Seabirds between Alaska and Hawaii

Seabirds were observed between Alaska and Hawaii along 158°W longitude from 24 October to 6 November 1976. Their distributions and abundances corresponded remarkably well to oceanographic regions. Indices of seabird density dropped in a series of plateaus from 44 birds/km² in the Alaska Current System to less than 1 bird/km² in subtropic waters. Northern distribution records were found for six species. The Subarctic Boundary marked the center of the separation between subarctic and subtropic pelagic avifaunas.