Mysterious tumors threaten endangered sea turtles
Oct. 23, 1997
MARATHON, Fla. (AP) _ A fishing boat captain spots a giant sea turtle in shallow water near a stand of mangroves just off the coast. He's seen turtles here before, only this time there's something horribly wrong.
The green turtle, as big as the roof of a compact car, is covered with a gruesome growth of gray, bulbous tissue. The mass _ half the size of the turtle itself _ is slowly starving the animal by covering the eyes it uses to find food.
The growths, noncancerous tumors called fibropapillomas, have turned up in alarming numbers on sea turtles all over the world, and researchers are scrambling to find a cure while there are still turtles left to save.
``The disease is taking the turtles faster than Mother Nature can replace them,'' said Richie Moretti, who runs the Turtle Hospital in the Florida Keys. ``It's definitely a race.''
The tumors themselves don't kill as much as they smother. Eyes and noses get covered. Lungs and the heart are constricted by the tumors on the inside. The turtle found by the boat captain was not only blinded, but the mass also covered its rectum, preventing it from eliminating waste.
Nicknamed Mini Pearl, after the fishing boat that saved it, the turtle underwent surgery at the hospital to remove the tumor and was recovering in a swimming pool. The giant, flaking mass was sent to a lab for study.
Researchers believe something is causing turtles' immune systems to weaken. What that is, they don't know.
But the prevalence of tumors in turtles found near shore areas suggests a possible link to runoff from fertilizer or farm waste. Some turtle habitats have an infection rate as high as 90 percent.
``Runoff is definitely a possibility because you see turtles with papillomas mostly in heavily populated areas,'' said Glenn Harman, a marine biologist at the Clearwater Marine Aquarium. ``But really, we just don't know. I wish I did.''
Scientists also have speculated that cyclical changes in water temperature may be decreasing the cold-blooded animals' ability to ward off viral intruders.
``There's some worldwide problem going on and how to tie it all together is not easy,'' said University of Florida veterinarian Elliott Jacobson, who has done research on the tumors.
Jacobson doesn't know how many green sea turtles have been affected by the tumors, or how many of the endangered turtles remain.
Turtles with tumors have been seen from Brazil to the coast of Florida, from Hawaii to Australia, and in Indonesia. Green sea turtles aren't the only ones turning up with the tumors; they have also been seen on loggerheads and olive ridley turtles.
A study last year by the Florida Department of Environmental Protection found that 10 percent of live loggerhead turtles caught in Florida Bay, at the southern tip of the state, are affected.
For Moretti, who has worked the last 10 years to heal injured and sick turtles, the tumor is the worst enemy yet.
``We're losing them to something we can't see,'' he said.
Mini Pearl is about 6 years old and 24 pounds with the tumor. The disease primarily afflicts young turtles, ages 5 to 10, and few turtles with the tumors survive, unless the growths are surgically removed.
At the Turtle Hospital, built on the site of a former strip joint, that is Mader's specialty. These days, much of his time is spent removing the fibropapillomas, although the hospital also has repaired turtle hernias, removed fishing line from turtle digestive tracts, and plans to perform soon what is thought to be the first ever turtle cornea transplant.
The operation on Mini, which required the reconstruction of the turtle's rectum, was a success. If the turtle stays healthy, it should grow to more than 500 pounds and live to be about 100.
``A few animals may be releasable, and many tumors may grow back,'' Jacobson said. ``But there's a lot that's learned from doing it, and there's some education of people about this, so this is helpful.''