ALBERT

Description: The dataset contains temperature, salinity, oxygen saturation, chlorophyll a and turbidity data from the AWIPEV underwater observatory from the year 2020 in a temporal resolution of 1 hour. The cabled observatory is located in 12m water depth and comprises single or multiple sensors for a specific parameter (see https://www.awi.de/en/science/biosciences/shelf-sea-system-ecology/main-research-focus/cosyna/underwater-node-spitsbergen.html). For a detailed description of the data see associated metadatafile "Metadata_description_svluwobs_data_2020.pdf"

Description: The dataset contains temperature, salinity, oxygen saturation, chlorophyll a and turbidity data from the Helgoland MarGate underwater observatory from the year 2017 in a temporal resolution of 1 hour. The cabled observatory is located in 10m water depth and comprises single or multiple sensors for a specific parameter (see https://www.awi.de/en/science/biosciences/shelf-sea-system-ecology/main-research-focus/cosyna/underwater-node-helgoland.html). For a detailed description of the data see associated metadatafile "metadata_heluwobs_2017_hydrography.pdf"

Description: The dataset contains temperature, salinity, oxygen saturation, chlorophyll a and turbidity data from the AWIPEV underwater observatory from the year 2019 in a temporal resolution of 1 hour. The cabled observatory is located in 12m water depth and comprises single or multiple sensors for a specific parameter (see https://www.awi.de/en/science/biosciences/shelf-sea-system-ecology/main-research-focus/cosyna/underwater-node-spitsbergen.html). For a detailed description of the data see associated metadatafile "metadata_svulobs_2019_hydrography.pdf"

Description: The dataset contains temperature, salinity, oxygen saturation, chlorophyll a and turbidity data from the Helgoland MarGate underwater observatory from the year 2020 in a temporal resolution of 1 hour. The cabled observatory is located in 10m water depth and comprises single or multiple sensors for a specific parameter (see https://www.awi.de/en/science/biosciences/shelf-sea-system-ecology/main-research-focus/cosyna/underwater-node-helgoland.html). For a detailed description of the data see associated metadatafile "Metadata_description_heluwobs_data_2020.pdf"

Description: The dataset contains temperature, salinity, oxygen saturation, chlorophyll a and turbidity data from the Helgoland MarGate underwater observatory from the year 2019 in a temporal resolution of 1 hour. The cabled observatory is located in 10m water depth and comprises single or multiple sensors for a specific parameter (see https://www.awi.de/en/science/biosciences/shelf-sea-system-ecology/main-research-focus/cosyna/underwater-node-helgoland.html). For a detailed description of the data see associated metadatafile "metadata_heluwobs_2019_hydrography.pdf"

Description: The dataset contains temperature, salinity, oxygen saturation, chlorophyll a and turbidity data from the AWIPEV underwater observatory from the year 2021 in a temporal resolution of 1 hour. The cabled observatory is located in 12m water depth and comprises single or multiple sensors for a specific parameter (see https://www.awi.de/en/science/biosciences/shelf-sea-system-ecology/main-research-focus/cosyna/underwater-node-spitsbergen.html). For a detailed description of the data see associated metadatafile metadata_svulobs_2021_hydrography.pdf

Description: The dataset contains temperature, salinity, oxygen saturation, chlorophyll a and turbidity data from the Helgoland MarGate underwater observatory from the year 2018 in a temporal resolution of 1 hour. The cabled observatory is located in 10m water depth and comprises single or multiple sensors for a specific parameter (see https://www.awi.de/en/science/biosciences/shelf-sea-system-ecology/main-research-focus/cosyna/underwater-node-helgoland.html). For a detailed description of the data see associated metadatafile "metadata_heluwobs_2018_hydrography.pdf".

Description: In recent years, several studies postulate a significant increase in the transport of warm Atlantic water masses towards Svalbard driven by climate change. A consequence of this Arctic “Atlantification” seems to be a higher abundance of Gadus morhua (Atlantic cod) in these areas. Similar increases in cod stocks were reported between the 1920s and 1960s, a period known as Early Arctic Warming. As a major competitor for food and habitat resources, an increase in the overall abundance of G. morhua in the Arctic will have considerable consequences for the ecosystem. The native cod stock of Boreogadus saida (polar cod) is most susceptible to these changes in the area. In this study, we hypothesis that G. morhua has established a local “non-migratory” spawning stock at Svalbard, similar to a local coastal cod stock in Norway. We specifically focus on two questions: 1) Is there a correlation between the overall abundance and distribution patterns of Atlantic cod stocks at the coast of Svalbard with longer-term temperature patterns? Is there an increase in the overall abundance of Gadus morhua during periods when warmer water surround Svalbard? 2) Is the Atlantic cod stock on the west coast of Svalbard genetically / morphologically distinguishable from that of the Norwegian coast, where the migratory origin of Gadus morhua is assumed? And if so, can this stock establish as a local spawning stock? In the framework of a cooperative sampling programme from 2018 to 2020, together with Norwegian and AWI colleagues, genetic analysis at individual and population level will be conducted. Together with catch data modelling approaches, we aim to improve our knowledge on possible future distribution patterns of Atlantic cod migrating towards Arctic waters and their effects on the local Arctic community.

Description: Northern Europe’s coastlines are often characterised as high-energy environments exposed to severe wind and storm impacts over the year. Many of these densely populated areas are therefore protected by different kinds of coastal artificial protection measures. Helgoland island, located in the southern North Sea, is protected by over 10 000 tetrapods (4 footed concrete breakwaters) to avoid erosion and land loss over time. Artificial structures like tetrapods are used world wide for coastal protection measures, but there is only limited knowledge available on their influence on the coastal ecosystem and the associated biota. In 2009 the Centre for Scientific Diving of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Sciences, established a sublittoral experimental tetrapod field (MarGate) to study the effects of artificial constructions on the coastal environment. As in previous investigations SCUBA supported underwater visual census was used to identify fish species, their abundance and to distinguish between young-of-the-year (YOY) and older fish. Fish data have been collected from June to August 2015 on a monthly basis along predefined transect lines with a total of 60 stations. In sum, 785 individuals were assessed and 9 species identified, with Pomatoschistus minutus being the most abundant species. An accumulation of fish, especially of YOY fish near the tetrapods could be shown. This indicates that the submerged tetrapods off Helgoland have been established as enhanced nursery ground and habitat for local fish species. The presented data are part of an ongoing long term assessment project to finally get a better understanding of the role of artificial reefs on coastal ecosystems.

Description: The Arctic is a hotspot for anthropogenic global warming and especially Svalbard is strongly affected by increasing water temperatures. The Atlantification of the Arctic is characterized by a northward shift of boreal species like Atlantic cod towards colder habitats. The effects on the local fish community are still unclear. In addition, the warming leads to a possible relocation of spawning grounds whereby the Svalbard shelf could provide a potential new habitat and spawning ground. The assessment and sampling of fish in Svalbard waters is difficult due to the remote location, cold temperatures and polar night. The Svalbard underwater observatory installed in 2012 in Kongsfjorden provides the unique opportunity to deliver 24/7 near-real time data and imagery of the shallow water community. With the observatory it is possible to assess the water column in a depth between 11 m and the surface. As the shallow water is the main habitat for juvenile cod the year-round observation is of high interest. But also this system needs to be maintained throughout the whole year being affected by drift ice collisions or general biofouling. Therefore, scientific diving is essential for the maintenance of this installation. Challenges that have been overcome in year-round diving missions include cold temperatures, low visibilities and marine mammals like polar bears.