This undated image released by the Wider Caribbean Sea Turtle Conservation Network, or Widecast, shows Jairo Mora Sandoval, center, speaking to people at an unknown location in Costa Rica. (Widecast/Associated Press)

Jairo Mora Sandoval knew his work was dangerous. The 26-year-old Costa Rican, who was paid to protect endangered leatherback sea turtles and their eggs on a Caribbean beach in the tiny Central American nation, had been threatened many times — probably by poachers, possibly by drug traffickers. Both kinds of criminals share a keen interest with conservationists in the 11-mile stretch of public sand just outside the city of Limon, in the country’s poorest province.

But in what is quickly becoming a watershed moment for environmental activists, Mora was kidnapped with four foreign volunteers and killed Friday, the first slaying anyone can remember among the legions who flock to eco-friendly Costa Rica to help protect endangered species. The four female volunteers, three from the United States and one from Spain, were tied up and robbed but left unharmed.

The killing already has begun to scare away volunteers, many of whom are young Americans, according to Mora’s nonprofit employer. Some believe the slaying could even affect the Costa Rican economy, which depends heavily on eco-tourism. It has drawn reaction from the Costa Rican president and the U.S. Embassy and has prompted a meeting of interested organizations held by the Costa Rican Ministry of the Environment on Tuesday.

The slaying also is seen as another sign that drug trafficking, once a small concern in Costa Rica, could be encroaching on a nation that prides itself on the many ways it is different from the rest of Central America.

“The work of protecting nesting beaches is basically done by nonprofit organizations and individuals who donate their time and resources to help. This entire conservation strategy is at risk,” said Todd Steiner, executive director of the Turtle Island Restoration Network in Olema, Calif. “It’s critical that the whole world pays attention to this and assures that these murderers are brought to justice and there is a commitment from the government to protect individuals, the endangered species and the tourists who basically make the economy of Costa Rica work.”

Steiner’s organization and other conservation groups have pledged a $12,000 reward for information that leads to the arrest and conviction of Mora’s killers.

“We’ve never experienced anything remotely like this,” said David Godfrey, executive director of the Sea Turtle Conservancy in Gainesville, Fla., the 54-year-old organization whose founder, Archie Carr, is considered the father of sea turtle protection efforts. “. . . We’re all still a little bit in shock and trying to figure out how best to respond.”

Mora and the four volunteers had finished their patrol of leatherback nesting sites on Moin beach about 3 a.m. Friday and were driving along a beachfront road when they came to a spot blocked by a downed palm tree, Cristina Volkart Obando, vice president of the board of directors of the Wider Caribbean Sea Turtle Conservation Network (Widecast), said in a telephone interview from San Jose, Costa Rica. When Mora got out to move the tree, a group of masked, armed men grabbed him and the women and took them to an abandoned house, where the women were tied up and robbed of their money and cellphones.

Mora was stripped naked, tied to the rear bumper of the car and dragged up the beach, Volkart said. Then he was shot in the face. His body was found on the beach about 7 a.m., she said. According to a Costa Rican newspaper, Mora died of injuries caused by blunt force trauma.

Widecast had employed Mora for about two years to walk Moin beach at night during nesting season, when leatherbacks, which can grow to 2,000 pounds, lay an average of 80 eggs in many hundreds of nests, she said. The primary breadwinner for his mother and sisters, Mora had been working with sea turtles since he was 15, she said. “It is not easy work,” she said. “You have to do it during the night, you have to do it during the rain . . . For him it was always the turtles. Working with the turtles, that was his main reward.”

Poachers can get $1 for a sea turtle egg, she and Godfrey said, from Costa Ricans who eat them for food or as alleged aphrodisiacs and fertility agents. Sea turtle shells and meat also are prized commodities. It is illegal to take any of the three.

Mora patrolled unarmed and was instructed to back off and call authorities if he saw poaching or other illegal activity. But police and the coast guard have not been very responsive this season, Volkart said, and Mora was vocal about the need for a better response, she said. Recently he was quoted in a local newspaper saying that poachers often are connected to drug traffickers, Volkart said. “He wasn’t scared of saying things, what was going on there,” Volkart said, though that courage often brought threats. The organization would withdraw Mora for a few weeks but always sent him back, confident that the harassment would not lead to violence, she said.

“The thing is, here in Costa Rica, until now . . . never, ever [has] someone crossed that line to make threats real,” she said.

Already, three groups have canceled their volunteer projects with Widecast, she said, and the organization has pulled out of Moin beach. The U.S. Embassy posted a message on its Facebook page saying that it is “deeply concerned about the senseless death of Jairo Mora Sandoval, a committed environmentalist who was raising the alarm about the threats conservationists receive from criminal groups trafficking in drugs or wildlife.”

Carr, founder of the Sea Turtle Conservancy, started his work in the 1950s in Tortuguero, Costa Rica, just 50 miles but a world away from Moin beach, Godfrey said. The turtles there nest in what is now a national park, protected by government personnel.

But Moin is a public beach, he noted, where authorities are spread thin and locals may have resented volunteers interfering with a tradition of consuming turtle eggs that goes back generations. “Maybe there’s a level of acceptance that egg poaching and turtle poaching is part of the history of Costa Rica and even though it’s illegal, that’s going to happen,” he said.

Steiner’s organization sent a group of volunteers to Costa Rica this weekend, but only after checking on the safety of the area, and Godfrey’s has concluded that it won’t charge its normal cancellation fee to anyone who pulls out because of Mora’s killing.

But the group’s work has to continue, he said. “This whole organization exists to study and protect sea turtles. The roots of our work are on the Caribbean coast of Costa Rica,” he said. “We don’t walk away from that.”