The global average for turtles hooked per 1,000 fishing long-lines is three. In Costa Rica, an estimated 10 to 14 turtles are caught per 1,000 long-lines, giving the country the inglorious distinction of world leader in the category.
From 1999-2008, observers from the Marine Turtle and Restoration Program (Pretoma) monitored 218 expeditions that left from the Playas del Coco beach and fished the Gulf of Papagayo in the northwestern Guanacaste province. During the observations, Pretoma employees aboard a fleet of 12 boats kept a running tally of the number of turtles hooked during the 10-year span. Given their findings, Pretoma multiplied the amount of hooked turtles by 450, which is roughly the number of national fishing boats.
“We determined that if one boat catches a certain amount of turtles per 1,000 hooks, then we could extrapolate the information to calculate an average for all the national fishing boats,” said Randall Arauz, president of Pretoma. “The sample size is small but given the information we obtained, it’s safe to say that hundreds of thousands of turtles are being hooked in Costa Rican waters.”
While Costa Rican waters have the highest catch rate of turtles per 1,000 hooks, Arauz said the number isn’t particularly surprising due to the high concentration of turtles on both coasts.
“No other country has two arribada [mass nesting] beaches within 50-kilometers of its beaches. It’s not that surprising that Costa Rica has the highest percentage,” Arauz said.
Though the high incidence of hooked turtles in turtle-dense waters is expected, Arauz said that the figure represents a need for a national fishing schedule. According to national fishing statistics during the last 10 years, the highest catch rate for mahi-mahi in Costa Rican waters is from December to May.
When the mahi-mahi catch decreases in September and October, the number of sharks and turtles caught spikes.
“Even when there aren’t any mahi-mahi being caught, fishermen are still out there long-line fishing and catching mostly sharks and turtles,” Arauz said. “What we need to do is make a schedule in Costa Rica for when to fish for each type of fish. It would reduce the amount of irresponsible fishing in national waters. It’s a very obvious solution.”
An often-cited figure estimates that 80-90 percent of the ocean’s sharks have disappeared in the last 50 years. Mahi-mahi populations have also diminished significantly since 1990. The opposite effect is true for turtles. Given the sharp decline in the number of sharks, the turtle population is growing.
“Sharks feed on turtles so it is logical that turtles, without the effect of that predator, are more abundant,” Arauz said. “It’s disappointing to see the ocean’s natural course disrupted. It all stems from mismanagement. It could all be changed so easily if countries managed their waters more responsibly.”