Institute of Marine Research, University of Bergen, Bergen, Norway. susanne.balzer@imr.no|Institute of Marine Research, University of Bergen, Bergen, Norway. susanne.balzer@imr.no|Institute of Marine Research, University of Bergen, Bergen, Norway. susanne.balzer@imr.no|Institute of Marine Research, University of Bergen, Bergen, Norway. susanne.balzer@imr.no|Institute of Marine Research, University of Bergen, Bergen, Norway. susanne.balzer@imr.no