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  • 1
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    Springer
    In:  In: Deep Oil Spills: Facts, Fate, and Effects. , ed. by Murawski, S. A., Ainsworth, C. H., Gilbert, S., Hollander, D. J., Paris, C. B., Schlüter, M. and Wetzel, D. L. Springer, Cham, Switzerland, pp. 139-154. ISBN 978-3-030-11604-0
    Publication Date: 2021-01-18
    Description: Deepwater spills pose a unique challenge for reliable predictions of oil transport and fate, since live oil spewing under very high hydrostatic pressure has characteristics remarkably distinct from oil spilling in shallow water. It is thus important to describe in detail the complex thermodynamic processes occurring in the near-field, meters above the wellhead, and the hydrodynamic processes in the far-field, up to kilometers away. However, these processes are typically modeled separately since they occur at different scales. Here we directly couple two oil prediction applications developed during the Deepwater Horizon blowout operating at different scales: the near-field Texas A&M Oilspill Calculator (TAMOC) and the far-field oil application of the Connectivity Modeling System (oil-CMS). To achieve this coupling, new oil-CMS modules were developed to read TAMOC output, which consists of the description of distinct oil droplet “types,” each of specific size and pseudo-component mixture that enters at a given mass flow rate, time, and position into the far field. These variables are transformed for use in the individual-based framework of CMS, where each droplet type fits into a droplet size distribution (DSD). Here we used 19 pseudo-components representing a large range of hydrocarbon compounds and their respective thermodynamic properties. Simulation results show that the dispersion pathway of the different droplet types varies significantly. Indeed, some droplet types remain suspended in the subsea over months, while others accumulate in the surface layers. In addition, the decay rate of oil pseudo-components significantly alters the dispersion, denoting the importance of more biodegradation and dissolution studies of chemically and naturally dispersed live oil at high pressure. This new modeling tool shows the potential for improved accuracy in predictions of oil partition in the water column and of advancing impact assessment and response during a deepwater spill.
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  • 2
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    In:  In: Deep Oil Spills: Facts, Fate, and Effects. , ed. by Murawski, S. A., Ainsworth, C. H., Gilbert, S., Hollander, D. J., Paris, C. B., Schlüter, M. and Wetzel, D. L. Springer, Cham, Switzerland, pp. 25-42. ISBN 978-3-030-11604-0
    Publication Date: 2021-01-18
    Description: Petroleum is one of the most complex naturally occurring organic mixtures. The physical and chemical properties of petroleum in a reservoir depend on its molecular composition and the reservoir conditions (temperature, pressure). The composition of petroleum varies greatly, ranging from the simplest gas (methane), condensates, conventional crude oil to heavy oil and oil sands bitumen with complex molecules having molecular weights in excess of 1000 daltons (Da). The distribution of petroleum constituents in a reservoir largely depends on source facies (original organic material buried), age (evolution of organisms), depositional environment (dysoxic versus anoxic), maturity of the source rock (kerogen) at time of expulsion, primary/secondary migration, and in-reservoir alteration such as biodegradation, gas washing, water washing, segregation, and/or mixing from different oil charges. These geochemical aspects define the physical characteristics of a petroleum in the reservoir, including its density and viscosity. When the petroleum is released from the reservoir through an oil exploration accident like in the case of the Deepwater Horizon event, several processes are affecting the physical and chemical properties of the petroleum from the well head into the deep sea. A better understanding of these properties is crucial for the development of near-field oil spill models, oil droplet and gas bubble calculations, and partitioning behavior of oil components in the water. Section 3.1 introduces general aspects of the origin of petroleum, the impact of geochemical processes on the composition of a petroleum, and some molecular compositional and physicochemical background information of the Macondo well oil. Section 3.2 gives an overview over experimental determination of all relevant physicochemical properties of petroleum, especially of petroleum under reservoir conditions. Based on the phase equilibrium modeling using equations of state (EOS), a number of these properties can be predicted which is presented in Sect. 3.3 along with a comparison to experimental data obtained with methods described in Sect. 3.2.
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  • 3
    Publication Date: 2021-01-08
    Description: Landslide is one of the dangerous types of natural hazards. This phenomenon causes damages in many countries every year. A detailed landslide hazard assessment is necessary to reduce these damages. This research aims to map the landslide susceptibility zoning (LSZ) using the fuzzy logic method and GIS in the Sorkhab basin as a part of the Zagros fold and thrust belt (FTB), northwestern Iran. All slide types were recorded in fieldwork as landslide inventory. Based on the results, four types, i.e., debris slide, earth slide, and rock fall and complex of landslides, was identified in the region. Then, the effect of each landslide contributing factor including topographical elevation heights, slope classes, aspect classes, geological units, proximity to faults, land covers, rainfall classes, and proximity to streams was constructed in GIS and subsequently normalized using fuzzy membership functions. Finally, by combining all standardized layers using the fuzzy gamma operator, a final map of LSZ was produced. The results showed that a 0.9 fuzzy gamma operator has a high accuracy for the LSZ map in the study area. Besides, the accuracy of the LSZ map revealed a strong relationship (R2) between susceptibility classes, and landslide inventory was calculated using a scatter plot equal to 0.79. Hence, the method represented an appropriate accuracy in predicting the landslide susceptibility in the study area.
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  • 4
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    In:  In: Volcanic Debris Avalanches. , ed. by Roverato, M., Dufresne, A. and Procter, J. Springer, Cham, pp. 255-279, 25 pp. ISBN 978-3-030-57411-6
    Publication Date: 2021-01-19
    Description: Landslide deposits offshore many volcanic islands provide evidence of catastrophic lateral collapses. These deposits span a larger volume range than their continental equivalents, and can generate devastating tsunamis. All historical volcanic-island lateral collapses have occurred in arc settings, and have been characterised by rapid failure and efficient tsunami generation. The varied morphology of their deposits is influenced both by lithological properties and the nature of the substrate. Many deposits show evidence of extensive seafloor erosion and transformation into debris flows, and the propagation of frontally-confined sediment deformation beyond and beneath the primary deposit. Mobilised volumes can far exceed that of the initial failure, and accurate deposit interpretation requires internal geophysical imaging and sampling. Around intraplate ocean-island volcanoes, multi-unit turbidites suggest that lateral collapses may occur in discrete stages; although this would reduce their overall tsunamigenic potential, the volumes of individual stages of collapse remain very large. Numerical models of both landslide and tsunami processes in ocean-island settings are difficult to test, and the smaller collapses that typify island arcs are an important focus of research due to their higher global frequency, availability of direct failure and tsunami observations, and a need to better understand the signals of incipient collapse to develop approaches for tsunami hazard mitigation.
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  • 5
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    In:  In: Pattern Recognition. ICPR International Workshops and Challenges. , ed. by Del Bimbo, A., Cucchiara, R., Sclaroff, S., Farinella, G. M., Mei, T., Bertini, M., Escalante, H. J. and Vezzani, R. Springer, Cham, pp. 398-413.
    Publication Date: 2021-08-02
    Description: Since the sunlight only penetrates a few hundred meters into the ocean, deep-diving robots have to bring their own light sources for imaging the deep sea, e.g., to inspect hydrothermal vent fields. Such co-moving light sources mounted not very far from a camera introduce uneven illumination and dynamic patterns on seafloor structures but also illuminate particles in the water column and create scattered light in the illuminated volume in front of the camera. In this scenario, a key challenge for forward-looking robots inspecting vertical structures in complex terrain is to identify free space (water) for navigation. At the same time, visual SLAM and 3D reconstruction algorithms should only map rigid structures, but not get distracted by apparent patterns in the water, which often resulted in very noisy maps or 3D models with many artefacts. Both challenges, free space detection, and clean mapping could benefit from pre-segmenting the images before maneuvering or 3D reconstruction. We derive a training scheme that exploits depth maps of a reconstructed 3D model of a black smoker field in 1400 m water depth, resulting in a carefully selected, ground-truthed data set of 1000 images. Using this set, we compare the advantages and drawbacks of a classical Markov Random Field-based segmentation solution (graph cut) and a deep learning-based scheme (U-Net) to finding free space in forward-looking cameras in the deep ocean.
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  • 6
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    In:  In: Pattern Recognition. ICPR International Workshops and Challenges. , ed. by Del Bimbo, A., Cucchiara, R., Sclaroff, S., Farinella, G. M., Mei, T., Bertini, M., Escalante, H. J. and Vezzani, R. Springer, Cham, pp. 375-389.
    Publication Date: 2021-08-03
    Description: Nowadays underwater vision systems are being widely applied in ocean research. However, the largest portion of the ocean - the deep sea - still remains mostly unexplored. Only relatively few image sets have been taken from the deep sea due to the physical limitations caused by technical challenges and enormous costs. Deep sea images are very different from the images taken in shallow waters and this area did not get much attention from the community. The shortage of deep sea images and the corresponding ground truth data for evaluation and training is becoming a bottleneck for the development of underwater computer vision methods. Thus, this paper presents a physical model-based image simulation solution, which uses an in-air texture and depth information as inputs, to generate underwater image sequences taken by robots in deep ocean scenarios. Different from shallow water conditions, artificial illumination plays a vital role in deep sea image formation as it strongly affects the scene appearance. Our radiometric image formation model considers both attenuation and scattering effects with co-moving spotlights in the dark. By detailed analysis and evaluation of the underwater image formation model, we propose a 3D lookup table structure in combination with a novel rendering strategy to improve simulation performance. This enables us to integrate an interactive deep sea robotic vision simulation in the Unmanned Underwater Vehicles simulator. To inspire further deep sea vision research by the community, we release the source code of our deep sea image converter to the public (https://www.geomar.de/en/omv-research/robotic-imaging-simulator).
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  • 7
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    In:  In: Pattern Recognition. ICPR International Workshops and Challenges. , ed. by Del Bimbo, A., Cucchiara, R., Sclaroff, S., Farinella, G. M., Mei, T., Bertini, M., Escalante, H. J. and Vezzani, R. Springer, Cham, pp. 390-397, 8 pp.
    Publication Date: 2021-03-08
    Description: In deep water conditions, vision systems mounted on underwater robotic platforms require artificial light sources to illuminate the scene. The particular lighting configurations significantly influence the quality of the captured underwater images and can make their analysis much harder or easier. Nowadays, classical monolithic Xenon flashes are gradually being replaced by more flexible setups of multiple powerful LEDs. However, this raises the question of how to arrange these light sources, given different types of seawater and-depending-on different flying altitudes of the capture platforms. Hence, this paper presents a rendering based coarse-to-fine approach to optimize recent multi-light setups for underwater vehicles. It uses physical underwater light transport models and target ocean and mission parameters to simulate the underwater images as would be observed by a camera system with particular lighting setups. This paper proposes to systematically vary certain design parameters such as each LED’s orientation and analyses the rendered image properties (such as illuminated image area and light uniformity) to find optimal light configurations. We report first results on a real, ongoing AUV light design process for deep sea mission conditions.
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  • 8
    Publication Date: 2021-02-23
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  • 9
    Publication Date: 2021-01-08
    Description: The COVID-19 pandemic necessitates a change in conference formats for 2020. This shift offers a unique opportunity to address long-standing inequities in access and issues of sustainability associated with traditional conference formats, through testing online platforms. However, moving online is not a panacea for all of these concerns, particularly those arising from uneven distribution of access to the Internet and other technology. With conferences and events being forced to move online, this is a critical juncture to examine how online formats can be used to best effect and to reduce the inequities of in-person meetings. In this article, we highlight that a thoughtful and equitable move to online formats could vastly strengthen the global socio-ecological research community and foster cohesive and effective collaborations, with ecology and society being the ultimate beneficiaries.
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  • 10
    Publication Date: 2021-01-08
    Description: The Bokanjac–Poličnik system, as a complex set of mutually interrelated Dinaric karst catchments and sub-catchments, is a highly vulnerable and limited groundwater source for the wider Zadar area in northern Dalmatia, Croatia. Based on hydrogeological, hydrochemical, and hydrological research, including the prediction of groundwater discharge by the end of the twenty-first century, a complex study was performed with the following main aims: (1) groundwater protection in the present state, (2) assessment of future groundwater protection, and (3) prediction of drinking water availability and quality under the predicted climate change conditions. Long-term prediction of changes in groundwater quantity, as well as investigations of trends in groundwater quality, will allow us to protect this essential natural resource with respect to possible negative trends. The results showed that a significant decrease in the quantity of available groundwater is possible and that extraction will have to be well planned because any decrease in the groundwater pressure in this area will cause a further decrease in quality, especially regarding the possibility of seawater intrusions into the aquifer. The results of this study were incorporated in sanitary protection zones.
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  • 11
    Publication Date: 2021-01-08
    Description: We examined small-scale distribution and feeding ecology of a non-native fish species, round goby (Neogobius melanostomus (Pallas, 1814)), in different habitats of a coastal lagoon situated in the south-western Baltic Sea. First observations of round goby in this lagoon were reported in 2011, 3 years before the current study was conducted, and information on this species’ basic ecology in different habitats is limited. We found that mainly juvenile round gobies are non-randomly distributed between habitats and that abundances potentially correlate positively with vegetation density and thus structural complexity of the environment. Abundances were highest in shallower, more densely vegetated habitats indicating that these areas might act as a refuge for small round gobies by possibly offering decreased predation risk and better feeding resources. Round goby diet composition was distinct for several length classes suggesting an ontogenetic diet shift concerning crustacean prey taxa between small (≤ 50 mm total length, feeding mainly on zooplankton) and medium individuals (51–100 mm, feeding mainly on benthic crustaceans) and another diet shift of increasing molluscivory with increasing body size across all length classes. Differences in round goby diet between habitats within the smallest length class might potentially be related to prey availability in the environment, which would point to an opportunistic feeding strategy. Here, we offer new insights into the basic ecology of round goby in littoral habitats, providing a better understanding of the ecological role of this invasive species in its non-native range, which might help to assess potential consequences for native fauna and ecosystems.
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  • 12
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    In:  In: Ecosystem collapse and climate change. , ed. by Canadell, J. G. and Jackson, R. B. Ecological studies, 241 . Springer, Cham, pp. 345-364, 20 pp. ISBN 978-3-030-71330-0
    Publication Date: 2021-07-29
    Description: Seagrass meadows deliver important ecosystem services such as nutrient cycling, enhanced biodiversity, and contribution to climate change mitigation and adaption through carbon sequestration and coastal protection. Seagrasses, however, are facing the impacts of ocean warming and marine heatwaves, which are altering their ecological structure and function. Shifts in species composition, mass mortality events, and loss of ecosystem complexity after sudden extreme climate events are increasingly common, weakening the ecosystem services they provide. In the west coast of Australia, Shark Bay holds between 0.7 and 2.4% of global seagrass extent (〉4300 km2), but in the austral summer of 2010/2011, the Ningaloo El Niño marine heatwave resulted in the collapse of ~1300 km2 of seagrass ecosystem extent. The loss of the seagrass canopy resulted in the erosion and the likely remineralization of ancient carbon stocks into 2–4 Tg CO2-eq over 6 years following seagrass loss, increasing emissions from land-use change in Australia by 4–8% per annum. Seagrass collapse at Shark Bay also impacted marine food webs, including dugongs, dolphins, cormorants, fish communities, and invertebrates. With increasing recurrence and intensity of marine heatwaves, seagrass resilience is being compromised, underlining the need to implement conservation strategies. Such strategies must precede irreversible climate change-driven tipping points in ecosystem functioning and collapse and result from synchronized efforts involving science, policy, and stakeholders. Management should aim to maintain or enhance the resilience of seagrasses, and using propagation material from heatwave-resistant meadows to restore impacted regions arises as a challenging but promising solution against climate change threats. Although scientific evidence points to severe impacts of extreme climate events on seagrass ecosystems, the occurrence of seagrass assemblages across the planet and the capacity of humans to modify the environment sheds some light on the capability of seagrasses to adapt to changing ecological niches.
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  • 13
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    In:  International Journal of Earth Sciences, 110 . pp. 1879-1881.
    Publication Date: 2021-09-23
    Description: Summary of Ilse Seibold's vita Ilse Seibold, née Usbeck, was born May 8, 1925 in Breslau, Silesia, and went to school in Halle/Saale during WW2. She started her studies of geology and paleontology at the University of Halle and at the Humboldt University in Berlin, and later at the University of Tübingen, where she received her doctorate as micropaleontologist in 1951 with Otto Schindewolf as her supervisor. She remained active as productive scientist over many decades. In 1952, she married Dr. Eugen Seibold, who in 1958 became professor at Kiel University, founded one of Europe's most important institutes for marine geology, and later became president of the German Science Foundation (DFG), and subsequently of the European Science Foundation (ESF). Being a scientist herself Ilse Seibold soon evolved to a deeply reflective insider of geological sciences. She followed her husband during his scientific career from his appointments in Tübingen, Bonn, Karlsruhe, Kiel, to Bonn and Strasbourg/Freiburg i.Br. She accompanied Eugen on his sabbatical leave at Scripps Institution of Oceanography in La Jolla, CA. She participated in countless international scientific meetings. Together with Eugen she published many papers that document her independence and autonomy as scientist. She gained deep insights into the origins of the geosciences and their historical evolution, up to the ideas of fine arts. We are happy that she documented in her publications a broad range of her scientific and distinguished-humane impressions.
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  • 14
    Publication Date: 2022-01-19
    Description: Global population projections foresee the biggest increase to occur in Africa with most of the available uncultivated land to ensure food security remaining on the continent. Simultaneously, greenhouse gas emissions are expected to rise due to ongoing land use change, industrialisation, and transport amongst other reasons with Africa becoming a major emitter of greenhouse gases globally. However, distinct knowledge on greenhouse gas emissions sources and sinks as well as their variability remains largely unknown caused by its vast size and diversity and an according lack of observations across the continent. Thus, an environmental research infrastructure—as being setup in other regions—is more needed than ever. Here, we present the results of a design study that developed a blueprint for establishing such an environmental research infrastructure in Africa. The blueprint comprises an inventory of already existing observations, the spatial disaggregation of locations that will enable to reduce the uncertainty in climate forcing’s in Africa and globally as well as an overall estimated cost for such an endeavour of about 550 M€ over the next 30 years. We further highlight the importance of the development of an e-infrastructure, the necessity for capacity development and the inclusion of all stakeholders to ensure African ownership.
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  • 15
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    In:  In: World Atlas of Submarine Gas Hydrates in Continental Margins. , ed. by Mienert, J., Berndt, C. 〈https://orcid.org/0000-0001-5055-0180〉, Tréhu, A. M., Camerlenghi, A. and Liu, C. S. Springer, Cham, pp. 451-461.
    Publication Date: 2022-01-06
    Description: The Black Sea has undergone several limnic and marine stages due to fluctuations in the global sea level. The exchange of saline water from the Mediterranean Sea to the Black Sea through the Bosporus Strait was interrupted when the sea level dropped below the Bosporus sill. This induced limnic conditions, while marine conditions were established after the reconnection to saline Mediterranean seawater. Extended river fan systems developed during sea level low-stands, providing large amounts of organic material being buried by rapid sedimentation on the slopes of the Black Sea margins. The biogenic degradation of this material produces most of the methane gas expelled into the anoxic water column today. This largely happens by ubiquitous cold vents at ~700 m water depth (i.e. at the stability boundary of methane hydrates) and by mud volcanoes in ~2000 m water depth. A significant amount of gas is expected to accumulate in the sediment within the methane hydrate stability zone. However, bottom-simulating reflectors, the seismic indicator for gas hydrates, are not found everywhere along the margin. Recent analyses of the Danube and Dniepr fans have revealed a discontinuous gas hydrate formation in an area with no active seeps, while areas of active seepage located in the vicinity of BSR reflections held no gas hydrates. In addition, the ongoing diffusion of salt into the uppermost Black Sea sediment pore space since the last glacial maximum further reduces the volume of the gas hydrate stability zone. Estimates of the total amount of gas stored in gas hydrates therefore require a detailed structural analysis prior to regional- or basin-scale modelling attempts.
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  • 16
    Publication Date: 2022-01-07
    Description: It is a good method to utilize the grain size distribution curves and cumulative frequency curves of marine or river sediments to estimate the hydrodynamic conditions, transportation processes and sedimentary environment. However, researchers can only rely on Excel or Grapher to plot the curves one by one at the present day. The manual plotting procedures are complicated, and calculating the truncation points is time-consuming. To solve the aforementioned problems, we have developed a software tool to plot cumulative frequency curves and calculate the values of truncation points automatically. The software has the ability to plot curves of hundreds of samples accurately and rapidly, promoting researchers to analyze transport mechanisms and hydrodynamic environments. And it is convenient to apply the software to compare the processes of transportation and deposition between different samples.
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  • 17
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    In:  In: World Atlas of Submarine Gas Hydrates in Continental Margins. , ed. by Mienert, J., Berndt, C. 〈https://orcid.org/0000-0001-5055-0180〉, Tréhu, A. M., Camerlenghi, A. and Liu, C. S. Springer, Cham, pp. 73-85.
    Publication Date: 2022-01-20
    Description: Marine electromagnetic methods provide useful and independent measures for the identification and quantification of submarine gas hydrates. The resistivity of seafloor sediments, drawn from area-wide electromagnetic data, mainly depends on the sediment porosity and the nature of the pore fluid. Gas hydrates and free gas are both electrically resistive. The replacement of saline water, thus conductive pore water with resistive gas hydrate or free gas, increases the sediment resistivity and can be used to provide accurate saturation estimates if the background lithology is known. While seismic methods are predominantly used to study the distribution of submarine gas hydrates, a growing number of global field studies have demonstrated that the joint interpretation of marine seismic and electromagnetic methods improves the evaluation of submarine gas hydrate targets. This article discusses the relationship between resistivity and free gas/gas hydrate saturation levels, how the resistivity of the sediment may be measured and summarizes the status and results of current and past field studies.
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  • 18
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    In:  Human-Environment Interactions
    Publication Date: 2022-03-21
    Type: info:eu-repo/semantics/book
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  • 19
    Publication Date: 2022-04-07
    Description: In times of accelerating climate change, species are challenged to respond to rapidly shifting environmental settings. Yet, faunal distribution and composition are still scarcely known for remote and little explored seas, where observations are limited in number and mostly refer to local scales. Here, we present the first comprehensive study on Eurasian-Arctic macrobenthos that aims to unravel the relative influence of distinct spatial scales and environmental factors in determining their large-scale distribution and composition patterns. To consider the spatial structure of benthic distribution patterns in response to environmental forcing, we applied Moran’s eigenvector mapping (MEM) on a large dataset of 341 samples from the Barents, Kara and Laptev Seas taken between 1991 and 2014, with a total of 403 macrobenthic taxa (species or genera) that were present in ≥ 10 samples. MEM analysis revealed three spatial scales describing patterns within or beyond single seas (broad: ≥ 400 km, meso: 100–400 km, and small: ≤ 100 km). Each scale is associated with a characteristic benthic fauna and environmental drivers (broad: apparent oxygen utilization and phosphate, meso: distance-to-shoreline and temperature, small: organic carbon flux and distance-to-shoreline). Our results suggest that different environmental factors determine the variation of Eurasian-Arctic benthic community composition within the spatial scales considered and highlight the importance of considering the diverse spatial structure of species communities in marine ecosystems. This multiple-scale approach facilitates an enhanced understanding of the impact of climate-driven environmental changes that is necessary for developing appropriate management strategies for the conservation and sustainable utilization of Arctic marine systems.
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  • 20
    Publication Date: 2022-04-29
    Description: Every year, vast quantities of plastic debris arrive at the ocean surface. Nevertheless, our understanding of plastic movements is largely incomplete and many of the processes involved with the horizontal and vertical displacement of plastics in the ocean are still basically unknown. In this chapter we review the dynamics associated with the transport of plastics and other pollutants at oceanic fronts. Fronts had been historically defined as simple barriers to exchange, but here we show that the role of these structures in influencing the transport of plastics is more complex. The tools used to investigate the occurrence of frontal structures at various spatial scales are reviewed in detail, with a particular focus on their potential applications to the study of plastic pollution. Three selected case studies are presented to better describe the role of fronts in favoring or preventing plastic exchanges: the large-scale Antarctic Circumpolar Current, a Mediterranean mesoscale front, and the submesoscale fronts in the Gulf of Mexico. Lastly, some aspects related to the vertical subduction of plastic particles at oceanic fronts are discussed as one of the most promising frontiers for future research. The accumulation of floating debris at the sea surface is mainly affected by the horizontal components of frontal dynamics. At the same time, vertical components can be relevant for the export of neutrally buoyant particles from the surface into the deep sea. Based on these evidences, we propose that submesoscale processes can provide a fast and efficient route of plastic transport within the mixed layer, while mesoscale instabilities and associated vertical velocities might be the dominant mechanism to penetrate the deeper ocean on slower but broader scales. We conclude that given the ubiquitous presence of fronts in the world’s ocean, their contribution to the global plastic cycle is probably not negligible and the role of these processes in vertically displacing neutrally buoyant microplastics should be investigated in more detail.
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  • 21
    Publication Date: 2022-05-20
    Description: The Barents Sea, located close to the Arctic Ocean, is a petroleum province featuring an extensive occurrence of gas hydrates and shallow gas in compacted sediments. Glacial erosion and uplift have contributed to the migration of gas originating from deeper rocks to the shallow sediments of this region, resulting in hydrates with higher-order hydrocarbons in addition to methane. This article documents reported gas hydrate indications and major controls on hydrate stability in the Barents Sea.
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  • 22
    Publication Date: 2022-05-25
    Description: Since global navigation satellite systems (GNSS) for determining the absolute geolocation do not reach into the ocean, underwater robots typically obtain a GNSS position at the water surface and then use a combination of different sensors for estimating their pose while diving, including inertial navigation, acoustic doppler velocity logs, ultra short baseline localization systems and pressure sensors. When re-navigating to the same seafloor location after several days, months or years, e.g. for coastal monitoring, the absolute uncertainty of such systems can be in the range of meters for shallow water, and tens of meters for deeper waters in practice. To enable absolute relocalization in marine data science applications that require absolute seafloor positions in the range of centimeter precision, in this contribution we suggest to equip the monitoring area with visual markers that can be detected reliably even in case they are partially overgrown or partially buried by sediment, which can happen quickly in coastal waters. Inspired by patterns successful in camera calibration, we create robust markers that exhibit features at different scales, in order to allow detection, identification and pose estimation from different cameras and various altitudes as visibility (and therefore the maximum possible survey altitude) in coastal waters can vary significantly across seasons, tides and weather. The low frequency content of the marker resembles a human-readable digit, in order to allow easy identification by scientists. We present early results including promising initial tests in coastal waters.
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  • 23
    Publication Date: 2022-06-02
    Description: While offshore groundwater has been utilized by coastal communities as far back as 1000 BC, only in the past 10 years has the global volume of fresh-to-brackish water hosted in offshore aquifers been truly appreciated. There are vast quantities (~300–500 × 103 km3) of offshore freshened groundwater sequestered in continental shelf sediments under water depths of less than 60 m within 110 km of the coastline. New marine geophysical methods now make it possible to map and quantify low salinity offshore groundwater bodies. To date, these offshore resources have not been developed. Offshore freshened groundwater could be produced if wells are located close to the shoreline and coastal desalination plants.
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  • 24
    Publication Date: 2022-07-11
    Description: Underwater images are challenging for correspondence search algorithms, which are traditionally designed based on images captured in air and under uniform illumination. In water however, medium interactions have a much higher impact on the light propagation. Absorption and scattering cause wavelength- and distance-dependent color distortion, blurring and contrast reductions. For deeper or turbid waters, artificial illumination is required that usually moves rigidly with the camera and thus increases the appearance differences of the same seafloor spot in different images. Correspondence search, e.g. using image features, is however a core task in underwater visual navigation employed in seafloor surveys and is also required for 3D reconstruction, image retrieval and object detection. For underwater images, it has to be robust against the challenging imaging conditions to avoid decreased accuracy or even failure of computer vision algorithms. However, explicitly taking underwater nuisances into account during the feature extraction and matching process is challenging. On the other hand, learned feature extraction models achieved high performance in many in-air problems in recent years. Hence we investigate, how such a learned robust feature model, D2Net, can be applied to the underwater environment and particularly look into the issue of cross domain transfer learning as a strategy to deal with the lack of annotated underwater training data.
    Type: Book chapter , NonPeerReviewed
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  • 25
    Publication Date: 2022-08-08
    Description: Fish food is an inevitable item in human consumption with healthy sourceof good quality proteins and fat. Aqua industry can help to improve food security,livelihoods for the poorest and to meet the world’s food demands. But producingmore seafood that is at affordable cost with rich nutrition is challenging for aquaindustry. Many factors affect the productivity of aqua industry; one such an impor-tant constraint is bacterial diseases. Hence, Aqua industry, a booming businesssector, immensely requires continued research with scientific and technical devel-opments, and innovations. Study of bacterialfish disease is one such thrust areawhich requires intense research to understand the causes and control bacterialdiseases infish. The appearance and development of afish disease is the result ofthe interaction among pathogen, host and environment. An insight into bacterialfishdiseases, clinical symptoms and treatment may help to manage the bacterial diseasesand so can make aqua industry a more profitablefield. This chapter deals withdifferent aspects of the most threatening bacterial diseases, occurring in farmedfishes and also in wildfishes, which are results infish loss and economic lossworldwide. A wide range of gram positive and gram-negative bacteria causingbacterial diseases, clinical symptoms, diagnosis, treatment, vaccines and the natureof water habitat are also discussed in this chapter.
    Type: Book chapter , NonPeerReviewed
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  • 26
    Publication Date: 2022-08-12
    Description: The Digital Earth project aimed for the integration of data science and Earth science. Here, we reflect on the main lessons learned that include the need for interdisciplinary collaboration, thinking out of the box, the concept of ‘thinking in workflows’ and models for the sustainable implementation of scientific software, data infrastructure and policies.
    Type: Book chapter , NonPeerReviewed
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  • 27
    Publication Date: 2022-08-12
    Description: Digital Earth is a project funded by the German Helmholtz Association with all centers of the research field Earth and Environment involved. The main goal of the Digital Earth project is to develop and bundle data science methods in extendable and maintainable scientific workflows that enable natural scientists in collaboration with data scientists to achieve a deeper understanding of the Earth system. This has been achieved by developing solutions for data analysis and exploration with visual and computational approaches with data obtained in a SMART monitoring approach and modeling studies, accompanied by a continuous evaluation of the collaboration processes. In this chapter, the history, setup, and focus of the Digital Earth project are described.
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  • 28
    Publication Date: 2022-08-17
    Description: The Digital Earth project aims at a strong interrelation between Data and Earth Science and a step-change in implementing data science methods within Earth science research. During the project, the progress of interdisciplinary collaboration and adoption of data science methods has been measured and assessed with the goal to trace the success of the project. This chapter provides the set-up of this evaluation and the results from two online questionnaires that were held after the start and before the end of the project.
    Type: Book chapter , NonPeerReviewed
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  • 29
    Publication Date: 2022-08-17
    Description: Diversity within marine microbiomes spans the three domains of life: microbial eukaryotes (i.e., protists), bacteria, and archaea. Although protists were the first microbes observed by microscopy, it took the advent of molecular techniques to begin to resolve their complex and reticulate evolutionary history. Symbioses between microbial entities have been key in this journey, and such interactions continue to shape the ecology of marine microbiomes. Nowadays, photosynthetic marine protists are appreciated for their activities as primary producers, rivalling land plant contributions in the global carbon cycle. Predatory protists are known for consuming prokaryotes and other protists, with some combining metabolisms into a mixotrophic lifestyle. Still, much must be learned about specific interactions and lifestyles, especially for uncultured groups recognized just by environmental sequences. With respect to the fate of protists in food webs, there are many paths to consider. Despite being in early stages of identifying interactions, whether mutualistic or death-inducing infections by parasites and viruses, knowledge is advancing rapidly via methods for interrogation in nature without culturing. Here, we review marine protists, their evolutionary histories, diversity, ecological roles, and lifestyles in all layers of the ocean, with reference to how views have shifted over time through extensive investigation.
    Type: Book chapter , PeerReviewed
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  • 30
    Publication Date: 2022-09-26
    Type: Article , NonPeerReviewed
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  • 31
    Publication Date: 2022-11-01
    Type: Article , NonPeerReviewed
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  • 32
    Publication Date: 2022-12-09
    Description: Data-driven science has turned into a fourth fundamental paradigm of performing research. Earth System Science, following a holistic approach in unraveling the complex network of processes and interactions shaping system Earth, particularly profits from embracing data-driven approaches next to observation and modeling. At the end, increasing digitalization of Earth sciences will lead to cultural transformation towards a Digital Earth Culture.
    Type: Book chapter , NonPeerReviewed
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  • 33
    Publication Date: 2022-12-19
    Description: A comprehensive study of the Earth system and its related processes requires a holistic examination and understanding of multidimensional data acquired with a large number of different sensors or produced by various models. To this end, the Digital Earth project developed a set of software solutions to study environmental data sets using visual approaches. In the following chapter, we present three data visualization products developed to deal with the challenges of the analysis and exploration of environmental data.
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  • 34
    Publication Date: 2022-12-19
    Description: Reliable data are the base of all scientific analyses, interpretations and conclusions. Evaluating data in a smart way speeds up the process of interpretation and conclusion and highlights where, when and how additionally acquired data in the field will support knowledge gain. An extended SMART monitoring concept is introduced which includes SMART sensors, DataFlows, MetaData and Sampling approaches and tools. In the course of the Digital Earth project, the meaning of SMART monitoring has significantly evolved. It stands for a combination of hard- and software tools enhancing the traditional monitoring approach where a SMART monitoring DataFlow is processed and analyzed sequentially on the way from the sensor to a repository into an integrated analysis approach. The measured values itself, its metadata, and the status of the sensor, and additional auxiliary data can be made available in real time and analyzed to enhance the sensor output concerning accuracy and precision. Although several parts of the four tools are known, technically feasible and sometimes applied in Earth science studies, there is a large discrepancy between knowledge and our derived ambitions and what is feasible and commonly done in the reality and in the field.
    Type: Book chapter , NonPeerReviewed
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