The Arctic Ocean is changing to a warmer and ice-free state, which may lead to substantial changes in biodiversity and ecosystem structures. An Atlantification of the zooplankton community is ongoing, but at which rate is poorly known at present stage. The aim of this project is to 1) determine the fate of boreal zooplankton carried into the Arctic Ocean and 2) revise Calanus spp. species distribution and reproductive success in the main inflow path to the Arctic Ocean. Particular focus is correct species identification by molecular methods since this is essential to predict the fate of zooplankton in a changing Arctic to a warmer state. In 2021 we will continue to identify Calanus spp. to species by molecularly tools focusing on their distribution in the North of Svalbard and in Svalbard fjords.