Sea turtles can get accidentally caught and killed in fishing operations, and new research out Monday seeks to map this phenomenon for the first time in a bid to save the endangered creatures.
The study in the journal Ecosphere said sea turtles in the East Pacific, North Atlantic, Southwest Atlantic and Mediterranean face the highest bycatch mortality rates.
However, not enough is known about the problem in much of the world, with "significant data gaps" in the Indian Ocean and the waters off Africa and southeast Asia highlighting the "urgent need for increased monitoring," said the study.
"We lose hundreds or thousands of turtles each year in populations that are already at risk," said lead author Bryan Wallace of Duke University. "Many sea turtle populations around the world could face local extinction if we don't reduce bycatch."
Researchers also found that near-shore fisheries pose a significant threat to turtles, rivaling that of large scale, open ocean fisheries.
The highest bycatch rates in the world were found in small-scale fishing operations off the coast of Baja California, Mexico. There, a 100-boat fishing fleet has been found to be lethal to as many loggerhead turtles annually as all other fisheries in the North Pacific combined, according to Conservation International.
Last year more than 2,000 turtles were killed by the small fleet, marking a 600 percent increase over previous mortality estimates, the group said.
The analysis was based on more than 1,800 bycatch records spanning back two decades, and was done by researchers from Conservation International, Oceanic Society, San Diego State University, Duke University and Stanford University.
"This study should serve as an initial roadmap to prioritize investment of limited resources to sustainably manage fisheries to minimize bycatch," Wallace said.
Previous research has shown that use of nets with turtle-sized escape hatches can drastically cut back on accidental deaths.
Six of the world's seven species of sea turtles are considered endangered.