Abstract
The pelagic distribution of the Short-tailed Albatross Phoebastria albatrus in the western North Pacific off the Nansei Islands to eastern Japan was examined from data collected by research vessels from 1999 to 2004. Fifteen groups and 325 individuals of Short-tailed Albatrosses were recorded during line-transect sighting surveys, and 25 groups and 45 individuals were recorded in opportunistic observations during cruising, drifting and experimental fishing. Results of the sighting survey revealed that Short-tailed Albatrosses appeared in three areas off Japan from the fourth quarter to the next second quarter: 1) off the Pacific coast of eastern Japan, 2) near Torishima of the Izu Islands, and 3) near Minamikojima of the Senkaku Islands. Geographical analysis of the occurrence points showed that large numbers of Short-tailed Albatrosses aggregated in the near-shore waters within 30 km of the breeding islands, and that they also utilized the Kuroshio-Oyashio mixture zone above the continental shelf edge and slope 200–1400 m in depth and 20–70 km offshore of the Pacific coast of eastern Japan. Results of this study suggest that a resting area near the breeding islands and a foraging area above the continental slope off eastern Japan are important marine habitats for the Short-tailed Albatross during the breeding period.
