Using a Bayesian general linear mixed regression modelling approach, experimental hooks sank to 85 cm ca.
There was a significant 53% (95% HDI: − 75 to − 25%) decrease in retained species’ catch rates on experimental hooks, indicating an unacceptable economic cost, and no significant effect for discarded species. We used a Bayesian random effects meta-analytic regression modelling approach to estimate pooled expected species-specific log relative risk of capture on conventional versus experimental gear. We conducted experimental fishing to compare the commercial viability of a weighted hook relative to conventional gear with weights attached 0.75 m from the hook. A branchline weight’s mass and distance from the hook affect seabird catch rates. Seabirds interacting with this fishery reach hooks at depths up to 1 m. Albatross bycatch in a US North Pacific tuna longline fishery has increased over the past decade and now exceeds 1000 annual captures.
Fisheries bycatch threatens the viability of some seabird populations and reduces fishing efficiency.