MARINE BIRDS IN THE MARGINAL ICE-ZONE OF THE BARENTS-SEA IN LATE WINTER AND SPRING

We recorded the distribution and abundance of marine birds in the nort hern Barents Sea from 27 February to 8 March 1987 and from 20 to 31 Ma y 1988. Birds were more abundant in waters associated with pack ice th an in open water away from pack ice. Within the pack ice, thick-billed murres (Uria lomvia) were the most commonly encountered birds in both periods. Murre densities in the pack ice north of the zone proximate to the ice edge were positively correlated with distance from the ice edge. Large leads were more frequently occupied by murres than small l eads, and had larger numbers of birds present. In spring, we found mor e birds along a well-defined ice edge than were present either in open water or in leads in the pack ice within 5 nautical miles of the ice edge. Transects along the ice edge revealed little correlation in abun dance between species, or within species when coverage was repeated du ring the same day. We conclude that the birds showed considerable spec ificity of habitat choice within the habitat divisions that we recogni zed and that avian patches were of short duration. We need information on the distribution, abundance and movements of prey patches if we ar e to understand the changing distribution patterns of the birds.