Scientists say tumors found on 70% of lagoon reptiles
By Suzanne Wentley Ft. Pierce Tribune staff writer
December 15, 2002

"It's not a pretty picture out here, as far as the tumors. No one has proved it yet, but to me, the water quality in the lagoon has something to do with it."
Michael Bresette, one of the founders of the Inland Research Group

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For the determined group of turtle researchers, it seemed like the morning on the water -- almost five hours of watching brown pelicans cruise over the light chop of the Indian River Lagoon -- would be wasted.

While little sea turtle heads broke through the green tint of the water's edge to catch a breath, no turtles found their way into the 150-meter net the team of three scientists had set.

But just as they were ready to call it a day, one mid-sized turtle dived straight into the middle of the net.

"All right, he's in there. Let's check him out," said Michael Bresette, one of the founders of Inland Research Group, a new non-profit organization designed to support long-term studies of the lagoon in Fort Pierce and Jensen Beach.

Aided by years of experience with sea turtles -- and protected by a state permit authorizing the research -- Bresette and fellow scientist Bruce Peeryy pulled the turtle into the boat they'd borrowed from the Florida Marine Research Institute and began to examine the startled creature.

Their regular job -- the one they get paid for -- is monitoring intake canals near the St. Lucie Nuclear Plant for sea turtles sucked in with the cooling water. On their days off, they volunteer their time to document the high occurrence of cancerous tumors on green sea turtles in the Indian River Lagoon.

Since starting the study in 1998, almost 70 percent of the turtles they've caught in the net have had the disease, known as fibropapillomatosis.

That number is compared with the turtles they catch at the power plant, which live their juvenile lives on the wormrock reef of the Atlantic Ocean. Only 3 percent of those turtles have the cauliflower-like tumors on their flippers, mouths and eyes.

The cancer doesn't directly kill the turtle, but the tumors often grow so large they restrict movement and sight, making it almost impossible for the animal to eat or escape predators and boats.

"It's not a pretty picture out here, as far as the tumors," Bresette said. "No one has proved it yet, but to me, the water quality in the lagoon has something to do with it. Cleaning up the Indian River Lagoon should be people's main priority."

Until the scientists committed their time, there was never a comprehensive study of the disease in the southern part of the Indian River Lagoon. The green sea turtle that swam into the net last week will add to the large database of scientific knowledge.

After pulling the turtle into the boat and struggling to free it from the net, Bresette and Peery conducted a standard examination of the patient with its green-and-brown, intricately mottled shell, large, dark eyes and breathing that sounded like a bored, heavy sigh.

First, the turtle was measured at 68.3 centimeters long, not far from the largest the team has ever caught in the lagoon, which was 70.4 centimeters.

"This is the size when we think they start to leave the area," Bresette said, explaining that most adult green turtles travel south to Central America or the Caribbean to mate.

The two scientists, earlier accompanied by fellow researcher Rick Herren, originally set out to capture a green sea turtle over 70 centimeters long so another researcher from the University of Central Florida could attach a satellite tag to track its movements out of the lagoon.

After measuring its head, body and shell, they checked for tumors. The turtle had regressed tumors, one the size of a golf ball on a back flipper and a few dark gray blotches on a front flipper. That's good news for the animal.

"It's got good body fat and is in good shape, except for the tumors. But they're regressing," Bresette said. "Ones who get it moderately and regress, they fare usually pretty well. When it's severe, it's not a good sign for them."

Because the turtle had no tags on it, Bresette and Peery used a cattle ear piercer to put two metal tags on the inside the turtle's front flippers.

Because those tags fall off after a little more than a year, they also injected the turtle with what is known as a pit tag -- a tag the size of a grain of rice that can be read with a special scanner.

With the tags in place, future researchers throughout the world will be able to compare the turtle's future health with the data collected locally.

After taking pictures, the two lifted the turtle by its shell and gently slipped it over the gunwale, to watch it swim away into the murky depths of the Indian River Lagoon -- but not before getting a good splashing.

"He sure got the last laugh with that one," Bresette said, looking down at his soaked T-shirt.

It was a typically smooth catch-and-release, Peery said -- unlike the time he was stung by an eagle ray that was unintentionally tangled in the net. The mesh of the net is too big to catch other kinds of fish, he said.

Last year, the scientists were commissioned by the U.S. Fish and Wildlife Service to conduct a similar study of sea turtle populations at the Key West National Wildlife Refuge. But there, instead of using a net in the clear waters, they caught the turtles "rodeo style," chasing them with a boat and having a diver jump on their backs, wrestling the animals into the boat.

After a five-year report is presented to the National Marine Fisheries Service and the Florida Fish and Wildlife Conservation Commission, Bresette and the other scientists with Inwater Research Group hope to continue the study in Fort Pierce and extend it south to Jensen Beach.

But it's a matter of money. The work is done mostly on days off, with equipment borrowed from the state. Bresette said he hopes to apply for grants soon and also is seeking donations from the public.

With extra money, the group can do blood work to determine the sex of the animals and also conduct radio telemetry, which can track the turtle throughout the lagoon.

"It's rewarding. You come to appreciate them even more," he said. "They're beautiful, tough animals."

- suzanne.wentley@scripps.com