Sample elaborations, data analyses, results and conclusions from the seagoing MOSAiC and SAS expeditions in the Central Arctic Ocean :Final report

As a result of global warming, the marine ecosystem around the North Pole, the Central Arctic Ocean (CAO), is in fast transition from a permanently to a seasonally ice-covered ocean. The sea-ice loss is expected to enable summer access to the CAO for non-icebreaking ships, including fishery vessels, in the near future. However, the lack of knowledge on the CAO ecosystem impedes any assessment of the sustainability of potential future fisheries in the CAO. Taking a precautionary approach, the EU and nine countries in October 2018 signed the Agreement to Prevent Unregulated High Seas Fisheries in the CAO (CAOFA). This agreement entered into force in June 2021 and, a.o., requires the establishment of a 16-year-long Joint Programme for Scientific Research and Monitoring (JPSRM) for collecting new ecosystem data in the CAO. To reduce the existing lack of knowledge, the EFICA Consortium participated in two icebreaker expeditions in the Eurasian Basin of the CAO: the MOSAiC expedition 2019-2020 and the SAS-Oden expedition in summer 2021 for collecting field data. This report contains results of data and sample analyses from these expeditions that are relevant for future fish stock modelling and assessment studies. Specifically, the following questions were answered based on the collected field data: Which species of nekton (fish and squid) occur in the CAO? What is the distribution, abundance and biomass of nekton and zooplankton? What is the ecology of the nekton? What is the carrying capacity of the CAO with respect to nekton? The project was highly exploratory, not only in its uniqueness of analysing ecosystem data from this remote area, but also in the development and adaptation of the applied methods. This innovation of methodology forms the basis of the recommendations for the JPSRM provided in this report.