Description: Optical imaging is a common technique in ocean research. Diving robots, towed cameras, drop-cameras and TV-guided sampling gear: all produce image data of the underwater environment. Technological advances like 4K cameras, autonomous robots, high-capacity batteries and LED lighting now allow systematic optical monitoring at large spatial scale and shorter time but with increased data volume and velocity. Volume and velocity are further increased by growing fleets and emerging swarms of autonomous vehicles creating big data sets in parallel. This generates a need for automated data processing to harvest maximum information. Systematic data analysis benefits from calibrated, geo-referenced data with clear metadata description, particularly for machine vision and machine learning. Hence, the expensive data acquisition must be documented, data should be curated as soon as possible, backed up and made publicly available. Here, we present a workflow towards sustainable marine image analysis. We describe guidelines for data acquisition, curation and management and apply it to the use case of a multi-terabyte deep-sea data set acquired by an autonomous underwater vehicle.

Description: Ecological impact of global change is generated by multiple synchronous or asynchronous drivers which interact with each other and with intraspecific variability of sensitivities. In three near-natural experiments, we explored response correlations of full-sibling germling families of the seaweed Fucus vesiculosus towards four global change drivers: elevated CO2 (ocean acidification, OA), ocean warming (OW), combined OA and warming (OAW), nutrient enrichment and hypoxic upwelling. Among families, performance responses to OA and OW as well as to OAW and nutrient enrichment correlated positively whereas performance responses to OAW and hypoxia anti-correlated. This indicates (i) that families robust to one of the three drivers (OA, OW, nutrients) will also not suffer from the two other shifts, and vice versa and (ii) families benefitting from OAW will more easily succumb to hypoxia. Our results may imply that selection under either OA, OW or eutrophication would enhance performance under the other two drivers but simultaneously render the population more susceptible to hypoxia. We conclude that intraspecific response correlations have a high potential to boost or hinder adaptation to multifactorial global change scenarios.

Description: Sharing and secondary analysis of data have become increasingly important for research. Especially in geography, the collection of digital data has grown due to technological changes. Responsible handling and proper documentation of research data have therefore become essential for funders, publishers and higher education institutions. To achieve this goal, universities offer support and training in research data management. This article presents the experiences of a pilot workshop in research data management, especially for geographers. A discipline-specific approach to research data management training is recommended. The focus of this approach increases researchers’ interest and allows for more specific guidance. The instructors identified problems and challenges of research data management for geographers. In regards to training, the communication of benefits and reaching the target groups seem to be the biggest challenges. Consequently, better incentive structures as well as communication channels have to be established.

Description: Abstract Legal requirement in Europe asks for Ecosystem-Based Fisheries Management (EBFM) in European seas, including considerations of trophic interactions and minimization of negative impacts of fishing on food webs and ecosystem functioning. Focusing on the interaction between fisheries and ecosystem components, the trophic model presented here shows for the first time the “big picture” of the western Baltic Sea (WBS) food web by quantifying structure and flows between all trophic elements and the impact of fisheries that were and are active in the area, based on best available recent data. Model results show that fishing pressures exerted on the WBS since the early nineties of the past century forces not only top predators such as harbour porpoises and seals but also cod and other demersal fish to heavily compete for fish as food and to cover their dietary needs by shifting to organisms lower in the trophic web, mainly to benthic macrofauna and / or search for suitable prey in adjacent ecosystems such as Kattegat, Skagerrak, central Baltic Sea and North Sea. While common sense implementations of EBFM have been proposed, such as fishing all stocks below Fmsy and reducing fishing pressure even further for forage fish such as herring and sprat, few studies compared such fishing to alternative scenarios. Different options for EBFM, with regards to recovery of depleted stocks and sustainable future catches, are presented here based on the WBS ecosystem model, the legal framework given by the new Common Fisheries Policy (CFP) and the Marine Strategy Framework Directive (MSFD) of the European Union. The model explores four legally valid future fishery scenarios: 1) business as usual, 2) maximum sustainable fishing (F = Fmsy), 3) half of Fmsy, and 4) EBFM with F = 0.5 Fmsy for forage fish and F = 0.8 Fmsy for other fish. In addition, a “No-fishing” scenario demonstrates, that neither individual stocks nor the whole system would collapse when all fishing activities from 2017 on would cease. Simulations show that “Business as usual” would perpetuate low 2016 catches from depleted stocks in an unstable ecosystem where endangered species may be lost. In contrast, an “EBFM” scenario - with herring and sprat fished at 0.5 Fmsy level and cod and other stocks fished at 0.8 Fmsy level - allows the recovery of all stocks with strongly increased catches close to the maximum (at Fmsy) for cod and flatfish and catches similar to the 2016 level for herring and sprat but with strongly reduced fishing effort. Model and methodology presented here are considered suitable to assess MSFD Criterion D4C2 in the WBS.

Description: Despite the importance of deep-sea corals, our current understanding of their ecology and evolution is limited due to difficulties in sampling and studying deep-sea environments. Moreover, a recent re-evaluation of habitat limitations has been suggested after characterization of deep-sea corals in the Red Sea, where they live at temperatures of above 20 °C at low oxygen concentrations. To gain further insight into the biology of deep-sea corals, we produced reference transcriptomes and studied gene expression of three deep-sea coral species from the Red Sea, i.e. Dendrophyllia sp., Eguchipsammia fistula, and Rhizotrochus typus. Our analyses suggest that deep-sea coral employ mitochondrial hypometabolism and anaerobic glycolysis to manage low oxygen conditions present in the Red Sea. Notably, we found expression of genes related to surface cilia motion that presumably enhance small particle transport rates in the oligotrophic deep-sea environment. This is the first study to characterize transcriptomes and in situ gene expression for deep-sea corals. Our work offers several mechanisms by which deep-sea corals might cope with the distinct environmental conditions present in the Red Sea As such, our data provide direction for future research and further insight to organismal response of deep-sea coral to environmental change and ocean warming.

Description: Despite the importance of deep-sea corals, our current understanding of their ecology and evolution is limited due to difficulties in sampling and studying deep-sea environments. Moreover, a recent re-evaluation of habitat limitations has been suggested after characterization of deep-sea corals in the Red Sea, where they live at temperatures of above 20 °C at low oxygen concentrations. To gain further insight into the biology of deep-sea corals, we produced reference transcriptomes and studied gene expression of three deep-sea coral species from the Red Sea, i.e. Dendrophyllia sp., Eguchipsammia fistula, and Rhizotrochus typus. Our analyses suggest that deep-sea coral employ mitochondrial hypometabolism and anaerobic glycolysis to manage low oxygen conditions present in the Red Sea. Notably, we found expression of genes related to surface cilia motion that presumably enhance small particle transport rates in the oligotrophic deep-sea environment. This is the first study to characterize transcriptomes and in situ gene expression for deep-sea corals. Our work offers several mechanisms by which deep-sea corals might cope with the distinct environmental conditions present in the Red Sea As such, our data provide direction for future research and further insight to organismal response of deep-sea coral to environmental change and ocean warming.

Description: According to classical plume theory, the Tristan da Cunha hotspot is thought to have played a major role in the rifting of the South Atlantic margins and the creation of the aseismic Walvis Ridge by impinging at the base of the continental lithosphere shortly before or during the breakup of the South Atlantic margins. But Tristan da Cunha is enigmatic, as it cannot be clearly identified as a hot-spot but classifies also highly as a more shallow type of anomaly that may actually have been caused by the opening of the South Atlantic. The equivocal character of Tristan is largely due to lack of geophysical data in this region. To understand the tectonic processes of the opening of the South Atlantic, the formation of the Walvis ridge and to understand whether Tristan da Cunha is the cause or the consequence of rifting, it is of central importance to characterize the region around Tristan da Cunha in a more coherent way. Within this research cruise we deployed 26 ocean bottom electromagnetic stations (OEBM) and 24 ocean bottom seismometer (OBS) for a long term acquisition (1 year) of magnetotelluric and seismological data, acquired bathymetry and gravity data and performed geological sampling on Tristan da Cunha. The data will be interpreted in the context of geochemical data and tectonic models developed within the SPP1375‚ South Atlantic Margin Processes and Links with onshore Evolution (SAMPLE).

Description: Lake Urmia, the second largest saline Lake on earth and a highly endangered ecosystem, is on the brink of a serious environmental disaster similar to the catastrophic death of the Aral Sea. Progressive drying has been observed during the last decade, causing dramatic changes to Lake Urmia’s surface and its regional water supplies. The present study aims to improve monitoring of spatiotemporal changes of Lake Urmia in the period 1975–2015 using the multi-temporal satellite altimetry and Landsat (5-TM, 7-ETM+ and 8-OLI) images. In order to demonstrate the impacts of climate change and human pressure on the variations in surface extent and water level, Lake Sevan and Van Lake with different characteristics were studied along with the Urmia Lake. Normalized Difference Water Index-Principal Components Index (NDWI-PCs), Normalized Difference Water Index (NDWI), Modified NDWI (MNDWI), Normalized Difference Moisture Index (NDMI), Water Ratio Index (WRI), Normalized Difference Vegetation Index (NDVI), Automated Water Extraction Index (AWEI), and MultiLayer Perceptron Neural Networks (MLP NNs) classifier were investigated for the extraction of surface water from Landsat data. The presented results revealed that MLP NNs has a better performance in the cases where the other models generate poor accuracy. The results show that the area of Lake Sevan and Van Lake have increased while the area of Lake Urmia has decreased by ~65.23% in the past decades, far more than previously reported (~25% to 50%). Urmia Lake’s shoreline has been receding severely between 2010 and 2015 with no sign of recovery, which has been partly blamed on prolonged droughts, aggressive regional water resources development plans, intensive agricultural activities, and anthropogenic changes to the system. The results also indicated that (among the proposed factors) changes in inflows due to overuse of surface water resources and constructing dams (mostly during 1995–2005) are the main reasons for Urmia Lake’s shoreline receding. The model presented in this manuscript can be used by managers as a decision support system to find the effects of building new dams or other infrastructures

Description: Arctic and subarctic regions are sensitive to climate change and, reversely, provide dramatic feedbacks to the global climate. With a focus on discovering paleoclimate and paleoceanographic evolution in the Arctic and Northwest Pacific Oceans during the last 20,000 years, we proposed this German–Sino cooperation program according to the announcement “Federal Ministry of Education and Research (BMBF) of the Federal Republic of Germany for a German–Sino cooperation program in the marine and polar research”. Our proposed program integrates the advantages of the Arctic and Subarctic marine sediment studies in AWI (Alfred Wegener Institute) and FIO (First Institute of Oceanography). For the first time, the collection of sediment cores can cover all climatological key regions in the Arctic and Northwest Pacific Oceans. Furthermore, the climate modeling work at AWI enables a “Data-Model Syntheses”, which are crucial for exploring the underlying mechanisms of observed changes in proxy records.