Trophic structure and biomass of high-Arctic zooplankton in the Eurasian Basin in 2017

• Main Author: Zakharova, Nadezhda
• Format: Thesis
• Language: unknown
• Published: Saint Petersburg University / University of Hamburg 2019
• Subjects: Arctic; Arctic Ocean; Barents Sea; Climate change; Fram Strait; Mesozooplankton; Nansen Basin; Ocean acidification; Sea ice; Zooplankton; Spitsbergen
• Online Access: https://epic.awi.de/id/eprint/52403/; https://epic.awi.de/id/eprint/52403/1/Zakharova_MT.pdf; https://hdl.handle.net/10013/epic.0eaaec65-5ded-408d-ab34-d3150b6ae0c4

The Arctic Ocean is experiencing some of the most pronounced effects of global climate change. Sea ice coverage and thickness have significantly decreased in the past decades and are predicted to continue in the future. Significant changes in the water column are expected to occur in the environment, such as increases of surface water temperature, ocean acidification, increased stratification, changes in circulation of water. With ongoing climate change, model-based studies indicate a northward migration of Atlantic species with an increased inflow of Atlantic water into the Arctic Ocean. A biogeographical shift in the increasing dominance of warm-temperate-boreal copepod species has been witnessed over the last decade in the Arctic Ocean. The northward expansion of zooplankton communities associated with warm Atlantic waters (AW) leads to a reduction in the number of cold water species. Changes in the zooplankton community will also lead to the changes in its quality as a food source for higher organisms in the Arctic food chain, since zooplankton is one of the main link in the Arctic food web. In this study pelagic zooplankton collected during the Polarstern expedition PS106 from 28 May to 20 July 2017 in the Arctic Ocean, north of Spitsbergen and the Barents sea, were analyzed. The research area comprised stations located on the shelf and slope of the Barents Sea and in the western Nansen Basin. In the sampling area Atlantic inflow from the Fram Strait meets the outflow of the Barents Sea and the southward-moving sea ice and polar surface waters. The Barents Sea shelf slope is a hot spot of atlantification and borealisation. The zooplankton community in this area is highly influenced by all these factors. Therefore, the objectives of this study were to investigate the variability in macrozooplankton species composition, biomass, and size composition of macro- and mesozooplankton across the Barents Sea shelf slope in relation to spatial and water masses influence parameters. In addition, the trophic structure ...