Practicality and Efficacy of Tori Lines to Mitigate Albatross Interactions in the Hawaii Deep-set Longline Fishery

The Hawaii deep-set longline fishery incidentally interacts with seabirds, primarily Laysan (Phoebastria immutabilis) and black-footed (P. nigripes) albatrosses. Following a successful introduction of a suite of seabird mitigation measures in 2001, black-footed albatross interactions have increased in the fishery over the past decade. The Western Pacific Regional Fishery Management Council (Council), at its 174th Meeting in October 2018, recommended that the National Marine Fisheries Service (NMFS) support the development of tori lines (also known as streamer or bird-scaring lines) and other alternative seabird bycatch mitigation measures. At its 176th Meeting in March 2019, the Council additionally recommended the development of draft minimum standards for tori lines. In 2019, the Council, Hawaii Longline Association, NMFS Pacific Islands Fisheries Science Center and NMFS Pacific Islands Regional Office implemented a cooperative research project to conduct a tori line demonstration and experiment in the Hawaii deep-set longline fishery. The project assessed the practicality of alternative tori line designs, determined the effect of tori line use on albatross interaction risk, and developed recommendations for tori line minimum standards. The project findings inform revisions to the Hawaii deep-set longline fishery seabird mitigation measures, expand the body of literature on tori line efficacy in longline fisheries, and highlight the potential for electronic monitoring (EM) systems to monitor variables that significantly explain seabird bycatch risk in longline fisheries.