Effects of recent decreases in arctic sea ice on an ice-associated marine bird

摘要: Recent major reductions in summer arctic sea ice extent could be expected to affecting the distributions and life histories of marine biota adapted living adjacent ice. Of concern are effects reductions, associated increasing SST, on most abundant forage fish Arctic, Arctic cod (Boreogadus saida), primary prey for region’s upper trophic level predators. The black guillemot (Cepphus grylle mandtii) is an ice-obligate diving seabird specializing feeding has been studied annually since 1975 at a breeding colony western Beaufort Sea. data set one few allowing assessment response predator recent decadal changes cryosphere. Analysis oceanographic conditions north from 2012 annual period when parents provision young (mid-July early September), found no regime shifts or SST until late 1990s with decreases increases first decade 21st Century. We examined variation conditions, nestling diet success, overwinter adult survival, comparing historical (1975–1984) (2003–2012) one. In retreated average 1.8 km per day 15 July 1 September distance 95.8 colony, while retreat averaged 9.8 506.9 same time period. island increased 2.9 C between two periods. While comprised over 95% provided nestlings period, 80% years had seasonal decreases, decreasing <5% diet, nearshore demersals, primarily sculpin (Cottidae), comprising majority diet. A five-fold increase rate starvation growth fledging mass were shift cod. Annual survival during nonbreeding season (September–May), showed significant difference periods, indicating change availability other wintering area Bering Our findings substantial decrease decreased have implications entire given ongoing predicted basin-wide