SANTA CRUZ, CA--Industrial fishing operations take plenty of blame for both depleting fish stocks and inadvertently catching innocent bystanders such as dolphins, sharks, seabirds, and sea turtles--a phenomenon known as "bycatch."
But new research shows that a small-scale Mexican fishery--operated by hand from small open boats--can kill as many critically endangered loggerhead sea turtles as all of the industrial fishing fleets in the North Pacific Ocean put together. On a per-hook or per-net basis, the Mexican fishery is 10 to 100 times as deadly, the study found. The research has already resulted in a voluntary turnaround in the fleet's fishing practices and the declaration of an offshore turtle refuge.
"The impacts of small-scale fisheries have been overlooked because they are inherently difficult to study," said lead author Hoyt Peckham, a Ph.D. candidate in ecology and evolutionary biology at the University of California, Santa Cruz.
Peckham and colleagues worked alongside Mexican fishermen to simultaneously measure and reduce the accidental turtle catches. Their findings suggest that small fishing operations, which are ubiquitous along coastlines the world over, can have drastic, unintended effects on ocean wildlife such as sea turtles. The work appears in the October 17 edition of the online, open-access journal PLoS ONE.
"It was really surprising to me, because when I think of bycatch I think of massive factory trawlers with huge catch rates decimating the oceans," Peckham said. "What's striking in this work is that some small-scale fleets can kill many more turtles, because they fish where turtles are most abundant."
One such place is off the coast of Baja California Sur, Mexico, where perennially rich turtle feeding waters overlap with a small patch of favored fishing grounds. Local fishermen ply these waters for halibut and other bottom-dwelling fish using gill nets and strings of hooks known as longlin
|Contact: Hugh Powell|
University of California - Santa Cruz