Study: Circle hooks help save sea turtles

Preliminary results from the first large-scale testing of specially designed fishing hooks are being presented at the Annual meeting of the Inter-American Tropical Tuna Commission in Lanzarotte, Spain. Thus far, the results indicate the use of circle hooks can reduce the number of endangered sea turtles killed in long line fishing operations by as much as 90 percent, World Wildlife Fund said Friday.

Incidental death—as a result of traditional long line fishing operations—is one of the main reasons for the precipitous decline of loggerhead, and giant leatherback turtles, whose numbers in the Eastern Pacific have plunged by more than 90 percent over the past 20 years.

The results of a year-long study involving 115 Ecuadorian fishing vessels found “bycatch” was dramatically reduced when the boats replaced their traditional “J” shaped hooks with specially designed circle hooks. “This is win-win situation. We were looking for a way to save the turtles without putting the fishermen out of business. The preliminary results indicate we’ve found it. Circle hooks seem to be an effective new tool in our efforts to address this urgent conservation problem” said Moises Mug, Fisheries Coordinator for WWF’s Latin America and Caribbean program.

Over the past year, Ecuador’s tuna and mahi-mahi fisheries each toasted one large and one small circle hook. Larger devices reduced the number of sea turtles that got hooked by 88 percent in the tuna fishery and 37 percent in the mahi-mahi fishery. The smaller hooks proved less effective, but still reduced bycatch rates by 44 and 16 percent, respectively.

“We believe mortality rates were reduced further because the circle hooks rounded shape was less likely than J hooks to get swallowed by turtles,” said Kim Davis, deputy Director of WWF-US’ marine program. “The hookings generally were in the mouth area, with a greater chance of the turtle being released without serious injury.”

So, when the survival rate for hooked turtles was factored into the results, the researchers estimated that the circle hooks reduced sea turtle mortality by 63 to 93 percent in the tuna fishery and 41 to 93 percent in the mahi-mahi fishery, depending on the size of the hook used.

Also encouraging was that catch rates for tuna were almost identical regardless of whether circle or J hooks were used. The catch rate was lower in the mahi-mahi fishery, however, and researchers said further refinement of fishing gear and better training of fishermen would be needed to close the gap.

The research was developed with the participation of many local stakeholders, government, industry, fishers unions and co-operatives, and environmental groups. “The Ecuadorian government and fishermen deserve a lot of credit for being leaders in this effort,” said Mug.

Fishermen attended training workshops and onboard monitors helped to collect the data. (PR)