Food and feeding ecology of the neritic-slope forager black-browed albatross and its relationships with commercial fisheries in Kerguelen waters

Food and feeding ecology of black-browed albatrosses Diomedea melanophrys r earing chicks was studied during 2 austral summers (1994 and 1995) at the K erguelen Islands. Dietary analysis and satellite tracking were used to esti mate potential interactions with commercial fisheries in the area. Fish com prised 73% by fresh mass of albatross diet; other significant food items we re penguins (14%) and cephalopods (10%). Twenty-one species of fish (232 in dividuals) were identified and included mainly nototheniid and channichthyi d species. The most important were Dissostichus eleginoides (18.3% by recon stituted mass), Channichthys rhinoceratus (16.9%), Lepidonotothen squamifro ns (11.6%), and to a lesser extent, Bathyraja sp. (4.5%) and Notothenia cya nobrancha (4.5%). The cephalopod diet was dominated by 3 taxa, the ommastre phid squids Todarodes sp.(7.6%) and Martialia hyadesi (3.6%), and the octop us Benthoctopus theilei (2.4%). Satellite tracking indicated that during tr ips lasting 2 to 3 d, albatrosses foraged mainly over the outer shelf and i nner shelf-break of the Kerguelen Archipelago. Birds moved to northern, eas tern and southern waters, but never to the western Kerguelen shelf where th ere was a commercial longline fishery for D. eleginoides. Interactions with trawlers targetting D, eleginoides and Champsocephalus gunnari were of min or importance in the northern shelf. There, offal from D. eleginoides was a vailable to the birds; fish and cephalopod bycatch were negligible. Most of the natural prey of black-browed albatrosses are primarily benthic and sem ipelagic organisms not known to occur near the surface. Since we demonstrat e that most of them were not scavenged behind fishing vessels, the way alba trosses catch demersal organisms remains a mystery.