Wintering seabirds in south-west Greenland, 2017

Abstract

The South-west Greenland Open Water Area is an internationally important wintering area for seabirds in the North Atlantic. Nearly two decades after the area was last surveyed, we conducted a replicate aerial survey in March 2017 to update information on the distribution and abundance of seabirds. With a total effort of about 5800 km, we covered the coastal area from Aasiaat (69°N) to Kap Farvel (60°N), 56% of the open water area in the fjords, and the offshore bank, Store Hellefiskebanke. Line transect survey methodology was used except in the fjords, which were censused by total counts. By means of distance sampling analyses, the abundances of the dominant species were estimated to be roughly 1100 000 king eiders (Somateria spectabilis), 443 000 common eiders (Somateria mollissima), 42 000 long-tailed ducks (Clangula hyemalis) and 76 000 Iceland gulls/glaucous gulls (Larus glaucoides/Larus hyperboreus). For the great black-backed gull (Larus marinus), great cormorant (Phalacrocorax carbo), mallard (Anas platyrhynchos) and red-breasted merganser (Mergus serrator), we present the first winter population estimates for the area (6100, 7700, 7600 and 3200 individuals, respectively). Areas around Kangaatsiaq, Nuuk and Julianehåbsbugten were identified as key wintering sites, as was Store Hellefiskebanke which held 99% of the king eiders. For all species assessed in 1999, abundance in the coastal survey area was considerably lower in 2017. In some cases, this may be due to changes in distribution patterns. However, for thick-billed murre (Uria lomvia), long-tailed duck and black-legged kittiwake (Rissa tridactyla), the reduced coastal abundances coincide with declining breeding populations.