Hook Comparison Project

The Hook Comparison Project in the Grenadian pelagic longline fishery has officially begun with fishing experiments comparing J hooks and circle hooks on commercial vessels.

In the Caribbean region, tunas are the preferred catch and have a higher value than billfish, as tunas can be exported if they are of sufficient quality. However, many in these regional fleets don't consider billfish as bycatch since these species provide both a source of food and revenue for local fishers. As such, the Caribbean Billfish Project (CBP) hopes to learn through these experiments if circle hooks can increase tuna catches. Circle hooks also tend to result in fish being caught in their mouths, rather than foul-or deep-hooking, which can result in more fish being landed alive. For tunas, being alive when harvested greatly improves the economic quality of the individual fish. By increasing the catch and economic value of tunas, the wider use of circle hooks in these pelagic longline fisheries could ultimately reduce incentives for fishers to target billfish while also providing the additional benefit of enhanced post-release survival for billfish that are subsequently released.

So far, Nova Southeastern University fisheries scientist Dr. David Kerstetter has collected data from one vessel and its first trip under the Hook Comparison Project. The analyses of these preliminary data show that the catch per unit effort (CPUE) are higher for circle hooks than for J hooks, and that circle hooks slightly increased the number of tuna and billfish caught still alive when the gear was retrieved. Although Dr. Kerstetter and his team will require more data for these trends to show any statistical significance, these new developments coincide with what has been reported in other prior hook comparison studies conducted in other countries. There are two vessels currently fishing Grenadian waters with onboard observers recording the species and condition of captured fish, and including the economic value of each individual tuna (the "grade") when sold, which will allow further analyses of the results. More information will be collected throughout the next two months.


Tuna Alternating Hooks
Tuna Graders decide the price paid for each tuna