Collaborating with Fishermen to Reduce Seabird Bycatch in U.S. West Coast Sablefish Longline Fisheries

Bird scaring lines (BSLs) protect longline fishing gear from seabird attacks, save bait and reduce incidental seabird mortality. We collaborated with fishermen to assess whether proposed regulations, based on Alaska BSL performance standards, will be practical and effective for west coast demersal longline fisheries. Unlike Alaska, some west coast vessels use floats and weights to keep hooks off the seafloor where macroinvertebrates degrade bait and target catch. Longlines with floats sank beyond the reach of albatrosses (2 m depth) 2.25 times further astern than gear without floats. Attack rates for most vessels without floats remained low within the distance astern at which gear sank to 2 m (66.3 m ± 7.3 SE). Therefore, most west coast vessels without floats can be protected using Alaska BSL specifications. However, the delayed sink rate of longlines with floats extended the seabird attack zone (149.7 m astern ± 19.7 SE) well beyond the BSL aerial extent (34.4 m astern ± 1.6 SE). Attack rates increased with distance astern for longlines with floats, even with the use of paired BSLs. Therefore, performance standards may be inadequate for this gear type and further refinement is needed.