San José, Costa Rica, since 1956

What killed the turtles?

The Osa Peninsula’s pristine beaches were left in disarray this week when 280 dead turtles and other sea animals washed ashore on Monday along 10 kilometers of coast between Punta Banco and Playa Pavones, in the Southern Zone. 

“Turtles do not normally die in mass like this,” said Didiher Chacón, Latin America director of the Wider Caribbean Sea Turtle Network (WIDECAST).

Most of the animals that washed ashore were olive ridley turtles, but officials also found marlin, sailfish and green turtles. Both species of sea turtles are recognized as vulnerable on the International Union for Conservation of Nature’s red list for endangered and threatened species.

On Tuesday morning, WIDECAST sent two investigative teams to the area. Researchers pulled five recently killed turtles and two live ones from the water for lab analysis. 

Coast Guard officials found another 15 dead olive ridley turtles during a boat patrol. Alarmed by the lack of physical damage to the turtles, the Coast Guard released a statement on Tuesday warning the public about possible bacteria infecting the area’s waters.

“It is possible that we are talking about a toxin like red tide,” Chacón said on Tuesday before lab results were finished. “But turtles usually do not have the same problems with bacteria that mammals do, and now, we are almost 100 percent sure it is something related to fishing.”

According to Chacón the absence of fishing hooks and lines on the turtles does not rule out fishermen as the cause.

“We did find hooks and lines in a fraction of the turtles on the beach,” he said, “but sometimes fishermen will remove the hook and cut the line. The lab tests will determine if the turtle drowned or not.”

Preliminary tests completed Wednesday afternoon showed foaming mucus and water in the turtles’ lungs. This, along with physical tests, showed the cause of death was forced submersion – likely from long-lines used by fishermen. 

Officials will send these and additional test results to the judicial system to determine if fishermen are to blame. As a protected marine area, long-line fishing is illegal in the Golfo Dulce. Both Chacón and the Waters and Oceans Vice Ministry also confirmed that there were indications that live bait was used.

According to a statement released by the Marine Turtle Restoration Program (PRETOMA), area residents have spotted long-line vessels in the gulf for the past 10 days.

“We have been patrolling the area, but because of the area’s proximity to Panama there is no way of knowing if this incident occurred here or in international waters,” said Jackelyn Rivera, an adviser at the recently created Waters and Oceans Vice Ministry, part of the Environment Ministry. “We have yet to find a fishing vessel nearby.”

Coast Guard Director Martín Arías, said, “If it was illegal fishing, we have no way of knowing if it took place in the Golfo Dulce.”

WIDECAST and other environmental groups criticized government agencies for failing to take action against illegal fishing in the gulf.

“At WIDECAST, we send boats out to tag turtles all the time, and there is not a population outside of the gulf significant enough to account for this number of dead turtles,” Chacón said. “It having happened outside of the gulf is an improbable scenario.”

In a joint statement issued on Wednesday, environmental groups said that local fishing organizations have been reporting the presence of long-line and live-bait fishing vessels in the area since early January. Conservationists accused the Coast Guard of ignoring those complaints, as well as other incidences involving sailfish and marlin. 

“What is happening in the south of Costa Rica is something that happens every day,” said Donald McGuiness, president of the Costa Rican Association for Responsible Fishing. “If long-lines are going to be used as a tool for fishing, it needs to be in an area with good conditions and space to use that tool. If not, the deaths of turtles will be permanent and inevitable.”

The incident has caused environmental groups to call for increased vigilance from the Coast Guard in the area, citing international laws requiring the country to protect endangered species.

“If there is no control and monitoring in these protected areas by government authorities, these situations will continue to happen,” said Mónica Gutiérrez, president of ProNature, an environmental group. “This is a joint effort; NGOs provide knowledge and resources, and the government should then ensure proper compliance through regulation.”

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