layers. Reduced sea ice cover and thickness may impact on the growth patterns of ice- algae and phytoplankton, with subsequent unknown effects on zooplankton, fish, and marine mammals. Species from more southerly [...] water, ice thickness, water mass movement and biological data on the activity of ice algae and phytoplankton during winter months are crucial to better understand the physical and biogeochemical processes [...] velocity distribution, temperature, salinity, and stratification. Ice-algae and free floating phytoplankton produce enormous amounts of biomass. Reduced sea ice cover and sea ice thickness could change