Managing pelagic longline-albatross interactions in the North Pacific Ocean

The Short-tailed Phoebastria albatrus, Black-footed P. nigripes and Laysan P. immutabilis Albatrosses, all native to the North Pacific, interact with demersal and pelagic longline vessels and may on occasion be caught by a baited hook and drown. This problem has been studied in detail for 105-115 pelagic longline vessels home-ported in Hawaii, which take between 1000-2000 each of both Black-footed and Laysan Albatrosses each year. No takes of Short-tailed Albatrosses have been reported for the Hawaii longline fishery, but between 1993 and 1997, five birds were incidentally caught in the Alaska longline fisheries. The Black-footed and Laysan Albatrosses are most vulnerable to longline fishing for Broad-billed Swordfish Xiphias gladius, where longlines are set near the surface, providing ample opportunity for albatrosses to intercept baited hooks. Studies of the rarer Black-footed Albatross population revealed fishery-induced mortality to be a chronic rather than a catastrophic source of mortality. Some simple mitigation methods implemented in the fishery should reduce the incidental catch of albatross by an order of magnitude and eventually lead to negligible take levels. However, the Hawaii-based longline vessels targeting swordfish represent only a small fraction of pelagic longline effort in the North Pacific and albatrosses will continue to be taken by Japanese, Taiwanese and Korean longliners operating in the same vicinity. These Asian vessels fish primarily for tuna Thunnus spp. and are likely to have much lower albatross take rates than the Hawaii-based fleet, but collectively these 3000+ vessels still represent a significant threat to North Pacific albatrosses. Although several multilateral agreements identify cost-effective methods to reduce significantly the incidental catch of seabirds in longline fisheries, very few international or national fishery management organizations require longline fishers to employ these mitigation measures. There is a need to strengthen international efforts to reduce seabird mortality on longlines, and for effective monitoring of albatross populations to gauge the success of mitigation measures.