Winter Seabird Populations in Open Waters of the Sea of Okhotsk

Abstract

Shipboard observations were conducted during the Sea of Okhotsk walleye pollock expedition in January–April 2015. The surveys showed that the modern winter avifauna of the open waters of the Sea of Okhotsk includes at least 19 species of seabirds. According to transect survey data, the average distribution density of all birds was 10.0 ind./km². Alcids (47.9%), procellariids (33.1%), and larids (18.8%) dominated among the winter populations, while albatrosses and storm petrels each accounted for 0.1%. The short-tailed shearwater, fork-tailed storm petrel, black-legged kittiwake, red-legged kittiwake, pigeon guillemot, and tufted puffin were recorded in the inner part of the sea in the winter for the first time. The changes in seabird populations might be due to a significant reduction in the ice cover of the Sea of Okhotsk.