Speakers: Hauke Flores (AWI Bremerhaven) and Mai Apasiri Klasmeier (Ruhr University Bochum). Moderation: Josefine Lenz (AWI & APECS)
In November 2019, the US icebreaker RV Sikuliaq headed to the north side of Alaska for a combined oceanographic and biological expedition. The biological work was performed within the ARICE-funded project GO-WEST. GO-WEST aimed to investigate the association of young polar cod (or Arctic cod, Boreogadus saida) with the newly forming sea ice, its prey field and carbon sources. Polar cod is a keystone species of the Arctic food web. The young (0-2 year-old) fish use the under-ice habitat as a foraging ground and shelter from predators. It has been hypothesized that juveniles get entrained with the new sea ice in autumn and use it as a transportation vector over large distances. The changing icescape of the Arctic Ocean will affect this close relationship between fish and sea ice. GO-WEST aimed to sample for the first time young polar cod at the underside of new sea ice between autumn and winter, and to investigate their survival conditions. To this end, we used a Surface and Under-Ice Trawl capable to skim the underside of sea ice. The first results of this expedition show that young polar cod were present in the under-ice habitat throughout the investigation area, along with their main prey species. During this webinar we will briefly explain how the expedition was planned and which logistical obstacles needed to be overcome. We will focus on how the field work was conducted in collaboration with the chief scientist and the crew of RV Sikuliaq, and how first raw data were generated. Finally we will give an outlook on sample elaboration, data processing and publications.