1 National Institute of Aquatic Resources, Technical University of Denmark2 Section for Ocean Ecology and Climate, National Institute of Aquatic Resources, Technical University of Denmark3 Fisheries and Oceans Canada4 University of Alaska Fairbanks5 University of Washington6 National Wildlife Research Centre7 Universidad de Malaga8 unknown9 World Wildlife Fund, Washington10 Snow Change Cooperative11 Fisheries and Oceans Canada12 Universidad de Malaga
The Arctic Ocean is undergoing major changes in many of its fundamental physical constituents, from a shift from multi- to first-year ice, shorter ice-covered periods, increasing freshwater runoff and surface stratification, to warming and alteration in the distribution of water masses. These changes have important impacts on the chemical and biological processes that are at the root of marine food webs, influencing their structure, function and biodiversity. Here we summarise current knowledge on the biodiversity of Arctic marine ecosystems and provide an overview of fundamental factors that structure ecosystem biodiversity in the Arctic Ocean. We also discuss climateassociated effects on the biodiversity of Arctic marine ecosystems and discuss implications for the functioning of Arctic marine food webs. Based on the complexity and regional character of Arctic ecosystem reponses to environmental changes, recommendations are made for the establishment of long-term observatories across the Arctic, in support of sustainable management and conservation actions.