Experiment to evaluate gear modification on rates of sea turtle bycatch in the swordfish lonline fishery in the Azores - Phase 4

The objective of this project was to conduct an experiment to evaluate effects of gear modification on rates of sea turtle bycatch in the swordfish longline fishery in the Azores. Based on results from Phases 1, 2 and 3 of this project (years 2000, 2001, 2002), the primary variables evaluated in Phase 4 of the project (year 2003) was hook type and size: Circle hook 16/0 non-offset (Mustad # 39960), Circle hook 18/0 non-offset (Lindgren-Pitman), and Japanese tuna hook 3.6mm S/S (Ocean Producers International # OPI023). Although the primary objective was to evaluate the effect of hook type on rates of sea turtle bycatch, the effect of hook type on the location of hooking (e.g. mouth versus esophagus) was also evaluated. The location of hooking has very important implications for the survival of the hooked turtles. Effect of hook type on rates of catch for target species was also evaluated.