Winter distribution of Steller's Eiders in the Varangerfjord, northern Norway

Abstract

Arctic warming and decreasing sea-ice cover along the Siberian coast in the Arctic Ocean leads to greater accessibility for operations such as oil drilling and traffic of tankers. This implies increasing risks for Steller’s Eider Polysticta stelleri wintering, moulting and staging along the coasts of the Varanger Peninsula, Norway. Steller’s Eiders were surveyed by monthly counts during winter and early spring 2016/2017 to investigate numbers and distribution throughout the winter. The highest number of wintering Steller’s Eiders was found in January, representing ~7 % of the European population. In February–April numbers were lower, but at a rather stable level. We found relatively little variation in distribution between months, although the birds were more evenly distributed along the coast later in winter. Mean flock size was significantly larger in January than in March and April. Feeding behaviour was exclusively observed in shallow water, generally at depths of up to 6 m. Areas of focus for an oil pollution emergency plan are pointed out and discussed.