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Tagging turtles, sharks at Cocos Island

Cocos Island, one of the most diverse marine ecosystems on the planet, is shrouded in mystery. While scientists know the National Park off the coast of Costa Rica is a hotbed of underwater life, remarkably little is known about how those creatures live and migrate through the area.

"No one had really studied it," said Todd Steiner, founder and director of the Marin-based Turtle Island Restoration Network (TIRN), which seeks to protect sea turtles, species whose numbers have decreased more than 90 percent since 1985. In 2007, Steiner's organization began an ambitious campaign to place radio and satellite tags on sea turtles around Cocos Island. The ultimate goal is to understand where the turtles travel in their lifespan in order to get those areas protected from commercial longline fishing.

Sonoma's Greg Holzer, an avid diver himself, held the lucky raffle ticket that won him a trip to accompany the group of researchers to the protected marine sanctuary in March, where he assisted in not only tagging green sea turtles, but also hammerhead sharks. Steiner explained that TIRN works with a Costa Rica-based conservation nonprofit Programa Restauración de Tortugas Marinas (PRETOMA), which has recently launched a campaign against shark finning. For Holzer, it was an opportunity he never thought he'd get.

"It was always on my bucket list, but how do you make that happen?" he said, adding that private divers can wait years to get access to Cocos, as the area is highly protected and offers limited tourist trips. "It does not get much better for a diver. You're going to the pinnacle of marine life. It's a rest stop for hundreds of species ..."

Holzer has been a longtime supporter of TIRN and last year he bought a $125 raffle ticket during a fundraiser, not even knowing what the grand prize was. Suffice it to say, he was more than pleasantly surprised when he was notified he had won, and that the grand prize was a trip to Cocos Island for a week packed with research diving aboard the Argos, a ship chartered to take the team around the island.

"I think we made 24 dives over the seven days we were there," he beamed. "Those times when I was pretty much alone at a depth of 100 feet with hundreds of sharks just passing me, that was just incredible."

TIRN invites private divers to pay their own way and join the organization's research trip, and also holds an annual raffle through which, like Holzer, the winner can join an expedition. The money raised through this type of eco-tourism helps fund the Cocos campaign.

"The primary way we're funding this research is through citizen science volunteers. People get to go to the most incredible underwater place on the planet," Steiner said, adding, "We still have one spot open for our trip this September that we're trying to fill."

The process of tagging hammerhead sharks is remarkably simple, Holzer explained. Barbed radio tags are placed at the end of spear guns or spears, and divers merely swim up to the hammerhead and poke it into the shark. The barbs catch under the sharks' skin, adhering the radio tag that will stay in place for about a year. When asked if the sharks, which can grow to 14 feet in length, ever snapped back, Holzer said no.

"They just swim away," he said. "The hammerhead is way laid back, and kind of shy."

Sea turtles, he said, were the tricky animals to tag. Divers work in teams, with one person "catching" the turtle by holding onto its shell; the second person then assists in the ascent, helping to control the turtle to ensure a safe rate of decompression as the turtle, which can weigh up to 150 pounds, is brought to the surface.

"Can you imagine wrestling with this guy under water?" Holzer laughed.

The turtles are brought on the boat, where a satellite tag is attached to a hole drilled into the shell. The process does not hurt the turtles, and allows researchers to track the animals' movement for years. And the research is already paying off, Steiner said.

While scientists have long known that adult sea turtles live around the Galapagos Islands, it wasn't clear where the turtles grew up. After tagging a total of 71 green sea turtles and two hawksbill sea turtles, TIRN learned that the juveniles spend their youth around Cocos Island.

"They stay there until they become large enough to be sexually mature," Steiner said.

Costa Rica has a 12-nautical-mile no-fishing zone to protect marine life around Cocos, but Steiner said their research has shown the defined area is not large enough to adequately protect the turtles from longline fishing. TIRN and PRETOMA are working with the governments of Costa Rica and Ecuador (which has sovereignty over the Galapagos Islands) to have the heavily utilized waterways between the two islands protected from fishing.

"As soon as anything travels outside the no-fishing zone, they're vulnerable," Steiner said. "If we know what times of the year they're migrating, we can protect those areas from fishing."

But Steiner said the organization's ultimate goal is much more lofty. Scientists have long theorized that the oceans have several "super highways," areas where huge numbers of marine life travel during their regular migration, much like birds. TIRN is hoping its research will prove these highways exist, and define where they are.

"We're just collecting more and more data that these marine life all travel these waterways, or ocean highways if you will," Steiner said, adding that they are working with the United Nation's High Seas Coalition on the project, but it will be an uphill battle as the area is not owned by any one country, meaning all of the United Nations will have to come to a consensus. 

"It's not going to be easy, but that's not what we're looking for. We're looking at really doing substantial, long-term protection of how we treat the oceans," Steiner said.

Holzer said he was honored to have a part, however small, in the protection effort. But he knows he got more out of the experience than anyone.

"It really does change the way you look at diving and marine life," he said.

TIRN is currently selling raffle tickets for $100 for a chance to join the expedition from April 17 to 27, 2012. The drawing will be held Dec. 15. For tickets, visit www.seaturtles.org and search "raffle."