Description: The European Research Infrastructure Consortium “Integrated Carbon Observation System” (ICOS) aims at delivering high quality greenhouse gas (GHG) observations and derived data products (e.g., regional GHG-flux maps) for constraining the GHG balance on a European level, on a sustained long-term basis. The marine domain (ICOS-Oceans) currently consists of 11 Ship of Opportunity lines (SOOP – Ship of Opportunity Program) and 10 Fixed Ocean Stations (FOSs) spread across European waters, including the North Atlantic and Arctic Oceans and the Barents, North, Baltic, and Mediterranean Seas. The stations operate in a harmonized and standardized way based on community-proven protocols and methods for ocean GHG observations, improving operational conformity as well as quality control and assurance of the data. This enables the network to focus on long term research into the marine carbon cycle and the anthropogenic carbon sink, while preparing the network to include other GHG fluxes. ICOS data are processed on a near real-time basis and will be published on the ICOS Carbon Portal (CP), allowing monthly estimates of CO2 air-sea exchange to be quantified for European waters. ICOS establishes transparent operational data management routines following the FAIR (Findable, Accessible, Interoperable, and Reusable) guiding principles allowing amongst others reproducibility, interoperability, and traceability. The ICOS-Oceans network is actively integrating with the atmospheric (e.g., improved atmospheric measurements onboard SOOP lines) and ecosystem (e.g., oceanic direct gas flux measurements) domains of ICOS, and utilizes techniques developed by the ICOS Central Facilities and the CP. There is a strong interaction with the international ocean carbon cycle community to enhance interoperability and harmonize data flow. The future vision of ICOS-Oceans includes ship-based ocean survey sections to obtain a three-dimensional understanding of marine carbon cycle processes and optimize the existing network design.

Description: Macrofauna data was collected using a box corer (0.25m² sampling area). The sampled sediment from each box corer was divided into eight subsamples (pseudoreplicates). The uppermost 12 cm of these subsamples were analyzed. Each subsample was processed through a 500-µm mesh size sieve. After sieving, residuals were fixed with 100% ethanol and stored at room temperature. Macrofaunal organisms were identified to the lowest possible taxonomical level. Whenever identification to species level was not possible, the sample was identified to the next identifiable taxonomical category and assigned a putative species name (e.g., 'Hesionidae genus sp. 1', 'Hesionidae genus sp. 2'). Posterior fragments, exuviae, xenobionts, meiofauna taxa (Nematoda, Ostracoda, Harpacticoida) and empty tubes were excluded from the analysis. Biomass (blotted wet weight, ww) was determined by weighing each specimen. Shelled organisms, such as mollusks, were weight in their shells.

Description: Oceans cover 〉70% of the earth and encompass variable habitats concerning salinity, temperature, pressure, light availability. The deep sea (〉1000 m water depth) constitutes more than 60% of the ocean´s biosphere and harbors an unparalleled biodiversity. It constitutes an extreme habitat due to high pressure, darkness and often low nutrient and oxygen concentrations. In order to ensure their survival, microorganisms thriving in such environments have to develop unique metabolic adaptations, thus represent an interesting resource for the discovery of new molecules. However, due to access difficulties to deep-sea habitats and the lack of suitable and affordable sampling techniques, deep-sea microorganisms have remained untapped for their potential in marine biodiscovery. In this study, we obtained deep-sea sediment samples from Arctic Ocean (-2432 m), sampled by an ROV during RV Polarstern expedition 108. Isolation of microorganisms has been performed using two specific media for bacteria and fungi, respectively. Isolates were identified by amplification of the 16S rRNA gene (bacteria) and ITS1-2 region (fungi) followed by Sanger sequencing. In total, 70 bacterial isolates were identified covering four phyla (52 Firmicutes, 1 Actinobacteria, 11 Proteobacteria and 6 Bacteroidetes) and seven fungal strains from two different phyla (6 Ascomycota and 1 Basidiomycota). Selected isolates were cultivated in two different media, followed by solvent (EtOAc) extraction and bioactivity screenings against a panel of clinically relevant microbial pathogens and six cancer cell lines. At 100 µg/mL concentration, three bacterial extracts showed antitumor activity (〉70%), whereas 17 exhibited activity (〉65%) against methicillin-resistant Staphylococcus aureus (MRSA). Notably, only one fungus showed a cultivation medium dependent-high antifungal activity (〉90%), highlighting the impact of culture media on the production of bioactive secondary metabolites.

Description: The 77th cruise of the RV MARIA S. MERIAN contributed to various large national and international research and infrastructure projects (FRAM, ARCHES, INTAROS, ICOS, SIOS) as well as to the research programme PACES-II (Polar Regions and Coasts in the changing Earth System) of the Alfred-Wegener-Institute Helmholtz-Center for Polar and Marine Research (AWI). Investigations within Work Package 4 (Arctic sea ice and its interaction with ocean and ecosystems) of the PACES-II programme, aim at assessing and quantifying ecosystem changes from surface waters to the deep ocean in response to the retreating sea ice, and at exploring the most important (feedback) processes determining temporal and spatial variability. Contributions to the PACES-II Work Package 6 (Large scale variability and change in polar benthic biota and ecosystem functions) include the identification of spatial patterns and temporal trends in relevant benthic community functions, and the development of a comprehensive science community reference collection of observational data. Work carried out within WPs 4 and 6 will support the time-series studies at the LTER (Long-Term Ecological Research) observatory HAUSGARTEN (Fig. 1.1), where we document Global Change induced environmental variations on a polar deep-water ecosystem. This work is carried out in close co-operation between the HGF-MPG Joint Research Group on Deep-Sea Ecology and Technology and the PEBCAO Group (Phytoplankton Ecology and Biogeochemistry in the Changing Arctic Ocean) at AWI as well as the working group Microbial Geochemistry at the GEOMAR and the HGF Young Investigators Group SEAPUMP (Seasonal and regional food web interactions with the biological pump).

Description: Macrobenthos plays an important role in ecosystem processes such as bioturbation, particle reworking and ventilation of the soil. Nevertheless, explaining the relationship between biodiversity and ecosystem function (BEF) remains a difficult task. This holds also true in remote polar regions such as the LTER observatory HAUSGARTEN in the Fram Strait. The local hydrographic regime is mainly influenced by the warm northern-bound West Spitsbergen Current, and the southwards flowing cold and less saline East Greenland Current. The currents are causing regional differences in sea-ice coverage. Distribution patterns of the sea-ice play a major role in determining the flux of potential food to the seafloor, thus shaping benthic communities. Recently, functional and biological trait analysis (BTA) became an important tool to investigate BEF-relationships in marine environments. However, this approach is relatively new for Arctic regions, especially deep-sea ecosystems. Therefore, our study aims to determine functional characteristics on a depth gradient in the deep Fram Strait. Deep-sea samples (1000 – 5500m) were collected in the Arctic autumn of 2018 on board of RV Maria S. Merian. An USNEL box corer (0.25m²) was deployed at nine sites along the bathymetric transect of the LTER observatory HAUSGARTEN offshore Svalbard. All material was treated trough a 0.5-mm sieve and fixed in 4% formalin. The specimens were identified to species level wherever possible and after assigning to modalities of selected traits used for BTA to observe functional changes along the depth gradient. Preliminary results on community structure and resulting functional differences between the benthic communities will be presented

Description: Water mass generation and mixing in the eastern Fram Strait are strongly influenced by the interaction between Atlantic and Arctic waters and by the local atmospheric forcing, which produce dense water that substantially contributes to maintaining the global thermohaline circulation. The West Spitsbergen margin is an ideal area to study such processes. Hence, in order to investigate the deep flow variability on short-term, seasonal, and multiannual timescales, two moorings were deployed at ~1040 m depth on the southwest Spitsbergen continental slope. We present and discuss time series data collected between June 2014 and June 2016. They reveal thermohaline and current fluctuations that were largest from October to April, when the deep layer, typically occupied by Norwegian Sea Deep Water, was perturbed by sporadic intrusions of warmer, saltier, and less dense water. Surprisingly, the observed anomalies occurred quasi-simultaneously at both sites, despite their distance (~170 km). We argue that these anomalies may arise mainly by the effect of topographically trapped waves excited and modulated by atmospheric forcing. Propagation of internal waves causes a change in the vertical distribution of the Atlantic water, which can reach deep layers. During such events, strong currents typically precede thermohaline variations without significant changes in turbidity. However, turbidity increases during April–June in concomitance with enhanced downslope currents. Since prolonged injections of warm water within the deep layer could lead to a progressive reduction of the density of the abyssal water moving toward the Arctic Ocean, understanding the interplay between shelf, slope, and deep waters along the west Spitsbergen margin could be crucial for making projections on future changes in the global thermohaline circulation.