ALBERT

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Makeely I. Blandford, Mohammad Katouli, Ben L. Gilby, Christian O'Dea, Andrew D. Olds, Thomas A. Schlacher〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dead animal bodies occur naturally in ecosystems, are regularly washed up along ocean beaches, and are a key component of many coastal food webs where scavenging animals consume carcasses. Microbes that decompose carcasses can, however, produce toxic chemicals during putrefaction. This is frequently assumed to have negative consequences for scavengers in the wild, but has been rarely quantified. In this study, we measured how changes in the microbial assemblages of decaying fish affect the toxicity of carcasses. We did this by allowing fish carcasses to decompose in the field for up to 31 days in the dunes of a sandy beach; an ecosystem where scavenging animals are common. Carcasses were sampled daily and the tissues tested for changes in culturable microbial communities using 100 μL samples of whole carcass homogenates on marine and sheep blood agar, and changes in cytotoxicity using Vero cell assays. Cytotoxicity peaked 11 days after deployment showing 95% rounded and detached cells. Cytotoxicity was lower in the early phases of decay as microbial communities developed and after approximately two weeks when carcasses dried. The peak in toxicity correlated with peaks in the abundance of 〈em〉Acinetobacter〈/em〉, and 〈em〉Vibrio〈/em〉 and 〈em〉Alivibrio〈/em〉; microbes known to produce toxins. This trajectory of toxicity suggests an ecological model where microbes may predictably determine the palatability of carrion in food webs, making both fresh and aged carcasses the least risky proposition for scavenging animals. This ‘fresh and aged carcasses are best’ model is highly amenable to testing in the context of carrion-centred food webs in multiple systems, and it has practical applications in conservation where animal carcasses are provided to threatened, and often iconic, scavenger species.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418310059-fx1.jpg" width="311" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Camille Le Guen, Samuele Tecchio, Jean-Claude Dauvin, Gwenola De Roton, Jérémy Lobry, Mario Lepage, Jocelyne Morin, Géraldine Lassalle, Aurore Raoux, Nathalie Niquil〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉During the last decades, the highly-anthropized Seine estuary has been impacted by modification of its habitats (building of a major extension of Le Havre harbour, i.e. Port2000) and a significant natural decrease in freshwater discharge. A Before/After analysis, using a toolbox of indicators, was applied to characterize the effects of both events on the estuarine ecosystem status. We selected from existing tool boxes several indicators derived from food web modelling or community composition data, such as biodiversity indicators, a guild-based index (〈em〉i.e.〈/em〉 Estuarine and Lagoon Fish Index ELFI) and ecological network analysis (ENA) indices. ENA and biodiversity indicators were applied on six spatial boxes describing the Seine estuary and its outlet. Results showed an increase in taxonomic and functional richness over time, mainly due to marinisation, and significant changes in food-web properties in relation to Port2000. ENA indices appeared as a promising method in ecological status assessment, especially for estuaries considered as inherently disturbed.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771419300484-fx1.jpg" width="253" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): A. Rosa, S. Cardeira, C. Pereira, M. Rosa, M. Madureira, F. Rita, J. Jacob, A. Cravo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the mass exchange patterns between coastal lagoons and ocean plays a key role to explain their impact upon the water quality and biological productivity of these systems. Ria Formosa is a temperate lagoon on the southwestern coast of Iberia, one of the most important coastal system in this region in terms of biological productivity, ecological and economic values. Given its relevance and strong interconnectivity with the adjoining ocean, the quantification of these exchanges is a key issue that had not yet been thoroughly addressed. In this context, this study is focused on understanding the role of Ria Formosa's main inlet in terms of mass budgets dynamics of water, nutrients, suspended solids and chlorophyll 〈em〉a〈/em〉 with the Atlantic Ocean and to identify its seasonal variability. In order to attain this purpose, the influence of the forcing mechanisms at different time scales, including tides, oceanographic/meteorological synoptic conditions and seasons, was assessed. To accomplish this, six semidiurnal tidal cycles surveys were conducted at Faro-Olhão inlet, comprising hourly water samples collection and 〈em〉in situ〈/em〉 measurements at a selected cross-section of the inlet channel. Results revealed that mass exchanges variability through Faro-Olhão inlet was mainly due to oceanographic processes (upwelling and coastal countercurrent events) and, secondly, to phytoplankton activity within the lagoon. Seasonally, regardless the direction of the residual current through the inlet, Ria Formosa acted as a source of material during Spring and Summer seasons, which contributed to increase the biological productivity of the coastal ocean. Upwelling events that occurred more evidently during the Autumn survey drove an import amount of nutrients into the lagoon, enhancing its biological productivity. Furthermore, the rainfall period that prevailed before the Winter survey contributed to export material and nutrients to the adjacent ocean, confirming that Ria Formosa fertilizes the coastal ocean, even during a period of low productivity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 14 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Luis G. Egea, Cristina Barrón, Rocío Jiménez–Ramos, Ignacio Hernández, Juan José Vergara, José Lucas Pérez–Lloréns, Fernando G. Brun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The knowledge of the production and carbon transference dynamics between adjacent communities is essential to gain a better understanding on the role of coastal areas in the global carbon cycle. Here, we assess the carbon metabolism (through dissolved oxygen –DO– concentration) and the net dissolved organic carbon (DOC) fluxes for benthic (dominated by the seagrass 〈em〉Cymodocea nodosa〈/em〉, the rhizophytic green algae 〈em〉Caulerpa prolifera〈/em〉 and unvegetated sediments) and pelagic plankton communities co〈em〉–〈/em〉habiting the same shallow coastal area in Cadiz Bay, southern Spain. Both the seagrass and macroalgae meadows were highly autotrophic, but the carbon metabolism of 〈em〉C. prolifera〈/em〉 community shifted seasonally from net autotrophic to net heterotrophic. Unvegetated benthic communities were slightly heterotrophic throughout the year, while plankton community was net autotrophic. This study reveals how the different components of the ecosystem (i.e. macrophyte, sediment or plankton community) may have a seasonal variability in the contribution to the NCP in shallow coastal areas. Moreover, our results suggest that pelagic communities can be essential to maintain autotrophy of coastal system during periods of low benthic productivity. Regarding DOC, benthic communities were net DOC producers, undergoing a marked seasonality with maximum net DOC production during summer. This indicated an extra carbon assimilation not usually contemplated in productivity studies, which entails an underestimation of gross production in these communities. A strong relationship between net DOC flux and net community production (NCP) was found for the three benthic communities. The plankton community was a net DOC consumer indicating a strong coupling between the benthic and pelagic compartments in the bay. When up〈em〉–〈/em〉scaling our results to the whole bay, the NCP estimated for the benthos was 8800 ± 3770 Tons C y〈sup〉−1〈/sup〉, and the net DOC flux was 2465 ± 830 Tons C y〈sup〉−1〈/sup〉, which were mainly due to vegetated communities, indicating the importance of coastal vegetated benthic ones in the carbon metabolism and DOC fluxes.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418304578-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 8 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): John W. Day, Gary P. Shaffer, Donald R. Cahoon, Ronald DeLaune〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Canals and spoil banks have contributed significantly to high rates of wetland loss in the Mississippi Delta. There has been relatively little research on management of canals and spoil banks and this needs to be a significant component of restoration of the delta. We analyze research on the role of backfilling canals in the context of delta restoration with special reference to Turner and McClenachan (2018) who state that if all canals were backfilled, it could significantly reduce or even reverse wetland loss and that most wetland loss is caused by canals. We agree with Turner and McClenachan that canals have been a significant cause of wetland loss in the Mississippi Delta and that removing spoil banks and backfilling canals should be an integral part of delta restoration. However, a number of factors need to be considered when choosing which canals to backfill including possible enhanced erosion due to exposure to wave action for newly created and remnant marsh, the current and future production history of oil and natural gas wells associated with canals, and other restoration activities in oil and gas fields. Turner and McClenachan's analysis using wetland loss patterns in 15-min quadrangles suggesting that canal density can explain most wetland loss in coastal Louisiana is flawed because of scale problems and other impacts of oil and gas activity. These impacts include subsurface induced subsidence and the impact of produced water and toxins on wetlands that are largely unrelated to surface alteration due to canals and spoil banks.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 6 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Rosalía Aguilar-Medrano, John R. Durand, Víctor H. Cruz-Escalona, Peter B. Moyle〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Estuarine fish assemblages are undergoing rapid change due to invasions of non-native species and physicochemical alteration of their habitats. Here, we examine the novel fish assemblages of the upper San Francisco Estuary (SFE) by first placing the fishes into ecological assemblages (EAs) of species that co-occur based on salinity, macrohabitat, and diet. We then used the morphological characteristics of each species to place them into functional groups (FGs) or potentially functionally independent species (FIS). Our question was: are there native and non-native species that occupy a similar niche in ecomorphological space, and thus potentially interact? Then, based on our results, we sought to understand if there is evidence that native species are being displaced by non-native species. The 43 species examined were placed into 17 EAs of potentially interacting species. Within these EAs, we identified 13 FGs and 13 FIS based on ecomorphology. Six FGs contain both native and non-native species indicating organization independent of the origin of the species. However, in most cases the native species were present in low abundance or were in categories of risk. Five FGs contained just non-native species that were found mainly in altered habitats and two FGs contained just native species. Overall, both native and non-native species appear to form a novel assemblage, although the decline of some native species in the face of potential competitors and predators suggests the final assemblage has not yet been determined. In addition, ongoing alterations of the SFE ecosystem increase the likelihood that invasions of new species will continue, causing further changes to the assemblage.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 5 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): H. Jimenez, A.L. Chang, G.M. Ruiz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Macrobenthos is used commonly in disturbance-related studies of coastal ecosystems, including those that evaluate invasions by non-native species (NIS), but still little is known about temporal variation in community characteristics, especially in bays and estuaries. In this study we investigated inter-annual changes in the soft-sediment benthic communities of San Francisco Bay over a period of five years, evaluating the contribution of NIS vs. native species to community attributes (species richness, abundance) and the efficacy of sampling (percent richness detected for each NIS and native species). Benthic macrofauna were collected, identified, and quantified from 10 stations (48–50 replicate samples) per year across the high salinity region of the Bay. A total of 36,872 individuals belonging to 126 morphospecies were collected; 61 species were native, accounting for 22% of total abundance, and 31 species were NIS, which reached 74% of total abundance. The other 34 species were either cryptogenic or unresolved taxa. Soft-sediment communities were mainly comprised of amphipods (〈em〉Ampelisca abdita〈/em〉, 〈em〉Sinocorophium heteroceratum〈/em〉, 〈em〉Monocorophium acherusicum〈/em〉), polychaetes (〈em〉Sabaco elongatus〈/em〉, 〈em〉Euchone limnicola〈/em〉) and bivalves (〈em〉Venerupis philippinarum〈/em〉). Community structure and composition were stable across years during the period of the study, despite a major marine heat wave and a record-breaking drought that raised average salinity levels for several years. The sampling was effective, especially for NIS, detecting a higher proportion (94–100%) of estimated richness for NIS compared to native species (74–89%) across the five year period, suggesting NIS were more evenly distributed in space and time and many native species occurred more patchily and less frequently.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418310485-fx1.jpg" width="492" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Changyou Wang, Rongguo Su, Laodong Guo, Bin Yang, Ying Zhang, Lei Zhang, Hui Xu, Wenjie Shi, Lansu Wei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nutrient pollution and algal blooms in coastal waters have long been a major concern, and understanding the response of algae to nutrient dynamics is thus essential. The minimum concentration under which 〈em〉Ulva prolifera〈/em〉 will not grow, estimated from a nutrient-alga coupling model developed in this study, was 6.5 μmol L〈sup〉−1〈/sup〉 for nitrate and 0.27 μmol L〈sup〉−1〈/sup〉 for phosphate. The model was parameterized with cultural experiments to examine the effects of nitrate and phosphate on the growth of 〈em〉Ulva prolifera〈/em〉 and the development of green tide. The cultural experiments showed that flux of nitrate absorbed by 〈em〉Ulva prolifera〈/em〉 increased significantly with the concentration of nitrate or phosphate, which followed the Michaelis-Menten equation, while the flux of phosphate linearly increased with its concentrations. Nitrate concentrations at 〉25 μmol L〈sup〉−1〈/sup〉 had little influence on the absorption of phosphate, but compensating absorption of phosphate occurred when the nitrate concentration was below 15 μmol L〈sup〉−1〈/sup〉. Phosphate concentrations had a remarkable enhancement to the absorption of nitrate when phosphate concentration was 〈1.4 μmol L〈sup〉−1〈/sup〉. The absorption rates of nitrate and phosphate by 〈em〉Ulva prolifera〈/em〉 followed the same variation trend as nutrient absorption fluxes. The increase in nitrate absorption rates has a limited impact on the relative growth rate of 〈em〉Ulva prolifera〈/em〉, while the increase in phosphate absorption rates has a marked impact on the relative growth rate. Our results provide new insights into the growth mechanism of 〈em〉Ulva prolifera〈/em〉 and the development and evolution of green tides in coastal marine environments. Applications of our model should help governmental agencies in environmental remediation and policy making.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 3 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Alethea S. Madgett, Kyari Yates, Lynda Webster, Craig McKenzie, Colin F. Moffat〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Scotland's marine food webs support a diversity of species and habitats. They contribute to maintaining the balance of the natural environment. Previous studies show that these ecosystems are contaminated by persistent organic pollutants and trace metals; with animals in higher trophic levels (e.g. cetaceans and pinnipeds) containing concentrations that are among the highest found in the ocean. Contaminants represent one of many pressures to which species and habitats are exposed. In assessing the contribution of contaminants to the overall pressure, measuring contaminants at a specific trophic level and then using trophic magnification factors (TMFs) to estimate concentrations at other trophic levels permits assessments across the food web, as well as allowing the adjustment of contaminant concentrations to a particular trophic level for comparison to assessment criteria. Fatty acid (FA) signatures and stable isotope (SI) ratios were used to develop a picture of Scottish marine food web ecology and reliably ascribe trophic levels to a wide range of species. Fatty acid trophic markers (FATMs) were used as trophic level indicators and with SI analysis, permitted identification of the mean trophic level of each species and determination of the feeding patterns and predator-prey relationships existing in the Scottish marine food web. Two hundred and eleven (211) samples comprising of seven fish species, one shark species, fourteen marine invertebrate species, three marine mammal species and two zooplankton species from different locations around Scotland were found to have mean trophic levels ranging from 1.47 ± 0.11 in zooplankton to 5.02 ± 0.35 in harbour seal. Fatty acid profile showed specific dietary information which differed between the eleven taxonomic classes and twenty-seven species. The organic and inorganic contaminant concentrations of the species for which trophic level has been determined, together with TMFs, will be reported in future papers.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771419300411-fx1.jpg" width="210" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 31 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 227〈/p〉 〈p〉Author(s): Martin Lykke Kristensen, David Righton, Diego del Villar-Guerra, Henrik Baktoft, Kim Aarestrup〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We tagged 125 sea trout kelts (460–925 mm) in seven Danish rivers with positively buoyant DSTs. Fifty-three (42%) tags were recovered, enabling a comparison of behaviour in kelts that survived the marine period and kelts that did not. Data revealed an estimated mean survival time at sea of 14.3 days (range 1–65 days) for fish that died at sea. Fish that did not survive had lower weight/length ratios when tagged than survivors (P = 0.005) but exhibited a similar diel diving pattern while at sea. Both surviving and non-surviving fish gradually increased diving activity and the daily visited maximum depths after sea entry, but some performed fewer dives and resided in shallower depths than others. This difference was pronounced when comparing surviving fish (most active divers) with fish caught by anglers (least active divers). The results show that the first weeks at sea are critical for kelt survival and that physical status of kelts may affect behaviour and probability of survival. The preference for shallower waters and less diving activity in some individuals indicate that coastally based fisheries and recreational angling may select against specific behavioural phenotypes which should be investigated more intensively.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771419301362-fx1.jpg" width="497" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 31 July 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Mochamad Furqon Azis Ismail, Joachim Ribbe〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Western boundary currents are characterized by high mesoscale eddy activity including that of cyclonic frontal eddies (CFEs). These form frequently adjacent to the shelf-break, export coastal water and affect biological productivity. Here, we study the physical properties of eddies identified within the intensification zone of the East Australian Current (EAC) through the analysis of remotely sensed data, the application of an ocean circulation model and the evaluation of Lagrangian simulations during austral winter 2007. We examine the spatial and temporal evolution of identified eddies, investigate their formation mechanism, and quantify the contribution made to cross-shelf exchanges. The mesoscale eddies are tracked from generation to decay using an eddy detection and tracking method. In this case study, we identify two CFEs referred to as C〈sub〉1〈/sub〉 and C〈sub〉2〈/sub〉 with lifetimes of 11 and 38 days and radii of 45 and 70 km, respectively, and one anticyclonic eddy (ACE) with a lifetime of 62 days and a radius of 60 km. Both CFEs interact with the ACE leading to quasi-stationary dipole-eddies located in the vicinity of the shelf. This is the first time dipole-eddies are reported for the intensification zone of the EAC. The location of CFEs characterised by negative sea surface height anomaly (SSHA) and clockwise rotation coincides with remotely-sensed sea surface temperature (SST) and chlorophyll-a (Chl-a) anomalies. CFEs C〈sub〉1〈/sub〉 and C〈sub〉2〈/sub〉 appear to contribute in different ways to the cross-shelf transport along the shelf-break. CFE C〈sub〉1〈/sub〉 drives a stronger onshore transport, while CFE C〈sub〉2〈/sub〉 appears to enhance the offshore transport. The estimated export of shelf water associated with CFE C〈sub〉2〈/sub〉 is estimated with about 1.23 Sv (∼106 km〈sup〉3〈/sup〉 day〈sup〉−1〈/sup〉). It renews the regional shelf water in about 7 days. The lifetime of CFE C〈sub〉2〈/sub〉 is about 38 days, thus the eddy had the potential to flush the shelf at least five times. The CFEs intensify the cross-shelf exchange that is due to the wind-driven cyclonic circulation of the Fraser Gyre. This seasonally occurring gyre dominates the local shelf during austral autumn and winter. The results from this study demonstrate the importance of CFEs in exporting cooler and Chl-a enriched shelf water into the warmer and oligotrophic waters of the southward-flowing EAC.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771419300307-fx1.jpg" width="293" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 19 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Alan L. Shanks〈/p〉

Description: 〈p〉Publication date: Available online 17 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Dan Baird, Harald Asmus, Ragnhild Asmus, Sabine Horn, Camille de la Vega〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉There is substantial evidence that climate warming affects terrestrial and marine ecosystems. In addition to the geographic shifts of marine species and communities, comprehensive mesocosm experiments provide insight in the behavior of species and simplified ecosystems under climate warming conditions. Food web dynamics and stability has been topical in contemporary ecology, and while these aspects receive considerable attention, few studies have quantitatively examined the impact of climate warming on complex marine ecosystems and their food webs. Here we examine the response of a large marine ecosystem, the Sylt-Rømø Bight in the northern German Wadden Sea, to warmer temperatures by means of ecological network analysis (ENA). Three quantitative network models (of 67 model compartments each) were constructed for each of 4 non-consecutive years (1995, 2007, 2011, 2013). A base-line model at the mean annual ambient temperature, and models at +3 °C and +5 °C above the annual mean were constructed for each year (a total of 12 models) and assessed by ENA protocols. Results showed i.a. an intensification of detrital production and consumption, substantial increase in the total system throughput (TSTP), decline in consumption of phytoplankton and macrophytes, an increase in the total overhead, an increase in community respiration, and an increase in the system's P/B and R/B ratios. The mean relative ascendency declined compared to the base models by 2.35% and 2.28% in the +3 °C and +5 °C networks models respectively. It is clear from the suite of system metrics and ratios that the ecosystem becomes less organized, more dissipative and shifts towards detritus based food webs at higher water temperatures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 16 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Jiaze Wang, Kehui Xu, Samuel J. Bentley, Crawford White, Xukai Zhang, Haoran Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The stratigraphic architecture of Plaquemines sub-delta lobe is identified from sedimentary cores and sub-bottom seismic data collected at Lower Breton Sound, Louisiana, USA. Four lithofacies are identified in cores from bottom to top: (1) organic-poor mud; (2) organic-poor silty sand; (3) massive mud; (4) organic-rich peat and root-rich soft mud. Overall, the lithofacies displays a typical progradational deltaic deposit at bottom with upward-coarsening feature, and then an upward-fining deposit overlying on top. Stratigraphic position of the organic-rich peat facies indicates that it is formed after the fluvial sediment source moves away from this region, and it is recognized as a termination of progradation of the Plaquemines sub-delta. Dated peat samples shows that sub-delta progradation stops between 876 and 1384 yr A.D., during which a 20–70 cm relative sea-level rise is detected. The geological framework reported in this study provides critical information for future modeling on river diversions. The stratigraphic architecture underlying Lower Breton Sound implicates that top three facies of root-rich soft mud, organic-rich peat and massive mud are likely to be eroded away before the development of new crevasse-splay or sub-delta, when sediment diversion is in operation. The deeper organic-poor silty sand lithofacies, however, can serve as a firm foundation to build new land.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 6 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): V. Venekey, T.P.G. Melo, J.S. Rosa-Filho〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the Amazonian coast seasonal changes of environmental characteristics are the main structuring factors of coastal benthic communities. Spatial and temporal variations in meiofauna and nematofauna were studied during rainy and dry seasons in the coastal zone of the Biological Reserve of Piratuba Lake (Bazil Amazonian coast). At each site (seven sites) five samples were taken in vegetated (inside the mangrove – 100 m from the border) and non-vegetated (outside of the mangrove – 100 m from the border) areas. Each sample was sliced in 0–2 cm, 2–5 cm and 5–10 cm deep layers. Water surface temperature and salinity were determined. Meiofauna was composed of 15 taxa: Nematoda, Copepoda, Ostracoda, Amphipoda, Cladocera, Isopoda, Acari, Polychaeta, Gastropoda, Turbellaria, Rotifera, Loricifera, Nemertea, Kinorhyncha, and Insect larvae. Nematoda (39 genera in 14 families) was the dominant group, accounting for 70% of the total individuals. 〈em〉Daptonema, Neochromadora, Hypodondolaimus〈/em〉, and 〈em〉Dichromadora〈/em〉 were dominant. Only salinity significantly changed between seasons and was significantly higher in the dry season. Meiofauna and nematofauna density and richness were lower than those in other mangroves worldwide. The significant changes in meiofauna and nematofauna between seasons and depths were related to higher salinity and food availability during the dry season and more food and oxygen available close to the surface (0–2 cm depth). Meiofauna did not show significant differences between vegetated and non-vegetated areas; however, higher density and richness were generally recorded in the vegetated areas, where food is more abundant, and the substrate is more stable. Non-selective deposit-feeding nematodes were dominant in all areas, seasons and depths. During the rainy season, the second most abundant feeding group was predators/omnivores as a response to an increase in organic detritus, whereas epigrowth feeders were the second most abundant group during dry season due to increased phytoplankton and phytobenthic production.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771417311873-fx1.jpg" width="364" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Karina Hartmann, Martin Stock〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Clay-rich salt marshes of mesotidal Wadden Sea coasts and of estuaries have been established mainly within artificial sedimentation fields in front of embankments. Natural salt marsh formation and natural range expansion outside artificial structures were rare. In the last three decades of this century natural marshes along the southern Wadden Sea coast of Schleswig-Holstein, Germany, started to grow outside groyne fields and extended on tidal mudflats. This growth happened without direct human influence and naturally structured marshes of considerable spatial dimension evolved.〈/p〉 〈p〉Due to a spread in recent decades, natural grown marshes in our study area – southern Schleswig-Holstein Wadden Sea coast - are younger than man-made marshes. Vegetation developed rapidly in response to fine-scaled geomorphological conditions. Meandering creeks and different surface elevation ranges of the developing natural salt marsh are special features. The naturally grown marshes show a high proportion of pioneer vegetation with 〈em〉Spartina anglica〈/em〉 and 〈em〉Salicornia europaea〈/em〉. Succession proceeds fast and elevated parts of the marsh were rapidly colonised with marsh vegetation of 〈em〉Puccinellia maritima〈/em〉 and 〈em〉Aster tripolium〈/em〉 in the lower marsh to late successional stages, like 〈em〉Halimione portulacoides〈/em〉 and 〈em〉Elymus athericus〈/em〉, on the higher elevated parts. Strikingly, median elevations of the vegetation zones in the natural marsh were several centimetres lower than those of the man-made marsh. The largest difference between both marsh types was the characteristic and the extent of drainage systems. Naturally grown marshes have a natural developed, fine-branched and four times shorter drainage system than man-made marshes with a dense drainage structure.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 13 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Troy A. Rogers, Anthony J. Fowler, Michael A. Steer, Bronwyn M. Gillanders〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Connectivity during the ontogenetic development of fishes identifies the spatial scale over which populations function, and the appropriate scale for conservation and management. For many marine species, spawning grounds and nursery areas are spatially segregated and larval dispersal is an obligate process that connects life history stages. This study investigated the spatial scale of early life history for one such species, the King George whiting (〈em〉Sillaginodes punctatus〈/em〉; Perciformes), through the retrospective analysis of otolith microstructure and elemental chemistry of recently-settled larvae. The aim was to determine whether the South Australian population constitutes a single panmictic stock, or if it comprises multiple sub-populations. Sizes (15.1–25.1 mm SL), ages (85–183 d) and hatch dates (24-Apr to 1-Aug) of larvae varied considerably between nursery areas at different spatial scales. Regional differences in multi-elemental otolith signatures indicated that multiple spawning grounds contribute to recruitment, and larvae that settled in each region dispersed through different water masses. Within each region, there were differences in hatch dates and otolith chemistry indicative of finer-scale relationships between particular spawning grounds and nursery areas, consistent with local oceanographic circulation patterns. Although multi-elemental signatures were year-specific, concentrations of Ba and Mn were largely responsible for spatial differences and assigned larvae to regional groups with 52–66% accuracy. The results suggest the State-wide stock is replenished by three putative source populations, and provide an example of how otolith chemistry can discriminate among geographically-close, yet-ecologically separated groups of fish in coastal marine ecosystems.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771419305062-fx1.jpg" width="497" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 12 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): H.E. Woo, T.V. Tran, I.C. Lee, J.O. Kim, Tadashi Hibino, Hideaki Nohara, K.H. Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Widespread pollutants from wastewater are serious threats to the ecosystem and aquatic environments in harbor areas. However, very few methods are available for the remediation of contaminated sediments. Herein we examine an 〈em〉in-situ〈/em〉 method using a new material, known as slaked lime–fly ash–cement mixture (SFCM), that removes phosphate and hydrogen sulfide from contaminated sediments. For this purpose, we analyze the effects of SFCM based on mesocosm experiments. After the application of SFCM, the hydrogen sulfide concentration significantly decreased from 130 to nearly 0 mg L〈sup〉−1〈/sup〉 and remained at this level for nearly six months. The phosphate concentration in the sediment decreased to its lowest level at 5 mg L〈sup〉−1〈/sup〉 and decreased for the remainder of the experimental period. These results demonstrate the successful removal of phosphate and hydrogen sulfide by applying SFCM. Results also showed that the pH remained between 8 and 8.2 after experimentation, which is similar to seawater pH. Based on these results, we conclude that SFCM is an effective material to mitigate contaminated coastal sediment in harbor areas.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 12 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Qingqiang Ren, Weiwei Xian, Chunlong Liu, Wenlong Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Identifying drivers of coastal nektonic invertebrate community structure requires detailed analyses of species assemblage composition and environmental variables. We analyze biological and environmental data collected over five spring seasons from 2013 to 2017 from waters in and adjacent to the Yangtze Estuary. Of 31 species, crustaceans were dominant in abundance and biomass. Abundance and biomass had different spatial distribution characteristics among years. The Taiwan Warm Current, low in dissolved oxygen (DO) and high in temperature (T), encroached into the East China Sea from Taiwan Strait, contributing to hypoxic conditions and warm waters. Yangtze River flows contributed to low estuarine salinity (S). Canonical correlation analysis (CCA) and analysis of similarities (ANOSIM) identified that nektonic invertebrate community structure fluctuated among five years and had significant spatial variation, of which communities of 2013, 2014 and 2015 differed significantly from all other years and no significant difference was apparent between that of 2016 and 2017, and two distinct assemblages were stratified by depth (D). Nekton abundance and biomass were highest in 2014, and varied significantly over time. D, DO, T and S were key factors structuring the nektonic invertebrate community. D significantly affected the spatial distribution of communities, while T significantly affected temporal variation. Hypoxic zones were associated with low abundance and biomass, indicating DO also strongly influenced community structure and species growth.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 8 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Annelore bezzi, Giulia Casagrande, Davide Martinucci, Simone Pillon, Carlo Del Grande, Giorgio Fontolan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Barriers and spits connected to fluvial sedimentary sources represent environments which tend to evolve rapidly and experience sudden transformations, mainly driven by changes in sediment supply and path. As a consequence, the variability of facies is significant even within small sedimentary records. The 7 km long barrier-spit system facing the Goro Lagoon, and fed by the mouth of the Po di Goro, is a typical example of an accretionary coastal morphotype, suitable to describe contiguous nearshore depositional environments and their stratigraphic signatures, variability, and relationships. Thirteen short cores of sediment were sampled in order to represent the variable depositional sub-environments from the shoreface (prodelta-delta front) to the back barrier, crossing the active barrier-spit and the ancient spit arms and relative swales. The description of the modern sedimentary records, improved upon using core X-rays, has been coupled with information on the morphological changes which occurred during the period of maximum spit development (1955–2000), based on available aerial photos and a cartographic/topographic dataset. The results obtained allow for the description and interpretation of the depositional environments changing at the human-scale. Sediments of the upper shoreface are quite uniform, composed by evenly laminated sands; the transition between delta front and prodelta at a depth of 6 m is marked by the alternation of sand and mud beds. These reflect the periodic changes in sediment supply by the river, as well as storm events. The most recent spit branch and the relative back barrier-swale environment are the result of the rapid progradation of the spit system, which implies phases of rapid longshore growth, hooked spit development, cannibalization, overwash, and breaching. Morphodynamic changes have resulted in an overlap of short sedimentary records where stratigraphic signatures are linked either to phases of sediment transport and selection by waves and tidal currents (cross-bedding, foreset and planar laminated sands, shell imbrication, massive beds) or to phases of sedimentary stasis when biological activity is predominant (algal mat and bioturbation). Human signature is also well marked inside the stratigraphic record. Clam harvesting is carried out within the lagoon causing the physical disturbance and winnowing of the superficial sediment, thus inducing the local formation of graded beds and shell rehash.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 7 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Nasreen Peer, Nelson AF. Miranda, Renzo Perissinotto〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Microphytobenthos (MPB) are important primary producers in mangroves, where they are an important source of food for fiddler crabs. The St Lucia mangroves are currently disconnected from the sea and thus considered a non-tidal mangrove ecosystem. Fiddler crabs occur close by, along with sympatric sesarmid crabs. This study examined the foraging effects of the fiddler crab 〈em〉Austruca occidentalis〈/em〉 on MPB biomass and composition. The effects of two dominant sesarmids, 〈em〉Chiromantes eulimene〈/em〉 and 〈em〉Neosarmatium africanum〈/em〉, on 〈em〉A. occidentalis〈/em〉 were also investigated as sesarmids are known to interfere with fiddler crab surface activities such as foraging and burrow maintenance.〈/p〉 〈p〉〈em〉In situ〈/em〉 experimental plots contained fiddler crabs at three different densities, combinations of fiddler crabs and sesarmids, and controls with no crabs. The biomass of three main microalgal groups were measured (i.e. diatoms, cyanobacteria and green algae) using a fluoroprobe and overall MPB biomass was measured using acetone extraction analysis.〈/p〉 〈p〉〈em〉Austruca occidentalis〈/em〉 affected cyanobacteria and diatoms, allowing green algae to increase in biomass during the experimental period. The presence of sesarmids was shown to affect cyanobacteria biomass more than either of the other two algal groups. Overall, MPB biomass was unaffected by fiddler crab density or sesarmid presence, suggesting that abiotic factors played a more important role in controlling biomass while biotic grazing and interference only affected microalgal group composition.〈/p〉 〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771419306006-fx1.jpg" width="367" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 7 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Dongxue Li, Zhiqiang Gao, Debin Song, Weitao Shang, Xiaopeng Jiang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Green tides in the Yellow Sea have occurred in large-scale blooms since 2007. Originating in the southern Yellow Sea and drifting northward continuously, these green tides have severely affected the coastal ecological environment. To analyze the influence of green tides on marine aquaculture in the Rongcheng coastal water (the northernmost sea area influenced by green tide), we used the Moderate Resolution Imaging Spectrometer (MODIS), GaoFen-1 (GF-1) satellite imagery and the sea surface wind (SSW) data. We also used field investigation to analyze the drift trajectory, drift speed, dissipation speed and distribution density of green tides. The results show that the main body of a green tide will drift northeast and continue in this direction after crossing the Rongcheng Chengshanjiao coastal water. Between 2013 and 2018, the drift speeds of green tides to the north of this area were within 1–5 km/d, the drift speed in the east-west direction was 0.3–4 km/d, and the interannual difference was not significant. The dissipation speed of the green tide in the Rongcheng Sea is generally within the range of 1–5 km〈sup〉2〈/sup〉/d and shows little interannual difference. The distribution density in the southern area of Rongcheng is the highest, ranging from 3% to 7%. The area with the highest frequency of influence is also the area with the greatest distribution density of green tides, and disasters are most severe here. A reasonable collection area is proposed, based on the above analysis. This research provides the basis for understanding the characteristics of green tides in the dissipation phase, and the prevention and control methods of green tide disasters in the Rongcheng coastal water.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 7 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Xia Hua, Huiming Huang, Yigang Wang, Yinyu Lan, Kun Zhao, Dake Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrodynamics and the estuarine turbidity maximum (ETM) were investigated along the Deepwater Navigation Channel (DNC) in the North Passage (NP) of the Changjiang River Estuary (CRE) during spring tides in March (dry season) and July (wet season) in 2016. The along-channel water current, salinity, and suspended sediment concentration (SSC) were measured and compared with a study undertaken in 2012. Results show that the magnitude of SSC in the dry season was significantly larger than that in the wet season in 2016, which was contrary to the results obtained in 2012 and the commonly held understanding that SSC is much higher in wet seasons than dry seasons in this region. Despite the abnormal magnitude of the SSC, the spatial distribution agreed with that of the 2012 observations, and corresponded to the salinity distribution. By analysing the bottom sediment flux and sediment transport over a flood-ebb tidal cycle, the immediate cause of the abnormal SSC magnitudes was found. In the dry season, the resuspension fluxes were more than doubled and tidal pumping terms were significantly larger than of those in the wet season, thus indicating that the resuspension effect was much stronger and able to bring more sediment into the water. Although the strong resuspension effect in the dry season was partly due to a slightly higher tidal dynamic, it was mainly due to the availability of sufficient sediment for resuspension, as induced by the strong cold-air front several days previous. On the contrary, the weak resuspension effect under a similar tidal dynamic in the wet season, was associated with insufficient sediment availability as a result of the limited influence of the typhoon in 2016. In addition, the quantity of sediments available for resuspension influenced the mobile suspension (MS) events of the ETM. Local resuspension and along-channel advection were both important in SSC variation processes and the effect of along-channel advection was more distinct when there was insufficient sediments for resuspension.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 6 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Inês Leal, Augusto A.V. Flores, Rachel Collin, Réjean Tremblay〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Settlement of most marine benthic invertebrates is intrinsically linked to the end of the pelagic life, but for a few, the transition to the benthos can be less well-defined. Early metamorphosed postlarvae of temperate and subtropical bivalves are known to delay final settlement, i.e., undergo secondary migrations, until detecting specific habitat cues. Here, we test the hypothesis that postlarval drifting occurs as well in tropical systems, being mediated by the nutritional quality of nearshore waters. We monitored early stages of the flat tree oyster 〈em〉Isognomon alatus〈/em〉 on the Caribbean coast of Panama, and observed successive numerical dominance of late-stage larvae (pediveligers) and postlarvae (juvenile drifters) of this isognomonid in the water column. Of all the pelagic individuals collected, 19% corresponded to juvenile drifters, suggesting that conditions favoring juvenile drifting were present at the time of sampling and/or juvenile drifting may be commonplace for this species. During 23 consecutive sampling days, we detected a single settlement peak of long-term drifters that followed a decrease in sea-surface salinity. The shell morphology of juveniles revealed that first settlement for 〈em〉I. alatus〈/em〉 takes place after theoretical competence, when prodissoconch II exceeds c. a. 300 μm. A shift in nearshore trophic conditions was detected after settlement, with particulate matter dominated by tracers of microalgae and vascular plant matter shifting to tracers for detritic matter and bacterial load. Essential fatty acids comprised 28% of the seston, yet, were minimally accumulated by 〈em〉I. alatus〈/em〉 pediveligers (2% of energetic reserves). We highlight the importance of accounting for juvenile drifters of 〈em〉I. alatus〈/em〉 on settlement estimates, as the spatial distribution of late larval stages and/or early settlers might not reflect their final distribution. This information is key to manage, exploit and/or conserve natural stocks.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771419305281-fx1.jpg" width="449" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Elisa Baldrighi, Jacques Grall, Nolwenn Quillien, Rita Carriço, Valentin Verdon, Daniela Zeppilli〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Open sandy beaches support key ecological functions and a distinctive biodiversity, but are threatened by an increasing anthropogenic pressure. Among these threats is the occurrence of green tides of 〈em〉Ulva〈/em〉 spp., expression of the eutrophication phenomenon. Our study aimed at determining the impact of green macroalgal accumulations on benthic meiofauna inhabiting two macrotidal sandy beaches of Brittany: Saint Nic (impacted) and Anse de Dinan (unimpacted). The presence of 〈em〉Ulva〈/em〉 enhanced total meiofaunal abundance and nematode functional diversity when compared to a state free from macroalgal mats. The stranded 〈em〉Ulva〈/em〉 supported high values of meiofaunal β-diversity as well. This unexpected response was likely due to the highly dynamic nature of open sandy beaches that prevents O〈sub〉2〈/sub〉 depletion within sediments. Natural seasonal changes in meiofaunal biomass and composition were also evident at both beaches and changes in environmental features, apart from eutrophication alone, do drive the variability in meiofaunal biomass and nematodes diversity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 2 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Tuyet T.N. Nguyen, Julien Némery, Nicolas Gratiot, Josette Garnier, Emilie Strady, Viet Q. Tran, An T. Nguyen, Thi N.T. Nguyen, Claire Golliet, Joanne Aimé〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Saigon River flows through one of the most rapidly growing megacities of Southeast Asia, Ho Chi Minh City (HCMC, 〉 8.4 million inhabitants). This tidal river is characterized by a tropical monsoon climate, alternating a wet and a dry season. In the last few decades, increased economic and urban developments of HCMC have led to harmful impacts on the water quality of this tidal river, with severe eutrophication events. This situation results from the conjunction of contrasting hydrological seasons and the lack of upgraded sanitation infrastructures: indeed, less than 10% of the domestic wastewater is collected and treated before being discharged directly into urban canals or rivers. This study focuses on P dynamics because this is considered the key nutrient factor controlling freshwater eutrophication. Based on field measurements and original laboratory experiments, we assessed the P levels in the river water and sediments, and investigated P adsorption/desorption capacity onto suspended sediment (SS) within the salinity gradient observed. Field surveys showed a clear impact of the HCMC megacity on the total P content in SS, which increased threefold at HCMC Center, as compared with the upstream values (0.3–0.8 gP kg〈sup〉−1〈/sup〉). Downstream, in the mixed estuarine area, the Total P was lower than 0.5 gP kg〈sup〉−1〈/sup〉. Laboratory experiments were carried out to characterize the influence of SS concentrations (SS = [0.25–0.9] g L〈sup〉−1〈/sup〉), salinity (S = [2.6–9.3]) and turbulence (G = [22–44] s〈sup〉−1〈/sup〉) on the sorption capacity of P onto sediment. The size of sediment particles and their propensity to flocculate were also originally measured with a recently developed instrument: the System for the Characterization of Aggregates and Flocs (SCAF®). Under the experimental conditions considered, SS concentrations had the greatest effect on the adsorption of P onto sediment, e.g., P adsorption capacity increased when SS concentrations rose. In contrast, salinity and turbulence had a smaller effect on the adsorption properties of sediments. Among these observed variables, the SS concentration was shown to be the main driver for adsorption capacity of P onto SS within the salinity gradient. We discuss the implication of these findings on understanding P dynamics within a highly urbanized, tropical estuary.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 217〈/p〉 〈p〉Author(s): Chao Chen, Jiaoqi Fu, Shuai Zhang, Xin Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As a dynamic belt between land and oceans, coastline provides rich information on land-ocean interactions. Sensitive to climate and anthropogenic influences, the changing coastline affects intertidal mudflat resources and the coastal environment. In this study, the greenness and wetness components of the tasseled cap transformation (TCT) were used to extract coastline information. Due to the high total suspended sediment content that leads to the failure of traditional method, sea-waterbody information extraction was initially carried out by TCT. After considering the characteristics of coastline in remote sensing images and coastline morphology in the natural world, the coastline with shorter length was eliminated and the intermittent coastline was connected based on the coordinate geometry description (such as length, distance, and direction). Finally, the results of the coastline information extraction were superimposed on the original images to evaluate accuracy. The experimental results indicated that the proposed method was more effective in clearly delineating the land-ocean boundary. The producer's accuracy and user's accuracy were 0.95 and 0.91, respectively, and the length extraction error was −2.16%. Therefore, the proposed method was more successful for coastline information extraction in the area with high sediment concentration.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 26 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): M.Siobhan Fennessy, Carles Ibáñez, Juan Calvo-Cubero, Peter Sharpe, Albert Rovira, John Callaway, Nuno Caiola〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Delta wetlands are increasingly recognized as important sinks for ‘blue carbon,’ although this and other ecosystem services that deltas provide are threatened by human activities. We investigated factors that affect sediment accretion using short term (3 years using marker horizons) and longer-term measures (∼50 year using 〈sup〉137〈/sup〉Cs soil core distribution and ∼100 year using 〈sup〉210〈/sup〉Pb distribution), the associated carbon accumulation rates, and resulting changes in surface elevation in the Ebro River Delta, Catalonia, Spain. Fifteen sites were selected, representing the geomorphological settings and range of salinities typical of the delta's wetlands. Sediment accretion rates as measured by 〈sup〉137〈/sup〉Cs distribution in soil cores ranged from 0.13 to 0.93 cm yr〈sup〉−1〈/sup〉. Surface elevations increased at all sites, from 0.10 to 2.13 cm yr〈sup〉−1〈/sup〉 with the greatest increases in natural impoundments with little connection to other surface waters. Carbon accumulation rates were highly spatially variable, ranging from 32 to 435 g C m〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉 with significantly higher rates at bay sites (p = 0.02) where hydrologic connectivity is high and sediment resuspension more intense. Sites with high connectivity had significantly higher rates of carbon accumulation (averaging 376 ± 50 g C m〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉) compared to sites with moderate or low connectivity. We also found high rates of carbon accumulation in brackish sites where connectivity was low and biomass production was characteristically higher than in saline sites. A stepwise regression model explained 81% of variability in carbon accumulation rates across all sites. Our data indicate deltaic wetlands can be important sinks for blue carbon, contributing to climate change mitigation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 May 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 220〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Gabriel Pereira Frota, Tatiana M.B. Cabrini, Ricardo S. Cardoso〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Sandy beaches are the most frequented coastal environments in the world, and they consequently suffer different types of impacts due to the rapid urban occupation and demographic growth in coastal regions, which generate stressful conditions for the resident species and reduce the environmental quality of the beaches for resident species. Crustaceans can be used as reliable bioindicators of human stress, and the amphipod 〈em〉Atlantorchestoidea brasiliensis〈/em〉 and the decapod 〈em〉Emerita brasiliensis〈/em〉 are highlighted. One tool for evaluating the environmental quality and the instability of individual development is fluctuating asymmetry (FA), which measures small, random deviations from a perfect bilateral symmetry. To evaluate the environmental quality of the beaches, some indices have been developed in recent years; among the most used are the conservation, recreation and urbanization indices, which offer easy-to-use metric for decision makers. This study aimed to quantify and compare the levels of FA in the populations of 〈em〉A. brasiliensis〈/em〉 and 〈em〉E. brasiliensis〈/em〉 on 14 beaches in Rio de Janeiro State with different levels of urbanization and conservation. For each species, two individual indices and two composite indices of asymmetry were calculated and tested in four bilateral traits. The urbanization, recreation and conservation indices were used to assess environmental quality of the sandy beaches. The results of the present study indicate a complex spatial distribution of FA in relation to the indices of the environmental quality of the beaches. The beaches that obtained the highest values in the conservation index obtained the lowest values of FA for both species. The beaches located in the Metropolitan region, specifically in the city of Rio de Janeiro, generally presented the highest levels of FA for both species. These species are susceptible to different forms of impacts due to their distinct characteristics in feeding behavior, development mode and beach zone occurrence. 〈em〉A. brasiliensis〈/em〉 is more susceptible to direct impacts on the beach, such as recreational activities, while 〈em〉E. brasiliensis〈/em〉 is more sensitive to impacts on water (contamination and physicochemical changes). Our results indicate that fluctuating asymmetry can be used as a good tool to evaluate impacts on sandy beaches, but additional studies should be conducted to improve the understanding of the spatial distribution of FA on sandy beaches.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418308035-fx1.jpg" width="270" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 29 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Chilwoo Lee, Sooncheol Hwang, Kideok Do, Sangyoung Son〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Unlike inundation from a tsunami, inundation originating from a tropical cyclone is rather complex since it is usually accompanied by torrential rain. Runoff in the vicinity of an estuarine outlet may thus incur additional inundation damage. In this study, a modeling system is proposed that considers the river discharge effect in addition to tides and surges to enhance the modeling accuracy of storm-induced inundation in coastal areas. The hydrodynamic model (Delft3D) and hydrological model (HEC-HMS) were coupled to account for all the flooding drivers, such as tides, storm surges, river discharges, and their interactions. In the coupled model, Delft3D was responsible for tidal and storm-induced surging motions, while HEC-HMS was used to calculate the river discharge at the downstream outlet of basins. Typhoon Maemi, which caused severe inundation damage to the Korean peninsula in 2003, was simulated by the model with a focus on the localized inundation process. The increase in inundation risk caused by river discharge was of particular interest and was assessed through a comparison of two different cases: Case ST (Storm-Tide) and Case STR (Storm-Tide-Riverine flow). The results clearly show that the case considering the rainfall-runoff process in the storm surge simulation outperforms that in which storm surge is not considered. A further detailed investigation of the inundation depth and coverage of both cases revealed several findings. The proposed model is expected to be of great aid in producing the flood hazard mapping with enhanced accuracy.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 26 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Justas Dainys, Eglė Jakubavičiūtė, Harry Gorfine, Žilvinas Pūtys, Tomas Virbickas, Darius Jakimavičius, Diana Šarauskienė, Diana Meilutytė-Lukauskienė, Arvydas Povilaitis, Arūnas Bukantis, Justas Kažys, Linas Ložys〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Climate change is likely to increasingly impact estuarine fish populations. Changes in water temperature or salinity can have deleterious effects on fish growth and behaviour. A decrease in the abundance of freshwater fish in the northern areas of the Curonian Lagoon has been attributed to increased salinity of inflowing water from the Baltic Sea. Thus, this study investigated the effects of possible changes in environmental salinity and temperature on the growth and behaviour of perch (〈em〉Perca fluviatilis〈/em〉 L.). Laboratory experiments revealed that brackish water (salinity 3 and 6) has neither a negative nor a positive effect on growth rates among perch young-of-the-year, when compared to freshwater (salinity 0). In contrast, results from behavioural experiments demonstrated that perch prefer to remain in brackish water (salinity 6) when given a choice between brackish and freshwater, and in warm water (18 °C) when given a choice between warm and cold water (12 °C). For this reason, the temperature rather than the salinity of inflowing colder brackish water from the Baltic Sea will be the most likely driver of short-term changes in fish distribution in the Curonian Lagoon.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Diane Espel, Noël J. Diepens, Olivier Boutron, Evelyne Buffan-Dubau, Yves Cherain, Eric Coulet, Patrick Grillas, Anne Probst, Jerome Silvestre, Arnaud Elger〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Seagrass decline due to a variety of stressors has been observed worldwide. In the shallow Vaccarès lagoon, Camargue, France, the dominant macrophyte species, 〈em〉Zostera noltei〈/em〉, has suffered two major declines since 1996. The first decline was well explained by salinity and turbidity variations, while the second one could not be explained by these parameters. Other stressors such as chemical contamination, eutrophication or temperature increase could be explanatory variables for this most recent decline. The aim of our study was to understand, 〈em〉via〈/em〉 scientific monitoring from 2011 to 2015, the influence of chemical contamination and its possible interactions with other biological and environmental pressures, on seagrass physiology and population dynamics in the Vaccarès lagoon.〈/p〉 〈p〉Multi-contamination by organic contaminants and trace metals was detected in the water and sediments, and their concentrations often exceeded environmental standards, particularly where seagrass regression was observed. Spatial variations in biological, environmental and chemical parameters in the lagoon were investigated by co-inertia analysis, which revealed significant relationships between environmental data, more particularly between contaminants, seagrass dynamics indices and biomarkers. Seagrass dynamics indices were negatively correlated with the concentrations of some herbicides in water (2,4-MCPA and bentazon) and with trace metals in sediments (arsenic). Rhizome starch contents in winter were negatively correlated with those herbicides and with several metals (arsenic, zinc, copper) in water and/or sediments. These results suggest that environmental contamination may play a role in seagrass decline. However, complementary investigations, such as monitoring over longer periods and additional toxicity tests, are required to address the causal link between contamination and seagrass decline.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Weiqing Meng, Rusty A. Feagin, Beibei Hu, Mengxuan He, Hongyuan Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Coastal wetland losses in China are globally-relevant issues, as formerly sequestered soil organic carbon is released as CO〈sub〉2〈/sub〉 into the atmosphere. Wetland losses also reduce the primary production by plants that would otherwise bury carbon in the future. More than 50% of these ecosystems have been lost globally over the last half century, with this number approaching 58% in China. The negotiation of international accords such as the Paris Climate Agreement rely on the accurate assessment of ecosystem-held carbon quantities. Our objective was to provide the first national scale survey of coastal wetland-based carbon in China. The average soil organic carbon stock (Mg SOC ha〈sup〉−1〈/sup〉) across all three types of ecosystems was 236.91, with an average of 344.67 for mangroves, 175.14 for seagrass, and 134.37 for salt marshes. The SOC stock was greatest at 30–60 cm of depth in the case of mangroves, as opposed to 0–20 cm of depth for salt marshes. In terms of the carbon content of the standing aboveground and belowground biomass (Mg C ha〈sup〉−1〈/sup〉), mangroves contained by far the most with an average of 253.98 and 83.96, respectively. Carbon burial rates, or the annual flux of SOC into the soil column (Mg C ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉), were 2.26 ± 0.39 for mangroves, 1.38 ± 0.38 for seagrass, and 2.18 ± 0.24 for salt marshes. Through our work, we found a total of 48.12–123.95 Tg of C in China's coastal wetlands (down to 1 m of soil column depth), with an annual burial of 0.84 Tg yr〈sup〉−1〈/sup〉. We estimate the average annual emissions of CO〈sub〉2〈/sub〉 to be on the order of 6.83 Tg CO〈sub〉2〈/sub〉 yr〈sup〉−1〈/sup〉, due to ongoing and extensive wetland loss and conversion.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 28 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Eva García-Seoane, Vítor Marques, Alexandra Silva, Maria Manuel Angélico〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study analyzed the spatial and temporal variation in the community composition of the pelagic species inhabiting the Atlantic Iberian waters using a multivariate approach. Trawl data (pelagic and bottom fishing) were collected during the spring acoustic surveys of pelagic fish from 1996 to 2015. There were significant effects of geographical area, periods, and type of trawls in terms of both, abundance and biomass. Sardine was typical throughout the study area whereas other species were typical of few areas, such as anchovy. The main difference between periods was the variation in typical pelagic species, diminishing the importance of sardine and increasing others, such as chub mackerel, bogue or anchovy. Depth also influenced the community structure with horse mackerel being principally responsible for sample similarity in bottom trawls. Surface temperature and salinity showed significant relationship with the taxa-derived multivariate data cloud but only explained between 5 and 7% of the total variability.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 27 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Edwin J. Bomer, Samuel J. Bentley, Frances Crawford, Joseph E.T. Hughes, Carol A. Wilson, Kehui Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉River-sediment diversions have been recognized as a key strategy for offsetting land loss in coastal Louisiana. Recently, much attention has been focused on sediment capture from the main stem river and conveyance of that material through diversion outflows. Yet, the performance and long-term feasibility of diversions as land-building agents also hinges upon the subsurface stratigraphic architecture of receiving basins, a concept that has largely been unexplored. A major core collection and analysis program was undertaken to study the geological properties of substrates in the Middle Barataria Bay and Middle Breton Sound diversion receiving basins, Louisiana, USA. Over a region of ∼200 square kilometers in both basins, 50 vibracores up to 5.5 m in length were collected in spring and summer of 2015. Cores were logged for bulk density and imaged with a Geotek Multi Sensor Core Logger. Split cores were then subsampled for granulometry, organic content, and 〈sup〉14〈/sup〉C dating. Both receiving basins are characterized by 1–2 m of organic-rich surficial strata, underlain by 〉 2 m of mineral-rich sand and silt beds that display a greater bulk density. Additionally, some cores contain deeper peaty strata intercalated within muds and sands. 〈sup〉14〈/sup〉C dates of these buried peats range between 1910 and 3203 calendar years before present demonstrating that relatively old deltaic strata exist at shallow depths. Age comparisons of stratigraphically-similar peat beds from this study and previous delta-lobe chronological models indicate that the St. Bernard lobe prograded eastward at a time-averaged rate of 75 m/yr. From a geotechnical standpoint, the surficial, uncompacted (〈2 m depth, average 1.15 g/cc bulk density) peaty strata in both basins are likely to erode and/or compact under the influence of diversion flows, but deeper consolidated mineral-rich strata (average 1.85 g/cc bulk density) are likely to be more resistant. Hydrodynamic models that predict the erosion associated with river-sediment diversion outflows in this region would benefit from incorporating a two-layer subsurface configuration, with a weaker, peat-like layer overlying a stronger, mineral-rich layer. The results of our study suggest that regions with an abundance of clastic strata at depth should be sought out when planning coastal restoration methods such as river-sediment diversions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 27 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): C.L. Osburn, J.N. Atar, T.J. Boyd, M.T. Montgomery〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Estuaries and coastal waters ultimately receive the terrestrial dissolved organic matter (DOM) exported from coastal watersheds, more directly during extreme precipitation events. Recent work suggests DOM's degradation in coastal waters varies with its quality, which also might vary as a function of precipitation, activating contributions from different sources within a watershed. The aim of this study was to determine the extent to which microbial degradation of terrestrial DOM in the Newport River Estuary, eastern North Carolina, was influenced by precipitation events occurring within the preceding seven days from sampling. We hypothesized that DOM stored in forested wetlands (〈em〉e.g.〈/em〉, pocosins and Cypress swamps) that become connected to the main channel of the Newport River during high precipitation events was more labile than DOM flowing into the estuary under low precipitation events. DOM quality was assessed with optical and stable C isotope (δ〈sup〉13〈/sup〉C) measurements, while DOM lability was assessed by measurements of bacterial production (BP) and mineralization of 〈sup〉14〈/sup〉C-labeled phenanthrene (Pmin), a polyaromatic tracer compound. Aromatic content of DOM, assessed by specific ultraviolet absorbance at 254 nm (SUVA〈sub〉254〈/sub〉) was highest in the river with values well over 5.0 L mg C〈sup〉−1〈/sup〉 m〈sup〉−1〈/sup〉, and decreased with salinity. Antecedent precipitation (AP) of at least 100 mm in the seven days prior to sampling resulted in dissolved organic carbon (DOC) concentrations 〉20 mg L〈sup〉−1〈/sup〉, at salinities 〈10. Similarly, fluorescence humification index (HIX) values were highest in the estuary after the highest AP. Generally depleted δ〈sup〉13〈/sup〉C-DOC values (−26 to −28‰) in the estuary up to a salinity of 30 indicated a substantial source of DOM likely originating from the forested swamps and tidal wetlands fringing the estuary. BP exhibited wide variability yet declined with salinity, while median values after higher AP (40 μg C L〈sup〉−1〈/sup〉 d〈sup〉−1〈/sup〉) were double that under lower AP. By contrast, aromatic mineralization (Pmin) rates increased as both DOC and CDOM concentrations, and SUVA〈sub〉254〈/sub〉 and HIX values, declined with salinity. However, Pmin rates were highest after the highest AP for the three events sampled. Results indicate that flooding of coastal wetlands mobilizes a large pool of labile DOM which have a large impact on the carbon cycle in estuaries. By altering the quality, as well as quantity of terrestrial organic matter inputs to estuarine systems, extreme events may also affect utilization of aromatic organics by estuarine microbial assemblages, an intriguing research question worthy of further study.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418306899-fx1.jpg" width="380" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 27 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Arnoldo Valle-Levinson, Carlos A.F. Schettini, Eliane C. Truccolo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Time series of current velocity profiles were obtained at the mouth and head of a Brazilian subtropical estuary, the Araranguá, to study its dry-period response to fortnightly tidal forcing, river pulses and wind forcing. The Araranguá exemplifies a series of river-dominated estuaries along southern Brazil with widths 〈200 m. A special feature of the Araranguá, as it is in dozens of subtropical estuaries in the world, is that depth increases landward. Its lower stretch runs parallel to a wind- and wave-dominated sandbar. Hydrographic data showed highly stratified mid and upper reaches, even during the dry period, and variable stratification in the lower reaches. Moored data were recorded at 7 and 30 km from the mouth during 70 days. Two pulses of moderate river discharge (〉30 m〈sup〉3〈/sup〉/s but 〈200 m〈sup〉3〈/sup〉/s) occurred during the observation span. The estuary responded to these pulses by enhancing estuarine exchange. Discharge 〉200 m〈sup〉3〈/sup〉/s appeared in two other occasions late in the observation period and caused seaward flushing of the entire system. Overall, the estuarine circulation resembled that of a fjord when river discharge was moderate and weaker: an active upper layer driven by river discharge moving over a semi-stagnant lower layer. Strongest subtidal exchange developed ∼2–3 days after neap tides, in contrast to other studies where fortnightly modulation is determined by vertical mixing from tides. In the lower estuary, subtidal flows seemed to result from a combination of vertical mixing, from tides and wind, and from tidal advection. Moreover, the lower estuary was much more sensitive to wind forcing than the upper estuary. The upper estuary responded preferentially to river discharge and tidal forcing.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 14 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): Alison C. Enchelmaier, Elizabeth A. Babcock, Neil Hammerschlag〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mangroves provide essential habitat for juvenile fish species. Restoration and monitoring are important conservation tools to ensure the recovery and maintenance of coastal mangrove habitats impacted by humans. In this study, Baited Remote Underwater Video Stations (BRVUS) were used to non-invasively examine the relative abundance and richness of fishes within restored mangrove pools in Biscayne Bay, Florida, 15 years after replanting. The potential influence of several environmental factors on fish abundance and richness within the restored mangrove pools was also evaluated. Limited seine sampling was also conducted to provide a comparison of the current fish assemblage with that of two prior surveys using seine nets. Twenty fish taxa were observed in the current study, consisting of five families, two genera, and thirteen species. Several environmental factors emerged as significant influences on the presence and abundance of different fish taxa, especially individual pools. A comparison of CPUE between current and prior seine studies found an increase in forage fish taxa and a shift from taxa that prefer a range of habitats to mangrove specific taxa, indicating an increased ecological function of these mangroves as fish habitat.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771417307473-fx1.jpg" width="499" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 217〈/p〉 〈p〉Author(s): Monica Montefalcone, Matteo Vacchi, Renata Archetti, Giandomenico Ardizzone, Patrick Astruch, Carlo Nike Bianchi, Sebastiano Calvo, Alessandro Criscoli, Yolanda Fernández-Torquemada, Filippo Luzzu, Gloria Misson, Carla Morri, Gérard Pergent, Agostino Tomasello, Marco Ferrari〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Marine coastal ecosystems are facing structural and functional changes due to the increasing human footprint worldwide, and the assessment of their long-term changes becomes particularly challenging. Measures of change can be done by comparing the observed ecosystem status to a purposely defined reference condition. In this paper, a geospatial modelling approach based on 2D mapping and morphodynamic data was used to predict the natural position of the upper limit (i.e., the landward continuous front) of 〈em〉Posidonia oceanica〈/em〉 seagrass meadows settled on soft bottom. This predictive model, formerly developed at the regional spatial scale, was here applied for the first time at the Mediterranean spatial scale in eight coastal areas of Spain, France, Italy, and Greece showing different coastal morphologies and hydrodynamic characteristics, and affected by a number of natural and/or human local disturbances. The model was effective in measuring the regression (i.e., seaward withdrawal) of the meadow upper limit. In all the meadows investigated the upper limit was regressed, laying deeper than the reference condition, with the proportion of regression ranging from 17.7% to 98.9%. The highest values of regression were found in Spain and in France, and were consistent with the highest levels of fragmentation detected with map analysis and of coastal pressures. This geospatial modelling approach represents an effective tool to define the reference conditions when proper pristine areas or historical data are not available, thus allowing the assessment of long-time changes experienced by seagrass ecosystems due to human impacts.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 217〈/p〉 〈p〉Author(s): Wenhong Pang, Zhijun Dai, Zhenpeng Ge, Shushi Li, Xuefei Mei, Jinghua Gu, Huang-Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cross-shore suspended sediment transport (SST) over meso-macro tidal beaches is of great importance to worldwide coastal erosion due to global sea-level rise. A continuous field experiment of about six tidal cycles measuring cross-shore SST near the seabed in different wave conditions was conducted over Yintan Beach, a meso-macro tidal beach to the north of Beibu Gulf, China. The surveyed data, including synchronous hydrodynamics and suspended sediment concentrations (SSC), were collected with three upward Acoustic Doppler Current Profilers (ADCPs), three Tide & Wave Recorders-2050 (RBRs) and three Optical Backscatter Sensors (OBSs). The results indicate that the SSCs in low and moderate wave heights were responsible for variations in cross-shore suspended sediment fluxes (SSF) at Yintan Beach. During moderate wave conditions, a greater average SSC of over 1.89 kg/m〈sup〉3〈/sup〉 and a longer flood tide duration occurred in rising tide compared with falling tide, accompanied by a maximum SSC of 2.67 kg/m〈sup〉3〈/sup〉 and offshore-directed flows due to cross-shore SST induced by tidal asymmetry. For the most landward measurement site at the surf zone, both net cross-shore SSF and maximum cross-shore SSF were larger than that in the offshore measurement sites over moderate wave conditions, which was ascribed to the strong offshore flows (undertow) induced by breaking waves and radiation stress 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈msub〉〈mrow〉〈mi〉S〈/mi〉〈/mrow〉〈mrow〉〈mi〉x〈/mi〉〈mi〉x〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 decay.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418302166-fx1.jpg" width="244" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Steven R. Booth, Kim Patten, Leslie New〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The response of estuarine invertebrates to the neonicotinoid insecticide imidacloprid following field applications in Willapa Bay, Washington (U.S.A.) was examined using Principal Response Curve (PRC) Analysis. A total of 60 analyses was conducted to examine responses of six taxonomic assemblages (polychaetes, non-juvenile polychaetes only, mollusks, non-juvenile mollusks only, crustaceans, and all invertebrates combined). Eight trials were conducted among five sites over the course of three years. Five of the eight featured a liquid formulation of imidacloprid and three a granular formulation. Both the response and treatment effects were significant (p 〈 0.05) among 49 of the analyses, but pre-treatment differences in the abundance and composition of the assemblages at test and control plots often confounded interpretation of results. In the majority of analyses, the response of the treated assemblage relative to the control assemblage remained relatively stable over time, indicating a neutral treatment effect. Only six of the 60 PRCs indicated a negative effect from imidacloprid application. Five of the six were assemblages of mollusks and one was an assemblage of crustaceans. Polychaetes were never negatively affected. The low frequency of a negative effect was likely due to imidacloprid exposures that were limited to low concentrations and short time periods, low toxicological susceptibility to imidacloprid for many taxa, and natural resilience to disturbance and extreme environmental events. The long-term use of imidacloprid to suppress burrowing shrimp in Willapa Bay would likely increase the diversity of benthic invertebrates.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771417311058-fx1.jpg" width="358" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Katharina Müller-Navarra, Yvonne Milker, Dorothea Bunzel, Sebastian Lindhorst, Jana Friedrich, Helge Arz, Gerhard Schmiedl〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Salt-marsh sediments of the southeastern North Sea provide an archive to unravel the influences of coastal management and natural processes such as storm-tide deposition on salt-marsh development. We present a record of salt-marsh evolution during the past century from the Bay of Tümlau (northwestern Germany) based on fossil foraminiferal assemblages and sedimentological data. After diking the hinterland of the Bay of Tümlau in 1935 CE and commencing marsh management, the environment at the study site changed from a tidal flat to a salt marsh. Salt-marsh sediment accretion is influenced by recurrent dredging events, as indicated by layers rich in calcareous tidal-flat foraminifera, and redeposition of siliciclastic particles from the surrounding tidal flats during storm tides. The latter fostered the establishment of a typical salt-marsh foraminiferal fauna dominated by the agglutinating species 〈em〉Entzia macrescens〈/em〉. Storm-tide layers have a lighter sediment color and commonly a more negatively skewed grain-size distribution with variable sorting. The observed long-term coarsening of the salt-marsh sediment likely reflects the landward progression of the vertical erosional cliff and the depletion of fine-grained sediment particles in the tidal flats under the influence of sea-level rise. Supra-tidal conditions, resulting from natural protection measures and abandonment of dredging, are indicated by the occurrence of 〈em〉Balticammina pseudomacrescens〈/em〉 around 2001 CE. This species is adapted to only occasional submergence during storm tides. The recent increase in elevation is accompanied by establishment of high-marsh vegetation and characterized by a present height of the marsh surface 50 cm above mean high water springs. During the past sixty years, average sediment accretion rates decreased from 18 to 11 mm yr〈sup〉−1〈/sup〉 reflecting the maturing of the salt marsh. These rates clearly outpace the recent mean sea-level rise in the southern North Sea demonstrating that the regional salt marshes are still resilient to sea-level rise.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Julia Donaton, Kimberly Durham, Robert Cerrato, Jenna Schwerzmann, Lesley H. Thorne〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Long-term studies of marine communities are critical to understanding shifts in marine ecosystems in response to ecological change. We examined the diet of stranded loggerhead sea turtles (〈em〉Caretta caretta〈/em〉) in New York waters between 1995 and 2014 using stomach content analysis, and quantified variability in loggerhead diet using Non-Metric Multidimensional Scaling (NMDS). Our results provide compelling evidence for a shift in the benthic community in New York waters associated with warming temperatures. We found two distinct clusters in loggerhead sea turtle diet, comprising samples in the years before and after 2000, respectively, indicating a temporal shift in prey composition after 2000. These patterns represented a shift from larger crab species such as rock crab (〈em〉Cancer irroratus〈/em〉) and spider crab (〈em〉Libinia〈/em〉 spp.) to smaller crab species such as hermit crabs (〈em〉Pagurus〈/em〉 spp.) in recent years. Sea surface temperature (SST) in New York waters increased during the 20-year study period, and changes in SST and the position of the Gulf Stream were the most important environmental variables explaining variability in loggerhead sea turtle diet. Our results reflect the importance of long-term data collection in evaluating ecological responses to climate-driven warming, and highlight the utility of marine vertebrates as indicators of changes to lower trophic level organisms.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): M.L. González-Regalado, P. Gómez, F. Ruiz, L.M. Cáceres, M.J. Clemente, J. Rodríguez Vidal, A. Toscano, G. Monge, M. Abad, T. Izquierdo, J.M. Campos, J. Bermejo, A. Martínez-Aguirre, M.I. Prudencio, M.I. Dias, R. Marques, J.M. Muñoz〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A multidisciplinary analysis of Holocene sediments from La Cascajera (Tinto-Odiel estuary, SW Spain) has allowed to differentiate five sedimentary facies (sandy tidal flat, clayey tidal flat, washover fan, salt marsh, edaphic horizon), according to their granulometric characteristics, internal structure, mineralogical composition, clay mineral assemblage and paleontological record. These data, coupled to 〈sup〉14〈/sup〉C AMS dating, suggest an evolution from a sandy tidal plain to a chenier before 2100 cal yr BP. This initial chenier was partially eroded later by regional storms between 2100 cal yr BP and 1900 cal yr BP, leading to the deposition of two washover fans. These facies have been eroded in the last centuries by the action of an ebb-tide channel.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418306085-fx1.jpg" width="139" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Luis Orlando, Leonardo Ortega, Omar Defeo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Sandy beaches comprise 31% of the ice free coasts of the world, providing a variety of ecosystem services essential to support human well-being, particularly protection against erosion and extreme climatic events. These highly dynamic environments are controlled principally by wave energy, tides and grain size, generating complex morphodynamic patterns that translate into strong area variation. Estimates of beach area and its variability are prime inputs for coastal management, a challenge that requires data representing a wide spatiotemporal scale. In this paper, a Landsat-based semi-automated methodology was developed to reconstruct the area of 21 sandy beaches of the Montevideo (Uruguay) coast from 1984 to 2016. This long-term information was also used to discern erosion-accretion cycles by means of wavelet analysis, and to explore the role of climatic forcing on these cycles through linear mixed models. A random forest classification algorithm was applied to Landsat images in order to estimate beach area. Long-term trends described a 27-year cycle with well-delimited quasi-decadal erosion and accretion phases related to climatic configurations. The beach area was negatively affected by an increase in sea level and climatic conditions of the previous year, being positively correlated with sea surface temperature anomalies and offshore winds (which favored accretion) and negatively correlated with onshore winds and intense El Niño Southern Oscillation (ENSO) events (favoring erosion). Our findings, together with the predicted increase in the occurrence and intensity of storms and extreme ENSO events, constitute a worrying scenario, as erosion in this populated coastal zone could have negative social, economic and ecological repercussions. The methodology developed here was useful to detect long-term changes in beach area and is entirely based on open-access information. Therefore, it is potentially applicable at any location on the planet. This approach is also useful to counteract the scarcity of long-term information that has precluded robust assessments of climate change effects on coastal zones.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Lydia L. Bach, Benjamin J. Saunders, Stephen J. Newman, Thomas H. Holmes, Euan S. Harvey〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fish communities are an important cultural, recreational and commercial resource that also have an important role in the functioning of marine ecosystems. Around the world fish assemblages are experiencing pressures from anthropogenic activities, and marine spatial planning is being established to mitigate these impacts and assist with biodiversity conservation. Information about how fish assemblages are structured across a range of spatial scales which encompass variations in physical, biotic and environmental parameters will assist marine spatial planning and management. We investigated differences in reef fish assemblage composition over three reef lines across an inshore to offshore gradient (3–23 m depth) at two marine reserves (70 km apart) in the Perth metropolitan region, Western Australia. There were significant increases in the number of individuals, species richness, and relative abundance of fish species across the shallow shelf depth gradient in the two locations. There were distinct fish assemblages associated with each reef line, correlated to depth and distance from shore. The differences across the shelf gradient, even over this small depth range, were greater than the differences between the two locations. These findings have implications for marine spatial management and the design of marine reserves that aim to conserve biodiversity. It may be most appropriate for such marine reserves to encompass a wide depth gradient, rather than a large longshore area. At the very least, cross and longshore patterns in fish assemblages should be taken into consideration and used to guide spatial management plans for biodiversity conservation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Xiaogang Chen, Jinlong Wang, Neven Cukrov, Jinzhou Du〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉As an important component of the hydrological and biogeochemical cycle, porewater discharge represents a significant pathway for releasing chemical solutes into coastal zones, particularly in highly permeable aquifers. In this study, a 〈sup〉222〈/sup〉Rn advection-diffusion model was used to estimate the porewater discharge in a coastal aquifer (Shengsi Island, East China Sea) during November 2015. Porewater discharge was estimated to range from 7.4 to 25.8 (mean: 12.9 ± 5.8) cm d〈sup〉−1〈/sup〉. Furthermore, the estimated porewater-derived nutrient fluxes (dissolved inorganic nitrogen (DIN), phosphorus (DIP) and silicon (DSi)) (mol m〈sup〉−2〈/sup〉 d〈sup〉−1〈/sup〉) were (1.7 ± 1.4) × 10〈sup〉−2〈/sup〉, (2.1 ± 1.1) × 10〈sup〉−4〈/sup〉 and (1.5 ± 1.3) × 10〈sup〉−2〈/sup〉, respectively. The Si/N ratio of coastal seawater at Shengsi Island was ∼0.83, which is close to that of porewater along the coastal aquifers of Shengsi Island (∼0.92) but higher than that of the Yangtze River Estuary (∼0.68). Thus, porewater-derived Si flux with a higher Si/N ratio may mitigate the outbreak of non-siliceous algae (i.e., 〈em〉Prorocentrum dentatum〈/em〉) in adjacent waters of Shengsi Island. By comparing the SGD-derived nutrient fluxes worldwide, this study suggests that Si flux with a higher Si/N ratio through porewater discharge (or SGD) may strongly influence the Si budget and cycling because such porewater/SGD-derived Si can compensate for the dwindling Si flux from riverine sources due to human activity (i.e., dam construction, reservoirs). Our results are expected to increase our understanding of not only biogenic elements of cycling processes but also eco-environment processes such as the occurrences of harmful algal blooms alone river-influenced coasts.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418301690-fx1.jpg" width="274" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Leonardo Lopes Costa, Ilana Rosental Zalmon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Our objective was to compare the efficiency of indirect (burrow density, size, depth and occupation rate) and direct (emersion from burrows, tolerance distance from humans and number of foraging crabs) metrics of the ghost crab 〈em〉Ocypode quadrata〈/em〉 for urbanization impact assessments. We sampled six beaches during high and low tourism seasons along a gradient of human pressure: high impact (urbanized), medium impact (intermediate) and low impact (non-urbanized). We found that the urbanization index and temperature explained the burrow density and size regardless of the bias related to the burrow occupation rate (∼60%) and counting period (diurnal or nocturnal). Moreover, the number of nocturnal foraging crabs explained most (57%) of the dissimilarity among the beaches under different levels of human impact. Thus, the counting of foraging crabs at night was found to be a relevant metric for beach impact evaluation. We strongly recommend integrating the counting foraging crabs with traditional burrow measurements (burrow density and size) in impact assessments of sandy beaches.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418306279-fx1.jpg" width="401" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Sun-Yong Ha, In-Young Ahn, Hye-Won Moon, Bohyung Choi, Kyung-Hoon Shin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study reports isotopic evidence of a unique and highly efficient trophic structure based on a rarely reported benthic diatom species in a rapidly warming Antarctic fjord (Marian Cove; MC). Recent surveys of MC revealed a very conspicuous feature, an 〈em〉intense, persistent benthic diatom bloom (‘benthic diatom bush’) overgrowing a variety of common megabenthic fauna, primarily filter feeders〈/em〉 (bivalves, ascidians, and demosponges), which occurred widely at shallow depths. To ascertain if the benthic diatom bloom is consumed as a primary food source, δ〈sup〉13〈/sup〉C and δ〈sup〉15〈/sup〉N were analyzed in the associated filter feeders and other herbivores, as well as in the diatom bush and other potential food sources (microphytobenthos, sedimentary organic matter and macroalgae). The analysis showed that the δ〈sup〉13〈/sup〉C values of all filter feeders (−23.5 to −25.2‰) were very similar to those of the diatom bush (−23.1 to −23.6‰), strongly suggesting that these benthic diatoms are the principal diet of the associated filter feeders. The isotopic signatures of the other food sources were very close to those of the diatom bush, indicating that the organic matter had the same origin, namely benthic diatoms. Given its quality, quantity and availability, the diatom bush could be regarded as the primary food source. The benthic diatom bush was predominated by the chain-forming centric diatom 〈em〉Paralia〈/em〉 sp., which occurs in shallow coastal waters with a wide range of salinity in various geographic localities. Thus, the 〈em〉Paralia〈/em〉 sp. bloom in this rapidly warming fjord also indicates its potential utility as an indicator of climate-induced environmental changes. Additional isotopic analysis of other common fauna showed that the benthic food web in this fjord comprised up to four trophic levels of consumers, with starfish and isopods at the apex. Given that filter feeders comprise the largest trophic group in the cove and many other Antarctic coastal waters, the results of this study strongly suggest that benthic diatoms are of prime importance in supporting the benthic food web in MC, and possibly other nearshore Antarctic waters. Further studies on the mechanism underlying benthic diatom blooms and their relevance to climate-induced processes would provide better project future scenarios for rapidly warming fjord ecosystems.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Aline Ferreira Quadros, Inga Nordhaus, Hauke Reuter, Martin Zimmer〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding local patterns of species-specific litterfall can help predict spatial differences in the amount and quality of organic matter input to systems under different environmental conditions. However, little is known about the drivers of differences in litterfall production in mangroves. Here we combined data from leaf litterfall (LL) studies (n = 13) and floristic studies (n = 16) conducted in the mangroves of the Ajuruteua peninsula (North of Brazil), at sites composed mainly of 〈em〉Rhizophora mangle〈/em〉 and/or 〈em〉Avicennia germinans〈/em〉. We investigated the relationship between LL and vegetation parameters (height, diameter, basal area, density, and relative density) using partial least-squares regressions (PLS-R), building four models with different combinations of these parameters. Vegetation parameters explained 69–85% of the annual LL of 〈em〉A. germinans〈/em〉 and 50–66% of 〈em〉R. mangle〈/em〉. Relatively strong, univariate significant relationships were also found between basal area and 〈em〉A. germinans〈/em〉 LL (R〈sup〉2〈/sup〉 = 0.40), and between height and 〈em〉R. mangle〈/em〉 LL (R〈sup〉2〈/sup〉 = 0.41). Nonetheless, models with four to five predictors yielded better fits. To illustrate the applicability of our approach we used the PLS-R models to calculate the LL of simulated sites. This simulation indicated a clear increase in LL production along the transition from 〈em〉Avicennia〈/em〉- to 〈em〉Rhizophora〈/em〉-dominated mangroves. As the leaf litter of these species differ substantially in chemical composition and decomposability, such transition in species composition will likely affect nutrient dynamics in the region. Thus, we suggest reporting species-specific site characteristics along with LL in future studies to obtain more robust models to predict future LL production at sites of changing vegetation structure.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 25 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science〈/p〉 〈p〉Author(s): W. Gregory Hood〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tidal channels are structurally and functionally prominent features in tidal marshes, so their restoration is central to marsh restoration. Prominent design questions in tidal marsh restoration include: How many tidal channels can a restoration site support, and thus, how many dike breaches should be made to restore tidal inundation and tidal channels? How much total channel surface area will be supported by a restored marsh, and thus, how many fish, shrimp, or other organisms can be supported by restored channel habitat? These basic design questions can be addressed by landscape allometry, which describes the proportional relative rates of change in a system between two entities of particular interest—in the case of marsh restoration, between the amount of marsh area to be restored and a wide variety of measures of tidal channel network geometry. This paper briefly reviews the development of landscape allometry, insights that it provides into landforms and related ecological patterns, and its utility and application to marsh restoration planning, design and monitoring. Its practical application is illustrated in a conceptual restoration design that is the basis for a current restoration project.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771417302500-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Elvira de Eyto, Sean Kelly, Elizabeth Ryder, Mary Dillane, Lorraine Archer, Donncha O'Cathain, Sile Daly, Kieran Lyons, Biel Obrador, Jennifer Brentrup, Andreja Naumoski, Russell Poole, Frances E. Lucy, Eleanor Jennings〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Coastal lagoons are a dynamic habitat, with varying marine and freshwater inputs determining the presence and extent of stratification, and the physical and chemical environment of the epi- and hypolimnion. As a result, the biotic assemblages that thrive in such environments are a diverse mix of species, with wide ranges of tolerances. While annual succession and vertical distribution of phytoplankton assemblages in marine and freshwater ecosystems are well documented, few data are available which describe the spatial and temporal variability of phytoplankton in coastal lagoons, even though these are a protected habitat under the European Union's Habitat Directive. In this study, high frequency monitoring (HFM) of chlorophyll fluorescence (ChlF) using a vertical profiling sonde was used to describe the variation in algal biomass over six annual cycles and through the water column of Lough Furnace, a perennially stratified coastal lagoon on the west coast of Ireland. Spot sampling, and species enumeration of phytoplankton were used to confirm the patterns observed in the fluorescence data, which indicated a general pattern of increasing biomass starting in spring, and a deepening of the deep chlorophyll maximum (DCM) over the summer. Typical of a stratified system, the DCM was often situated below the surface mixed layer, in saline hypoxic water. The best predictors of daily maximum ChlF were the depth of the surface mixed layer and daily solar radiation. We conclude that HFM allows an unprecedented glimpse into the substantial variability and complexity of phytoplankton distributions, a key biotic variable.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0272771418307236-fx1.jpg" width="350" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Mariska Astrid Kusumaningtyas, Andreas A. Hutahaean, Helmut W. Fischer, Manuel Pérez-Mayo, Daniela Ransby, Tim C. Jennerjahn〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Mangrove ecosystems are an important natural carbon sink that accumulate and store large amounts of organic carbon (C〈sub〉org〈/sub〉), in particular in the sediment. However, the magnitude of carbon stocks and the rate of carbon accumulation (CAR) vary geographically due to a large variation of local factors. In order to better understand the blue carbon sink of mangrove ecosystems, we measured organic carbon stocks, sources and accumulation rates in three Indonesian mangrove ecosystems with different environmental settings and conditions; (i) a degraded estuarine mangrove forest in the Segara Anakan Lagoon (SAL), Central Java, (ii) an undegraded estuarine mangrove forest in Berau region, East Kalimantan, and (iii) a pristine marine mangrove forest on Kongsi Island, Thousand Islands, Jakarta. In general, C〈sub〉org〈/sub〉 stocks were higher in estuarine than in marine mangroves, although a large variation was observed among the estuarine mangroves. The mean total C〈sub〉org〈/sub〉 stock in Berau (615 ± 181 Mg C ha〈sup〉−1〈/sup〉) is twice as high as that in SAL (298 ± 181 Mg C ha〈sup〉−1〈/sup〉). However, the Segara Anakan Lagoon displayed large within-system variation with a much higher C〈sub〉org〈/sub〉 stock in the eastern (483 ± 124 Mg C ha〈sup〉−1〈/sup〉) than in the central lagoon (167 ± 36 Mg C ha〈sup〉−1〈/sup〉). The predominant accumulation of autochthonous mangrove organic matter likely contributed to the higher C〈sub〉org〈/sub〉 stocks in Berau and the eastern SAL. Interestingly, the CAR distribution pattern in SAL is opposite to that of its C〈sub〉org〈/sub〉 stocks. The central SAL that receives high sediment inputs from the hinterland has a much higher CAR than the eastern SAL (658 ± 311 g C m〈sup〉−2〈/sup〉 yr〈sup〉−1〈/sup〉 and 194 ± 46 g C m〈sup〉−2〈/sup〉 yr〈sup〉−1〈/sup〉, respectively), while Berau has one of the highest CAR (1722 ± 183 g C m〈sup〉−2〈/sup〉 yr〈sup〉−1〈/sup〉) ever measured. It appears that these large differences are driven by the environmental setting and conditions, mainly sediment dynamics and hydrodynamics, landform, and vegetation conditions. It is inferred that quantifying carbon accumulation in sediments is a useful tool in estimating the present-day carbon storage of mangrove ecosystems. This is a precondition for taking measures under REDD+ (Reducing Emissions from Deforestation and Forest Degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries) schemes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Carl Lamborg, Tracy Mincer, William Buchanan, Caroline Collins, Gretchen Swarr, Priya Ganguli, Kristen Whalen, Michael Bothner, Ivan Valiela〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Experimental plots in Great Sippewissett Marsh (Falmouth, MA USA) have been undergoing long-term (〉48 years) fertilization through the application of commercial sewage sludge-based fertilizer. The experimental treatment focuses on the effect of added nitrogen on the salt marsh plots, but also supplies mercury (Hg) and other metals. This experiment provides a unique opportunity to test hypotheses regarding the Hg-related response of coastal marine ecosystems to eutrophication as well as assess the efficacy of salt marshes as sinks for increased loadings of Hg to the coastal zone. Hg inventories in sediments of control plots were similar to loadings from atmospheric deposition and inventories in the fertilized plots closely reflected the estimated loadings of Hg contained in the added fertilizer. In both the control and fertilized plots, distribution of Hg appeared somewhat different than the history of loadings, implying some level of Hg mobility. The relative abundance of monomethylmercury (CH〈sub〉3〈/sub〉Hg〈sup〉+〈/sup〉) within the plots varied with the amount of fertilizer applied with the highest percentage of Hg as CH〈sub〉3〈/sub〉Hg〈sup〉+〈/sup〉 found in the control plots, and the lowest percentages of CH〈sub〉3〈/sub〉Hg〈sup〉+〈/sup〉 and S were measured in plots fertilized at the highest dose. The results from this marsh suggest that eutrophication indirectly lowers CH〈sub〉3〈/sub〉Hg〈sup〉+〈/sup〉 production in this particular ecosystem, but perhaps not as a result of the sequestration of Hg(II) with S.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Kabir Suara, Richard Brown, Hubert Chanson〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Small tide dominated estuaries are affected by both large scale flow structures manifested as oscillatory residual currents and small scale bed generated turbulence. The present understanding of the effects and relative contributions of these factors are inadequate due to limited systematic observations. A field study was conducted in a small sub-tropical estuary in which high frequency (50 Hz) turbulence data were recorded continuously for about 48 h. A triple decomposition technique was introduced to isolate the contributions of tides, slow fluctuations and ‘true’ turbulence in the flow field. A striking feature of the data set was the slow fluctuations which exhibited large velocity amplitudes up to 50% of the tidal amplitude under neap tide conditions. The skewness of the fast ‘true’ turbulence were within the range of −4 and +2. The analysis of the fast fluctuations revealed that variation in the turbulence characteristics are linked with the tidal velocity suggesting that the dispersion and mixing are dependent on some large scale flow properties. The results also indicated enhanced mixing associated with the slow fluctuation in the flow field. The results provided useful sets of information about the properties of slow and fast fluctuating components and their variations through tidal cycles in a micro-tidal estuary.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Bijeesh Kozhikkodan Veettil, Raymond D. Ward, Ngo Xuan Quang, Ngo Thi Thu Trang, Tran Hoai Giang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Vietnamese mangroves are among the most productive and biologically important ecosystems of the world; providing habitat/nursing grounds for commercial and non-commercial fish species, food, medicine, building materials/fuel for local communities, as well as carbon storage (blue carbon) and coastal protection from storm events. However, Vietnam's mangroves have been lost in recent decades (∼38%) or degraded, predominantly driven by herbicides during the Vietnam War and later by conversion to aquaculture and coastal development, although there has been a recent slowing of this degradation as a result of restoration and protection schemes. This review article discusses the principal factors which influence mangroves in Vietnam including climate and climate change, hydrology, soil and topography, and anthropogenic factors such as aquaculture expansion, illegal logging, damming, pollution), which requires special attention. We further discuss the important role that Vietnamese mangrove forests play an in the socio-economic development of the country, even though the exploitation and protection of mangrove forests in many provinces are often uncontrolled. We discuss successful management practices including co-management models for mangrove restoration, which have been a success in Vietnam. Conservation and rehabilitation process of mangrove forests by various national and international agencies are still on-going and the success of such activities is influenced by various socio-economic, political as well as environmental factors. Further challenges in effective mangrove management arise due to climate change, which accelerates high atmospheric CO2, increased air temperature, sea level rise, storminess, ocean currents and alterations in precipitation regime. Recent developments in remote sensing applications can be utilized to improve the mapping and monitoring the changes in mangrove ecosystems in Vietnam thereby improving the effective management of mangrove forests.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Estuarine, Coastal and Shelf Science, Volume 218〈/p〉 〈p〉Author(s): Lucia Fanini, Wanda Plaiti, Nafsika Papageorgiou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Scientists active on sandy beach research were involved in a two-step process to depict the current status, highlighting critical points as well as strengths related to education on sandy beaches performed outside the academic environment. Firstly, an online questionnaire was submitted to the participants at the VIII International Sandy Beaches Symposium. The results were discussed and integrated by experiences at personal and institutional levels brought together by participants at the Symposium during a plenary workshop. Results highlighted a group of researchers engaged in education and outreach activities, willing to establish a dialogue which included the targets of education activities. Scientific literacy was seen as a necessary background for such a dialogue, in which specific gaps related to knowledge about sandy beaches could be addressed and rectified. A long-term vision and the establishment of a continuous path rather than one-off actions (as those related to specific, time-limited projects) was also seen as much needed for the implementation of effective actions. Main constraints preventing researchers from carrying out education activities outside academia were clearly identified as (in order of relevance): lack of recognition in terms of publications; lack of recognition in the academic environment; and lack of time. Considering these outcomes, the ideal dimension to establish effective solutions was identified at the national level. As a first step to counteract the constraints found, it is proposed to: target the collection of publishable data, e.g. basic indicators of success of education and outreach activities; and the use of “outreach” as an additional pillar for personnel evaluation. The provision of literacy principles should finally be the backbone of long-term actions.〈/p〉〈/div〉 〈/div〉