A comparison of circle hook and J hook performance in a western equatorial Atlantic Ocean pelagic longline fishery

Effects of circle hooks on pelagic catches in the Hawaii-based tuna longline fishery

“…Longline field trials in the western equatorial Atlantic Ocean demonstrated a significantly higher catchability for bigeye tuna on 18/0 circle hooks compared to Jhooks, which is contrary to our results (Pacheco et al, 2011). Catchability on 18/0 circle hooks in our study was reduced for incidental and bycatch species compared to J-hooks which is in contrast to most studies, especially for billfish.…”

Fishing gear modifications to reduce elasmobranch mortality in pelagic and bottom longline fisheries off Northeast Brazil

“…While there could be a concern regarding the impact of such modifications on the catch rate of valuable target species, such as tunas and billfishes, growing evidence has been demonstrating that some strategies have no negative effects on harvest, and so they would not necessarily pose any economical threat to fisheries. In spite of the catch rate of tunas and billfishes was not herein addressed, a recent study conducted in the same region verified that the circle hook utilized in this experiment did not exhibit any reduction in the CPUE of that target group when compared to the commonly used J-style hook (Pacheco et al, 2011). Thus, it seems advisable to consider such potentially effective measures for integrating more efficient management plans of oceanic fisheries, especially given the fact that they are comparably inexpensive and quick to implement.…”

Shark bycatch and mortality and hook bite-offs in pelagic longlines: Interactions between hook types and leader materials

“…Circle hooks, as opposed to J-hooks, have been suggested to be an effective tool to reduce bycatch mortality in pelagic longline fisheries (Cooke and Suski, 2004) because they tend to promote hooking in the jaw (Afonso et al, 2011;Montrey, 1999;Pacheco et al, 2011). Gut-hooked sharks show higher at-vessel (Afonso et al, 2011;Kaplan et al, 2007;Kerstetter and Graves, 2006) and postrelease (Campana et al, 2009;Moyes et al, 2006) mortalities due to damage to the esophagus and gastric wall (Borucinska et al, 2002) than jaw-hooked specimens, whose survival rate should be regulated mostly by soak time (Diaz and Serafy, 2005;Morgan and Carlson, 2010).…”