
    Keywords: Paleoecologia ; Microfósseis de água doce ; Espículas de esponjas ; Microfósseis de plantas ; Fitólitos ; Geomorfologia fluvial ; Mudanças climáticas ; Lagoas ; Quaternário Tardio ; ASFA_2015::P::Palaeoecology ; ASFA_2015::F::Fossils ; ASFA_2015::S::Sponges ; ASFA_2015::O::Organic carbon ; ASFA_2015::W::Wetlands ; ASFA_2015::H::Holocene ; ASFA_2015::F::Freshwater lakes ; ASFA_2015::C::Climatic changes ; ASFA_2015::G::Geomorphology ; ASFA_2015::F::Floodplains ; ASFA_2015::P::Plant fossils ; ASFA_2015::F::Fresh water ; ASFA_2015::R::Rivers
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 109pp.
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  • 25
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-30
    Description: Species are heterogeneously distributed and environmental changes, such as the construction of dams or extreme climate events, can modify the dynamics of aquatic organisms. Understanding the processes that drive diversity, across long time periods, can help in the establishment of increasingly accurate conservation measures. This thesis evaluated the patterns of β diversity and metacommunity structure at different spatial and temporal scales in three independent studies in the Upper Paraná river floodplain, Brazil. The first analyzed the seasonal variation of zooplankton β and Elements of Metacommunity Structure [EMS] of zooplankton, over four years (two years of prolonged drought and two years of extreme flooding), and on a smaller (sub-basins) and a larger scale (floodplain). Regardless of the hydrological period and spatial scale, zooplanktonic metacommunity structure remained practically constant throughout the four years, with the predominance of the Clementsian pattern. The predominance of the Clementsian pattern suggests that the associations of zooplankton species in the floodplain responded similarly to the environmental gradient and that the responses differed among species groups. In the second, the taxonomic (LCBD-t) and functional (LCBD-f) ecological uniqueness of zooplankton over 19 years was determined in lakes and lotic systems of two sub-basins (dammed and free-flowing), in addition to investigating which processes (temporal, environmental and biological) drive LCBD-t and LCBD-f. Regardless of the characteristics of each sub-basin, the highest LCBD-t and LCBD-f were related to lower species and trait richness, respectively. The temporal processes were the main drivers of the ecological uniqueness of zooplankton, and they were more important than the biological processes (phytoplankton biovolume and fish biomass, representing food resource and potential predation, respectively). Finally, it was tested whether, in a dammed sub-basin, a prolonged drought makes aquatic metacommunities (phytoplankton, zooplankton, and fish) more similar over time than a period that includes extreme flood events. Only zooplankton underwent homogenization during this period. The β diversity of phytoplankton and fish did not change between different hydrological periods, indicating that the dispersion type (passive or active) does not interfere with drought homogenization. The response between the biological groups was different, reinforcing that the groups are not surrogates of each other. The greater β diversity in the period with extreme floods shows, at least for zooplankton, the importance of the flood pulse, reducing the negative effects of prolonged drought in a dammed sub-basin. The results showed the predominance of a metacommunity pattern resulting from high turnover (Clementsian), indicating that conservation measures should include a greater number of sites, including those with less richness, as they may have a different composition (〉 LCBD). We also emphasize the importance of considering different scales, as each can provide unique insights. It is important that biodiversity studies consider β diversity to understand the mechanisms that drive the metacommunity in the face of environmental changes, especially over longer time scales.
    Description: As espécies estão distribuídas de forma heterogênea e alterações ambientais, como a construção de reservatórios ou eventos climáticos extremos, podem modificar a dinâmica dos organismos aquáticos. Entender os processos que impulsionam a diversidade, em longos períodos de tempo, pode auxiliar no estabelecimento de medidas de conservação cada vez mais precisas. Esta tese avaliou os padrões de diversidade β e estrutura de metacomunidade em diferentes escalas espaciais e temporais em três estudos independentes na planície de inundação do Alto rio Paraná, Brasil. No primeiro foi analisado a variação sazonal da diversidade β e Elementos da Estrutura da Metacomunidade [EMS] do zooplâncton, durante quatro anos (dois anos de seca prolongada e dois anos com inundação extrema), e em uma menor (sub-bacias) e maior escala (planície de inundação). Independente do período hidrológico e da escala, a estrutura da metacomunidade do zooplâncton se manteve praticamente constante ao longo dos quatro anos, com predomínio do padrão Clementsiano. A predominância desse padrão sugere que as associações de espécies responderam de forma semelhante ao gradiente ambiental e que as respostas diferiram entre os grupos de espécies. No segundo foi determinado a singularidade ecológica taxonômica (LCBD-t) e funcional (LCBD-f) do zooplâncton ao longo de 19 anos em lagos e sistemas lóticos de duas sub-bacias (represada e não represada), além de investigar quais processos (temporais, ambientais e biológicos) impulsionam a LCBD-t e LCBD-f. Independentemente das características de cada sub-bacia, os maiores LCBD-t e LCBD-f foram relacionados a menor riqueza de espécies e de traços, respectivamente. Os processos temporais foram os principais impulsionadores da singularidade ecológica do zooplâncton, sendo mais importante do que os processos biológicos (biovolume do fitoplâncton e biomassa dos peixes, representando recurso alimentar e potencial predador, respectivamente). Por último, foi testado se em uma sub-bacia represada, um período de seca prolongada torna as comunidades aquáticas (fitoplâncton, zooplâncton e peixes) mais semelhantes ao longo do tempo do que um período com inundações extremas. Apenas o zooplâncton sofreu homogeneização nesse período. A diversidade β do fitoplâncton e dos peixes não diferiu entre os períodos hidrológicos, indicando que o tipo de dispersão (passivo ou ativo) não interfere na homogeneização da seca. Como a resposta entre os grupos biológicos foi diferente, sugere-se que os grupos não são substitutos uns dos outros. A maior diversidade β no período com inundações extremas mostra, pelo menos para o zooplâncton, a importância do pulso de inundação, reduzindo os efeitos negativos da seca prolongada em uma sub-bacia represada. Os resultados mostraram a predominância de um padrão de metacomunidade resultante de alto turnover (Clementsiano), indicando que medidas de conservação devem incluir um maior número de locais, inclusive aqueles com menor riqueza, uma vez que podem ter composição distinta (〉 LCBD). Reforçamos também a importância de considerar diferentes escalas, uma vez que cada uma pode fornecer insights exclusivos. É importante que estudos de biodiversidade considerem a diversidade β para compreender os mecanismos que impulsionam as metacomunidade diante das alterações ambientais, especialmente em escalas temporais mais longas.
    Description: PhD
    Keywords: Zooplâncton de água doce ; Ecossistemas aquáticos continentais ; Metacomunidades, Ecologia de ; Diversidade-beta ; Traços funcionais ; Escala espaço-temporal ; ASFA_2015::Y::Zooplankton ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::F::Freshwater fish ; ASFA_2015::P::Phytoplankton ; ASFA_2015::E::Ecosystem diversity ; ASFA_2015::T::Temporal variations ; ASFA_2015::S::Spatial variations ; ASFA_2015::A::Aquatic environment ; ASFA_2015::F::Floodplains
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 186pp.
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    Publication Date: 2022-06-21
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(6),(2022): 1191-1204, https://doi.org/10.1175/jpo-d-21-0242.1.
    Description: A simplified quasigeostrophic (QG) analytical model together with an idealized numerical model are used to study the effect of uneven ice–ocean stress on the temporal evolution of the geostrophic current under sea ice. The tendency of the geostrophic velocity in the QG model is given as a function of the lateral gradient of vertical velocity and is further related to the ice–ocean stress with consideration of a surface boundary layer. Combining the analytical and numerical solutions, we demonstrate that the uneven stress between the ice and an initially surface-intensified, laterally sheared geostrophic current can drive an overturning circulation to trigger the displacement of isopycnals and modify the vertical structure of the geostrophic velocity. When the near-surface isopycnals become tilted in the opposite direction to the deeper ones, a subsurface velocity core is generated (via geostrophic setup). This mechanism should help understand the formation of subsurface currents in the edge of Chukchi and Beaufort Seas seen in observations. Furthermore, our solutions reveal a reversed flow extending from the bottom to the middepth, suggesting that the ice-induced overturning circulation potentially influences the currents in the deep layers of the Arctic Ocean, such as the Atlantic Water boundary current.
    Description: This work was funded by the National Key Research and Development Program of China (Grant 2017YFA0604600), the National Natural Science Foundation of China (Grant 41676019), the Fundamental Research Funds for the Central Universities (Grant 2019B81214), the Postgraduate Research and Practice Innovation Program of Jiangsu Province (Grant KYCX19_0384), and the National Science Foundation (MAS, Grants OPP-1822334, OCE-2122633).
    Keywords: Arctic ; Sea ice ; Channel flows ; Vertical motion ; Ekman pumping ; Idealized models ; Quasigeostrophic models
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 27
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    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-28
    Description: In Neotropical rivers the predation by fish and the structuring of the habitat by macrophytes influence the dynamics of the zooplankton community, altering the richness and composition of species and the richness and functional composition of the zooplankton and thus the functioning of the ecosystem. We analyzed the influence of macrophytes bank structure and predation by forage fish species on taxonomic and functional zooplankton diversity, estimated by different diversity indices (taxonomic and functional richness, taxonomic beta diversity and functional beta diversity). Thus, we assume that different levels of macrophytes structure and fish predation will alter the taxonomic and functional composition of the zooplankton (alpha and beta) between the analyzed points. Beta diversity was split into two distinct components, turnover and nesting. The zooplankton species richness was positively associated with the macrophytes richness and the macrophytes diversity. In turn, the functional richness of zooplankton had a positive association with fish richness and macrophytes richness. For the variation of total taxonomic beta diversity of zooplankton, the Generalized Dissimilarity Modeling (GDM) explained 32.58% of the total among the predictor variables. The macrophytes biomass represented the taxonomic turnover. The variation in total functional beta diversity of the zooplankton explained 9.98% by the GDM model. The abundance of fish represented the functional nesting. Macrophytes structure represented the taxonomic components and predation represented the functional components. The limnological heterogeneity of the coastal region of the Bay River made possible the colonization by multispecies macrophytes banks, influencing the alteration of the fish and zooplankton community and the more heterogeneous the environmental conditions, the greater is the capacity of colonization of different species, which can present different functional traits. The results indicate the importance of maintaining heterogeneous locations, the need to preserve the tributaries in river floodplain systems as they serve as nursery for fish spawning and contribute to a greater richness of fish, which causes an increase in the functional diversity of zooplankton.
    Description: Em rios neotropicais a predação por peixes e a estruturação do habitat por macrófitas influenciam na dinâmica da comunidade zooplanctônica, alterando a riqueza e composição de espécies e a riqueza e composição funcional do zooplâncton e, assim, o funcionamento do ecossistema. Analisou-se a influência da estruturação dos bancos de macrófitas e a predação por espécies de peixes forrageiras sobre a diversidade taxonômica e funcional zooplanctônica, estimadas por diferentes índices de diversidade (riqueza taxonômica e funcional, diversidade beta taxonômica e diversidade beta funcional). Assim, supõe-se que diferentes níveis de estruturação por macrófitas e predação por peixes alterarão a composição taxonômica e funcional do zooplâncton (alfa e beta) entre os pontos analisados. A diversidade beta foi particionada em dois componentes distintos, o turnover e o aninhamento. A riqueza de espécies do zooplâncton associou-se de forma positiva com a riqueza de macrófitas e a diversidade de macrófitas. Por sua vez, a riqueza funcional do zooplâncton teve associação positiva com a riqueza de peixes e a riqueza de macrófitas. Para a variação da diversidade beta total taxonômica do zooplâncton, a Modelagem de Dissimilaridade Generalizada (GDM) explicou 32,58% do total dentre as variáveis preditoras. A biomassa de macrófitas representou o turnover taxonômico. A variação da diversidade beta total funcional do zooplâncton, explicou 9,98% pelo modelo da GDM. A abundância de peixes representou o aninhamento funcional. A estruturação por macrófitas representou os componentes taxonômicos e a predação representou os componentes funcionais. A heterogeneidade limnológica da região litorânea do rio Baía possibilitou a colonização por bancos de macrófitas multiespecíficos, influenciando na alteração da comunidade de peixes e de zooplâncton e quanto mais heterogêneas as condições ambientais, maior é a capacidade de colonização de diferentes espécies, que podem apresentar distintos traços funcionais. Os resultados indicam a importância da manutenção de locais heterogêneos, a necessidade de preservação dos tributários em sistemas rio-planície de inundação por servirem como berçário para desova de peixes e contribuir para uma maior riqueza de peixes, o que causa um aumento na diversidade funcional do zooplâncton.
    Description: Masters
    Keywords: Zooplâncton de água doce ; Riqueza taxonômica e funcional ; Diversidade beta ; Taxonomic richness ; Functional richness ; Beta diversity ; Nestedness ; Turnover ; Comunidades, Ecologia de ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::Y::Zooplankton ; ASFA_2015::M::Macrophytes ; ASFA_2015::T::Taxonomy ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::P::Predation
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 49pp.
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  • 28
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    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-28
    Description: The patterns and processes that cause a system of regionalization of organisms on the planet are historical and ecological hypotheses that biogeography seeks to elucidate. The Neotropical region is home to one of the greatest richness of freshwater fish in the world that exhibit distinct biogeographic patterns based on ecology, systematics, and evolution. Through methodologies within the scope of historical and/or ecological biogeography, the aims of this study are to present new approaches and contributions to the knowledge of the geographic distribution of freshwater fish in this region, investigating the evolutionary biogeography of Cnesterodontini and Anablepidae, as well as the spatial patterns of ichthyofauna beta-diversity in the Ivaí river basin, Paraná State. The results highlighted well-defined scenarios of the hydrological barriers formation, mainly between coastal basins and drainages that flow into the La Plata River system in South America. These findings enabled congruent relationships of biogeographic areas within the proposals for evolutionary diversification to the Neotropical freshwater fishes. Furthermore, dispersal events caused by headwater captures and sea-level changes satisfactorily complemented the biogeographic patterns and area relationships evidenced for other Neotropical fish lineages, showing similar diversification patterns in the Central Brazil drainages and in the Atlantic coast drainages. The results also showed strong spatial segregation of the ichthyofauna throughout the Ivaí River basin (upper Paraná River system) with emphasis on the mutual influences of niche- and dispersal-based processes. These findings can support new theoretical and methodological references for the main mechanisms and patterns specific to the metacommunities of aquatic organisms. Applying the results herein obtained in historical and ecological consonance has great potential to aid an effective management for the conservation of freshwater fish diversity, whether considering lineages with species at high risk of extinction or even river basins of fundamental importance for maintaining biodiversity and ecosystem functionality in continental aquatic environments.
    Description: Os padrões e processos que ocasionam um sistema de regionalização dos organismos no planeta são hipóteses históricas e ecológicas que a biogeografia busca elucidar. A região Neotropical abriga uma das maiores riquezas de peixes de água doce do mundo, os quais exibem padrões biogeográficos distintos baseados na ecologia, sistemática e evolução. Por intermédio de metodologias dentro do escopo da biogeografia histórica e/ou ecológica, os objetivos deste estudo são apresentar novas abordagens e contribuições ao conhecimento da distribuição geográfica dos peixes de água doce nesta região ao investigar a biogeografia evolutiva de Cnesterodontini e Anablepidae, bem como os padrões espaciais da diversidade beta da ictiofauna na bacia do rio Ivaí, estado do Paraná. Os resultados destacaram cenários bem definidos da formação de barreiras hidrológicas, principalmente entre bacias hidrográficas costeiras e drenagens que fluem para o sistema do rio da Prata na América do Sul. Essas descobertas possibilitaram congruentes relacionamentos de áreas biogeográficas dentro das propostas de diversificação evolutiva à ictiofauna neotropical. Ainda, eventos de dispersão ocasionados por capturas de cabeceiras e mudanças no nível do mar complementaram satisfatoriamente os padrões biogeográficos e os relacionamentos de áreas evidenciados para outras linhagens de peixes neotropicais, apresentando padrões de diversificação semelhantes nas drenagens do Brasil Central e nas drenagens da costa atlântica. Os resultados também evidenciaram forte segregação espacial da ictiofauna ao longo da extensão da bacia do rio Ivaí (sistema do alto rio Paraná), com destaques às influências mútuas de processos baseados em nicho e dispersão. As novas descobertas podem subsidiar referenciais teóricos e metodológicos para os principais mecanismos e padrões específicos às metacomunidades de organismos aquáticos. A aplicação dos resultados aqui obtidos em consonância histórica e ecológica tem grande potencial ao auxílio de um manejo eficaz para a conservação da diversidade de peixes de água doce, seja considerando linhagens com espécies enquadradas em elevado risco de extinção, ou até mesmo bacias hidrográficas de fundamental importância para a manutenção da biodiversidade e funcionalidade ecossistêmica em ambientes aquáticos continentais.
    Description: PhD
    Keywords: Anablepidae (Teleostei: Cyprinodontiformes) "Onesided livebearer" ; Cnesterodontini (Teleostei: Poeciliidae) ; Peixes de água doce de pequeno porte ; Biogeografia cladística e conservação ; Ictiofauna Neotropical ; Metacomunidades aquáticas ; Áreas prioritárias ; Padrões de diversidade beta ; Linhagem marinha ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::F::Freshwater fish ; ASFA_2015::B::Biogeography ; ASFA_2015::C::Cladistics ; ASFA_2015::I::Ichthyofauna ; ASFA_2015::C::Conservation
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 161pp.
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  • 29
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    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-28
    Description: The assessment of sustainable development in sub-watersheds plays a central role in rationalizing the decisions taken. A promising form of average indicators of this development is through indicators, and when many are used, they are usually aggregated into indices, which provide a simplified and multidimensional view of the system under analysis. Several sustainability indices for watersheds are proposed in the literature. However, incorporation of extraordinary indicators, that biodiversity, a gap is still a major upgrade. Therefore, the use of biodiversity indicators as representative of the environmental dimension constitutes an advance on the indices presented in the literature recently. The objective was to evaluate the sustainability gradient in the hydrographic basins of the Upper Paraná River, through an eco-environmental sustainability index of hydrographic sub-basins (ISE-sb) that incorporates protected ecological. For this purpose, the indicators selected based on the propositions of Agenda 2030 were identified in four dimensions of sustainability, economic, economic, environmental and thought through a process of sustainability: normal and social. Then, the importance of the indicators was considered, using the multi-criteria analysis based on the Hierarchical Process Analysis (HP) method. The ISE-sb was calculated by means of the weighted media between the sub-indices that represent as dimensions. Finally, we apply the Gi* statistic to identify hotspots and coldspots. The results show that among the dimensions of sustainability, the highest was the one that presented a positive amount of low values. The regions located in the eastern portion, or serra do mar, southern portion, and the Federal District formed sustainability hotspots, while the sub-basins located in the states of Goiás, Mato Grosso do Sul and Minas Gerais formed the sustainability coldposts. A sustainable spatial planning of the hydrographic sub-basins is recommended, adopting cold areas as priorities for sustainability. It highlights the main methodological limitation, a potential reproducibility of the tool in other spaces.
    Description: A avaliação do desenvolvimento sustentável em sub-bacias hidrográficas tem um papel central na racionalização das tomadas de decisões. Uma forma promissora de medir esse desenvolvimento, é por meio de indicadores, e quando muitos indicadores são usados, eles são usualmente agregados em índices, que fornecem uma visão simplificadae multidimensional do sistema em análise. Diversos índices de sustentabilidade para bacias hidrográficas são propostos na literatura. Entretanto, a incorporação de indicadores ecológicos aquáticos, que agreguem aspectos da biodiversidade é, ainda, uma lacuna ainda a ser preenchida. Portanto, a utilização de indicadores de biodiversidade como representantes da dimensão ambiental, se constitui em um avanço aos índices recentemente apresentados na literatura. O objetivo ,foi avaliar o gradiente de sustentabilidade nas bacias hidrográficas do alto rio Paraná, por meio de um índice de sustentabilidade ecoambiental de sub-bacias (ISE-sb) que incorpora indicadores ecológicos aquáticos. Com esse propósito, os indicadores selecionados com base nas proposições da Agenda 2030, foram divididos em quatro dimensões de sustentabilidade: social, econômica, ecoambiental e ambiental negativo, e passaram por um processo de normalização e filtragem. Em seguida, foi ponderada a importância dos indicadores, utilizando-se da análise de multicritério baseada no método Análise de Processos Hierárquicos (AHP).O ISE-sb foi calculado por meio da média ponderada entre os subíndices que representam as dimensões. Por fim aplicamos a estatística espacial Gi* para identificar agrupamentos de hotspots e coldspots. Os resultados mostram que entre as dimensões da sustentabilidade, aquela que apresentou a maior quantidade de valores baixos, foia ambiental positiva. As regiões localizadas na porção leste, ou serra do mar, porção sul, e o Distrito Federal formaram hotspots de sustentabilidade, enquanto que as sub-bacias localizadas nos estados de Goiás, Mato Grosso do Sul e Minas Gerais formaram os coldposts de sustentabilidade. Recomenda-se um planejamento espacial sustentável das sub-bacias hidrográficas, adotando as áreas de coldspots como prioritárias para sustentabilidade. Evidencia a principal limitação metodológica, a potencial reprodutibilidade da ferramenta em outros espaços.
    Description: Masters
    Keywords: Bacias hidrográficas ; Ecologia ; Manejo ; Conservação e preservação ; Sustentabilidade ; Biomonitoramento ; Ictiofauna ; Monitoramento ; Indicadores ambientais ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::C::Conservation ; ASFA_2015::M::Management ; ASFA_2015::S::Sustainability ; ASFA_2015::B::Bioindicators ; ASFA_2015::I::Ichthyofauna ; ASFA_2015::E::Environmental monitoring ; ASFA_2015::R::River basins ; ASFA_2015::H::Hot spots
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 70pp.
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  • 30
    facet.materialart.
    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-28
    Description: Human activities have caused degradation of aquatic ecosystems and reduced biodiversity. The dams in particular directly impact the spatial and temporal variation of aquatic communities, and especially the phytoplankton community that responds quickly and efficiently to changes in the environment. The impact of a dam in an Amazon river (Jirau Hydroelectric Power Plant) on the spatial and temporal variation of the composition (beta diversity) of phytoplankton was investigated, from October 2009 to July 2017. The hypothesis was tested that the bus modifies beta diversity on a local and regional scale, and alters each location's contribution to beta diversity. The contribution of the sites to the beta diversity was evaluated as a function of the distance from the bus and the environmental heterogeneity. The phytoplankton composition was different between the phases before, fill and after the damming. Biotic homogenization was verified in the tributaries closest to the dam. The more distant sites presented greater contribution to diversity, but were associated with lower values of richness. The dam caused unidirectional changes, locally and regionally, that is, the community moved to a new state over time, and also caused biotic homogenization locally. The impact of the dam was observed only on the tributaries, indicating that run-of-river dams have a greater impact on the tributaries than on the main channel.
    Description: As atividades humanas têm causado degradação dos ecossistemas aquáticos e reduz a biodiversidade. Os barramentos em especial, impactam diretamente a variação espacial e temporal das comunidades aquáticas, e especialmente a comunidade fitoplanctônica que responde de forma rápida e eficiente às mudanças do ambiente. Investigou-se o impacto de um barramento em um rio amazônico (Usina Hidrelétrica de Jirau) sobre a variação espacial e temporal da composição (diversidade beta) do fitoplâncton, no período de outubro de 2009 a julho de 2017. Foi testado a hipótese de que o barramento modifica a diversidade beta em escala local e regional, e altera a contribuição de cada local à diversidade beta. Avaliou-se a contribuição dos locais para a diversidade beta em função da distância do barramento e da heterogeneidade ambiental. A composição fitoplanctônica foi diferente entre as fases antes, enchimento e após o barramento. Verificou-se homogeneização biótica nos tributários mais próximos a barragem. Os locais mais distantes apresentaram maior contribuição a diversidade, mas foram associados a menores valores de riqueza. O barramento causou mudanças unidirecionais, localmente e regionalmente, ou seja, a comunidade passou para um novo estado ao longo do tempo, e também causou homogeneização biótica localmente. Observou-se o impacto do barramento somente nos tributários, indicando que as barragens a fio de água têm maior impacto nos tributários do que no canal principal.
    Description: Masters
    Keywords: Fitoplâncton de água doce ; Barramento ; Impactos antrópicos ; Diversidade beta ; Homogeneização biótica ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::P::Phytoplankton ; ASFA_2015::I::Impacts ; ASFA_2015::B::Biotic environment ; ASFA_2015::R::River basins ; ASFA_2015::E::Environmental impact ; ASFA_2015::R::Reservoirs (water)
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 53pp.
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    Publication Date: 2022-09-13
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Liu, C.-Z., Dick, H. J. B., Mitchell, R. N., Wei, W., Zhang, Z.-Y., Hofmann, A. W., Yang, J.-F., & Li, Y. Archean cratonic mantle recycled at a mid-ocean ridge. Science Advances, 8(22), (2022): eabn6749, https://doi.org/10.1126/sciadv.abn6749.
    Description: Basalts and mantle peridotites of mid-ocean ridges are thought to sample Earth’s upper mantle. Osmium isotopes of abyssal peridotites uniquely preserve melt extraction events throughout Earth history, but existing records only indicate ages up to ~2 billion years (Ga) ago. Thus, the memory of the suspected large volumes of mantle lithosphere that existed in Archean time (〉2.5 Ga) has apparently been lost somehow. We report abyssal peridotites with melt-depletion ages up to 2.8 Ga, documented by extremely unradiogenic 187Os/188Os ratios (to as low as 0.1095) and refractory major elements that compositionally resemble the deep keels of Archean cratons. These oceanic rocks were thus derived from the once-extensive Archean continental keels that have been dislodged and recycled back into the mantle, the feasibility of which we confirm with numerical modeling. This unexpected connection between young oceanic and ancient continental lithosphere indicates an underappreciated degree of compositional recycling over time.
    Description: This study was financially supported by the National Science Fund for Distinguished Young Scholars 42025201 (to C.-Z.L.), the National Key Research and Development Project of China 2020YFA0714801 (to C.-Z.L.), the Strategic Priority Research Program of the Chinese Academy of Sciences XDA13010106 (to C.-Z.L.), the Strategic Priority Research Program of the Chinese Academy of Sciences XDB42020301 (to C.-Z.L.), and NSF grants 2114652 and 1657983 (to H.J.B.D.).
    Repository Name: Woods Hole Open Access Server
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  • 32
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    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-08-31
    Description: The construction of dams is among the main anthropogenic impacts in natural freshwater systems. The first consequence of impoundments is the formation of reservoirs upstream, which represents a completely new environment compared to the natural river. In addition to this primary impact, the variations in the reservoir water level may be considered another facet of disturbances. Although several studies investigated the processes that occur in reservoirs, there is a shortfall regarding the effects of the dam operation scheme on ecosystem health. Most dams are designed to operate under two almost contrasting schemes: storage (STR) and run-of-river (ROR). These alternative operation schemes result in very different temporal variations, with STR reservoirs presenting rapid fluctuations while ROR reservoirs have a relatively constant volume. Likewise, this difference in the temporal dynamics of water level likely affects the stability of these ecosystems. In order to investigate how the dam operation scheme could affect the temporal stability of freshwater ecosystems, we used the fish communities from two reservoirs in the Iguaçu River that operate under contrasting schemes. The hypothesis was that the STR reservoir would be less stable, considering the environmental heterogeneity created by frequent water level variations, and the interactions among species would be less important for the structure of the resident fish community. In the first approach, the focus was on stability in terms of the ability to resist and recover (i.e., resistance and resilience) to disturbances. In the second approach, empirical data and simulations were used to assess which mechanism (species interactions, environmental or demographic stochasticity) underlie the synchrony of fish communities. Contrary to the expectation, the results showed the ROR reservoir as less stable than the STR, and the mechanisms underlying species synchrony coincided between reservoirs but played opposite roles. More specifically, the temporal dynamics imposed by ROR operation may have weakened the species-environment relationships, which led to a less stable community. Although the results were consistent, they were only primary evidence and such cause-effect relationships between dam operation and its effects on ecosystem stability require further investigations.
    Description: A construção de barragens está entre os principais impactos antropogênicos em ambientes de água doce. A primeira consequência dos barramentos é a formação de um reservatório à montante, que representa um ambiente completamente modificado, em relação ao rio natural. Impactos secundários, como as variações no nível da água, também podem ser considerados outros tipos de distúrbio. Embora vários estudos investigaram os processos que ocorrem em reservatórios, existe uma lacuna a respeito dos efeitos do modo de operação da barragem sobre a estado dos ecossistemas. A maioria das barragens é projetada para operar sob dois modos: acumulação (ACU) e fio d’água (FDA). Esses modos alternativos resultam em variações temporais muito distintas, com reservatórios ACU apresentando flutuações rápidas, enquanto reservatórios FDA possuem volume relativamente constante. Do mesmo modo, essa diferença na dinâmica temporal do nível da água provavelmente afeta a estabilidade desses ecossistemas. A fim de investigar como o modo de operação da barragem pode afetar a estabilidade temporal dos ambientes de água doce, foram utilizadas comunidades de peixes de dois reservatórios do rio Iguaçu, que operam sob modos diferentes. A hipótese testada foi que o reservatório ACU seria menos estável, considerando a heterogeneidade ambiental criada pelas variações frequentes no nível da água, e as interações entre as espécies seriam menos importantes para a estrutura da comunidade de peixes. Na primeira abordagem, o foco foi na estabilidade em termos da habilidade em resistir e se recuperar (i.e., resistência e resiliência) aos distúrbios. Na segunda abordagem, dados empíricos e simulações foram utilizados para verificar quais mecanismos (interações entre espécies, ou estocasticidade ambiental/demográfica) seriam subjacentes à sincronia das comunidades de peixes. Ao contrário do esperado, os resultados mostraram que o reservatório FDA foi menos estável do que o reservatório ACU e os mecanismos subjacentes à sincronia das espécies coincidiram entre os reservatórios, mas com papéis opostos. Mais especificamente, a dinâmica temporal imposta pela operação do reservatório FDA provavelmente enfraqueceu as relações espécie-ambiente, o que levou a uma comunidade menos estável. Embora os resultados sejam consistentes, são apenas indícios primários e as relações de causa-e-efeito entre o modo de operação da barragem e a estabilidade dos ecossistemas requer investigações futuras.
    Description: PhD
    Keywords: Peixes de água doce ; Reservatórios de água doce ; Environmental stochasticity ; Reservatórios ; Comunidades, Ecologia de ; Competição interespecífica ; Impactos ambientais antropogênicos ; Manejo ; ASFA_2015::F::Freshwater fish ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::N::Niches ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::I::Impacts ; ASFA_2015::C::Competition ; ASFA_2015::R::Reservoirs (water) ; ASFA_2015::S::Species diversity ; ASFA_2015::I::Interactions ; ASFA_2015::I::Impoundments
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 98pp.
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  • 33
    facet.materialart.
    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-09-01
    Description: Plagioscion squamosissimus (Heckel, 1840) (Sciaenidae), known as “corvina” is a native species of Amazon basin and it is a model for studding their parasites. Intending to analyze ectoparasites ecological aspects, such as distribution and interactions, gills of twenty specimens were analyzed, from rio Tapajós, in the region of Santarém-PA, Brazil. Ecological analyzes considered distribution of parasites between host specimens and also microhabitats occupied by ectoparasites. Eighteen ectoparasites species were founded, fourteen monogenetic and four copepods. Considering species abundance, monogenetic were the dominant group and Euryhaliotrema thatcheri was the most abundant in all analyzed hosts. There was a significate correlation between some parasite species abundance and prevalence with total length and host condition factor. Each species of parasite presented an aggregate distribution pattern. The community of P. squamosissimus ectoparasites were interactive. Considering the distribution of the species in the gills, there was a significant difference in the composition between arches, segments and regions. It is suggested that this distribution is related to factors related to microhabitat, such as water flow and area available for fixation of parasites, as well as the structures of fixation of each species and interactions such as positive associations and competition. During the investigation of the material, specimens that differed from the species already described were founded, so three new monogenetic species were proposed, belonging to the genus Aetheolabes, Anakohnia and Euryhaliotrema, based on their morphological characteristics.
    Description: A corvina de água doce ou pescada branca, Plagioscion squamosissimus (Heckel, 1840) (Sciaenidae) se distribui pela bacia Amazônica e que como hospedeira, consiste em um modelo para o estudo de seus parasitas. Analisou-se os aspectos ecológicos da fauna ectoparasitária de P. squamosissimus, tais como a distribuição e as interações e entre as espécies, por meio das brânquias de vinte espécimes coletados no rio Tapajós, região de Santarém-PA. Considerou-se a distribuição de parasitas entre os espécimes de hospedeiros e também, a partir dos microhabitats que os ectoparasitas ocupavam nesses espécimes. Foram encontradas dezoito espécies de ectoparasitas, dentre os quais catorze monogenéticos e quatro copépodes. Em relação a abundância das espécies, os monogenéticos destacaram-se como grupo dominante e, dentre estas espécies, Euryhaliotrema thatcheri apresentou-se como a mais abundante em todos os hospedeiros analisados. Houve correlação da abundância e da prevalência de algumas espécies de parasitas com o comprimento total e o fator de condição dos hospedeiros. Cada espécie de parasita apresentou padrão de distribuição agregado. A comunidade de ectoparasitas de P. squamosissimus foi considerada interativa. Em relação à distribuição das espécies nas brânquias, houve diferença significativa na composição entre os arcos, segmentos e regiões. Sugere-se que esta distribuição se relaciona com fatores referentes ao microhabitat, como o fluxo de água e a área disponível para fixação dos parasitas, bem como as estruturas de fixação de cada espécie e também interações como associações positivas e competição. Durante a investigação do material, os espécimes encontrados diferiram das espécies previamente descritas, de modo que realizou-se a proposta de três novas espécies de monogenéticos pertencentes aos gêneros Aetheolabes, Anakohnia e Euryhaliotrema a partir de suas características morfológicas.
    Description: PhD
    Keywords: Fauna ectoparasitária ; Monogenea ; Copepoda ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::F::Freshwater fish ; ASFA_2015::P::Parasites ; ASFA_2015::E::Ectoparasites ; ASFA_2015::E::Ectoparasitism
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 83pp.
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  • 34
    Publication Date: 2022-10-27
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Meaders, J. L., de Matos, S. N., & Burgess, D. R. A pushing mechanism for microtubule aster positioning in a large cell type. Cell Reports, 33(1), (2020): 108213, doi:10.1016/j.celrep.2020.108213.
    Description: After fertilization, microtubule (MT) sperm asters undergo long-range migration to accurately position pronuclei. Due to the large sizes of zygotes, the forces driving aster migration are considered to be from pulling on the astral MTs by dynein, with no significant contribution from pushing forces. Here, we re-investigate the forces responsible for sperm aster centration in sea urchin zygotes. Our quantifications of aster geometry and MT density preclude a pulling mechanism. Manipulation of aster radial lengths and growth rates, combined with quantitative tracking of aster migration dynamics, indicates that aster migration is equal to the length of rear aster radii, supporting a pushing model for centration. We find that dynein inhibition causes an increase in aster migration rates. Finally, ablation of rear astral MTs halts migration, whereas front and side ablations do not. Collectively, our data indicate that a pushing mechanism can drive the migration of asters in a large cell type.
    Description: We would like to thank Dr. Jesse Gatlin for sending us the Tau-mCherry fusion protein for imaging live MTs. We would also like to thank Dr. Timothy Mitchison, Dr. Christine Field, and Dr. James Pelletier for supplying us with CA4, p150-CC1, and EB1-GFP peptides, as well as for fruitful discussions. Finally, we would like to thank Dr. Charles Shuster and Leslie Toledo-Jacobo for constructive feedback when preparing the manuscript. We thank Bret Judson and the Boston College Imaging Core for infrastructure and support. This material is based upon work supported by NSF grant no. 124425 to D.R.B.
    Keywords: Dynein ; Aster ; Microtubule ; Centrosome ; Pronucleus ; Fertilization ; Aster position
    Repository Name: Woods Hole Open Access Server
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  • 35
    Publication Date: 2022-10-27
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Stolp, Z. D., Kulkarni, M., Liu, Y., Zhu, C., Jalisi, A., Lin, S., Casadevall, A., Cunningham, K. W., Pineda, F. J., Teng, X., & Hardwick, J. M. Yeast cell death pathway requiring AP-3 vesicle trafficking leads to vacuole/lysosome membrane permeabilization. Cell Reports, 39(2), (2022): 110647, https://doi.org/10.1016/j.celrep.2022.110647.
    Description: Unicellular eukaryotes have been suggested as undergoing self-inflicted destruction. However, molecular details are sparse compared with the mechanisms of programmed/regulated cell death known for human cells and animal models. Here, we report a molecular cell death pathway in Saccharomyces cerevisiae leading to vacuole/lysosome membrane permeabilization. Following a transient cell death stimulus, yeast cells die slowly over several hours, consistent with an ongoing molecular dying process. A genome-wide screen for death-promoting factors identified all subunits of the AP-3 complex, a vesicle trafficking adapter known to transport and install newly synthesized proteins on the vacuole/lysosome membrane. To promote cell death, AP-3 requires its Arf1-GTPase-dependent vesicle trafficking function and the kinase Yck3, which is selectively transported to the vacuole membrane by AP-3. Video microscopy revealed a sequence of events where vacuole permeability precedes the loss of plasma membrane integrity. AP-3-dependent death appears to be conserved in the human pathogenic yeast Cryptococcus neoformans.
    Description: Funding sources: National Institutes of Health, United States grants AI144373 and NS127076 (J.M.H.), AI115016 and AI153414 (K.W.C.), and AI052733, AI152078, and HL059842 (A.C.); National Natural Science Foundation of China 31970550; and the Priority Academic Program Development of the Jiangsu Higher Education Institutes (X.T.).
    Keywords: Yeast ; Programmed cell death ; Vesicle trafficking ; AP-3 ; Vacuole ; Cryptococcus ; Yck3 ; Regulated cell death ; Lysosome ; Vacuolar membrane permeabilization
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  • 36
    Publication Date: 2022-05-26
    Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Renfrew, I. A., Pickart, R. S., Vage, K., Moore, G. W. K., Bracegirdle, T. J., Elvidge, A. D., Jeansson, E., Lachlan-Cope, T., McRaven, L. T., Papritz, L., Reuder, J., Sodemann, H., Terpstra, A., Waterman, S., Valdimarsson, H., Weiss, A., Almansi, M., Bahr, F., Brakstad, A., Barrell, C., Brooke, J. K., Brooks, B. J., Brooks, I. M., Brooks, M. E., Bruvik, E. M., Duscha, C., Fer, I., Golid, H. M., Hallerstig, M., Hessevik, I., Huang, J., Houghton, L., Jonsson, S., Jonassen, M., Jackson, K., Kvalsund, K., Kolstad, E. W., Konstali, K., Kristiansen, J., Ladkin, R., Lin, P., Macrander, A., Mitchell, A., Olafsson, H., Pacini, A., Payne, C., Palmason, B., Perez-Hernandez, M. D., Peterson, A. K., Petersen, G. N., Pisareva, M. N., Pope, J. O., Seidl, A., Semper, S., Sergeev, D., Skjelsvik, S., Soiland, H., Smith, D., Spall, M. A., Spengler, T., Touzeau, A., Tupper, G., Weng, Y., Williams, K. D., Yang, X., & Zhou, S. The Iceland Greenland Seas Project. Bulletin of the American Meteorological Society, 100(9), (2019): 1795-1817, doi:10.1175/BAMS-D-18-0217.1.
    Description: The Iceland Greenland Seas Project (IGP) is a coordinated atmosphere–ocean research program investigating climate processes in the source region of the densest waters of the Atlantic meridional overturning circulation. During February and March 2018, a field campaign was executed over the Iceland and southern Greenland Seas that utilized a range of observing platforms to investigate critical processes in the region, including a research vessel, a research aircraft, moorings, sea gliders, floats, and a meteorological buoy. A remarkable feature of the field campaign was the highly coordinated deployment of the observing platforms, whereby the research vessel and aircraft tracks were planned in concert to allow simultaneous sampling of the atmosphere, the ocean, and their interactions. This joint planning was supported by tailor-made convection-permitting weather forecasts and novel diagnostics from an ensemble prediction system. The scientific aims of the IGP are to characterize the atmospheric forcing and the ocean response of coupled processes; in particular, cold-air outbreaks in the vicinity of the marginal ice zone and their triggering of oceanic heat loss, and the role of freshwater in the generation of dense water masses. The campaign observed the life cycle of a long-lasting cold-air outbreak over the Iceland Sea and the development of a cold-air outbreak over the Greenland Sea. Repeated profiling revealed the immediate impact on the ocean, while a comprehensive hydrographic survey provided a rare picture of these subpolar seas in winter. A joint atmosphere–ocean approach is also being used in the analysis phase, with coupled observational analysis and coordinated numerical modeling activities underway.
    Description: The IGP has received funding from the U.S. National Science Foundation: Grant OCE-1558742; the U.K.’s Natural Environment Research Council: AFIS (NE/N009754/1); the Research Council of Norway: MOCN (231647), VENTILATE (229791), SNOWPACE (262710) and FARLAB (245907); and the Bergen Research Foundation (BFS2016REK01). We thank all those involved in the field work associated with the IGP, particularly the officers and crew of the Alliance, and the operations staff of the aircraft campaign.
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  • 37
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2019. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 49(12), (2019): 3127-3143, doi: 10.1175/JPO-D-19-0011.1.
    Description: The Intermediate Western Boundary Current (IWBC) transports Antarctic Intermediate Water across the Vitória–Trindade Ridge (VTR), a seamount chain at ~20°S off Brazil. Recent studies suggest that the IWBC develops a strong cyclonic recirculation in Tubarão Bight, upstream of the VTR, with weak time dependency. We herein use new quasi-synoptic observations, data from the Argo array, and a regional numerical model to describe the structure and variability of the IWBC and to investigate its dynamics. Both shipboard acoustic Doppler current profiler (ADCP) data and trajectories of Argo floats confirm the existence of the IWBC recirculation, which is also captured by our Regional Oceanic Modeling System (ROMS) simulation. An “intermediate-layer” quasigeostrophic (QG) model indicates that the ROMS time-mean flow is a good proxy for the IWBC steady state, as revealed by largely parallel isolines of streamfunction ψ⎯ and potential vorticity Q⎯; a ψ⎯−Q⎯ scatter diagram also shows that the IWBC is potentially unstable. Further analysis of the ROMS simulation reveals that remotely generated, westward-propagating nonlinear eddies are the main source of variability in the region. These eddies enter the domain through the Tubarão Bight eastern edge and strongly interact with the IWBC. As they are advected downstream and negotiate the local topography, the eddies grow explosively through horizontal shear production.
    Description: We thank Frank O. Smith for copy editing and proofreading this manuscript. This study was financed in part by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—CAPES, Brazil—Finance Code 001 and by Projeto REMARSUL (Processo CAPES 88882.158621/2014-01), Projeto VT-Dyn (Processo FAPESP 2015/21729-4) and Projeto SUBMESO (Processo CNPq 442926/2015-4). Rocha was supported by a WHOI Postdoctoral Scholarship.
    Description: 2020-06-06
    Keywords: South Atlantic Ocean ; Instability ; Mesoscale processes ; Intermediate waters ; In situ oceanic observations ; Quasigeostrophic models
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  • 38
    Publication Date: 2022-05-26
    Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kwon, Y., Seo, H., Ummenhofer, C. C., & Joyce, T. M. Impact of multidecadal variability in Atlantic SST on winter atmospheric blocking. Journal of Climate, 33(3), (2020): 867-892, doi: 10.1175/JCLI-D-19-0324.1.
    Description: Recent studies have suggested that coherent multidecadal variability exists between North Atlantic atmospheric blocking frequency and the Atlantic multidecadal variability (AMV). However, the role of AMV in modulating blocking variability on multidecadal times scales is not fully understood. This study examines this issue primarily using the NOAA Twentieth Century Reanalysis for 1901–2010. The second mode of the empirical orthogonal function for winter (December–March) atmospheric blocking variability in the North Atlantic exhibits oppositely signed anomalies of blocking frequency over Greenland and the Azores. Furthermore, its principal component time series shows a dominant multidecadal variability lagging AMV by several years. Composite analyses show that this lag is due to the slow evolution of the AMV sea surface temperature (SST) anomalies, which is likely driven by the ocean circulation. Following the warm phase of AMV, the warm SST anomalies emerge in the western subpolar gyre over 3–7 years. The ocean–atmosphere interaction over these 3–7-yr periods is characterized by the damping of the warm SST anomalies by the surface heat flux anomalies, which in turn reduce the overall meridional gradient of the air temperature and thus weaken the meridional transient eddy heat flux in the lower troposphere. The anomalous transient eddy forcing then shifts the eddy-driven jet equatorward, resulting in enhanced Rossby wave breaking and blocking on the northern flank of the jet over Greenland. The opposite is true with the AMV cold phases but with much shorter lags, as the evolution of SST anomalies differs in the warm and cold phases.
    Description: We gratefully acknowledge support from the NSF Climate and Large-scale Dynamics Program (AGS-1355339) to Y-OK, HS, CCU, and TMJ, the NASA Physical Oceanography Program (NNX13AM59G) to Y-OK, HS, and TMJ, NOAA CPO Climate Variability and Predictability Program (NA13OAR4310139) and DOE CESD Regional and Global Model Analysis Program (DE-SC0019492) to Y-OK, and NSF Physical Oceanography Program (OCE-1419235) to HS. We are very grateful to the three anonymous reviewers and editor Dr. Mingfang Ting, for their thorough and insightful suggestions. The NOAA 20CR dataset was downloaded from the NOAA Earth System Research Laboratory Physical Science Division webpage (https://www.esrl.noaa.gov/psd/data/20thC_Rean/). Support for the 20CR Project version 2c dataset is provided by the U.S. Department of Energy, Office of Science Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office. The HadISST dataset was downloaded from the U.K. Met Office Hadley Centre webpage (https://www.metoffice.gov.uk/hadobs/hadisst/). The ERA-20C dataset was downloaded from the ECMWF webpage (https://apps.ecmwf.int/datasets/data/era20c-daily/). The ERSST5 dataset was provided by the NOAA Earth System Research Laboratory Physical Science Division (https://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.v5.html).
    Keywords: North Atlantic Ocean ; Atmosphere-ocean interaction ; Blocking ; Climate variability ; Multidecadal variability ; North Atlantic Oscillation
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  • 39
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(2), (2020): 415-437, doi:10.1175/JPO-D-19-0019.1.
    Description: Results are presented from two dye release experiments conducted in the seasonal thermocline of the Sargasso Sea, one in a region of low horizontal strain rate (~10−6 s−1), the second in a region of intermediate horizontal strain rate (~10−5 s−1). Both experiments lasted ~6 days, covering spatial scales of 1–10 and 1–50 km for the low and intermediate strain rate regimes, respectively. Diapycnal diffusivities estimated from the two experiments were κz = (2–5) × 10−6 m2 s−1, while isopycnal diffusivities were κH = (0.2–3) m2 s−1, with the range in κH being less a reflection of site-to-site variability, and more due to uncertainties in the background strain rate acting on the patch combined with uncertain time dependence. The Site I (low strain) experiment exhibited minimal stretching, elongating to approximately 10 km over 6 days while maintaining a width of ~5 km, and with a notable vertical tilt in the meridional direction. By contrast, the Site II (intermediate strain) experiment exhibited significant stretching, elongating to more than 50 km in length and advecting more than 150 km while still maintaining a width of order 3–5 km. Early surveys from both experiments showed patchy distributions indicative of small-scale stirring at scales of order a few hundred meters. Later surveys show relatively smooth, coherent distributions with only occasional patchiness, suggestive of a diffusive rather than stirring process at the scales of the now larger patches. Together the two experiments provide important clues as to the rates and underlying processes driving diapycnal and isopycnal mixing at these scales.
    Description: Results are presented from two dye release experiments conducted in the seasonal thermocline of the Sargasso Sea, one in a region of low horizontal strain rate (~10−6 s−1), the second in a region of intermediate horizontal strain rate (~10−5 s−1). Both experiments lasted ~6 days, covering spatial scales of 1–10 and 1–50 km for the low and intermediate strain rate regimes, respectively. Diapycnal diffusivities estimated from the two experiments were κz = (2–5) × 10−6 m2 s−1, while isopycnal diffusivities were κH = (0.2–3) m2 s−1, with the range in κH being less a reflection of site-to-site variability, and more due to uncertainties in the background strain rate acting on the patch combined with uncertain time dependence. The Site I (low strain) experiment exhibited minimal stretching, elongating to approximately 10 km over 6 days while maintaining a width of ~5 km, and with a notable vertical tilt in the meridional direction. By contrast, the Site II (intermediate strain) experiment exhibited significant stretching, elongating to more than 50 km in length and advecting more than 150 km while still maintaining a width of order 3–5 km. Early surveys from both experiments showed patchy distributions indicative of small-scale stirring at scales of order a few hundred meters. Later surveys show relatively smooth, coherent distributions with only occasional patchiness, suggestive of a diffusive rather than stirring process at the scales of the now larger patches. Together the two experiments provide important clues as to the rates and underlying processes driving diapycnal and isopycnal mixing at these scales.
    Description: 2020-08-06
    Keywords: Ocean ; Atlantic Ocean ; Diapycnal mixing ; Diffusion ; Dispersion ; Mixing
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  • 40
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 37(5), (2020): 789-806, doi:10.1175/JTECH-D-18-0244.1.
    Description: Realistic ocean state prediction and its validation rely on the availability of high quality in situ observations. To detect data errors, adequate quality check procedures must be designed. This paper presents procedures that take advantage of the ever-growing observation databases that provide climatological knowledge of the ocean variability in the neighborhood of an observation location. Local validity intervals are used to estimate binarily whether the observed values are considered as good or erroneous. Whereas a classical approach estimates validity bounds from first- and second-order moments of the climatological parameter distribution, that is, mean and variance, this work proposes to infer them directly from minimum and maximum observed values. Such an approach avoids any assumption of the parameter distribution such as unimodality, symmetry around the mean, peakedness, or homogeneous distribution tail height relative to distribution peak. To reach adequate statistical robustness, an extensive manual quality control of the reference dataset is critical. Once the data have been quality checked, the local minima and maxima reference fields are derived and the method is compared with the classical mean/variance-based approach. Performance is assessed in terms of statistics of good and bad detections. It is shown that the present size of the reference datasets allows the parameter estimates to reach a satisfactory robustness level to always make the method more efficient than the classical one. As expected, insufficient robustness persists in areas with an especially low number of samples and high variability.
    Description: This study has been conducted using EU Copernicus Marine Service Information and was supported by the European Union within the EU Copernicus Marine Service In Situ phase-I and phase-II contracts led by Ifremer. The publication was also supported by SOERE CTDO2 in France. The Argo data were collected and made freely available by the International Argo Program and the national programs that contribute to it (see http://www.argo.ucsd.edu, http://argo.jcommops.org). The Argo Program is part of the Global Ocean Observing System (http://doi.org/10.17882/42182). The marine mammal data were collected and made freely available by the International MEOP Consortium and the national programs that contribute to it (see http://www.meop.net; https://doi.org/10.17882/45461). Aleix Gelabert and Dídac Costa were the skippers of the OPOO, sponsored by the Intergovernmental Oceanographic Commission (UNESCO) and Pharmaton. The BWR is a periodic oceanic race organized by the Fundació Navegació Oceànica de Barcelona (FNOB). Reviewer D. Briand provided some useful comments on the final version of the draft paper before submission.
    Description: 2020-11-04
    Keywords: Ocean ; Climatology ; Salinity ; Temperature ; Data quality control ; Oceanic variability
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  • 41
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(5), (2020): 1245-1263, doi:10.1175/JPO-D-19-0213.1.
    Description: We use laboratory experiments and theoretical modeling to investigate the surface expression of a subglacial discharge plume, as occurs at many fjords around Greenland. The experiments consider a fountain that is released vertically into a homogeneous fluid, adjacent either to a vertical or a sloping wall, that then spreads horizontally at the free surface before sinking back to the bottom. We present a model that separates the fountain into two separate regions: a vertical fountain and a horizontal, negatively buoyant jet. The model is compared to laboratory experiments that are conducted over a range of volume fluxes, density differences, and ambient fluid depths. It is shown that the nondimensionalized length, width, and aspect ratio of the surface expression are dependent on the Froude number, calculated at the start of the negatively buoyant jet. The model is applied to observations of the surface expression from a Greenland subglacial discharge plume. In the case where the discharge plume reaches the surface with negative buoyancy the model can be used to estimate the discharge properties at the base of the glacier.
    Description: We gratefully acknowledge technical assistance from Anders Jensen and thank anonymous reviewers for improving the clarity of the manuscript. CM thanks the Weston Howard Jr. Scholarship for funding. Support to CC was given by NSF project OCE-1434041 and OCE-1658079.
    Description: 2020-10-27
    Keywords: Ocean ; Glaciers ; Ice sheets ; Convection ; Laboratory/physical models
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  • 42
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(3), (2020): 679-694, doi:10.1175/JPO-D-19-0218.1.
    Description: The zonally integrated flow in a basin can be separated into the divergent/nondivergent parts, and a uniquely defined meridional overturning circulation (MOC) can be calculated. For a basin with significant volume exchange at zonal open boundaries, this method is competent in removing the components associated with the nonzero source terms due to zonal transports at open boundaries. This method was applied to the zonally integrated flow in the Indian Ocean basin extended all the way to the Antarctic by virtue of the ECCO dataset. The contributions due to two major zonal flow systems at open boundaries, the Indonesian Throughflow (ITF) and the Antarctic Circumpolar Current (ACC), were well separated from the rotational flow component, and a nondivergent overturning circulation pattern was identified. Comparisons with previous studies on the MOC of the Indian Ocean in different seasons showed overall consistency but with refinements in details to the south of the entry of the ITF, reflecting the influence of ITF on the MOC pattern in the domain. Other options of decomposition are also examined.
    Description: LH was supported by the National Basic Research Program of China through Grant 2019YFA0606703 and “The Fundamental Research Funds of Shandong University” (2019GN051). The authors thank the anonymous reviewers and the editor for their constructive comments. Code availability: The Matlab code that performs the decomposition and produces some figures in this paper is available at https://github.com/lei-han-SDU/IMOC/.
    Description: 2020-09-02
    Keywords: Meridional overturning circulation ; Ocean circulation ; Streamfunction
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  • 43
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    Unknown
    American Meteorological Society
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(9), (2020): 2491-2506, doi:10.1175/JPO-D-20-0056.1.
    Description: An idealized two-layer shallow water model is applied to the study of the dynamics of the Arctic Ocean halocline. The model is forced by a surface stress distribution reflective of the observed wind stress pattern and ice motion and by an inflow representing the flow of Pacific Water through Bering Strait. The model reproduces the main elements of the halocline circulation: an anticyclonic Beaufort Gyre in the western basin (representing the Canada Basin), a cyclonic circulation in the eastern basin (representing the Eurasian Basin), and a Transpolar Drift between the two gyres directed from the upwind side of the basin to the downwind side of the basin. Analysis of the potential vorticity budget shows a basin-averaged balance primarily between potential vorticity input at the surface and dissipation at the lateral boundaries. However, advection is a leading-order term not only within the anticyclonic and cyclonic gyres but also between the gyres. This means that the eastern and western basins are dynamically connected through the advection of potential vorticity. Both eddy and mean fluxes play a role in connecting the regions of potential vorticity input at the surface with the opposite gyre and with the viscous boundary layers. These conclusions are based on a series of model runs in which forcing, topography, straits, and the Coriolis parameter were varied.
    Description: This study was supported by National Science Foundation Grant OPP-1822334. Comments and suggestions from two anonymous referees greatly helped to improve the paper.
    Description: 2021-02-17
    Keywords: Eddies ; Ekman pumping/transport ; Ocean circulation ; Ocean dynamics ; Potential vorticity ; Shallow-water equations
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  • 44
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 101(6), (2020): E897-E904, doi:10.1175/BAMS-D-19-0047.1.
    Description: Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.
    Description: We thank U.S. CLIVAR and ISSI for funding the two working groups. We thank all members of the working groups for helpful discussions, and the U.S. CLIVAR and ISSI offices and their sponsoring agencies (NASA, NOAA, NSF, DOE, ESA, Swiss Confederation, Swiss Academy of Sciences, and University of Bern) for supporting these groups and activities.
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  • 45
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(4), (2020): 887-905, doi:10.1175/JPO-D-19-0110.1.
    Description: The Equatorial Undercurrent (EUC) encounters the Galápagos Archipelago on the equator as it flows eastward across the Pacific. The impact of the Galápagos Archipelago on the EUC in the eastern equatorial Pacific remains largely unknown. In this study, the path of the EUC as it reaches the Galápagos Archipelago is measured directly using high-resolution observations obtained by autonomous underwater gliders. Gliders were deployed along three lines that define a closed region with the Galápagos Archipelago as the eastern boundary and 93°W from 2°S to 2°N as the western boundary. Twelve transects were simultaneously occupied along the three lines during 52 days in April–May 2016. Analysis of individual glider transects and average sections along each line show that the EUC splits around the Galápagos Archipelago. Velocity normal to the transects is used to estimate net horizontal volume transport into the volume. Downward integration of the net horizontal transport profile provides an estimate of the time- and areal-averaged vertical velocity profile over the 52-day time period. Local maxima in vertical velocity occur at depths of 25 and 280 m with magnitudes of (1.7 ± 0.6) × 10−5 m s−1 and (8.0 ± 1.6) × 10−5 m s−1, respectively. Volume transport as a function of salinity indicates that water crossing 93°W south (north) of 0.4°S tends to flow around the south (north) side of the Galápagos Archipelago. Comparisons are made between previous observational and modeling studies with differences attributed to effects of the strong 2015/16 El Niño event, the annual cycle of local winds, and varying longitudes between studies of the equatorial Pacific.
    Description: This work was supported by National Science Foundation (Grants OCE-1232971 and OCE-1233282) and the NASA Earth and Space Science Fellowship Program (Grant 80NSSC17K0443).
    Keywords: Tropics ; Boundary currents ; Topographic effects ; Transport ; Upwelling/downwelling ; In situ oceanic observations
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  • 46
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(10), (2020): 2849-2871, https://doi.org/10.1175/JPO-D-20-0086.1.
    Description: The structure, transport, and seasonal variability of the West Greenland boundary current system near Cape Farewell are investigated using a high-resolution mooring array deployed from 2014 to 2018. The boundary current system is comprised of three components: the West Greenland Coastal Current, which advects cold and fresh Upper Polar Water (UPW); the West Greenland Current, which transports warm and salty Irminger Water (IW) along the upper slope and UPW at the surface; and the Deep Western Boundary Current, which advects dense overflow waters. Labrador Sea Water (LSW) is prevalent at the seaward side of the array within an offshore recirculation gyre and at the base of the West Greenland Current. The 4-yr mean transport of the full boundary current system is 31.1 ± 7.4 Sv (1 Sv ≡ 106 m3 s−1), with no clear seasonal signal. However, the individual water mass components exhibit seasonal cycles in hydrographic properties and transport. LSW penetrates the boundary current locally, through entrainment/mixing from the adjacent recirculation gyre, and also enters the current upstream in the Irminger Sea. IW is modified through air–sea interaction during winter along the length of its trajectory around the Irminger Sea, which converts some of the water to LSW. This, together with the seasonal increase in LSW entering the current, results in an anticorrelation in transport between these two water masses. The seasonality in UPW transport can be explained by remote wind forcing and subsequent adjustment via coastal trapped waves. Our results provide the first quantitatively robust observational description of the boundary current in the eastern Labrador Sea.
    Description: A.P., R.S.P., F.B., D.J.T., and A.L.R. were funded by Grants OCE-1259618 and OCE-1756361 from the National Science Foundation. I.L.B, F.S., and J.H. were supported by U.S. National Science Foundation Grants OCE-1258823 and OCE-1756272. Mooring data from MA2 was funded by the European Union 7th Framework Programme (FP7 2007-2013) under Grant 308299 (NACLIM) and the Horizon 2020 research and innovation program under Grant 727852 (Blue-Action). J.K. and M.O. acknowledge EU Horizon 2020 funding Grants 727852 (Blue-action) and 862626 (EuroSea) and from the German Ministry of Research and Education (RACE Program). G.W.K.M. acknowledges funding from the Natural Sciences and Engineering Research Council.
    Keywords: Boundary currents ; Convection ; Deep convection ; Transport ; In situ oceanic observations ; Seasonal cycle
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  • 47
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 101(11), (2020): E1996-E2004, https://doi.org/10.1175/BAMS-D-19-0305.1.
    Description: A long-standing challenge in oceanography is the observing, modeling, and prediction of vertical transport, which links the sunlit and atmospherically mediated surface boundary layer with the deeper ocean. Vertical motions play a critical role in the exchange of heat, freshwater, and biogeochemical tracers between the surface and the ocean interior. The most intense vertical velocities occur at horizontal scales less than 10 km, making them difficult to observe in the ocean and to resolve in models. Understanding how finescale turbulent motions and 0.1–10 km submesoscale processes contribute to the large-scale budgets of nutrients, oxygen, carbon, and heat and affect sea surface temperature, the air–sea exchange of gases, and the carbon cycle is one of the key challenges in oceanography.
    Description: CALYPSO is a Departmental Research Initiative (DRI) funded by the U.S. Office of Naval Research (ONR). It is a collaborative program involving more than 30 scientists and students and multiple institutions in the United States, Spain, and Italy. Measurements were conducted from the NRV Alliance, Pourquoi Pas?, and SOCIB. We are grateful to the captains and crews of these research vessels and the technical and scientific staff involved in making measurements, running models, analyzing data, and providing support.
    Description: 2021-05-01
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  • 48
    Publication Date: 2022-05-26
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(4), (2020): 1045-1064, doi:10.1175/JPO-D-19-0137.1.
    Description: Three simulations of the circulation in the Gulf of Mexico (the “Gulf”) using different numerical general circulation models are compared with results of recent large-scale observational campaigns conducted throughout the deep (〉1500 m) Gulf. Analyses of these observations have provided new understanding of large-scale mean circulation features and variability throughout the deep Gulf. Important features include cyclonic flow along the continental slope, deep cyclonic circulation in the western Gulf, a counterrotating pair of cells under the Loop Current region, and a cyclonic cell to the south of this pair. These dominant circulation features are represented in each of the ocean model simulations, although with some obvious differences. A striking difference between all the models and the observations is that the simulated deep eddy kinetic energy under the Loop Current region is generally less than one-half of that computed from observations. A multidecadal integration of one of these numerical simulations is used to evaluate the uncertainty of estimates of velocity statistics in the deep Gulf computed from limited-length (4 years) observational or model records. This analysis shows that the main deep circulation features identified from the observational studies appear to be robust and are not substantially impacted by variability on time scales longer than the observational records. Differences in strengths and structures of the circulation features are identified, however, and quantified through standard error analysis of the statistical estimates using the model solutions.
    Description: This work was supported by the Gulf Research Program of the National Academy of Sciences under Awards 2000006422 and 2000009966. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Gulf Research Program or the National Academy of Sciences. The authors acknowledge the GLORYS project for providing the ocean reanalysis data used in the ROMS simulation. GLORYS is jointly conducted by MERCATOR OCEAN, CORIOLIS, and CNRS/INSU. Installation, recovery, data acquisition, and processing of the CANEK group current-meter moorings were possible because of CICESE-PetróleosMexicanos Grant PEP-CICESE 428229851 and the dedicated work of the crew of the B/O Justo Sierra and scientists of the CANEK group. The authors thank Dr. Aljaz Maslo, CICESE, for assistance with analysis of model data. The Bureau of Ocean Energy Management (BOEM), U.S. Dept. of the Interior, provided funding for the Lagrangian Study of the Deep Circulation in the Gulf of Mexico and the Observations and Dynamics of the Loop Current study. HYCOM simulation data are available from the HYCOM data server (https://www.hycom.org/data/goml0pt04/expt-02pt2), MITgcm data are available from the ECCO data server (http://ecco.ucsd.edu/gom_results2.html), and the ROMS simulation data are available from GRIIDC (NA.x837.000:0001).
    Keywords: Ocean circulation ; Abyssal circulation ; Bottom currents/bottom water ; Eddies ; Ocean models
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  • 49
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    Unknown
    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-06
    Description: Invasive species can have many negative impacts on the biodiversity, ecosystem services, human health and the economy, and therefore need to be managed. An amphibious weed of global importance, Alternanthera philoxeroides, and the macroecological patterns of its biological control were evaluated using one of its main specialist herbivores, Agasicles hygrophila. This was considered the first successful case of biological control of an aquatic plant, although it is not equally effective on a global scale. Due to their different environmental tolerances and the greater phenotypic plasticity of the plant, the distribution of both species do not always overlap in the globe, creating geographic variability in the efficiency of biocontrol. The first approach was to analyze the current global potential distribution of A. philoxeroides and A. hygrophila to seek the areas of overlaps and gaps between them. The overlapping areas would be the most relevant for using A. hygrophila as alligator weed biological control in the globe. However, in response of climate change, it seems that the alligator weed is worryingly spreading across the globe, which can worsen in future scenarios and alter its distribution in the next decades. The second approach evaluated the effects of climate change on the global distribution of A. philoxeroides and A. hygrophila. New distribution areas for both species in future global warming scenarios and new overlapping and non-overlapping areas across the globe were identified. Species Distribution Models (SDMs) were applied in both chapters to predict the potential distribution of the two species in present and future scenarios considering different environmental predictors in each one. Currently, the southeast coast of the USA, southeast China and New South Wales, Australia are the most favorable areas in the world to apply alligator weed biocontrol, while the west coast and mid-latitudes in the east of the USA and the eastern Australia are not favorable. The results were corroborated by reports in the literature that demonstrated successful control in overlapping areas and failures in non-overlapping areas of the models’ distributions. However, while general geographic patterns will hold in future scenarios, it is predicted a major northward expansion of the alligator weed, but not of the insect, especially in the USA, Canada, Europe, China, South Korea and Japan, which will create a new zone of low or no control efficiency at higher latitudes. These macroecological patterns will help direct efforts to apply the biological control for the alligator weed not only today, but also in future climate change scenarios.
    Description: Espécies invasoras podem causar muitos impactos negativos na biodiversidade, nos serviços ecossistêmicos, na saúde humana e na economia e, portanto, precisam ser manejadas. Avaliou-se uma erva daninha anfíbia de importância global, Alternanthera philoxeroides, e nos padrões macroecológicos de seu controle biológico usando um de seus principais herbívoros especialistas, Agasicles hygrophila. Este foi considerado o primeiro caso bem sucedido de controle biológico de uma macrófita, embora não seja igualmente eficaz em escala global. Devido às suas diferentes tolerâncias ambientais e à maior plasticidade fenotípica da planta, a distribuição de ambas as espécies nem sempre se sobrepõe no globo, criando variabilidade geográfica na eficiência do biocontrole. O primeiro enfoque foi analisar a distribuição potencial global atual de A. philoxeroides e A. hygrophila para buscar as áreas de sobreposição e não sobreposição entre elas. As áreas sobrepostas seriam as mais relevantes para o uso de A. hygrophila como controle biológico da erva-de-jacaré no globo. Entretanto, em resposta às mudanças climáticas, a erva-de-jacaré está se expandindo de forma preocupante pelo globo, o que pode agravar em cenários futuros e alterar sua distribuição nas próximas décadas. O segundo enfoque avaliou-se os efeitos das mudanças climáticas na distribuição global de A. philoxeroides e A. hygrophila. Identificou-se as novas áreas de distribuição para ambas as espécies em cenários futuros de aquecimento global e as novas áreas sobrepostas e não sobrepostas em todo o globo. Modelos de Distribuição de Espécies (MDEs) foram aplicados em ambas as abordagens para predizer a distribuição potencial das duas espécies em cenários presentes e futuros considerando diferentes preditores ambientais em cada um. Atualmente, a costa sudeste dos EUA, sudeste da China e Sidnei, Austrália, são as áreas mais favoráveis no mundo para aplicar o biocontrole da erva-de-jacaré, enquanto a costa oeste e latitudes médias no leste dos EUA e no leste da Austrália não são favoráveis. Os resultados foram corroborados por relatos na literatura que demonstraram controle bem-sucedido em áreas sobrepostas e mal-sucedido em áreas não sobrepostas das distribuições dos modelos. Entretanto, embora os padrões geográficos gerais se mantenham em cenários futuros, é prevista uma grande expansão da erva-de-jacaré, mas não do inseto, para o norte, especialmente nos EUA, Canadá, Europa, China, Coreia do Sul e Japão, o que criará uma nova zona de baixa ou nenhuma eficiência de controle em latitudes mais altas. Esses padrões macroecológicos ajudarão a direcionar os esforços para aplicar o controle biológico da erva-de-jacaré não apenas atualmente, mas também em cenários futuros de mudanças climáticas.
    Description: PhD
    Keywords: Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) “erva-de-jacaré” ; Plantas aquáticas invasoras ; Macrófitas aquáticas de água doce ; Insetos especialistas ; Herbivoria ; Controle biológico ; Mudanças climáticas ; Macroecologia ; ASFA_2015::A::Aquatic plants ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::A::Alien species ; ASFA_2015::M::Macrophytes ; ASFA_2015::A::Aquatic insects ; ASFA_2015::B::Biological control ; ASFA_2015::I::Insects (aquatic) ; ASFA_2015::C::Climatic changes ; ASFA_2015::H::Herbivores
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
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  • 50
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-11
    Description: The industrial advance of Europe between the 19th and 20th centuries resulted in major environmental impacts. Among these impacts, the deposition of acid compounds through acid rain stands out, and this phenomenon led to the acidification of water bodies. However, from the 1980s on, with the application of stricter environmental regulations, a gradual recovery of abiotic parameters began, including pH values, which began to return to less acidic ranges. Thus, we investigated the responses of the benthic community to the gradual recovery of abiotic variables after years of intense acidification, analyzing changes in community structure and, specifically, variations in beta diversity. The study was developed with data from streams in Wales, collected and provided by two research projects that monitor the region's water bodies. The streams were classified according to abiotic characteristics and the surrounding vegetation (Acid Forest, Acid Moorland and Circumneutral Moorland). In the first approach, the community of 69 streams was analyzed, testing whether (i) the composition of macroinvertebrate communities differed among the types of environments and years analyzed; and whether (ii) in early years beta diversity among streams was lower than in more recent years, as well as in streams of a more acidic category. Samples were collected in 1984, 1995, and 2012, with the earliest year under the greatest influence of acidification. A segregation in macroinvertebrate composition was observed between 1984 and the other years, and this difference in community composition between the years suggests that environmental recovery with rising pH values, allowed the entry and establishment of new macroinvertebrate species in the streams. The lowest beta diversity value was also observed in 1984, indicating biotic homogenization in this period and an increase in community dissimilarity over time. In the second approach, we investigated the hypothesis that a gradual increase in temporal beta diversity (TBI) values occurs over time. This was done by sampling eight streams in Wales over the period 1985 to 2018, and comparing beta diversity between the reference year 1985 with all other years. There was an increase in TBI values over the years for all environments, showing evidence of biological recovery concomitant with restoration of abiotic values. The results contributed to the understanding that the biotic community also responds to environmental recovery, and there are different ways to evaluate this process, such as beta diversity. The importance of long-term research is emphasized so that such changes can be monitored.
    Description: O avanço industrial da Europa entre os séculos XIX e XX resultou em grandes impactos ambientais. Dentre esses impactos, destaca-se a deposição de compostos ácidos através da chuva ácida, e tal fenômeno levou à acidificação de corpos d’água. Contudo, a partir da década de 1980, com a aplicação de normas ambientais mais rígidas, teve início uma recuperação gradual dos parâmetros abióticos, incluindo os valores de pH, que começaram a retornar para faixas menos ácidas. Investigou-se as respostas da comunidade bentônica diante da recuperação gradual das variáveis abióticas após anos de intensa acidificação, analisando mudanças na estrutura da comunidade e, especificamente, as variações da diversidade beta. Os estudos foram desenvolvidos com dados de riachos do País de Gales, coletados e cedidos por dois projetos de pesquisas galeses que monitoram os corpos aquáticos da região, sendo os riachos classificados de acordo com as características abióticas e da vegetação do entorno (Acid Forest, Acid Moorland e Circumneutral Moorland). Na primeira abordagem, analisou-se a comunidade de 69 riachos, testando se (i) a composição das comunidades difere entre os tipos de ambientes e anos analisados; e se (ii) nos anos iniciais a diversidade beta entre os riachos foi menor do que nos anos mais recentes, assim como nos riachos de uma categoria mais ácida. As amostras foram coletadas em 1984, 1995 e 2012, sendo o ano mais antigo sob maior influência da acidificação. Observou-se uma segregação na composição da biota entre 1984 e os demais anos, e essa diferença na composição da comunidade entre os anos sugere que a recuperação ambiental com ascensão nos valores de pH, permitiu a entrada e estabelecimento de novas espécies de macroinvertebrados nos riachos. O menor valor de diversidade beta também foi observado em 1984, indicando homogeneização biótica neste período e aumento da dissimilaridade das comunidades com o tempo. Na segunda abordagem, investigou-se a hipótese de que ocorre um aumento gradativo nos valores de diversidade beta temporal (TBI) ao longo do tempo. Para tanto, foram amostrados oito riachos no País de Gales no período entre 1985 e 2018, e comparado a diversidade beta dos riachos entre o ano referência 1985 com todos os demais anos. Houve um aumento dos valores de TBI ao longo dos anos para todos ambientes, mostrando indícios de recuperação biológica concomitante com o restabelecimento dos valores abióticos. Os resultados contribuíram para o entendimento de que a comunidade biótica também responde à recuperação ambiental. Sendo a diversidade beta uma das formas de se avaliar tal processo. E ressalta-se a importância de pesquisas de longa duração para que tais respostas bióticas possam ser monitoradas.
    Description: PhD
    Keywords: Macroinvertebrados bentônicos de água doce ; Diversidade beta ; Recuperação ambiental ; Acidificação ambiental ; Chuva ácida ; Riachos ; Riachos acidificados ; ASFA_2015::M::Macrobenthos ; ASFA_2015::A::Acid rain ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::S::Streams ; ASFA_2015::A::Acidification ; ASFA_2015::S::Stream ecology
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 55pp.
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  • 51
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-12
    Description: Macrophytes are widely recognized for increasing habitat complexity and driving a relevant role in structuring communities in aquatic ecosystems. We investigated how the density, coverage and diversity of macrophytes can influence multiple aspects of fish community, including functional alpha and beta diversity, foraging efficiency, trophic niche breadth and overlap, total abundance and biomass of fish, as well as of certain species and sizes of fish. We used 30 macrophyte stands sampled in the littoral zone of a tropical river, as well as a dataset of 88 shallow temperate lakes. In the latter case, two spatial scales were considered (lake and points within a lake), since there is usually a negative relationship between fish and macrophyte coverage, and this relationship may be more evident at the point scale, while the effect is attenuated at the lake scale. The results showed that macrophytes can select functional characteristics of fish communities and influence their alpha and beta functional diversity. The highest values of functional alpha diversity occurred in intermediate macrophyte density and high macrophyte diversity. The variation in macrophyte density was strongly responsible for variations in functional beta diversity. Fish showed general trophic responses to the variation in macrophyte attributes, but these responses also depended on fish feeding habits, with herbivores niche breadth responding in the opposite way to omnivores. The increase in macrophyte density led to an increase in fish consumption of higher plants and foraging efficiency, and reduced trophic niche breadth. Fish niche overlap was higher at intermediate levels of macrophyte density. Fish responses depended on fish species identity, lake productivity and water depth. The deeper and more eutrophic the lakes, the more fish tended to occupy macrophyte-covered points within a lake. The results emphasize how aquatic plants can affect the fish community by influencing swimming, food availability and interactions between species, and that the relationship between fish and macrophytes can vary according to the scale of the study and the fish characteristics. The application of the results obtained here has great potential to help in projects of management and conservation of biodiversity, and in the choice of the best configurations of macrophyte stands for the maintenance of ichthyofauna.
    Description: As macrófitas são amplamente reconhecidas por aumentarem a complexidade do habitat e exercerem papel relevante na estruturação das comunidades em ecossistemas aquáticos. Investigou-se como a densidade, cobertura e diversidade de macrófitas podem influenciar múltiplos aspectos da comunidade de peixes, incluindo diversidade alfa e beta funcional, eficiência de forrageamento, amplitude e sobreposição de nicho trófico, abundância e biomassa de total de peixes, bem como de determinadas espécies e tamanhos de peixes. Utilizou-se 30 bancos de macrófitas amostrados na zona litorânea de um rio tropical, bem como, um conjunto de dados de 88 lagos rasos temperados. Neste ultimo caso, foram consideradas duas escalas espaciais (lago e pontos dentro do lago), visto que geralmente há uma relação negativa entre peixes e a cobertura de macrófitas, e essa relação pode ser mais evidente na escala de ponto dentro do lago, enquanto o efeito é atenuado na escala de lago. Os resultados evidenciaram que as macrófitas podem selecionar características funcionais das comunidades de peixes e influenciar sua diversidade funcional alfa e beta. Os maiores valores de diversidade alfa funcional ocorreram em densidades intermediárias e elevada diversidade de macrófitas. A variação na densidade de macrófitas foi fortemente responsável pelas variações na diversidade beta funcional. Os peixes apresentaram respostas tróficas gerais à variação dos atributos das macrófitas, mas estas respostas também dependeram dos hábitos alimentares dos peixes, com a amplitude de nicho dos herbívoros respondendo de forma oposta à amplitude de onívoros. O aumento na densidade de macrófitas levou a um aumento no consumo de vegetais superiores pelos peixes e na eficiência de forrageamento, e reduziu a amplitude do nicho trófico. A sobreposição de nicho de peixes foi maior nos níveis intermediários de densidade de macrófitas. As respostas dos peixes dependeram da identidade da espécie de peixe, produtividade da lagoa e profundidade da água. Quanto mais profundos e eutróficos eram os lagos, mais os peixes tenderam a ocupar pontos cobertos por macrófitas dentro de um lago. Mediante os resultados, ressaltamos como as plantas aquáticas podem afetar a comunidade de peixes por influenciarem na natação, disponibilidade de alimento e interações entre as espécies, e que a relação entre peixe e macrófita pode variar de acordo com a escala do estudo e as características dos peixes considerados. A aplicação dos resultados aqui obtidos tem grande potencial de auxílio em projetos de manejo e conservação da biodiversidade, e na escolha das melhores configurações de bancos de macrófitas para a manutenção da ictiofauna.
    Description: PhD
    Keywords: Peixes de água doce ; Macrófitas aquáticas submersas ; Comunidades, Ecologia de ; Diversidade funcional e taxonômica ; Diversidade taxonômica ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::M::Macrophytes ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::F::Freshwater fish ; ASFA_2015::F::Floodplains ; ASFA_2015::A::Assemblages ; ASFA_2015::T::Trophic levels ; ASFA_2015::E::Ecosystems
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 153pp.
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  • 52
    Publication Date: 2022-10-12
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(10), (2022): 2431-2444, https://doi.org/10.1175/jpo-d-22-0024.1.
    Description: A three-dimensional inertial model that conserves quasigeostrophic potential vorticity is proposed for wind-driven coastal upwelling along western boundaries. The dominant response to upwelling favorable winds is a surface-intensified baroclinic meridional boundary current with a subsurface countercurrent. The width of the current is not the baroclinic deformation radius but instead scales with the inertial boundary layer thickness while the depth scales as the ratio of the inertial boundary layer thickness to the baroclinic deformation radius. Thus, the boundary current scales depend on the stratification, wind stress, Coriolis parameter, and its meridional variation. In contrast to two-dimensional wind-driven coastal upwelling, the source waters that feed the Ekman upwelling are provided over the depth scale of this baroclinic current through a combination of onshore barotropic flow and from alongshore in the narrow boundary current. Topography forces an additional current whose characteristics depend on the topographic slope and width. For topography wider than the inertial boundary layer thickness the current is bottom intensified, while for narrow topography the current is wave-like in the vertical and trapped over the topography within the inertial boundary layer. An idealized primitive equation numerical model produces a similar baroclinic boundary current whose vertical length scale agrees with the theoretical scaling for both upwelling and downwelling favorable winds.
    Description: This research is supported in part by the China Scholarship Council (201906330102). H. G. is financially supported by the China Scholarship Council to study at WHOI for 2 years as a guest student. M.S. is supported by the National Science Foundation Grant OCE-1922538. Z. C. is supported by the ‘Taishan/Aoshan’ Talents program (2017ASTCPES05) the Fundamental Research Funds for the Central Universities (202072001).
    Description: 2023-03-30
    Keywords: Ekman pumping/transport ; Upwelling/downwelling ; Coastal flows
    Repository Name: Woods Hole Open Access Server
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  • 53
    Publication Date: 2022-10-12
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(10), (2022): 2325–2341, https://doi.org/10.1175/jpo-d-21-0015.1.
    Description: The ocean surface boundary layer is a gateway of energy transfer into the ocean. Wind-driven shear and meteorologically forced convection inject turbulent kinetic energy into the surface boundary layer, mixing the upper ocean and transforming its density structure. In the absence of direct observations or the capability to resolve subgrid-scale 3D turbulence in operational ocean models, the oceanography community relies on surface boundary layer similarity scalings (BLS) of shear and convective turbulence to represent this mixing. Despite their importance, near-surface mixing processes (and ubiquitous BLS representations of these processes) have been undersampled in high-energy forcing regimes such as the Southern Ocean. With the maturing of autonomous sampling platforms, there is now an opportunity to collect high-resolution spatial and temporal measurements in the full range of forcing conditions. Here, we characterize near-surface turbulence under strong wind forcing using the first long-duration glider microstructure survey of the Southern Ocean. We leverage these data to show that the measured turbulence is significantly higher than standard shear-convective BLS in the shallower parts of the surface boundary layer and lower than standard shear-convective BLS in the deeper parts of the surface boundary layer; the latter of which is not easily explained by present wave-effect literature. Consistent with the CBLAST (Coupled Boundary Layers and Air Sea Transfer) low winds experiment, this bias has the largest magnitude and spread in the shallowest 10% of the actively mixing layer under low-wind and breaking wave conditions, when relatively low levels of turbulent kinetic energy (TKE) in surface regime are easily biased by wave events.
    Description: This paper is VIMS Contribution 4103. Computational resources were provided by the VIMS Ocean-Atmosphere and Climate Change Research Fund. AUSSOM was supported by the OCE Division of the National Science Foundation (1558639).
    Keywords: Turbulence ; Wind shear ; Boundary layer ; Parameterization
    Repository Name: Woods Hole Open Access Server
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  • 54
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(1), (2021): 19-35, https://doi.org/10.1175/JPO-D-19-0233.1.
    Description: In the Beaufort Sea in September of 2015, concurrent mooring and microstructure observations were used to assess dissipation rates in the vicinity of 72°35′N, 145°1′W. Microstructure measurements from a free-falling profiler survey showed very low [O(10−10) W kg−1] turbulent kinetic energy dissipation rates ε. A finescale parameterization based on both shear and strain measurements was applied to estimate the ratio of shear to strain Rω and ε at the mooring location, and a strain-based parameterization was applied to the microstructure survey (which occurred approximately 100 km away from the mooring site) for direct comparison with microstructure results. The finescale parameterization worked well, with discrepancies ranging from a factor of 1–2.5 depending on depth. The largest discrepancies occurred at depths with high shear. Mean Rω was 17, and Rω showed high variability with values ranging from 3 to 50 over 8 days. Observed ε was slightly elevated (factor of 2–3 compared with a later survey of 11 profiles taken over 3 h) from 25 to 125 m following a wind event which occurred at the beginning of the mooring deployment, reaching a maximum of ε= 6 × 10−10 W kg−1 at 30-m depth. Velocity signals associated with near-inertial waves (NIWs) were observed at depths greater than 200 m, where the Atlantic Water mass represents a reservoir of oceanic heat. However, no evidence of elevated ε or heat fluxes was observed in association with NIWs at these depths in either the microstructure survey or the finescale parameterization estimates.
    Description: This work was supported by NSF Grants PLR 14-56705 and PLR-1303791 and by NSF Graduate Research Fellowship Grant DGE-1650112.
    Keywords: Ocean ; Arctic ; Internal waves ; Turbulence ; Diapycnal mixing
    Repository Name: Woods Hole Open Access Server
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  • 55
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(1),(2021): 3-17, https://doi.org/10.1175/JPO-D-20-0064.1.
    Description: The strong El Niño of 2014–16 was observed west of the Galápagos Islands through sustained deployment of underwater gliders. Three years of observations began in October 2013 and ended in October 2016, with observations at longitudes 93° and 95°W between latitudes 2°N and 2°S. In total, there were over 3000 glider-days of data, covering over 50 000 km with over 12 000 profiles. Coverage was superior closer to the Galápagos on 93°W, where gliders were equipped with sensors to measure velocity as well as temperature, salinity, and pressure. The repeated glider transects are analyzed to produce highly resolved mean sections and maps of observed variables as functions of time, latitude, and depth. The mean sections reveal the structure of the Equatorial Undercurrent (EUC), the South Equatorial Current, and the equatorial front. The mean fields are used to calculate potential vorticity Q and Richardson number Ri. Gradients in the mean are strong enough to make the sign of Q opposite to that of planetary vorticity and to have Ri near unity, suggestive of mixing. Temporal variability is dominated by the 2014–16 El Niño, with the arrival of depressed isopycnals documented in 2014 and 2015. Increases in eastward velocity advect anomalously salty water and are uncorrelated with warm temperatures and deep isopycnals. Thus, vertical advection is important to changes in heat, and horizontal advection is relevant to changes in salt. Implications of this work include possibilities for future research, model assessment and improvement, and sustained observations across the equatorial Pacific.
    Description: We gratefully acknowledge the support of the National Science Foundation (OCE-1232971, OCE-1233282) and the Ocean Observing and Monitoring Division of the National Oceanographic and Atmospheric Administration (NA13OAR4830216).
    Keywords: Ocean ; Tropics ; Currents ; El Nino ; In situ oceanic observations
    Repository Name: Woods Hole Open Access Server
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  • 56
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gomaa, F., Utter, D. R., Powers, C., Beaudoin, D. J., Edgcomb, V. P., Filipsson, H. L., Hansel, C. M., Wankel, S. D., Zhang, Y., & Bernhard, J. M. Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments. Science Advances, 7(22), (2021): eabf1586, https://doi.org/10.1126/sciadv.abf1586.
    Description: Oceanic deoxygenation is increasingly affecting marine ecosystems; many taxa will be severely challenged, yet certain nominally aerobic foraminifera (rhizarian protists) thrive in oxygen-depleted to anoxic, sometimes sulfidic, sediments uninhabitable to most eukaryotes. Gene expression analyses of foraminifera common to severely hypoxic or anoxic sediments identified metabolic strategies used by this abundant taxon. In field-collected and laboratory-incubated samples, foraminifera expressed denitrification genes regardless of oxygen regime with a putative nitric oxide dismutase, a characteristic enzyme of oxygenic denitrification. A pyruvate:ferredoxin oxidoreductase was highly expressed, indicating the capability for anaerobic energy generation during exposure to hypoxia and anoxia. Near-complete expression of a diatom’s plastid genome in one foraminiferal species suggests kleptoplasty or sequestration of functional plastids, conferring a metabolic advantage despite the host living far below the euphotic zone. Through a unique integration of functions largely unrecognized among “typical” eukaryotes, benthic foraminifera represent winning microeukaryotes in the face of ongoing oceanic deoxygenation.
    Description: his project was funded by the U.S. NSF IOS 1557430 and 1557566. H.L.F. acknowledges support from the Swedish Research Council VR (grant number 2017-04190).
    Repository Name: Woods Hole Open Access Server
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  • 57
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 38(1), (2021): 3-16, https://doi.org/10.1175/JTECH-D-20-0110.1.
    Description: Airborne expendable bathythermographs (AXBTs) are air-launched, single-use temperature–depth probes that telemeter temperature observations as VHF-modulated frequencies. This study describes the AXBT Real-Time Editing System (ARES), which is composed of two components: the ARES Data Acquisition System, which receives telemetered temperature–depth profiles with no external hardware other than a VHF radio receiver, and the ARES Profile Editing System, which quality controls AXBT temperature–depth profiles. The ARES Data Acquisition System performs fast Fourier transforms on windowed segments of the demodulated signal transmitted from the AXBT. For each segment, temperature is determined from peak frequency and depth from elapsed time since profile start. Valid signals are distinguished from noise by comparing peak signal levels and signal-to-noise ratios to predetermined thresholds. When evaluated using 387 profiles, the ARES Data Acquisition System produced temperature–depth profiles nearly identical to those generated using a Sippican MK-21 processor, while reducing the amount of noise from VHF interference included in those profiles. The ARES Profile Editor applies a series of automated checks to identify and correct common profile discrepancies before displaying the profile on an editing interface that provides simple user controls to make additional corrections. When evaluated against 1177 tropical Atlantic and Pacific AXBT profiles, the ARES automated quality control system successfully corrected 87% of the profiles without any required manual intervention. Necessary future work includes improvements to the automated quality control algorithm and algorithm evaluation against a broader dataset of temperature–depth profiles from around the world across all seasons.
    Description: This work was sponsored by the Office of Naval Research (Grants N000141812819 and N0001420WX00345) and the U.S. Navy’s Civilian Institution Office with the MIT–WHOI Joint Program.
    Keywords: Ocean ; In situ oceanic observations ; Profilers, oceanic
    Repository Name: Woods Hole Open Access Server
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  • 58
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 102(1), (2021): E99-E122, https://doi.org/10.1175/BAMS-D-19-0005.1.
    Description: The Red Sea, home to the second-longest coral reef system in the world, is a vital resource for the Kingdom of Saudi Arabia. The Red Sea provides 90% of the Kingdom’s potable water by desalinization, supporting tourism, shipping, aquaculture, and fishing industries, which together contribute about 10%–20% of the country’s GDP. All these activities, and those elsewhere in the Red Sea region, critically depend on oceanic and atmospheric conditions. At a time of mega-development projects along the Red Sea coast, and global warming, authorities are working on optimizing the harnessing of environmental resources, including renewable energy and rainwater harvesting. All these require high-resolution weather and climate information. Toward this end, we have undertaken a multipronged research and development activity in which we are developing an integrated data-driven regional coupled modeling system. The telescopically nested components include 5-km- to 600-m-resolution atmospheric models to address weather and climate challenges, 4-km- to 50-m-resolution ocean models with regional and coastal configurations to simulate and predict the general and mesoscale circulation, 4-km- to 100-m-resolution ecosystem models to simulate the biogeochemistry, and 1-km- to 50-m-resolution wave models. In addition, a complementary probabilistic transport modeling system predicts dispersion of contaminant plumes, oil spill, and marine ecosystem connectivity. Advanced ensemble data assimilation capabilities have also been implemented for accurate forecasting. Resulting achievements include significant advancement in our understanding of the regional circulation and its connection to the global climate, development, and validation of long-term Red Sea regional atmospheric–oceanic–wave reanalyses and forecasting capacities. These products are being extensively used by academia, government, and industry in various weather and marine studies and operations, environmental policies, renewable energy applications, impact assessment, flood forecasting, and more.
    Description: The development of the Red Sea modeling system is being supported by the Virtual Red Sea Initiative and the Competitive Research Grants (CRG) program from the Office of Sponsored Research at KAUST, Saudi Aramco Company through the Saudi ARAMCO Marine Environmental Center at KAUST, and by funds from KAEC, NEOM, and RSP through Beacon Development Company at KAUST.
    Repository Name: Woods Hole Open Access Server
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  • 59
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Le Roux, V., Urann, B. M., Brunelli, D., Bonatti, E., Cipriani, A., Demouchy, S., & Monteleone, B. D. Postmelting hydrogen enrichment in the oceanic lithosphere. Science Advances, 7(24), (2021): eabf6071, https://doi.org/10.1126/sciadv.abf6071.
    Description: The large range of H2O contents recorded in minerals from exhumed mantle rocks has been challenging to interpret, as it often records a combination of melting, metasomatism, and diffusional processes in spatially isolated samples. Here, we determine the temporal variations of H2O contents in pyroxenes from a 24-Ma time series of abyssal peridotites exposed along the Vema fracture zone (Atlantic Ocean). The H2O contents of pyroxenes correlate with both crustal ages and pyroxene chemistry and increase toward younger and more refractory peridotites. These variations are inconsistent with residual values after melting and opposite to trends often observed in mantle xenoliths. Postmelting hydrogen enrichment occurred by ionic diffusion during cryptic metasomatism of peridotite residues by low-degree, volatile-rich melts and was particularly effective in the most depleted peridotites. The presence of hydrous melts under ridges leads to widespread hydrogen incorporation in the oceanic lithosphere, likely lowering mantle viscosity compared to dry models.
    Description: Funding for this study was supported by NSF EAR-P&G 1524311 and 1839128 to V.L.R. and the Andrew W. Mellon Foundation Award for Innovative Research to V.L.R. A.C. and D.B. were funded by the Italian Programma di Rilevante Interesse Nazionale PRIN 20178LPCPW and PRIN2017KY5ZX8, respectively. Revisions were performed within the duration of a “Visiting Scholar at SCIENCE 2020” award to V.L.R. (University of Copenhagen, Denmark), with support from the Department of Geosciences and Natural Resource Management, Section for Geology.
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  • 60
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(11), (2020): 3267–3294, https://doi.org/10.1175/JPO-D-19-0310.1.
    Description: As part of the Flow Encountering Abrupt Topography (FLEAT) program, an array of pressure-sensor equipped inverted echo sounders (PIESs) was deployed north of Palau where the westward-flowing North Equatorial Current encounters the southern end of the Kyushu–Palau Ridge in the tropical North Pacific. Capitalizing on concurrent observations from satellite altimetry, FLEAT Spray gliders, and shipboard hydrography, the PIESs’ 10-month duration hourly bottom pressure p and round-trip acoustic travel time τ records are used to examine the magnitude and predictability of sea level and pycnocline depth changes and to track signal propagations through the array. Sea level and pycnocline depth are found to vary in response to a range of ocean processes, with their magnitude and predictability strongly process dependent. Signals characterized here comprise the barotropic tides, semidiurnal and diurnal internal tides, southeastward-propagating superinertial waves, westward-propagating mesoscale eddies, and a strong signature of sea level increase and pycnocline deepening associated with the region’s relaxation from El Niño to La Niña conditions. The presence of a broad band of superinertial waves just above the inertial frequency was unexpected and the FLEAT observations and output from a numerical model suggest that these waves detected near Palau are forced by remote winds east of the Philippines. The PIES-based estimates of pycnocline displacement are found to have large uncertainties relative to overall variability in pycnocline depth, as localized deep current variations arising from interactions of the large-scale currents with the abrupt topography around Palau have significant travel time variability.
    Description: Support for this research was provided by Office of Naval Research Grants N00014-16-1-2668, N00014-18-1-2406, N00014-15-1-2488, and N00014-15-1-2622. R.C.M. was additionally supported by the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the Weston Howland Jr. Postdoctoral Scholarship.
    Keywords: Tropics ; Currents ; Eddies ; ENSO ; Internal waves ; Mesoscale processes
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  • 61
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    American Meteorological Society
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(11),(2020): 3331–3351, https://doi.org/10.1175/JPO-D-20-0035.1.
    Description: This study examines the generation of warm spiral structures (referred to as spiral streamers here) over Gulf Stream warm-core rings. Satellite sea surface temperature imagery shows spiral streamers forming after warmer water from the Gulf Stream or newly formed warm-core rings impinges onto old warm-core rings and then intrudes into the old rings. Field measurements in April 2018 capture the vertical structure of a warm spiral streamer as a shallow lens of low-density water winding over an old ring. Observations also show subduction on both sides of the spiral streamer, which carries surface waters downward. Idealized numerical model simulations initialized with observed water-mass densities reproduce spiral streamers over warm-core rings and reveal that their formation is a nonlinear submesoscale process forced by mesoscale dynamics. The negative density anomaly of the intruding water causes a density front at the interface between the intruding water and surface ring water, which, through thermal wind balance, drives a local anticyclonic flow. The pressure gradient and momentum advection of the local interfacial flow push the intruding water toward the ring center. The large-scale anticyclonic flow of the ring and the radial motion of the intruding water together form the spiral streamer. The observed subduction on both sides of the spiral streamer is part of the secondary cross-streamer circulation resulting from frontogenesis on the stretching streamer edges. The surface divergence of the secondary circulation pushes the side edges of the streamer away from each other, widens the warm spiral on the surface, and thus enhances its surface signal.
    Description: Authors W. G. Zhang and D. J. McGillicuddy are both supported by the National Science Foundation through Grant OCE 1657803.
    Keywords: Buoyancy ; Eddies ; Frontogenesis/frontolysis ; Mesoscale processes ; Transport ; Vertical motion
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  • 62
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Clemens, S. C., Yamamoto, M., Thirumalai, K., Giosan, L., Richey, J. N., Nilsson-Kerr, K., Rosenthal, Y., Anand, P., & McGrath, S. M. Remote and local drivers of Pleistocene South Asian summer monsoon precipitation: a test for future predictions. Science Advances, 7(23), (2021): eabg3848, https://doi.org/10.1126/sciadv.abg3848.
    Description: South Asian precipitation amount and extreme variability are predicted to increase due to thermodynamic effects of increased 21st-century greenhouse gases, accompanied by an increased supply of moisture from the southern hemisphere Indian Ocean. We reconstructed South Asian summer monsoon precipitation and runoff into the Bay of Bengal to assess the extent to which these factors also operated in the Pleistocene, a time of large-scale natural changes in carbon dioxide and ice volume. South Asian precipitation and runoff are strongly coherent with, and lag, atmospheric carbon dioxide changes at Earth’s orbital eccentricity, obliquity, and precession bands and are closely tied to cross-equatorial wind strength at the precession band. We find that the projected monsoon response to ongoing, rapid high-latitude ice melt and rising carbon dioxide levels is fully consistent with dynamics of the past 0.9 million years.
    Description: S.C.C. and S.M.M. were supported by U.S. NSF OCE1634774. M.Y. was funded by JSPS grants JPMXS05R2900001 and 19H05595 and JAMSTEC Exp. 353 postcruise study. K.N.-K. and P.A. were supported by UK-IODP, Open University, and NERC (NE/L002493/1), K.T. was supported by the Technology and Research Initiative Fund, Arizona Board of Regents.
    Repository Name: Woods Hole Open Access Server
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  • 63
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(11), (2020): 3235–3251, https://doi.org/10.1175/JPO-D-20-0095.1.
    Description: The dense outflow through Denmark Strait is the largest contributor to the lower limb of the Atlantic meridional overturning circulation, yet a description of the full velocity field across the strait remains incomplete. Here we analyze a set of 22 shipboard hydrographic–velocity sections occupied along the Látrabjarg transect at the Denmark Strait sill, obtained over the time period 1993–2018. The sections provide the first complete view of the kinematic components at the sill: the shelfbreak East Greenland Current (EGC), the combined flow of the separated EGC, and the North Icelandic Jet (NIJ), and the northward-flowing North Icelandic Irminger Current (NIIC). The total mean transport of overflow water is 3.54 ± 0.29 Sv (1 Sv ≡ 106 m3 s−1), comparable to previous estimates. The dense overflow is partitioned in terms of water mass constituents and flow components. The mean transports of the two types of overflow water—Atlantic-origin Overflow Water and Arctic-origin Overflow Water—are comparable in Denmark Strait, while the merged NIJ–separated EGC transports 55% more water than the shelfbreak EGC. A significant degree of water mass exchange takes place between the branches as they converge in Denmark Strait. There are two dominant time-varying configurations of the flow that are characterized as a cyclonic state and a noncyclonic state. These appear to be wind-driven. A potential vorticity analysis indicates that the flow through Denmark Strait is subject to symmetric instability. This occurs at the top of the overflow layer, implying that the mixing/entrainment process that modifies the overflow water begins at the sill.
    Description: Funding for the study was provided by National Science Foundation (NSF) Grants OCE-1259618, OCE-1756361, and OCE-1558742. The German research cruises were financially supported through various EU Projects (e.g. THOR, NACLIM) and national projects (most recently TRR 181 “Energy Transfer in Atmosphere and Ocean” funded by the German Research Foundation and RACE II “Regional Atlantic Circulation and Global Change” funded by the German Federal Ministry for Education and Research). GWKM acknowledges the support of the Natural Sciences and Engineering Research Council of Canada. LP was supported by NSF Grant OCE-1657870.
    Keywords: Currents ; Instability ; Ocean circulation ; Ocean dynamics ; Potential vorticity
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  • 64
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 102(10), (2021): E1897–E1935, https://doi.org/10.1175/BAMS-D-19-0316.1.
    Description: Life on Earth vitally depends on the availability of water. Human pressure on freshwater resources is increasing, as is human exposure to weather-related extremes (droughts, storms, floods) caused by climate change. Understanding these changes is pivotal for developing mitigation and adaptation strategies. The Global Climate Observing System (GCOS) defines a suite of essential climate variables (ECVs), many related to the water cycle, required to systematically monitor Earth’s climate system. Since long-term observations of these ECVs are derived from different observation techniques, platforms, instruments, and retrieval algorithms, they often lack the accuracy, completeness, and resolution, to consistently characterize water cycle variability at multiple spatial and temporal scales. Here, we review the capability of ground-based and remotely sensed observations of water cycle ECVs to consistently observe the hydrological cycle. We evaluate the relevant land, atmosphere, and ocean water storages and the fluxes between them, including anthropogenic water use. Particularly, we assess how well they close on multiple temporal and spatial scales. On this basis, we discuss gaps in observation systems and formulate guidelines for future water cycle observation strategies. We conclude that, while long-term water cycle monitoring has greatly advanced in the past, many observational gaps still need to be overcome to close the water budget and enable a comprehensive and consistent assessment across scales. Trends in water cycle components can only be observed with great uncertainty, mainly due to insufficient length and homogeneity. An advanced closure of the water cycle requires improved model–data synthesis capabilities, particularly at regional to local scales.
    Description: WD acknowledges ESA’s QA4EO (ISMN) and CCI Soil Moisture projects. WD, CRV, AG, and KL acknowledge the G3P project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement 870353. MIH and MS acknowledge ESA’s CCI Water Vapour project. MS and RH acknowledges the support by the EUMETSAT member states through CM SAF. DGM acknowledges support from the European Research Council (ERC) under Grant Agreement 715254 (DRY–2–DRY). Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004).
    Description: 2022-04-01
    Keywords: Hydrologic cycle ; Satellite observations ; Surface fluxes ; Surface observations ; Water masses/storage ; Water budget/balance
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  • 65
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Seltzer, A. M., Bekaert, D. V., Barry, P. H., Durkin, K. E., Mace, E. K., Aalseth, C. E., Zappala, J. C., Mueller, P., Jurgens, B., & Kulongoski, J. T. Groundwater residence time estimates obscured by anthropogenic carbonate. Science Advances, 7(17), (2021): eabf3503, https://doi.org/10.1126/sciadv.abf3503.
    Description: Groundwater is an important source of drinking and irrigation water. Dating groundwater informs its vulnerability to contamination and aids in calibrating flow models. Here, we report measurements of multiple age tracers (14C, 3H, 39Ar, and 85Kr) and parameters relevant to dissolved inorganic carbon (DIC) from 17 wells in California’s San Joaquin Valley (SJV), an agricultural region that is heavily reliant on groundwater. We find evidence for a major mid-20th century shift in groundwater DIC input from mostly closed- to mostly open-system carbonate dissolution, which we suggest is driven by input of anthropogenic carbonate soil amendments. Crucially, enhanced open-system dissolution, in which DIC equilibrates with soil CO2, fundamentally affects the initial 14C activity of recently recharged groundwater. Conventional 14C dating of deeper SJV groundwater, assuming an open system, substantially overestimates residence time and thereby underestimates susceptibility to modern contamination. Because carbonate soil amendments are ubiquitous, other groundwater-reliant agricultural regions may be similarly affected.
    Description: his work was conducted as a part of the USGS National Water Quality Assessment Program (NAWQA) Enhanced Trends Project (https://water.usgs.gov/nawqa/studies/gwtrends/). Measurements at Argonne National Laboratory were supported by Department of Energy, Office of Science under contract DE-AC02-06CH11357. Measurements at Pacific Northwest National Laboratory were part of the Ultra-Sensitive Nuclear Measurements Initiative conducted under the Laboratory Directed Research and Development Program. PNNL is operated by Battelle for the U.S. Department of Energy under Contract DE-AC05-76RL01830. This work was also partially supported by NSF award OCE-1923915 (to A.M.S. and P.H.B. at WHOI).
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  • 66
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(2), (2021): 457–474, https://doi.org/10.1175/JPO-D-20-0088.1.
    Description: The meridional shift of the Kuroshio Extension (KE) front and changes in the formation of the North Pacific Subtropical Mode Water (STMW) during 1979–2018 are reported. The surface-to-subsurface structure of the KE front averaged over 142°–165°E has shifted poleward at a rate of ~0.23° ± 0.16° decade−1. The shift was caused mainly by the poleward shift of the downstream KE front (153°–165°E, ~0.41° ± 0.29° decade−1) and barely by the upstream KE front (142°–153°E). The long-term shift trend of the KE front showed two distinct behaviors before and after 2002. Before 2002, the surface KE front moved northward with a faster rate than the subsurface. After 2002, the surface KE front showed no obvious trend, but the subsurface KE front continued to move northward. The ventilation zone of the STMW, defined by the area between the 16° and 18°C isotherms or between the 25 and 25.5 kg m−3 isopycnals, contracted and displaced northward with a shoaling of the mixed layer depth hm before 2002 when the KE front moved northward. The STMW subduction rate was reduced by 0.76 Sv (63%; 1 Sv ≡ = 106 m3 s−1) during 1979–2018, most of which occurred before 2002. Of the three components affecting the total subduction rate, the temporal induction (−∂hm/∂t) was dominant accounting for 91% of the rate reduction, while the vertical pumping (−wmb) amounted to 8% and the lateral induction (−umb ⋅ ∇hm) was insignificant. The reduced temporal induction was attributed to both the contracted ventilation zone and the shallowed hm that were incurred by the poleward shift of KE front.
    Description: Xiaopei Lin is supported by the National Natural Science Foundation of China (41925025 and 92058203) and China’s national key research and development projects (2016YFA0601803). Baolan Wu is supported by the China Scholarship Council (201806330010). Lisan Yu thanks NOAA for support for her study on climate change and variability.
    Keywords: Boundary currents ; Decadal variability ; Fronts ; Water masses/storage
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  • 67
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(8),(2021): 2463–2482, https://doi.org/10.1175/JPO-D-20-0291.1.
    Description: This paper presents analyses of drifters with drogues at different depths—1, 10, 30, and 50 m—that were deployed in the Mediterranean Sea to investigate frontal subduction and upwelling. Drifter trajectories were used to estimate divergence, vorticity, vertical velocity, and finite-size Lyapunov exponents (FTLEs) and to investigate the balance of terms in the vorticity equation. The divergence and vorticity are O(f) and change sign along trajectories. Vertical velocity is O(1 mm s−1), increases with depth, indicates predominant upwelling with isolated downwelling events, and sometimes changes sign between 1 and 50 m. Vortex stretching is one of the significant terms, but not the only one, in the vorticity balance. Two-dimensional FTLEs are 2 × 10−5 s−1 after 1 day, 2 times as large as in a 400-m-resolution numerical model. Three-dimensional FTLEs are 50% larger than 2D FTLEs and are dominated by the vertical shear of horizontal velocity. Bootstrapping suggests uncertainty levels of ~10% of the time-mean absolute values for divergence and vorticity. Analysis of simulated drifters in a model suggests that drifter-based estimates of divergence and vorticity are close to the Eulerian model estimates, except when drifters get aligned into long filaments. Drifter-based vertical velocity is close to the Eulerian model estimates at 1 m but differs at deeper depths. The errors in the vertical velocity are largely due to the lateral separation between drifters at different depths and are partially due to only measuring at four depths. Overall, this paper demonstrates how drifters, heretofore restricted to 2D near-surface observations, can be used to learn about 3D flow properties throughout the upper layer of the water column.
    Description: Authors Rypina and Pratt were supported by U.S. Office of Naval Research (ONR) Grant N000141812417. Author Getscher acknowledges support from the U.S. Navy Civilian Institution Office with the MIT–WHOI Joint Program. Author Mourre acknowledges support from ONR Grant N00014-16-1-3130. We also thank Eugenio Cutolo for the initial technical support in the implementation of the ultra-high-resolution WMOP simulation. CALYPSO is a Departmental Research Initiative funded by the ONR.
    Description: 2022-01-16
    Keywords: Convergence/divergence ; Fronts ; Nonlinear dynamics ; Small scale processes ; Trajectories ; Upwelling/downwelling ; Vertical motion
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  • 68
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zhang, Y., Gazel, E., Gaetani, G. A., & Klein, F. Serpentinite-derived slab fluids control the oxidation state of the subarc mantle. Science Advances, 7(48), (2021): eabj2515, https://doi.org/10.1126/sciadv.abj2515.
    Description: Recent geochemical evidence confirms the oxidized nature of arc magmas, but the underlying processes that regulate the redox state of the subarc mantle remain yet to be determined. We established a link between deep subduction-related fluids derived from dehydration of serpentinite ± altered oceanic crust (AOC) using B isotopes and B/Nb as fluid proxies, and the oxidized nature of arc magmas as indicated by Cu enrichment during magma evolution and V/Yb. Our results suggest that arc magmas derived from source regions influenced by a greater serpentinite (±AOC) fluid component record higher oxygen fugacity. The incorporation of this component into the subarc mantle is controlled by the subduction system’s thermodynamic conditions and geometry. Our results suggest that the redox state of the subarc mantle is not homogeneous globally: Primitive arc magmas associated with flat, warm subduction are less oxidized overall than those generated in steep, cold subduction zones.
    Description: Y.Z. acknowledges funding from the National Science Foundation of China (91958213), the Chinese Academy of Sciences (XDB42020402), and the Shandong Provincial Natural Science Foundation, China (ZR2020QD068). This study was supported in part by the U.S. National Science Foundation NSF EAR 1826673 to E.G. and G.A.G. and OCE 1756349 to E.G.
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  • 69
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 102(10), (2021): E1936–E1951, https://doi.org/10.1175/BAMS-D-20-0113.1.
    Description: In the Bay of Bengal, the warm, dry boreal spring concludes with the onset of the summer monsoon and accompanying southwesterly winds, heavy rains, and variable air–sea fluxes. Here, we summarize the 2018 monsoon onset using observations collected through the multinational Monsoon Intraseasonal Oscillations in the Bay of Bengal (MISO-BoB) program between the United States, India, and Sri Lanka. MISO-BoB aims to improve understanding of monsoon intraseasonal variability, and the 2018 field effort captured the coupled air–sea response during a transition from active-to-break conditions in the central BoB. The active phase of the ∼20-day research cruise was characterized by warm sea surface temperature (SST 〉 30°C), cold atmospheric outflows with intermittent heavy rainfall, and increasing winds (from 2 to 15 m s−1). Accumulated rainfall exceeded 200 mm with 90% of precipitation occurring during the first week. The following break period was both dry and clear, with persistent 10–12 m s−1 wind and evaporation of 0.2 mm h−1. The evolving environmental state included a deepening ocean mixed layer (from ∼20 to 50 m), cooling SST (by ∼1°C), and warming/drying of the lower to midtroposphere. Local atmospheric development was consistent with phasing of the large-scale intraseasonal oscillation. The upper ocean stores significant heat in the BoB, enough to maintain SST above 29°C despite cooling by surface fluxes and ocean mixing. Comparison with reanalysis indicates biases in air–sea fluxes, which may be related to overly cool prescribed SST. Resolution of such biases offers a path toward improved forecasting of transition periods in the monsoon.
    Description: This work was supported through the U.S. Office of Naval Research’s Departmental Research Initiative: Monsoon Intraseasonal Oscillations in the Bay of Bengal, the Indian Ministry of Earth Science’s Ocean Mixing and Monsoons Program, and the Sri Lankan National Aquatic Resources Research and Development Agency. We thank the Captain and crew of the R/V Thompson for their help in data collection. Surface atmospheric fields included fluxes were quality controlled and processed by the Boundary Layer Observations and Processes Team within the NOAA Physical Sciences Laboratory. Forecast analysis was completed by India Meteorological Department. Drone image was taken by Shreyas Kamat with annotations by Gualtiero Spiro Jaeger. We also recognize the numerous researchers who supported cruise- and land-based measurements. This work represents Lamont-Doherty Earth Observatory contribution number 8503, and PMEL contribution number 5193.
    Description: 2022-04-01
    Keywords: Atmosphere-ocean interaction ; Monsoons ; In situ atmospheric observations ; In situ oceanic observations
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  • 70
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Trembath-Reichert, E., Shah Walter, S. R., Ortiz, M. A. F., Carter, P. D., Girguis, P. R., & Huber, J. A. Multiple carbon incorporation strategies support microbial survival in cold subseafloor crustal fluids. Science Advances, 7(18), (2021): eabg0153, https://doi.org/10.1126/sciadv.abg0153.
    Description: Biogeochemical processes occurring in fluids that permeate oceanic crust make measurable contributions to the marine carbon cycle, but quantitative assessments of microbial impacts on this vast, subsurface carbon pool are lacking. We provide bulk and single-cell estimates of microbial biomass production from carbon and nitrogen substrates in cool, oxic basement fluids from the western flank of the Mid-Atlantic Ridge. The wide range in carbon and nitrogen incorporation rates indicates a microbial community well poised for dynamic conditions, potentially anabolizing carbon and nitrogen at rates ranging from those observed in subsurface sediments to those found in on-axis hydrothermal vent environments. Bicarbonate incorporation rates were highest where fluids are most isolated from recharging bottom seawater, suggesting that anabolism of inorganic carbon may be a potential strategy for supplementing the ancient and recalcitrant dissolved organic carbon that is prevalent in the globally distributed subseafloor crustal environment.
    Description: The Gordon and Betty Moore Foundation sponsored most of the observatory components at North Pond through grant GBMF1609. This work was supported by the National Science Foundation through grants NSF OCE-1745589, OCE-1635208, and OCE-1062006 to J.A.H. and NSF OCE-1635365 to P.R.G. and S.R.S.W.; NASA Postdoctoral Fellowship with the NASA Astrobiology Institute to E.T.-R.; L’Oréal USA For Women in Science Fellowship to E.T.-R.; and Woods Hole Partnership Education Program, sponsored by the Woods Hole Diversity Initiative to M.A.F.O. The Center for Dark Energy Biosphere Investigations (C-DEBI OCE-0939564) also supported the participation of J.A.H. and P.D.C. This is C-DEBI contribution number 564.
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  • 71
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(1), (2021): 247-266, https://doi.org/10.1175/JPO-D-20-0098.1.
    Description: This study focuses on mechanisms of shelf valley bathymetry affecting the spread of riverine freshwater in the nearshore region. In the context of Changjiang River, a numerical model is used with different no-tide idealized configurations to simulate development of unforced river plumes over a sloping bottom, with and without a shelf valley off the estuary mouth. All simulated freshwater plumes are surface-trapped with continuously growing bulges near the estuary mouth and narrow coastal currents downstream. The simulations indicate that a shelf valley tends to compress the bulge along the direction of the valley long axis and modify the incident angle of the bulge flow impinging toward the coast, which then affects the strength of the coastal current. The bulge compression results from geostrophic adjustment and isobath-following tendency of the depth-averaged flow in the bulge region. Generally, the resulting change in the direction of the bulge impinging flow enhances down-shelf momentum advection and freshwater delivery into the coastal current. Sensitivity simulations with altered river discharges Q, Coriolis parameter, shelf bottom slope, valley geometry, and ambient stratification show that enhancement of down-shelf freshwater transport in the coastal current, ΔQc, increases with increasing valley depth within the bulge region and decreasing slope Burger number of the ambient shelf. Assuming potential vorticity conservation, a scaling formula of ΔQc/Q is developed, and it agrees well with results of the sensitivity simulations. Mechanisms of valley influences on unforced river plumes revealed here will help future studies of topographic influence on river plumes under more realistic conditions.
    Description: This work is conducted by Canbo Xiao and Weifeng (Gordon) Zhang during CX’s one-year visit at Woods Hole Oceanographic Institution (WHOI) in 2018–19. CX was supported by China Scholarship Council.
    Keywords: Continental shelf/slope ; Buoyancy ; Coastal flows ; Topographic effects ; Runoff ; Numerical analysis/modeling
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  • 72
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Spingys, C. P., Garabato, A. C. N., Legg, S., Polzin, K. L., Abrahamsen, E. P., Buckingham, C. E., Forryan, A., & Frajka-Williams, E. E. Mixing and transformation in a deep western boundary current: a case study. Journal of Physical Oceanography, 51(4), (2021): 1205-1222, https://doi.org/10.1175/JPO-D-20-0132.1
    Description: Water-mass transformation by turbulent mixing is a key part of the deep-ocean overturning, as it drives the upwelling of dense waters formed at high latitudes. Here, we quantify this transformation and its underpinning processes in a small Southern Ocean basin: the Orkney Deep. Observations reveal a focusing of the transport in density space as a deep western boundary current (DWBC) flows through the region, associated with lightening and densification of the current’s denser and lighter layers, respectively. These transformations are driven by vigorous turbulent mixing. Comparing this transformation with measurements of the rate of turbulent kinetic energy dissipation indicates that, within the DWBC, turbulence operates with a high mixing efficiency, characterized by a dissipation ratio of 0.6 to 1 that exceeds the common value of 0.2. This result is corroborated by estimates of the dissipation ratio from microstructure observations. The causes of the transformation are unraveled through a decomposition into contributions dependent on the gradients in density space of the: dianeutral mixing rate, isoneutral area, and stratification. The transformation is found to be primarily driven by strong turbulence acting on an abrupt transition from the weakly stratified bottom boundary layer to well-stratified off-boundary waters. The reduced boundary layer stratification is generated by a downslope Ekman flow associated with the DWBC’s flow along sloping topography, and is further regulated by submesoscale instabilities acting to restratify near-boundary waters. Our results provide observational evidence endorsing the importance of near-boundary mixing processes to deep-ocean overturning, and highlight the role of DWBCs as hot spots of dianeutral upwelling.
    Description: CS, ACNG, AF, and EFW were supported by the U.K. Natural Environment Research Council (NERC) Grant NE/K013181/1. ACNG was supported by the Royal Society and Wolfson Foundation. EPA and CEB were supported by NERC Grant NE/K012843/1. CEB was funded by an MSCA grant (No. 798319) from the European Union’s Horizon 2020 program. EPA was supported by NERC Grant NE/N018095/1. SL and KP were supported by U.S. National Science Foundation Grants OCE-1536453 and OCE-1536779. SL acknowledges support of Award NA18OAR4320123 from the National Oceanic and Atmospheric Administration, U.S. Department of Commerce. The statements, findings, conclusions, and recommendations are those of the authors, and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration, or the U.S. Department of Commerce.
    Keywords: Bottom currents ; Diapycnal mixing ; Turbulence ; Southern Ocean
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  • 73
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(3), (2021): 955–973, https://doi.org/10.1175/JPO-D-20-0240.1.
    Description: Fresh Arctic waters flowing into the Atlantic are thought to have two primary fates. They may be mixed into the deep ocean as part of the overturning circulation, or flow alongside regions of deep water formation without impacting overturning. Climate models suggest that as increasing amounts of freshwater enter the Atlantic, the overturning circulation will be disrupted, yet we lack an understanding of how much freshwater is mixed into the overturning circulation’s deep limb in the present day. To constrain these freshwater pathways, we build steady-state volume, salt, and heat budgets east of Greenland that are initialized with observations and closed using inverse methods. Freshwater sources are split into oceanic Polar Waters from the Arctic and surface freshwater fluxes, which include net precipitation, runoff, and ice melt, to examine how they imprint the circulation differently. We find that 65 mSv (1 Sv ≡ 106 m3 s−1) of the total 110 mSv of surface freshwater fluxes that enter our domain participate in the overturning circulation, as do 0.6 Sv of the total 1.2 Sv of Polar Waters that flow through Fram Strait. Based on these results, we hypothesize that the overturning circulation is more sensitive to future changes in Arctic freshwater outflow and precipitation, while Greenland runoff and iceberg melt are more likely to stay along the coast of Greenland.
    Description: We gratefully acknowledge the U.S. National Science Foundation: this work was supported by Grants OCE-1258823, OCE-1756272, OCE-1948335, and OCE-2038481. L.H.S. thanks the U.S. Norway Fulbright Foundation for the Norwegian Arctic Chair Grant 2019-20 that made the visit to Scripps Institution of Oceanography possible. N.P.H. acknowledges support by the U.K. Natural Environment Research Council (NERC) National Capability program CLASS (NE/R015953/1), and Grants U.K.-OSNAP (NE/K010875/1, NE/K010875/2) and U.K.-OSNAP Decade (NE/T00858X/1). We acknowledge the World Climate Research Programme, which, through its Working Group on Coupled Modelling, coordinated and promoted CMIP6.
    Keywords: Arctic ; North Atlantic Ocean ; Conservation equations ; Meridional overturning circulation ; Ocean circulation ; Inverse methods
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  • 74
    Publication Date: 2022-05-27
    Description: Author Posting. © American Meteorological Society, 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 51(7), (2021): 2087–2102, https://doi.org/10.1175/JPO-D-20-0255.1.
    Description: The boundary current system in the Labrador Sea plays an integral role in modulating convection in the interior basin. Four years of mooring data from the eastern Labrador Sea reveal persistent mesoscale variability in the West Greenland boundary current. Between 2014 and 2018, 197 middepth intensified cyclones were identified that passed the array near the 2000-m isobath. In this study, we quantify these features and show that they are the downstream manifestation of Denmark Strait Overflow Water (DSOW) cyclones. A composite cyclone is constructed revealing an average radius of 9 km, maximum azimuthal speed of 24 cm s−1, and a core propagation velocity of 27 cm s−1. The core propagation velocity is significantly smaller than upstream near Denmark Strait, allowing them to trap more water. The cyclones transport a 200-m-thick lens of dense water at the bottom of the water column and increase the transport of DSOW in the West Greenland boundary current by 17% relative to the background flow. Only a portion of the features generated at Denmark Strait make it to the Labrador Sea, implying that the remainder are shed into the interior Irminger Sea, are retroflected at Cape Farewell, or dissipate. A synoptic shipboard survey east of Cape Farewell, conducted in summer 2020, captured two of these features that shed further light on their structure and timing. This is the first time DSOW cyclones have been observed in the Labrador Sea—a discovery that could have important implications for interior stratification.
    Description: A. P. and R. S. P. were funded by National Science Foundation Grants OCE-1259618 and OCE-1756361. I. L. B. and F. S. were funded by National Science Foundation Grants OCE-1258823 and OCE-1756272. N. P. H. was supported by the Natural Environment Research Council U.K. OSNAP program (NE/K010875/1 and NE/K010700/1). M. A. S. was supported by NSF Grants OCE-1558742 and OPP-1822334.
    Description: 2021-12-08
    Keywords: Boundary currents ; Eddies ; Transport
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  • 75
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Johnson, A. C., Ostrander, C. M., Romaniello, S. J., Reinhard, C. T., Greaney, A. T., Lyons, T. W., & Anbar, A. D. Reconciling evidence of oxidative weathering and atmospheric anoxia on Archean Earth. Science Advances, 7(40), (2021): eabj0108, https://doi.org/10.1126/sciadv.abj0108.
    Description: Evidence continues to emerge for the production and low-level accumulation of molecular oxygen (O2) at Earth’s surface before the Great Oxidation Event. Quantifying this early O2 has proven difficult. Here, we use the distribution and isotopic composition of molybdenum in the ancient sedimentary record to quantify Archean Mo cycling, which allows us to calculate lower limits for atmospheric O2 partial pressures (PO2) and O2 production fluxes during the Archean. We consider two end-member scenarios. First, if O2 was evenly distributed throughout the atmosphere, then PO2 〉 10–6.9 present atmospheric level was required for large periods of time during the Archean eon. Alternatively, if O2 accumulation was instead spatially restricted (e.g., occurring only near the sites of O2 production), then O2 production fluxes 〉0.01 Tmol O2/year were required. Archean O2 levels were vanishingly low according to our calculations but substantially above those predicted for an abiotic Earth system.
    Description: We would like to thank our funding sources, including FESD “Dynamics of Earth System Oxygenation” (NSF EAR 1338810 to A.D.A.), NASA Earth and Space Science Fellowship awarded to A.C.J. (80NSSC17K0498), NSF EAR PF to A.C.J. (1952809), and WHOI Postdoctoral Fellowship to C.M.O. C.T.R. acknowledges support from the NASA Astrobiology Institute. We also acknowledge support from the Metal Utilization and Selection across Eons (MUSE) Interdisciplinary Consortium for Astrobiology Research, sponsored by the National Aeronautics and Space Administration Science Mission Directorate (19-ICAR19_2-0007).
    Repository Name: Woods Hole Open Access Server
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    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bekaert, D. V., Auro, M., Shollenberger, Q. R., Liu, M.-C., Marschall, H., Burton, K. W., Jacobsen, B., Brennecka, G. A., McPherson, G. J., von Mutius, R., Sarafian, A., & Nielsen, S. G. Fossil records of early solar irradiation and cosmolocation of the CAI factory: a reappraisal. Science Advances, 7(40), (2021): eabg8329, https://doi.org/10.1126/sciadv.abg8329.
    Description: Calcium-aluminum–rich inclusions (CAIs) in meteorites carry crucial information about the environmental conditions of the nascent Solar System prior to planet formation. Based on models of 50V–10Be co-production by in-situ irradiation, CAIs are considered to have formed within ~0.1 AU from the proto-Sun. Here, we present vanadium (V) and strontium (Sr) isotopic co-variations in fine- and coarse-grained CAIs and demonstrate that kinetic isotope effects during partial condensation and evaporation best explain V isotope anomalies previously attributed to solar particle irradiation. We also report initial excesses of 10Be and argue that CV CAIs possess essentially a homogeneous level of 10Be, inherited during their formation. Based on numerical modeling of 50V–10Be co-production by irradiation, we show that CAI formation during protoplanetary disk build-up likely occurred at greater heliocentric distances than previously considered, up to planet-forming regions (~1AU), where solar particle fluxes were sufficiently low to avoid substantial in-situ irradiation of CAIs.
    Description: This study was funded by NASA Emerging Worlds grant NNX16AD36G to S.G.N. and prepared by LLNL under contract DE-AC52-07NA27344 with release number LLNL-JRNL-819045. M.C.L acknowledges the support by the NASA grant 80NSSC20K0759. The UCLA ion microprobe facility is partially supported by a grant from the NSF Instrumentation and Facilities program.
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    Publication Date: 2022-09-25
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(4), (2022): 597–616, https://doi.org/10.1175/jpo-d-21-0121.1.
    Description: We provide a first-principles analysis of the energy fluxes in the oceanic internal wave field. The resulting formula is remarkably similar to the renowned phenomenological formula for the turbulent dissipation rate in the ocean, which is known as the finescale parameterization. The prediction is based on the wave turbulence theory of internal gravity waves and on a new methodology devised for the computation of the associated energy fluxes. In the standard spectral representation of the wave energy density, in the two-dimensional vertical wavenumber–frequency (m–ω) domain, the energy fluxes associated with the steady state are found to be directed downscale in both coordinates, closely matching the finescale parameterization formula in functional form and in magnitude. These energy transfers are composed of a “local” and a “scale-separated” contributions; while the former is quantified numerically, the latter is dominated by the induced diffusion process and is amenable to analytical treatment. Contrary to previous results indicating an inverse energy cascade from high frequency to low, at odds with observations, our analysis of all nonzero coefficients of the diffusion tensor predicts a direct energy cascade. Moreover, by the same analysis fundamental spectra that had been deemed “no-flux” solutions are reinstated to the status of “constant-downscale-flux” solutions. This is consequential for an understanding of energy fluxes, sources, and sinks that fits in the observational paradigm of the finescale parameterization, solving at once two long-standing paradoxes that had earned the name of “oceanic ultraviolet catastrophe.”
    Description: The authors gratefully acknowledge support from the ONR Grant N00014-17-1-2852. YL gratefully acknowledges support from NSF DMS Award 2009418.
    Description: 2022-09-25
    Keywords: Ocean ; Gravity waves ; Nonlinear dynamics ; Ocean dynamics ; Mixing ; Fluxes ; Isopycnal coordinates ; Nonlinear models
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-09-27
    Description: The zooplankton body size is influenced by several factors, which in the natural ecosystem, can act directly, or interact, indirectly affecting the community structure. Water temperature, food availability, trophic status and predation by vertebrates are the main factors that influence the size structure of this community. Here we investigate how these factors can act on this characteristic of zooplankton directly or indirectly, mediated by the interaction between the factors. For this, we use a structural equation model that allows investigating complex interactions in natural ecosystems. The trophic state and the predation by fish were the main size planters of zooplankton. The trophic state positively influenced the small zooplankton, and indirectly the large zooplankton, mediated by the increase in fish abundance. The results indicated that the community size structure was regulated by top-down (predation) and bottom-up (nutrient availability) mechanisms, however the magnitude of the relationships was variable. Therefore, the results of the present study show that in tropical aquatic ecosystems there is a complex web of interactions that determine the structure of the zooplankton community.
    Description: O tamanho corporal do zooplâncton é influenciado por diversos fatores, que no ecossistema natural, podem agir de forma direta, ou interagir, afetando indiretamente a estrutura da comunidade. Temperatura da água, disponibilidade de alimento, estado trófico e predação por vertebrados são os principais fatores que influenciam na estrutura de tamanho desta comunidade. Aqui investigamos como estes fatores podem agir sobre a essa característica do zooplâncton de forma direta ou indireta, mediada pela interação entre os fatores. Para isso, utilizamos um modelo de equação estrutural que permite investigar complexas interações em ecossistemas naturais. O estado trófico e a predação por peixes foram os principais estruturadores de tamanho do zooplâncton. O estado trófico influenciou positivamente o zooplâncton de pequeno porte, e indiretamente o zooplâncton de grande porte, mediado pelo aumento na abundância dos peixes. Os resultados indicaram que a estrutura de tamanho da comunidade foi regulada por mecanismos top-down (predação) e bottom-up (disponibilidade de nutrientes), entretanto a magnitude das relações foi variável. Portanto, os resultados do estudo evidenciam que em ecossistemas aquáticos tropicais existe uma complexa teia de interações que determinam a estrutura da comunidade zooplanctônica.
    Description: Masters
    Keywords: Zooplâncton de água doce ; Ecologia de ecossistemas ; Estado trófico ; Tamanho corporal ; Predação ; ASFA_2015::Y::Zooplankton ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::E::Ecosystems ; ASFA_2015::P::Predation ; ASFA_2015::F::Food webs ; ASFA_2015::B::Body size ; ASFA_2015::F::Floodplains ; ASFA_2015::T::Trophic status
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
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  • 79
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    PANGAEA
    In:  EPIC3INTERACT Webinar on Data Repositories, Online, 2022-05-12Bremerhaven, PANGAEA
    Publication Date: 2022-10-04
    Repository Name: EPIC Alfred Wegener Institut
    Type: Conference , notRev
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    American Association for the Advancement of Science
    In:  EPIC3Science, American Association for the Advancement of Science, 371(6531), pp. 811-818
    Publication Date: 2022-10-01
    Description: Geological archives record multiple reversals of Earth's magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion 41 to 42 thousand years ago (ka). We use ancient New Zealand kauri trees (Agathis australis) to develop a detailed record of atmospheric radiocarbon levels across the Laschamps Excursion. We precisely characterize the geomagnetic reversal and perform global chemistry-climate modeling and detailed radiocarbon dating of paleoenvironmental records to investigate impacts. We find that geomagnetic field minima ~42 ka, in combination with Grand Solar Minima, caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record.
    Repository Name: EPIC Alfred Wegener Institut
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  • 81
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-04
    Description: Invaded communities were evaluated under two contexts: 1) how native communities respond to massive introduction events and 2) how invaded communities change through time. A common topic was defined to represent the modifications in communities after invasion, the co-occurrence between species. The objective of this thesis was to answer three questions: 1) whether the impact caused by non-native species is determined by the level of similarity between native and non-native species; 2) whether the impact would have the same pattern through time; and 3) whether there is any attribute of the non-native species population that determines the level of the impact. The data set from the project Pesquisas Ecológicas de Longa Duração (PELD) performed at the Upper Paraná River floodplain (Sítio PELD/PIAP) was used to answer these questions.First, it was evaluated the non-native species effects on the co-occurrence between species after the invasion of more than 30 non-native fish species at once. It was tested if the functional dissimilarity between native and non-native species drives the co-occurrence patterns between them. After, it was estimated the co-occurrence in a time series of 30 years. The non-native species evaluated were introduced by several introduction vectors. It was tested if the non-native species abundance and time since introduction drive the co-occurrence between native and non-native species. The abundance was used as the attribute of non-native species population to test if the effect of abundance is mediated by the phylogenetic distance between species. The results found showed that the co-occurrence between native and non-native species is affected by functional and phylogenetic distance. Therefore, integrating functional and phylogenetic diversity to assess the spatial distribution of organisms has potential to improve the understanding of co-occurrence patterns between native and non-native species. The results also showed that co-occurrence patterns may be more sensitive to the temporal variability in non-native population attributes (i.e. abundance) than time since introduction. It was showed that evaluating patterns of several non-native species may provide a broader understating of the entire community after invasions.
    Description: Avaliou-se comunidades invadidas sob dois contextos: 1) como comunidades nativas respondem a eventos de introdução em massa e 2) como comunidades invadidas mudam no tempo. Definiu-se um tema comum para representar as modificações nas comunidades após a invasão, a coocorrência entre espécies. O objetivo desta tese foi responder três questões: 1) se o impacto causado pela espécie não nativa é determinado pelo nível de similaridade entre espécies nativas e não nativas; 2) se o impactoteria o mesmo padrão no tempo; e 3) se existe algum atributo da população de espécies não nativas que determina o nível do impacto. Utilizou-se o conjunto de dados do projeto Pesquisas Ecológicas de Longa Duração (PELD) realizado na planície de inundação do Alto Rio Paraná (Sítio PELD/PIAP) para responder essas questões. Primeiro, avaliou-se os efeitos de espécies não nativas na coocorrência entre espécies após a invasão de mais de 30 espécies de peixes não nativos de uma só vez. Testou-se se a dissimilaridade funcional entre espécies nativas e não nativas impulsiona os padrões de coocorrência entre elas. Após, estimou-se a coocorrência em uma série temporal de 30 anos. As espécies não nativas avaliadas são originárias de diversos vetores de introdução. Testou-se se a abundância de espécies não nativas e o tempo desde a introdução impulsionam a coocorrência entre espécies nativas e não nativas. A abundância foi utilizada como atributo da população das espécies não nativas para testar se o efeito da abundância é mediado pela distância filogenética entre as espécies. Os resultados encontrados mostraram que a coocorrência entre as espécies nativas e não nativas é afetada pela distância funcional e filogenética. Portanto, integrar diversidade funcional e filogenética para entender a distribuição espacial dos organismos tem potencial para melhorar a compreensão de padrões de coocorrência entre espécies nativas e não nativas. Os resultados também mostraram que os padrões de coocorrência podem ser mais sensíveis à variabilidade temporal nos atributos da população não nativa (i.e., abundância) do que o tempo desde a introdução. Mostrou-se que a avaliação de padrões de várias espécies não nativas fornece uma compreensão mais ampla de toda a comunidade após invasões.
    Description: PhD
    Keywords: Peixes de água doce ; Comunidades, Ecologia de ; Invasões biológicas ; Diversidade funcional e taxonômica ; Espécies nativas e não nativas ; Coocorrência ; ASFA_2015::F::Freshwater fish ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::A::Alien species ; ASFA_2015::S::Species diversity ; ASFA_2015::F::Floodplains
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-05
    Description: Thiarids are pantropical gastropods endemic to South America and are found in lentic and lotic freshwater environments. These gastropods act as intermediate hosts for several species of digeneans. However, it is important to consider that there are difficulties for a correct identification of these digeneans in certain stages of the life cycle since the larvae have a reduced size and few morphological characteristics for diagnosis. In this way, techniques based on molecular markers become an extremely important tool, combining the use of ribosomal and mitochondrial regions. Considering that there are no records in the literature of studies involving parasites and gastropods as intermediate hosts in the Ivaí River, this study is the first regarding these relationships. Seventy-six specimens of gastropods were collected. Of these, 21 were parasitized. As for the parasites, 16 different morphotypes were found. The gastropod DNA was amplified using the COI marker. The gastropods showed genetic similarity with Aylacostoma chloroticum with different percentages of identity. As for the parasites, COI and 28S markers were used for DNA amplification. Four different taxa were characterized with both markers. With the mitochondrial marker it was possible to confirm only one genus among the digeneans found. However, the 28S ribosomal marker proved to be more effective for the identification of Ivaí River parasites, showing higher similarity values in relation to sequences available in the databases and lower values of genetic distance. In this way, it was possible to confirm the classification of the morphotypes into two distinct genera.
    Description: Os tiarídeos são gastrópodes pantropicais endêmicos da América do Sul e são encontrados em ambientes de água doce lênticos e lóticos. Esses gastrópodes atuam como hospedeiros intermediários de várias espécies de digenéticos. No entanto, é importante considerar que existem dificuldades para uma identificação correta desses digenéticos em determinadas fases do ciclo de vida, visto que as larvas possuem um tamanho reduzido e poucas características morfológicas para diagnóstico. Dessa maneira, técnicas baseadas em marcadores moleculares tornam-se uma ferramenta de extrema importância, combinando a utilização de regiões ribossômicas e mitocondriais. Considerando que não há registros na literatura de estudos envolvendo parasitas e gastrópodes como hospedeiros intermediários no rio Ivaí, este estudo é o primeiro a respeito dessas relações. Foram coletados 76 espécimes de gastrópodes. Desses, 21 encontravam-se parasitados. Quanto aos parasitas, foram encontrados 16 morfotipos distintos. O DNA dos gastrópodes foi amplificado utilizando o marcador COI. Os gastrópodes apresentaram similaridade genética com Aylacostoma chloroticum com diferentes percentuais de identidade. Quanto aos parasitas, para amplificação do DNA foram utilizados os marcadores COI e 28S. Quatro taxa diferentes foram caracterizados com ambos os marcadores. Com o marcador mitocondrial foi possível confirmar apenas um gênero dentre os digenéticos encontrados. Todavia, o marcador ribossômico 28S se mostrou mais eficaz para a identificação dos parasitas do rio Ivaí, apresentando maiores valores de similaridade em relação a sequências disponíveis nos bancos de dados e menores valores de distância genética. Dessa maneira, foi possível confirmar a classificação dos morfotipos em dois gêneros distintos.
    Description: Masters
    Keywords: Digenea (Trematoda: Platyhelminthes) “digenéticos” ; Gastrópodes (Mollusca) ; Genética molecular ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::M::Mollusks (freshwater) ; ASFA_2015::P::Parasites ; ASFA_2015::M::Molluscs (freshwater) ; ASFA_2015::M::Molecular biology
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 51pp.
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-05
    Description: Ludwigia has some invasive macrophyte species that have not yet been explored under the scope of phylogeography, a promising area to understand the ecology of invasions using barcode molecular markers sensitive to intraspecific variations. Thus, it was theorized that barcode markers used in invasive species of Ludwigia occurring in non-native regions would be phylogeographically informative. Sequences of the molecular markers trnH-psbA, rbcL, matK and phyC from invasive populations of L. peploides and L. grandiflora were used as they are the only ones available in Genbank. A gene tree was generated by the Neighborn-Joining method and a haplotypic network by the Median-Joining method for each species. The trnH-psbA marker was the only phylogeographically informative marker for detecting intraspecific variations in the analyzed taxa. Three haplotypes were detected for L. grandiflora and two haplotypes for L. peploides. Three geographically distinct founder populations of L. grandiflora were introduced in Europe, with Hg1 shared with the US population, while L. peploides has a founder population in Europe and another in the US. The long history of the introduction of these species in Europe and the limited geographic scope of molecular sampling demonstrate that these data are underestimated. A search in the Web of Science database exposed a paucity of molecular data for invasive species of Ludwigia, highlighting the contribution of the results to the information on these haplotypic relationships in the context of invasive biology. Therefore, the detection of haplotypic diversity of invasive species of Ludwigia proved to be promising when investigated by the phylogeographic scope, supporting a better understanding of the management and ecology of these haplotypes in non-native areas.
    Description: Ludwigia possui algumas espécies de macrófitas invasoras que ainda não foram exploradas sob o escopo da filogeografia, uma promissora área para compreender a ecologia das invasões utilizando marcadores moleculares barcode sensíveis a variações intraespecíficas. Assim, testou-se quais marcadores barcode utilizados em espécies invasoras de Ludwigia ocorrentes em regiões não nativas seriam filogeograficamente informativos. Utilizou-se sequências dos marcadores moleculares trnH-psbA, rbcL, matKe phyC de populações invasoras de L. peploides e L. grandiflora por serem as únicas disponíveis no Genbank. Gerou-se uma árvore gênica pelo método Neighborn-Joining e uma rede haplotípica pelo método Median-Joining para cada espécie. O marcador trnH-psbA foi o único informativo filogeograficamente por detectar variações intraespecíficas nos táxons analisados. Detectou-se três haplótipos para L. grandiflorae dois haplótipos para L. peploides. Três populações fundadoras geograficamente distintas de L. grandiflora foram introduzidas na Europa, sendo Hg1 compartilhado com a população estadunidense, enquanto L. peploidespossui uma população fundadora na Europa e outra nos EUA. O antigo histórico de introdução dessas espécies na Europa e a abrangência geográfica limitada da amostragem molecular demonstram que esses dados estão subestimados. Uma pesquisa feita na base de dados Web of Science expôs uma escassez de dados moleculares para espécies invasoras de Ludwigia, ressaltando a contribuição dos resultados quanto as informações sobre essas relações haplotípica no contexto da biologia das invasões. Portanto, a detecção da diversidade haplotípica de espécies invasoras de Ludwigia mostrou-se promissora quando investigada pelo escopo filogeográfico, subsidiando o melhor entendimento sobre o manejo e a ecologia desses haplótipos em áreas não nativas.
    Description: Masters
    Keywords: Ludwigia (Onagraceae) “cruz-de-malta” ; Macrófitas aquáticas invasoras ; Filogeografia ; Biogeografia ; Marcadores moleculares ; Manejo ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::M::Macrophytes ; ASFA_2015::B::Biogeography ; ASFA_2015::A::Alien species ; ASFA_2015::M::Molecular biology ; ASFA_2015::M::Molecular structure
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 29pp.
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  • 84
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-05
    Description: South America has fish endemic to continental fresh waters, but derived from clades predominantly and ancestrally distributed in marine environments, such as Platanichthys platana. This species is considered the smallest sardine of the Clupeidae with its type locality in the La Plata river. In 2007, there were the first records of P. platana in the upper Paraná river basin and in 2012 in the upper Paraná river floodplain. The variation in the length of specimens from this basin generated curiosity about their identity and origin of introduction. Sequences from the COI region of the specimens were used for genetic distance calculations, construction of gene trees and haplotype networks. The results obtained indicate that all analyzed specimens belong to P. platana. Eight haplotypes were found, some exclusive to the coastal basins of Santa Catarina, Rio Grande do Sul and Negro river basin. The basins of the La Plata river, the Lago and the upper Paraná river floodplain shared different haplotypes. The phylogeographic pattern presented in this study can be justified by the presence of populations of P. platana in the same paleoarea, before the geological process that configured the current architectures of the observed basins, by vicariance. During the Mesozoic and Cenozoic several vicarious events occurred between the coastal watersheds of Brazil that can be attributed to marine regressions and transgressions by continental lands. It is also assumed that specimens from the upper Paraná river floodplain were introduced to the region from Argentine regions.
    Description: A América do Sul apresenta peixes endêmicos de águas doces continentais, mas derivados de clados predominantemente e ancestralmente distribuídos em ambientes marinhos, como Platanichthys platana. Essa espécie é considerada a sardinha de menor tamanho de Clupeidae com sua localidade-tipo no rio de La Plata. Em 2007, houve os primeiros registros de P. platana na bacia do alto rio Paraná e em 2012 na planície de inundação do alto rio Paraná. A variação do comprimento dos espécimes dessa bacia gerou curiosidade sobre sua identidade e origem de introdução. Sequências da região COI dos espécimes foram e utilizadas para cálculos de distância genética, construção de árvores gênicas e rede de haplótipos. Os resultados obtidos indicam que todos os exemplares analisados pertencem a P. platana. Oito haplótipos foram encontrados, alguns exclusivos dos exemplares das bacias litorâneas de Santa Catarina, do Rio Grande do Sul e bacia do rio Negro. As bacias do rio de La Plata, do Lago e da planície de inundação do alto rio Paraná compartilharam diferentes haplótipos. O padrão filogeográfico apresentado nesse estudo pode ser justificado pela presença de populações de P. platana em uma mesma paleoarea, antes do processo geológico que configurou as atuais arquiteturas das bacias observadas, pela vicariância. Durante o Mesozóico e Cenozóico vários eventos vicariantes ocorreram entre as bacias hidrográficas costeiras do Brasil que podem ser atribuídos às regressões e transgressões marinhas por terras continentais. Pressupõe-se também que os espécimes da planície de inundação do alto rio Paraná tenham sido introduzidos na região a partir de regiões argentinas.
    Description: Masters
    Keywords: Platanichthys platana (Regan, 1917) (Clupeiformes, Clupeidae) “sardinha” ; Biogeografia ; Genética molecular ; Diversidade genética ; Bacias hidrográficas ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::F::Freshwater fish ; ASFA_2015::B::Biogeography ; ASFA_2015::G::Genetic diversity ; ASFA_2015::R::River basins ; ASFA_2015::R::Reservoirs (water)
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 36pp.
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-10-05
    Description: Non native species can negatively affect the invaded environment. Often, these species have biological characteristics that benefit other non natives and facilitate their invasion, so knowing the facilitation mechanisms between invaders are useful to mitigate their damage to the ecosystem. Thus, in this study we tested the hypothesis that Pterygoplichthys ambrosettii, a non native catfish, has habits that can alter nutrient concentrations (phosphorus and nitrogen) in the water column, and positively affect the growth of an invasive macrophyte species in detriment of a native one, characterizing ecological facilitation among invasive species. Therefore, an experiment was conducted with six treatments and four replicas, using the invasive macrophyte Hydrilla verticillata and the native Egeria najas, in the presence and absence of P. ambrosettii, all with occurrence recorded in the upper Paraná River floodplain. The results showed that the treatments with P. ambrosettii had a lower amount of dissolved oxygen, higher electrical conductivity, higher concentration of chlorophyll-a, total phosphorus (TP) and inorganic nitrogen (NI). Macrophyte biomass was significantly higher in monoculture treatments with fish, with this effect being more intense for H. verticillata. When in the same treatment, in the absence of P. ambrosettii, H. verticillata showed greater biomass than E. najas, but with the fish presence, the macrophyte species did not differ in their biomass, indicating that the high concentration of nutrients makes the coexistence of these macrophytes possible. The results found will be useful for future actions to manage invasive species, especially in habitats where they co-occur.
    Description: Espécies invasoras podem impactar negativamente o ambiente invadido. Frequentemente, estas espécies possuem características biológicas que beneficiam outras não nativas e facilitam sua invasão, portanto conhecer os mecanismos de facilitação entre invasoras é essencial para mitigar os danos ao ecossistema. Desta forma, neste estudo testamos a hipótese de que Pterygoplichthys ambrosettii, um cascudo invasor, com hábitos que podem alterar as concentrações de nutrientes (fósforo e nitrogênio) na coluna d'água, afeta positivamente o crescimento de uma espécie de macrófita invasora em detrimento de uma nativa, caracterizando a facilitação ecológica entre espécies invasoras. Para isso um experimento foi conduzido, utilizando a macrófita invasora Hydrilla verticillata e a nativa Egeria najas, na presença e ausência de P. ambrosettii (bem como ambas coocorrendo na presença e ausência do peixe), todos com ocorrência registrada na planície de inundação do alto rio Paraná. Os tratamentos com P. ambrosettii apresentaram menor quantidade de oxigênio dissolvido, maiores valores para a condutividade elétrica, clorofila-a, fósforo total (TP) e nitrogênio inorgânico (NI). A biomassa das macrófitas foi significativamente maior nos tratamentos de monocultura com peixe, sendo este efeito mais intenso para H. verticillata. Quando juntas na ausência de P ambrosettii, H. verticillata apresentou maior biomassa que E. najas, mas com a presença do peixe, as espécies não diferiram em sua biomassa, sugerindo que a alta concentração de nutrientes torna possível a coexistência das macrófitas. Os resultados encontrados se mostram úteis para o conhecimento da biologia destas espécies invasoras, assim como para futuras ações de manejo em pequenos habitats onde estas coocorrem.
    Description: Masters
    Keywords: Pterygoplichthys ambrosettii (Holmberg, 1893) (Siluriformes: Loricariidae) "cascudo blindado" ; Hydrilla verticillata (L.f.) Royle, 1839 (Hydrocharitaceae) "hydrilla" ; Egeria najas Planchon (Hydrocharitaceae) "lodinho branco" ; Macrófitas aquáticas invasoras ; Facilitação, Mecanismos de ; Nutrientes ; Concentração ; Interação ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::F::Freshwater fish ; ASFA_2015::M::Macrophytes ; ASFA_2015::F::Floodplains ; ASFA_2015::A::Alien species ; ASFA_2015::N::Nutrition ; ASFA_2015::E::Environmental impact
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 35pp.
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  • 86
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-08-12
    Description: Aquatic environments are known to present a spatio-temporal difference in nutrient concentration. Furthermore, other processes also interfere in the dynamics of aquatic macrophyte communities, such as interspecific competition. The performance of two species of emerging macrophytes, Polygonum ferrugineum and Polygonum acuminatum, was analyzed under the influence of the presence of competitor and nutrient variation. An experiment was carried out in which stem fragments of each species were planted in monoculture and mixed culture and submitted to two nutrient treatments: low and high. The experiment lasted 60 days. The measured parameters as well as the relative competition index (RCI) were analyzed using two-way ANOVA by permutation with two fixed factors (nutrient and species). The height and biomass parameters (aerial, root and total) were different among the species. In the biomass parameters there was a difference between the nutrients. The relative growth rate indicated a difference between the nutrient concentrations. Interaction between the factors was observed for height and root:shoot ratio. For the RCI, no significant difference was observed for any parameter. The development of individuals was not affected by the presence of a competitor. P. ferrugineum developed a greater amount of biomass than P. acuminatum. However, the growth rates between the species did not differ, indicating that there is no competitive advantage of the first species over the second species. Regarding nutrients, under conditions of high amount of nutrients, the parameters measured showed higher values, but the difference was not exacerbated. Under low nutrient conditions, the species P. ferruginum developed higher values, indicating phenotypic plasticity in the adjustment of the root portion, in order to find and absorb more nutrients. However, there is no competitive advantage, since the RCI does not express it. Therefore, the presence of competitors, the variation of nutrients and the interaction of these two factors do not explain the distribution of species in aquatic environments nor the dominance of P. ferrugineum over P. acuminatum in the distribution.
    Description: Os ambientes aquáticos são conhecidos por apresentarem diferença espaço-temporal na concentração de nutrientes. Ademais, outros processos também interferem na dinâmica das comunidades de macrófitas aquáticas, como a competição interespecífica. Analizou-se o desempenho de duas espécies de macrófitas emergentes, sendo Polygonum ferrugineum e Polygonum acuminatum, sob influência da presença de competidor e da variação de nutriente. Realizou-se um experimento no qual fragmentos caulinares de cada espécie foram plantados em monocultura e cultura mista e submetidos a dois tratamentos de nutriente: baixo e alto. O experimento durou 60 dias. Os parâmetros mensurados bem como o índice de competição relativa (RCI) foram analisados por meio da ANOVA bifatorial por permutação com dois fatores fixos (nutriente e espécie). Os parâmetros altura e biomassa (aérea, radicular e total) diferenciaram-se entre as espécies. Nos parâmetros de biomassa houve diferença entre os nutrientes. A taxa de crescimento relativo indicou diferença entre as concentrações de nutrientes. Interação entre os fatores foi observada para altura e proporção raíz:parte aérea. Para o RCI não foi observado diferença significativa para nenhum parâmetro. O desenvolvimento dos indivíduos não foi afetado pela presença de competidor. P. ferrugineum desenvolveu maior quantidade de biomassa que P. acuminatum. Entretanto, as taxas de crescimento entre as espécies não diferiram, indicando não haver vantagem competitiva da primeira sobre a segunda espécie. Em relação aos nutrientes, em condições de alta quantidade de nutrientes, os parâmetros mensurados apresentaram valores maiores, mas a diferença não foi exacerbada. Em condições de baixo nutriente, a espécie P. ferruginum desenvolveu valores maiores, indicando plasticidade fenotípica no ajuste da porção radicular, afim de encontrar e absorver mais nutrientes. Contudo, não se configura vantagem competitiva, uma vez que o RCI não a expressa. Logo, a presença de competidor, a variação de nutrientes e a interação desses dois fatores não explicam a distribuição das espécies nos ambientes aquáticos e nem a dominância de P. ferrugineum sob P. acuminatum na distribuição.
    Description: Masters
    Keywords: Macrófitas emergentes congêneres (Polygonum) ; Ecologia ; Competição ; Nutrientes ; ASFA_2015::M::Macrophytes ; ASFA_2015::E::Ecology ; ASFA_2015::C::Competition ; ASFA_2015::N::Nutrient cycles
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 25pp.
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  • 87
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-08-12
    Description: The hydrological regime is the main driver of ecosystems, as it has strong control over environmental and biological variables. The types of lake systems comprise different, including those sporadically isolated and isolated individuals (LP) to isolated individuals. It is expected that variations in the hydrological level exert different types of habitats on these two types of communities, directly influencing the structure of the communities of these vertebrae, as well as the benthic macroinvertebrates. Evidence of biodiversity from macroinvertebrate communities and LPs to hydrological variations still in LE is scarce and comes from small in spatial and temporal scales. Invest as a richness, density and beta diversity of macroinvertebrates of the community at different hydrological periods (lower, intermediate and high-level periods in LE and LP. A time series of 1 of the hydrological level and biological samples from six lakes were used (LE and 3 LP) from 3 biological years of the upper Paraná River flooding. Richness was obtained in periods of major and minor oscillations and high density in periods of hydrological oscillations. These curvilinear relationships are both LE and for LP, the diversity of benthic macroinvertebrates between periods of low oscillations differed, high beta only in LE. The low regional level periods more for water level beta diversity) the low water level periods BD, the LP higher. According to Redundancy Analysis (RDA), both in LE and macroinvertebrate diversity was mainly structured by environmental factors (ie, oxygen, consonance, turbidity, fish density and macrophyte richness) during periods of low water level. On the other hand, during periods of high hydrological level, the hydrological level was a single structuring forcing of macroinvertebrate diversity. Based on the results obtained, the responses of the macroinvertebrate community to hydrological oscillations tend to be different in LE and LP. Specifically, these are the most pronounced responses in LE, where local environmental factors play a stronger structuring role. The greatest contribution that LE and LP occur to macroinvertebrate diversity in different hydrological periods. Therefore, this evidence that preserves the wide variety of LE and LP in the floodplain is critical to maintaining local and regional biotic communities.
    Description: O regime hidrológico é o principal direcionador dos ecossistemas de planície de inundação, pois apresenta forte controle sobre variáveis ambientais e biológicas. Os sistemas de planície são compostos por diferentes tipos de lagos, incluindo aqueles esporadicamente (LE) conectados e aqueles permanentemente (LP) conectados aos rios. É esperado que as variações no nível hidrológico exerçam pressões distintas sobre esses dois tipos de lagos, influenciando diretamente a estrutura das comunidades desses habitats, assim como os macroinvertebrados bentônicos. Evidências de como a biodiversidade das comunidades de macroinvertebrados respondem a variações hidrológicas em LE e LP ainda são escassas e oriundas de estudos em pequenas escalas espaciais e temporais. Investigou-se como a riqueza, densidade e diversidade beta da comunidade de macroinvertebrados respondem a diferentes períodos hidrológicos (períodos de nível baixo, intermediário e alto) em LE e LP. Utilizou-se uma série temporal de 14 anos do nível hidrológico e amostragens biológicas de seis lagos rasos (3 LE e 3 LP) da planície de inundação do alto rio Paraná. Obteve-se maior riqueza e densidade em períodos de oscilações intermediárias e menor em períodos de baixa e alta oscilações hidrológicas. Essas relações curvilíneas ocorreram tanto LE quanto para LP. Contudo, a diversidade beta de macroinvertebrados bentônicos diferiu entre períodos de oscilações baixa, intermediária e alta apenas em LE. Os LE contribuíram mais para a diversidade beta regional (nível de planície) durante períodos de baixo nível de água (LCBD maior), os LP contribuíram mais durante períodos de nível alto de água. De acordo com a Análise de Redundância (RDA), tanto em LE quanto em LP a diversidade dos macroinvertebrados foi fortemente estruturada por fatores ambientais (i.e., oxigênio, condutividade, turbidez, densidade de peixes e riqueza de macrófitas) durante períodos de baixo nível de água. Durante períodos de nível hidrológico alto, o nível hidrológico foi a única força estruturante da diversidade dos macroinvertebrados. Mediante os resultados obtidos, as respostas da comunidade de macroinvertebrados para as oscilações hidrológicas tendem a ser diferentes em LE e LP. Especificamente, essas respostas são mais pronunciadas em LE, onde os fatores ambientais locais exercem um papel estruturante mais forte. A maior contribuição que LE e LP tem para diversidade de macroinvertebrados ocorre em períodos hidrológicos distintos. Portanto, isso evidencia que preservar a grande variedade de LE e LP em planície de inundação é fundamental para manter a biodiversidade local e regional de comunidades bióticas.
    Description: Masters
    Keywords: Macroinvertebrados bentônicos de água doce ; Comunidades, Ecologia de ; Estrutura ; Lagos temporários e permanentes ; Conexão ; Regime hidrológico ; ASFA_2015::M::Macrobenthos ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::L::Lakes ; ASFA_2015::H::Hydrologic cycle ; ASFA_2015::F::Floods ; ASFA_2015::D::Droughts ; ASFA_2015::B::Benthic communities ; ASFA_2015::F::Floodplains
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 34pp.
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  • 88
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-08-12
    Description: Changes in water level influence the establishment and ecological interactions developed between aquatic macrophytes.With the aim of investigate how changes in water level, the density of the invasive macrophyte Urochloa arrecta and the species richness influence the establishment of Paspalum repens, we set up two experiments in a greenhouse with three water levels (high, medium and static) and two levels of density and species richness. At the end of the experiments, we measured the following response variables: leaf area surface, shoot biomass, root biomass, total biomass, shoot length, and root length of P. repens. Using the total biomass, we calculated the relative interaction index (RII) to verify the type of ecological interaction developed between P. repens and its neighbors species. Each response variable was analyzed with a two-way ANOVA. Among the results obtained, we highlight: i) the predominantly negative values of the RII, indicating competition between P. repens and its neighbors in all the conditions tested in this work and ii) positive values of leaf area surface and shoot biomass at water levels high, especially in the experiment that analyzed the effect of the density of U. arrecta on P. repens, which highlights the strategies adopted by this species to establish itself in environments with high densities of the invasive species in scenarios of water level changes. Finally, these results indicate the effects of changes in water level, density of U. arrecta and species richness on P. repens, contributing to the understanding of the dynamics of macrophyte communities in freshwater ecosystems.
    Description: Mudanças do nível d’água influenciam o estabelecimento e as interações ecológicas desenvolvidas entre macrófitas aquáticas. Com o objetivo de investigar como mudanças no nível d’água, a densidade da macrófita invasora Urochloa arrecta e a riqueza de espécies influenciam no estabelecimento da macrófita nativa Paspalum repens, foram montados dois experimentos em casa de vegetação com três níveis d’água (alto, médio e estático) e dois níveis de densidade e riqueza de espécies. Ao final do experimento foram mensuradas as seguintes variáveis resposta: superfície da área foliar, biomassa aérea, biomassa da raiz, biomassa total, comprimento aéreo e comprimento da raiz de Paspalum repens. Utilizando a biomassa total, foi calculado o índice de interação relativa (RII) para verificar o tipo de interação ecológica desenvolvida entre P. repens e suas espécies vizinhas. Cada variável resposta foi analisada com uma Anova bifatorial. Dentre os resultados obtidos, destacamos: i) os valores preponderantemente negativos do RII, indicando competição de P. repens com suas vizinhas em todas as condições testadas neste trabalho e ii) valores positivos da superfície da área foliar e biomassa aérea em níveis d’água alto, especialmente no experimento que foi analisado o efeito da densidade de U. arrecta sobre P. repens, o que evidencia as estratégias adotadas por esta espécie para se estabelecer em ambientes com altas densidades da espécie invasora em cenários de mudanças do nível d’água. Esses resultados indicam, por fim, os efeitos da mudança do nível da água, da densidade de U. arrecta e da riqueza de espécies sobre P. repens, contribuindo para o entendimento da dinâmica das comunidades de macrófitas em ambientes aquáticos continentais.
    Description: Masters
    Keywords: Paspalum repens P. J. Bergius (Poaceae) ; Poaceae (Gramineae) “brachiaria” ; Macrófitas aquáticas invasoras emergentes ; Comunidades, Ecologia de ; Competição ; Espécies invasoras ; Estufas ; Experimentos ; ASFA_2015::M::Macrophytes ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::D::Dams ; ASFA_2015::R::Reservoirs (water) ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::A::Alien species ; ASFA_2015::C::Competition ; ASFA_2015::W::Water reservoirs ; ASFA_2015::E::Experimental research
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 49pp.
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  • 89
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-08-12
    Description: Dams and predicted future extreme weather events can affect the structure of aquatic communities, both at a local and regional scale. They can influence, for example, the importance of sites and species for regional diversity as they promote local processes of extinction and colonization, as well as processes of biotic homogenization on a regional scale. It was investigated how damming and prolonged flood and drought periods influenced the local contribution to beta diversity (LCBD) based on phytoplankton functional groups (GFR), as well as the contribution of each GFR to beta diversity (SCBD). The relationship between the number of GFR (Functional richness - RF) on the LCBD was also evaluated. For this, it was analyzed data collected in years with extreme drought (2000-2001) and flood (2010-2011) from three sub-basins of the upper Paraná River floodplain were used, which have different damming effects (presence, indirect influence, and absence). Nutrient concentrations and pH influenced the beta diversity in the three sub-basins in the two periods. Extreme drought periods and the presence of a dam were related to higher values of LCBD and RF. High LCBD values were related to low RF values. Environments with the absence and indirect influence of the dam had higher RF values in the flood and higher LCBD values in the drought. GFR H1 (N-fixing cyanobacteria), Lo (large mucilaginous cyanobacteria), and P (filamentous diatoms) presented the greatest contribution to beta diversity. The damming region was related to filamentous cyanobacteria in the drought. The results showed that both damming and climatic periods influenced the contribution of sites to regional diversity. However, they also suggested that the greatest biotic uniqueness observed in the damming region and in the dry period was related to organisms that can affect water diversity and quality, such as cyanobacteria. It appears that these environments have unique environmental and biotic conditions that require greater attention in terms of monitoring to prevent the proliferation of organisms with toxigenic potential. The construction of dams in search of energy security, associated with the predicted scenario of an increase in extreme events, favors biotic uniqueness. Understanding how communities respond to these changes is crucial for the ecology of aquatic environments.
    Description: Os barramentos e os eventos hidrológicos extremos atuais e os preditos para o futuro podem afetar a estrutura das comunidades aquáticas, tanto em escala local quanto regional. Estes eventos podem influenciar a importância de locais e espécies para a diversidade regional pois promovem processos locais de extinção e colonização, assim como processos de homogeneização biótica em escala regional. Foi investigado como o efeito de barramento e períodos de cheia e seca prolongados influenciam a contribuição local para a diversidade beta (LCBD) fitoplanctônica, baseada em grupos funcionais de Reynolds (GFR), e a contribuição de cada grupo funcional para a diversidade beta (SCBD). a relação entre o número de GFR (Riqueza Funcional – RF) sobre o LCBD. Para isso, utilizados dados de três sub-bacias da planície de inundação do alto rio Paraná, que possuem diferentes efeitos de barramento (presença, influência indireta e ausência), nos anos de seca (2000-2001) e cheia (2010-2011) extremas. As concentrações de nutrientes e o pH estiveram relacionadas com os padrões da diversidade beta nas três sub-bacias e nos dois períodos. Períodos de seca extrema e ambientes com presença de barramento apresentaram maiores valores de LCBD e RF. Altos valores de LCBD estiveram relacionados a baixos valores de RF. Ambientes com ausência e influência indireta de barramento apresentaram maiores valores de RF na cheia e maiores valores de LCBD na seca. Os GFR H1 (cianobactérias N-fixadoras), Lo (grandes cianobactérias mucilaginosas) e P (diatomáceas filamentosas) apresentaram maior contribuição à diversidade beta. A região com barramento esteve relacionada com cianobactérias filamentosas na seca. Os resultados mostraram que tanto barramento quanto períodos hidrológicos influenciaram a contribuição dos locais à diversidade regional. Porém, a maior singularidade biótica observada na região com barramento e no período seco esteve relacionada com organismos que podem afetar à diversidade e qualidade de água, como as cianobactérias. Esses ambientes aparentam possuir condições ambientais e bióticas exclusivas que requerem maior atenção em relação a monitoramento para evitar a proliferação de organismos com potencial toxigênico. A construção de barramentos em busca da segurança energética, associada ao cenário predito de aumento de eventos extremos, favorece a singularidade biótica. Entender como as comunidades respondem a essas alterações é crucial para ecologia de ambientes aquáticos.
    Description: Masters
    Keywords: Fitoplâncton de água doce ; Ecologia ; Barramento ; Diversidade beta ; Eventos hidrológicos extremos ; ASFA_2015::P::Phytoplankton ; ASFA_2015::E::Ecology ; ASFA_2015::F::Floodplains ; ASFA_2015::C::Climatic changes ; ASFA_2015::D::Dams ; ASFA_2015::A::Aquatic communities ; ASFA_2015::W::Weather conditions
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 41pp.
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  • 90
    Publication Date: 2022-08-12
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 39(7), (2022): 1053–1083, https://doi.org/10.1175/jtech-d-21-0167.1.
    Description: The Ka-band Radar Interferometer (KaRIn) on the Surface Water and Ocean Topography (SWOT) satellite will revolutionize satellite altimetry by measuring sea surface height (SSH) with unprecedented accuracy and resolution across two 50-km swaths separated by a 20-km gap. The original plan to provide an SSH product with a footprint diameter of 1 km has changed to providing two SSH data products with footprint diameters of 0.5 and 2 km. The swath-averaged standard deviations and wavenumber spectra of the uncorrelated measurement errors for these footprints are derived from the SWOT science requirements that are expressed in terms of the wavenumber spectrum of SSH after smoothing with a filter cutoff wavelength of 15 km. The availability of two-dimensional fields of SSH within the measurement swaths will provide the first spaceborne estimates of instantaneous surface velocity and vorticity through the geostrophic equations. The swath-averaged standard deviations of the noise in estimates of velocity and vorticity derived by propagation of the uncorrelated SSH measurement noise through the finite difference approximations of the derivatives are shown to be too large for the SWOT data products to be used directly in most applications, even for the coarsest footprint diameter of 2 km. It is shown from wavenumber spectra and maps constructed from simulated SWOT data that additional smoothing will be required for most applications of SWOT estimates of velocity and vorticity. Equations are presented for the swath-averaged standard deviations and wavenumber spectra of residual noise in SSH and geostrophically computed velocity and vorticity after isotropic two-dimensional smoothing for any user-defined smoother and filter cutoff wavelength of the smoothing.
    Description: This research was supported by NASA Grant NNX16AH76G.
    Keywords: Sea level ; Altimetry ; Remote sensing ; Satellite observations ; Error analysis
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 91
    Publication Date: 2022-08-30
    Description: Most tropical corals live in symbiosis with Symbiodiniaceae algae whose photosynthetic production of oxygen (O2) may lead to excess O2 in the diffusive boundary layer (DBL) above the coral surface. When flow is low, cilia-induced mixing of the coral DBL is vital to remove excess O2 and prevent oxidative stress that may lead to coral bleaching and mortality. Here, we combined particle image velocimetry using O2-sensitive nanoparticles (sensPIV) with chlorophyll (Chla)-sensitive hyperspectral imaging to visualize the microscale distribution and dynamics of ciliary flows and O2 in the coral DBL in relation to the distribution of Symbiodiniaceae Chla in the tissue of the reef building coral, Porites lutea. Curiously, we found an inverse relation between O2 in the DBL and Chla in the underlying tissue, with patches of high O2 in the DBL above low Chla in the underlying tissue surrounding the polyp mouth areas and pockets of low O2 concentrations in the DBL above high Chla in the coenosarc tissue connecting neighboring polyps. The spatial segregation of Chla and O2 is related to ciliary-induced flows, causing a lateral redistribution of O2 in the DBL. In a 2D transport-reaction model of the coral DBL, we show that the enhanced O2 transport allocates parts of the O2 surplus to areas containing less chla, which minimizes oxidative stress. Cilary flows thus confer a spatially complex mass transfer in the coral DBL, which may play an important role in mitigating oxidative stress and bleaching in corals.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , NonPeerReviewed
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  • 92
    Publication Date: 2022-08-29
    Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(8), (2022): 1593-1611, https://doi.org/10.1175/jpo-d-21-0180.1.
    Description: This study presents novel observational estimates of turbulent dissipation and mixing in a standing meander between the Southeast Indian Ridge and the Macquarie Ridge in the Southern Ocean. By applying a finescale parameterization on the temperature, salinity, and velocity profiles collected from Electromagnetic Autonomous Profiling Explorer (EM-APEX) floats in the upper 1600 m, we estimated the intensity and spatial distribution of dissipation rate and diapycnal mixing along the float tracks and investigated the sources. The indirect estimates indicate strong spatial and temporal variability of turbulent mixing varying from O(10−6) to O(10−3) m2 s−1 in the upper 1600 m. Elevated turbulent mixing is mostly associated with the Subantarctic Front (SAF) and mesoscale eddies. In the upper 500 m, enhanced mixing is associated with downward-propagating wind-generated near-inertial waves as well as the interaction between cyclonic eddies and upward-propagating internal waves. In the study region, the local topography does not play a role in turbulent mixing in the upper part of the water column, which has similar values in profiles over rough and smooth topography. However, both remotely generated internal tides and lee waves could contribute to the upward-propagating energy. Our results point strongly to the generation of turbulent mixing through the interaction of internal waves and the intense mesoscale eddy field.
    Description: The observations were funded through grants from the Australian Research Council Discovery Project (DP170102162) and Australia’s Marine National Facility. Surface drifters were provided by Dr. Shaun Dolk of the Global Drifter Program. AC was supported by an Australian Research Council Postdoctoral Fellowship. AC, HEP, and NLB acknowledge support from the Australian Government Department of the Environment and Energy National Environmental Science Program and the ARC Centre of Excellence in Climate Extremes. KP acknowledges the support from the National Science Foundation.
    Keywords: Diapycnal mixing ; Eddies ; Fronts ; Inertia-gravity waves ; Ocean dynamics
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 93
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-08-30
    Description: Despite growing interest in the effects of non-native invasive species in changing alternative trophic states in shallow lakes, little is known when it comes to tropical regions. We carried out a systematic review to identify which terms, species, definitions and objectives were most addressed in these studies, as well as to identify possible global patterns and trends regarding the growth of these research over the years and the hot spots of publications. Our results showed that although there was a non-linear growth in the number of studies published in the last three decades regarding state shifts in freshwater environments, only a small number of them addresses the influence that non-native invasive species have in triggering trophic states changes in aquatic environments and even less in shallow lakes. In our discussion, we explore the possible reasons and consequences that these patterns bring to this area of ecology, as well as expand the results and make the work available so that it can be used as recomendation for future projects related to the topic.
    Description: Lagos rasos são os ecossistemas de água doce mais abundantes do planeta, suportam elevada diversidade de espécies e proveem diversos serviços ecossistêmicos, porém, a dinâmica natural desses ecossistemas está ameaçada devido ao estabelecimento de espécies invasoras não nativas. Apesar do crescente interesse acerca dos impactos que espécies invasoras não nativas causam nos ecossistemas invadidos, pouco ainda se sabe sobre a influência delas para a estabilidade e mudança de estado trófico em lagos rasos. Foi realizada uma revisão sistematizada da literatura para identificar quais termos, espécies, definições e objetivos foram mais abordados nesses estudos, assim como identificar possíveis padrões e tendências globais quanto à distribuição das pesquisas ao longo dos anos e seu local de origem. Embora tenha havido um crescimento na quantidade de estudos publicados nas últimas três décadas sobre estados tróficos em ambientes aquáticos, apenas uma pequena quantidade deles aborda a influência das espécies invasoras nãonativas na mudança de estado trófico nestes ecossistemas. Foram exploradas as possíveis razões e as consequências que esses padrões e métodos trazem para essa área da ecologia, de forma que a discussão aqui feita sugere diversas recomendações para futuros trabalhos e pesquisadores considerarem.
    Description: Masters
    Keywords: Ecossistemas aquáticos ; Lagos rasos ; Invasões biológicas ; Eutrofização ; Revisão sistemática ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::L::Lakes ; ASFA_2015::E::Eutrophication ; ASFA_2015::A::Alien species ; ASFA_2015::R::Reviews (literature)
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 36pp.
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  • 94
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-08-30
    Description: Global climate change has as its main result an increase in the frequency and severity of extreme events, such as longer periods of drought, and more hot days throughout the year, which makes drought events even more severe. Certain plant species have a high invasive potential, which is due to their tolerance to adverse conditions and the recovery of their individuals after some disturbance, which increases the possibility of colonization and establishment in new environments, interfering with native communities. The effect of interspecific competition between the invasive plant Urochloa mutica and the native species Panicum dichotomiflorum was experimentally analyzed on its establishment, resistance and resilience, simulating conditions of extreme water events and the distribution of Panicum dichotomiflorum and Urochloa mutica, particularly in protected areas environmental. The results obtained showed that the native species grew less with the water changes, mainly due to the lack of water, and the invasive species did not show strong growth alterations with the disturbances used. Furthermore, the species were shown to alter the growth variables in competition, impacting the native species more. On the other hand, the species in terms of temporal stability did not change growth and both may have advantages in impacted environments. Regarding the distribution of species, the results showed that the dispersion of the invasive exotic plant will be greater in areas that already have its presence, and also that this species may invade new places, such as Germany and Austria. In a future scenario of global climate change in 2070, this invasive species could occur in protected areas. Regarding the national territory, U. mutica will lose part of its distribution in Brazil, mainly in the north and northeast regions, including areas of protection and conservation. For P. dichotomiflorum, it is possible that it will lose a large part of its natural habitat in the two future scenarios, but it will increase its occurrence in other places, being able to become a potential invasive. Therefore, the results achieved indicate that both species have important characteristics in coping with climate change and show that the native species has an invasive behavior, with information of enormous value to environmental managers, especially in the management work of the two species of Poaceae, which have invasive potential for preserved areas, and in research that evidence areas susceptible to invasion.
    Description: As mudanças climáticas globais tem como principal resultado o aumento na frequência e na severidade de eventos extremos, tais como períodos mais prolongados de seca, e mais dias quentes ao longo do ano, o que torna os eventos de seca ainda mais severos. Certas espécies vegetais possuem alto potencial invasor, que se deve à sua tolerância a condições adversas e à recuperação de seus indivíduos após algum distúrbio, o que aumenta a possibilidade de colonização e estabelecimento em novos ambientes, interferindo em comunidades nativas. Analisou-se experimentalmente o efeito da competição interespecífica da planta invasora Urochloa mutica com a espécie nativa Panicum dichotomiflorum, em seu estabelecimento, resistência e resiliência, simulando condições de eventos hídricos extremos e a distribuição de Panicum dichotomiflorum e Urochloa mutica, particularmente em áreas de proteção ambiental. Os resultados alcançados mostraram que a espécie nativa, cresceu menos com as mudanças hídricas, principalmente pela falta de água e a espécie invasora mostrou não sofrer fortes alterações de crescimento com os distúrbios empregados. As espécies mostraram alterar as variáveis de crescimento em competição, impactando de maior maneira a espécie nativa. Por outro lado, as espécies em termos de estabilidade temporal não alteraram o crescimento e ambas podem apresentar vantagens em ambientes impactados. Em relação à distribuição das espécies, os resultados mostraram que a dispersão da planta exótica invasora será maior em áreas que possuem sua presença, e também que essa espécie poderá invadir novos lugares, como Alemanha e Áustria. Em cenário futuro de mudança climática global em 2070, essa espécie invasora pode ocorrer em áreas protegidas. Com relação ao território nacional, U. mutica perderá parte da sua distribuição no Brasil, principalmente na região norte e nordeste, incluindo áreas de proteção e conservação. Para P. dichotomiflorum, é possível que perdera grande parte de seu habitat natural nos dois cenários futuros, mas aumentará sua ocorrência em outros lugares, podendo se tornar uma invasora em potencial. Portanto, os resultados alcançados indicam que ambas as espécies possuem características importantes no enfrentamento às mudanças climáticas e evidenciam que a espécie nativa apresenta comportamento invasor, com informações de enorme valia para gestores ambientais, especialmente nos trabalhos de manejo das duas espécies de Poaceae, que têm potencial invasor para áreas preservadas, e em pesquisas que evidenciem áreas suscetíveis a invasões.
    Description: Masters
    Keywords: Poaceae (Gramineae) ; Urochloa mutica (Poaceae : Monocotiledônea) ; Panicum dichotomiflorum (Poaceae : Monocotiledônea) ; Macrófitas aquáticas ; Espécies invasoras e nativas ; Espécies invasoras ; Espécies nativas ; Competição ; Mudanças climáticas ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::M::Macrophytes ; ASFA_2015::A::Alien species ; ASFA_2015::C::Competition ; ASFA_2015::C::Climatic changes
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 67pp.
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  • 95
    Publication Date: 2022-08-25
    Description: Author Posting. © American Meteorological Society , 2021. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Han, L., Seim, H., Bane, J., Todd, R. E., & Muglia, M. A shelf water cascading event near Cape Hatteras. Journal of Physical Oceanography, 51(6), (2021): 2021–2033, https://doi.org/10.1175/JPO-D-20-0156.1.
    Description: Carbon-rich Middle Atlantic Bight (MAB) and South Atlantic Bight (SAB) shelf waters typically converge on the continental shelf near Cape Hatteras. Both are often exported to the adjacent open ocean in this region. During a survey of the region in mid-January 2018, there was no sign of shelf water export at the surface. Instead, a subsurface layer of shelf water with high chlorophyll and dissolved oxygen was observed at the edge of the Gulf Stream east of Cape Hatteras. Strong cooling over the MAB and SAB shelves in early January led to shelf waters being denser than offshore surface waters. Driven by the density gradient, the denser shelf waters cascaded beneath the Gulf Stream and were subsequently entrained into the Gulf Stream, as they were advected northeastward. Underwater glider observations 80 km downstream of the export location captured 0.44 Sv (1 Sv ≡ 106 m3 s−1) of shelf waters transported along the edge of the Gulf Stream in January 2018. In total, as much as 7 × 106 kg of carbon was exported from the continental shelf to a greater depth in the open ocean during this 5-day-long cascading event. Earlier observations of near-bottom temperature and salinity at a depth of 230 m captured several multiday episodes of shelf water at a location that was otherwise dominated by Gulf Stream water, indicating that the January 2018 cascading event was not unique. Cascading is an important, yet little-studied pathway of carbon export and sequestration at Cape Hatteras.
    Description: This research was funded by the National Science Foundation (Grants OCE-1558920 to University of North Carolina at Chapel Hill and OCE-1558521 to Woods Hole Oceanographic Institution) as part of PEACH. We acknowledge and thank Sara Haines for the processing and QC of the mooring data, and we thank the PEACH group for helpful discussions and for their support. Additional thanks are given to the crew of R/V Armstrong (AR-26).
    Keywords: Continental shelf/slope ; Fronts ; In situ oceanic observations
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 96
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-24
    Description: Human activities cause drastic changes in the functioning of ecosystems, such as the reduction of biodiversity. Phytoplankton are among the first to respond to these changes. Eutrophication can cause cyanobacterial blooms and select species with different functional traits, according to hydrodynamic conditions (e.g. water residence time - TR) and luminous availability. The effects of the Human Influence Index (IIH) and RT on the magnitude of the relationship between environment (phosphorus, nitrogen and turbidity) and biovolume of the functional morphological groups (GFBMs) of cyanobacteria III, VII and VIII. Phytoplankton from Brazilian lakes, reservoirs and rivers were sampled at different periods of the hydrological cycle (N = 3203). The biovolume of GFBMs was affected positively by phosphorus and negatively by nitrogen and turbidity. IIH and TR showed negative effects on the biovolume-environment relationship. The meta-regressions showed different relationships between biovolume and nitrogen for groups III, VII and VIII, as well as negative relationships in temporal data, which indicates that hydrological events had an effect on them. The results indicated that local variables, such as hydrodynamic conditions, can affect the strength of the relationships between biovolume, nitrogen and phosphorus, which causes a negative effect on GFBMs.
    Description: Atividades antrópicas causam mudanças drásticas no funcionamento dos ecossistemas, como a redução da biodiversidade. Os fitoplanctontes são um dos primeiros a responder a essas mudanças. A eutrofização pode causar florações de cianobactérias e selecionar espécies com distintos traços funcionais, de acordo com as condições hidrodinâmicas (e. g. tempo de residência da água - TR) e disponibilidade luminosa. Avaliou-se por meio de metanálises, os efeitos do Índice de Influência Humana (IIH) e do TR sobre a magnitude da relação entre ambiente (fósforo, nitrogênio e turbidez) e biovolume dos grupos morfológicos funcionais (GFBMs) de cianobactérias III, VII e VIII. Amostrou-se o fitoplâncton de lagos, reservatórios e rios brasileiros, em distintos períodos do ciclo hidrológico (N= 3203). O biovolume dos GFBMs foi afetado positivamente pelo fósforo e negativamente pelo nitrogênio e turbidez. O IIH e TR apresentaram efeitos negativos sobre a relação biovolume-ambiente. As metaregressões evidenciaram distintas relações entre biovolume e nitrogênio para os grupos III, VII e VIII, assim como relações negativas em dados temporais, o que indica que eventos hidrológicos teve efeito sobre elas. Os resultados indicaram que variáveis locais, como as condições hidrodinâmicas, podem afetar a força das relações entre biovolume, nitrogênio e fósforo, o que ocasiona efeito negativo sobre os GFBMs.
    Description: Masters
    Keywords: Cianobactérias planctônicas ; Ecologia ; Abordagem funcional ; Variabilidade espaço-temporal ; Impactos antrópicos ; ASFA_2015::P::Phytoplankton ; ASFA_2015::E::Ecology ; ASFA_2015::F::Functional morphology ; ASFA_2015::T::Temporal variations ; ASFA_2015::I::Impacts ; ASFA_2015::P::Planktonic algae ; ASFA_2015::P::Plankton blooms
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 49pp.
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  • 97
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-24
    Description: The invasion success of non-native species depends on several factors, and native populations and biotic characteristics of non-native environments can offer resistance to non-native species development. Reservoirs can facilitate submerged macrophyte invasion once it modifies the environment and provides favorable abiotic conditions to macrophyte establishment and development. However, previous colonization of native species can resist the development of invasive ones through priority effects. In this investigation we used large data-set (1120 samplings during 4 years) obtained in the Itaipu Reservoir (Brazil/Paraguay) to assess the relationship between the abundance of the native submerged macrophyte Egeria najas and of the invasive Hydrilla verticillata and the water level, littoral slope and Secchi disk depth. We also investigated how the concomitant and previous abundance of both macrophytes correlates. A spatial-temporal modeling was applied using Integrated Nested Laplace Approximations method, which controls the effect of spatial-temporal autocorrelation. Our results indicate an important role of water transparency, littoral slope and water level oscillations (in terms of amplitude and increased hydrometric level), in a short period of time (30 days) for the temporal dynamics of the abundance of both species. However, alterations of the hydrometric levels and of the littoral slope affected H. verticillata to a greater extent than E. najas. In addition, the abundance of each species was related with its own abundance in previous samplings, highlighting the importance of vegetative propagule pressure and resistance structures for population recovery. The magnitude of the interaction between both species in concomitant occurrence in the same site was abundance dependent.
    Description: O sucesso da invasão de espécies não nativas depende de vários fatores. Populações nativas e características bióticas de ambientes não nativos podem oferecer resistência ao desenvolvimento de espécies não nativas. Porém, a colonização prévia de espécies nativas pode impor resistência ao desenvolvimento de espécies invasoras por meio de efeitos de prioridade. Nesta investigação utilizou-se um grande conjunto de dados (1120 amostragens durante 4 anos) obtidos Reservatórios podem facilitar a invasão de macrófitas submersas, uma vez que modificam o ambiente e fornecem condições abióticas favoráveis para o estabelecimento e desenvolvimento de macrófitas no reservatório de Itaipu (Brasil/Paraguai) para avaliar a relação entre a abundância da macrófita submersa nativa Egeria najas e da invasora Hydrilla verticillata e o nível da água, declividade litorânea e profundidade do disco de Secchi. Também se investigou, como a abundância concomitante e prévia de ambas as macrófitas se correlaciona. Uma modelagem espaço-temporal foi aplicada usando o método de Aproximações Aninhadas Integradas de Laplace, que controla o efeito da autocorrelação espaço-temporal. Os resultados indicam um importante papel da transparência da água, declividade litorânea e oscilações do nível da água (em termos de amplitude e aumento do nível hidrométrico), em um curto período de tempo (30 dias) para a dinâmica temporal da abundância das duas espécies. Contudo, as alterações dos níveis hidrométricos e do declive litorâneo afetaram mais H. verticillata em comparação a E. najas. Ademais, a abundância de cada espécie foi relacionada com a sua própria abundância em amostragens anteriores, evidenciando a importância da pressão do propágulo vegetativo e das estruturas de resistência para a recuperação populacional. A magnitude da interação entre as duas espécies ao ocorrerem concomitantemente no mesmo ponto foi dependente da abundância.
    Description: Masters
    Keywords: Ecologia de reservatórios ; Macrófitas aquáticas submersas nativas e invasoras ; Abundância ; Preditores abióticos e bióticos ; Nível da água ; Abundância prévia ; Efeitos de prioridade ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::M::Macrophytes ; ASFA_2015::W::Water levels ; ASFA_2015::A::Abundance ; ASFA_2015::T::Temporal variations ; ASFA_2015::P::Prediction ; ASFA_2015::A::Abiotic factors ; ASFA_2015::R::Reservoirs (water)
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 36pp.
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  • 98
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-24
    Description: Freshwater ecosystems such as the Upper Paraná River floodplain are constantly subjected to environmental changes caused by natural disturbances, but mainly by anthropogenic impacts (such as dams), which have drastically affected the biodiversity of these aquatic systems. One way to assess the rates of environmental change in systems such as plains is through biomonitoring studies on large temporal scales, with diatoms being excellent bioindicators in determining environmental changes in different aquatic ecosystems. Based on this, the temporal pattern of the periphytic diatom community of a lake in the upper Paraná River floodplain was investigated in order to seek patterns that reflect the environmental changes in this plain, covering studies with different approaches, such as ecology, taxonomic and of environmental education. As a result of these different studies, it is noteworthy that the association of the taxonomic and functional approach in the components of beta diversity was extremely important for the interpretation of variation in the composition of diatom species in a long time series, especially when considering the importance of the contribution beta diversity site - LCBD. It was also sought to highlight the use of diatoms as indicators in determining hydrological changes, reinforcing the need for continuous monitoring of the region, in order to follow the direction of ecological changes, both hydrological and climatic in this plain. The importance of taxonomic studies in the plain was also highlighted in this thesis, in order to better understand the local biodiversity of diatoms, since new species such as Staurosirella paranaensis are being registered. Finally, this thesis includes a proposal for educational games on microalgae and their ecological importance in the environmental indication of aquatic bodies, to emphasize the relevance of environmental education in the research, teaching and extension process.
    Description: Ecossistemas de água doce como a planície de inundação do alto rio Paraná estão constantemente submetidos a mudanças ambientais causadas por distúrbios naturais, mas principalmente por impactos antrópicos (como barramentos), que tem afetado drasticamente a biodiversidade desses sistemas aquáticos. Uma forma de avaliar as taxas de alterações ambientais em sistemas como as planícies, é por meio dos estudos de biomonitoramento em grandes escalas temporais, sendo as diatomáceas excelentes bioindicadoras na determinação de mudanças ambientais nos diversos ecossistemas aquáticos. Com base nisso, foi investigado o padrão temporal da comunidade de diatomáceas perifíticas de um lago da planície de inundação do alto rio Paraná, a fim de buscar padrões que refletem as alterações ambientais desta planície, abrangendo estudos com diferentes abordagens, como ecologia, taxonômica e de educação ambiental. Como resultado destes diferentes estudos, ressalta-se que a associação da abordagem taxonômica e funcional nos componentes da diversidade beta foi de extrema importância para a interpretação de variação da composição de espécies de diatomáceas em uma longa série temporal, principalmente quando consideramos a importância da contribuição local da diversidade beta - LCBD. Também se buscou evidenciar o uso das diatomáceas como indicadores na determinação das alterações hidrológicas, reforçando a necessidade de um monitoramento contínuo da região, no intuito de acompanhar a direção das mudanças ecológicas, tanto hidrológicas quanto climáticas desta planície. A importância dos estudos taxonômicos na planície, também foi destaque nesta tese, a fim de conhecer melhor a biodiversidade local de diatomáceas, uma vez que novas espécies estão sendo registradas, como a Staurosirella paranaensis. Por fim, esta tese engloba uma proposta de jogos didáticos sobre microalgas e a importância ecológica delas na indicação ambiental de corpos aquáticos, no intuito de ressaltar a relevância da educação ambiental no processo de pesquisa, ensino e extensão.
    Description: PhD
    Keywords: Algas perifíticas ; Diatomáceas ; Microalgas perífiticas de água doce ; Comunidades, Ecologia de ; Bioindicadores ; Mudanças climáticas ; Taxonomia ; Jogos didáticos ; ASFA_2015::A::Algae ; ASFA_2015::D::Diatoms ; ASFA_2015::P::Phytoplankton ; ASFA_2015::B::Bioindicators ; ASFA_2015::E::Environmental monitoring ; ASFA_2015::T::Taxonomy ; ASFA_2015::F::Freshwater ecology
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 140pp.
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  • 99
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-24
    Description: The degree at which populations are correlated in space is called spatial synchrony and can be affected by interspecific interactions, dispersion, and large-scale environmental factors, i. e. Moran effect. The study of this phenomenon can help understanding the temporal stability of communities and the underlying mechanisms. The influence of damming in a river from the Amazon basin (Santo Antônio do Jari HPP) on the synchrony of the environment and the phytoplankton community was evaluated, both for the total density and for different Reynolds functional groups. Was investigated whether the effects would be similar for the main channel (Jari River), tributaries, and for the total area (Jari + tributaries). The mean synchrony values and the confidence intervals of each abiotic variable, functional group, and the total density were estimated for the total area, Jari River and tributaries. Matrix-based multiple regression were also performed to identify the most important drivers of synchrony of the phytoplankton. Changes in the synchrony patterns were verified after the damming. The temporal dynamics of environmental variables, total density and of some functional groups was more synchronous when considering only the Jari River, than the total area or only tributaries. Environmental synchrony and environmental distance were the main mechanisms behind synchrony for some functional groups.
    Description: O grau de correlação de populações no espaço é denominado sincronia espacial e pode ser afetado por interações interespecíficas, dispersão e fatores ambientais de ampla escala, (i. e., efeito Moran). O estudo deste fenômeno pode colaborar na compreensão da estabilidade temporal das comunidades e a descobrir quais os mecanismos associados ao processo. Avaliou-se a influência de um barramento em um rio da bacia Amazônica (UHE Santo Antônio do Jari) sobre a sincronia espacial ambiental e do fitoplâncton do rio Jari e tributários. Mensurou-se a sincronia (total, média e intervalo de confiança) para cada variável abiótica, para a densidade de toda a comunidade e para cada grupo funcional de Reynolds, considerando a área total (11 locais - rio Jari + tributários), apenas rio Jari (cinco locais) e apenas tributários (seis locais), utilizando uma série temporal de oito anos. Regressões matriciais múltiplas foram utilizadas para identificar os fatores determinantes da sincronia do fitoplâncton. Verificou-se mudanças nos padrões de sincronia após o barramento. A dinâmica temporal das variáveis ambientais, da densidade de toda a comunidade e de alguns grupos funcionais apresentou-se mais sincrônica quando considerado somente o rio Jari, do que toda a área ou somente os tributários. Em geral, a distância ambiental mostrou-se o preditor mais importante para explicar a sincronia espacial do que a distância geográfica.
    Description: Masters
    Keywords: Fitoplâncton de água doce ; Comunidades, Ecologia de ; Abordagem funcional ; Impacto ambiental ; Sincronia espacial ; Barramento ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::P::Phytoplankton ; ASFA_2015::M::Monitoring ; ASFA_2015::E::Environmental impact ; ASFA_2015::C::Communities (ecological) ; ASFA_2015::R::Reservoirs (water)
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 42pp.
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  • 100
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    Universidade Estadual de Maringá. Departamento de Biologia. Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais.
    Publication Date: 2022-06-24
    Description: The survival and growth of fish larvae during ontogeny are related to the ability to obtain adequate food, providing subsidies for individuals reach the adult age. The foraging capacity, availability and abundance of prey and morphological development, especially swimming performance and visual acuity are important factors in reproductive success. In this study, the aspects related to feeding during the ontogeny of fish larvae from a floodplain system were analyzed, evaluating the coexistence capacity and the predator-prey interaction. Specifically, the objectives were (1) to analyze the inter and intraspecific variations in the diet of three invasive fish species (Auchenipterus osteomystax, Plagioscion squamosissimus and Hypophthalmus oremaculatus) during their initial ontogeny and the relationship with coexistence; and (2) to apply a new approach in trophic ecology studies during ontogeny, evaluating the interaction and organization of the predator-prey network, using A. osteomystax as model. The larvae of invasive fish species had different diets inter and intraspecifically, low diet overlap and high niche breadth primarily for P. squamosissimus. The coexistence of larvae of these species is probably possible due to low competition, differentiation of trophic guilds, resource partitioning and trophic plasticity. Regarding the predator-prey network, A. osteomystax showed a nested structure, low connectivity and a pattern of segregation in resource consumption. The larvae fed exclusively on aquatic insects, impacting the robustness of the network when the most frequent prey in the diet is removed, here represented by Diptera and Chironomidae pupa. Furthermore, the correlation between metric variables and morphological networks showed that the species is of more general position as the network develops, increasing its capacity predation. Both studies demonstrated the importance of knowing the species-habitat interaction and the processes that govern prey capture, avoiding inter and intraspecific competition through resource partitioning and behavioral and foraging changes during ontogeny.
    Description: A sobrevivência e o crescimento das larvas de peixes durante a ontogenia estão relacionados com a capacidade de se obter alimento adequado, o qual fornece subsídios para que os indivíduos alcancem a vida adulta. A capacidade de forrageamento, a disponibilidade e abundância de presas e o desenvolvimento morfológico, principalmente da capacidade natatória e acuidade visual são fatores preponderantes no sucesso reprodutivo. Analisou-se, os aspectos relacionados à alimentação durante a ontogenia das larvas de peixes de um sistema de planície de inundação, avaliando a capacidade de coexistência e a interação predador-presa. Especificamente os objetivos foram (1) analisar as variações inter e intraespecíficas da dieta de três espécies de peixes invasoras (Auchenipterus osteomystax, Plagioscion squamosissimus e Hypophthalmus oremaculatus) durante a sua ontogenia inicial e a relação com a coexistência; (2) aplicar uma nova abordagem em estudos de ecologia trófica durante a ontogenia, avaliando a interação e organização da rede predador-presa, usando como modelo A. osteomystax. As larvas apresentaram dietas distintas tanto inter, quanto intraespecificamente, baixa sobreposição alimentar a alta amplitude de nicho principalmente para P. squamosissimus. A coexistência das larvas destas espécies é possível provavelmente devido à baixa competição, diferenciação de guildas tróficas, particionamento de recursos e plasticidade trófica. Em relação à rede predador-presa, A. osteomystax apresentou estrutura aninhada, baixa conectância e um padrão de segregação no consumo de recursos. As larvas desta espécie alimentaram-se exclusivamente de insetos aquáticos, com impacto na robustez da rede quando ocorre a remoção de presas mais frequentes na dieta, aqui representada por pupa de Diptera e Chironomidae. A correlação entre variáveis morfológicas e as métricas de redes mostrou que a espécie assume uma posição mais generalista na rede conforme ocorre seu desenvolvimento, aumentando sua capacidade de predação. Ambos os estudos demonstraram a importância de se conhecer a interação espécie-habitat e os processos que regem a captura de presas, evitando a competição inter e intraespecífica através do particionamento de recursos e mudanças comportamentais e de forrageamento durante a ontogenia.
    Description: PhD
    Keywords: Peixes de água doce ; Ictioplâncton de água doce ; Larvas ; Ecologia ; Alimentação ; Relação presa-predador ; ASFA_2015::F::Freshwater fish ; ASFA_2015::F::Freshwater ecology ; ASFA_2015::I::Ichthyoplankton ; ASFA_2015::L::Larvae ; ASFA_2015::P::Predators ; ASFA_2015::P::Prey ; ASFA_2015::F::Floodplains ; ASFA_2015::T::Trophic relationships ; ASFA_2015::F::Food chains
    Repository Name: AquaDocs
    Type: Thesis/Dissertation
    Format: 66pp.
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