Description: Modern digital scientific workflows - often implying Big Data challenges - require data infrastructures and innovative data science methods across disciplines and technologies. Diverse activities within and outside HGF deal with these challenges, on all levels. The series of Data Science Symposia fosters knowledge exchange and collaboration in the Earth and Environment research community.

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: A physical - biogeochemical survey was carried out in the northeastern tropical Atlantic and in the western tropical South Atlantic. The main objective of the works in the oxygen minimum zone of the eastern tropical North Atlantic was to improve oxygen budget estimates. Additional objectives were to investigate the role of zooplankton for fluxes of particulate and dissolved organic matter and to advance quantitative understanding of nitrogen fixation in the tropical Atlantic. The main objective of the measurements program in the western tropical South Atlantic was to investigate the variability of transport and water mass properties of the western boundary circulation. A major component of the work program was the recovery of nine and the redeployment of eight moorings. The moorings positioned off Cape Verde, in the tropical northeastern Atlantic and at the western boundary off Brazil are collecting velocity, oxygen, temperature, and salinity time series since several years. All moorings were successfully recovered and redeployed. Section work focused on 23°W from 15°N to 5.5°S, on 11.5°S from 32°W to the coast of Brazil and on 5°S from 29.5°W to the coast of Brazil. Parameters measured along the sections included temperature-salinity-depth, oxygen and turbulence profiles, lowered acoustic Doppler current profiles, underwater vision profiles, shipboard velocity profiles, multinet and Working Party 2 net casts, and photosynthetically active radiation profiles. Water samples were analyzed for numerous variables including salinity, oxygen concentrations, tracer concentrations (CFC-12, SF6, CF3SF5), nutrients in micro and nano range, and halocarbons. Filtered samples were taken for NanoSIMS, flow cytometry, dissolved organic phosphorus, DNA/RNA, particulate organic matter, particulate organic nitrogen, and chlorophyll a. Samples of Heme content and dissolved iron were taken from a towed trace metal clean fish. Furthermore, on-board incubations to quantify nitrogen and carbon fixation and primary productivity were performed. The measurement program was successfully completed and all data sets were acquired as planned.

Description: Final Report, EU Concerted Action Introductions with Ships (MAS3-CT97-0111): Until recently, the importance of ballast water as a major transfer vector that affect aquatic ecosystem stability and modify biodiversity was not generally recognised, although studies on species transfer via ballast water in maritime countries have increased world-wide. Despite considerable research effort (national and international), there has been virtually no consideration of the effectiveness or standardisation of ballast water sampling methodology in order to monitor effectiveness of control measures. One key objective of the Concerted Action was to test monitoring systems for sampling ballast water. Two major intercalibration workshops compared sampling techniques. The largely varying conditions onboard ships require to develop a “tool box” rather than singling out one method, thereby combining qualitative and quantitative sample analysis for plankton species composition and abundance. The two intercalibration workshops delivered results allowing better comparisons of ship sampling studies around the world. The second key issue was to gain more insight on species composition in ballast water during ship voyages. This was achieved by ocean-going workshops (OGWs). The data obtained during five OGWs, using the “tool box” originated from European voyages (three OGWs) and during inter-ocean voyages (two OGWs). In total, approximately 700 samples were collected during more than 100 days at sea. More species and specimens were found in new ballast water, and communities were in general similar to outside seawater where ballasting took place. The highest number of phytoplankton species found was 52, including potentially toxic species. At most, 40 zooplankton taxa were found. Abundance and diversity of phyto- and zooplankton species remained fairly stable for 3-4 days, followed by an exponential decline. In some cases no living zooplankton were found after 9 days, in others about 10% of the taxa survived, remaining viable for 25 days (i.e. voyage Hong Kong – Hamburg). Sampling showed that in calm conditions phytoplankton exhibited a vertical zonation in ballast tanks. During rough weather mixing occurred causing increasing in mortality. For the first time in ballast water studies, traps were used with bait and light as attractants, catching taxa not seen in the net samples before. The effect of mid ocean exchange (MOE), recommended by International Maritime Organization (IMO) as a measure against unintentional introduction via ships, was studied. In many cases the number of taxa increased rather than declined while densities of specimens were diluted. A public awareness was launched, preparing a video, a leaflet, flyers, press releases, newsletter articles of International Aquatic Societies, an Internet homepage (visit the homepage at: http://members.aol.com/sgollasch/sgollasch/index.htm *) and several posters. A book on case histories, listing species previously introduced to European waters, was prepared especially to address harbour and regulatory authorities. Assessment of potential control measures (treatment) to reduce risks arising from ballast water releases included the evaluation and development of guidelines for ballast water treatment options. All participants provided input on references (e.g. grey literature, governmental reports, internal reports from harbour authorities, interim project reports) into a database kept by the co-ordinator. The Concerted Action reviewed and considered shipping studies both within and outside the EU. This provided a more balanced view of the state of the art and also enabled the Intercalibration workshops to consider and compare sampling methods as used throughout the world. During the CA many of these studies were completed and new ones studies commenced. It is recommended that the EU takes advantage of the well developed expertise within the network of the CA partners to gain momentum in an area where global solutions are urgently needed.

Description: Laufzeit des Vorhabens: 01.01.2014-31.12.2017 : Berichtszeitraum: 01.01.2014-31.12.2017