Annual Report on the Hawaii Longline Fishing Experiments to Reduce Sea Turtle Bycatch under ESA Section 10 Permit 1303

Fishing experiments were designed to test various gear modifications for the pelagic longline fishery in Hawaii, United States, to reduce sea turtle interactions. The experiments tested (1) daytime "stealth gear" (2) deep daytime setting, and (3) circle hooks combined with hook timers. Stealth gear and deep setting both caught significantly fewer swordfish compared to the control, although overall catch was reduced by 39% using stealth gear and was approximately similar to the control using deep setting. Neither gear configuration resulted in the take of any sea turtles (compared to one turtle in the control). Initial testing of hook timers with circle hooks resulted in the catch of two sea turtles. Circle hooks were also 40% as effective as J hooks at catching swordfish, and 94% as effective at catching tuna (by weight and value).