Habitats of two albatross species during the non-breeding season in the North Pacific Transition Zone

The North Pacific Transition Zone (NPTZ) is one of the most productive offshore regions. To identify important habitats for pelagic top predators within this region, we investigated the at-sea distributions of black-footed (Phoebastria nigripes) and Laysan albatrosses (P. immutabilis) by vessel-based surveys during their non-breeding season (July and October in 2010 and September and October in 2011). We developed statistical models using satellite-based oceanographic data at spatial scales of 4, 20 and 80 km to explain their densities. For both species, sea surface temperatures (SST) and distance to the Emperor Seamounts emerged as important factors in the better-fitting models at all spatial scales. In addition, black-footed albatrosses were widely distributed in the NPTZ (SST 17.7–27.4 °C), whereas Laysan albatrosses favoured northern and colder waters (13.6–25.4 °C). Our results also indicated that the Emperor Seamounts, where trawling and longline fishing occur, were an important habitat for both species in the NPTZ. Therefore, careful attention should be paid to interactions between fisheries and albatross species in this region.