A green sea turtle swims off the coast of Turks and Caicos. Photo by Peter Richardson/Exeter
COCKBURN TOWN, Turks and Caicos Islands, Aug. 27 (UPI) -- By declining to harvest tumor-marred sea turtles in Turks and Caicos, fishermen may be increasing the prevalence of fibropapillomatosis disease.
Fibropapillomatosis is a contagious disease that causes pink tumors to grow on the skin of green sea turtles. The tumors are benign, but they can sometimes impede the animal's eyesight or swimming ability.
Green turtles are endangered, but a small, closely-regulated fishing industry is permitted in the waters off Turks and Caicos, a British Overseas Territory in the Caribbean. While conducting a recent survey of fishing activity and the rate of fibropapillomatosis, researchers found that fishermen on the islands had failed to harvest a single infected turtle.
In interviews, fishermen told researchers they prefer not to eat the flesh of turtle that appears diseased, even though research suggests fibropapillomatosis is not a threat to human health.
"Most of the fishermen we spoke to said they had caught diseased turtles, but they told us that they didn't want to eat turtles with tumours, so they threw them back" Tom Stringell, a researcher at the University of Exeter's Center for Ecology and Conservation, said in a press release. "We know a lot about the consequences of culling diseased creatures to take them out of the general population, and this practice has the opposite effect, effectively increasing the proportion of diseased animals in the population."
As Stringell and his colleagues explain in their study, published in the journal Frontiers in Marine Science, taking only healthy turtles increases the ratio of infected to uninfected turtles -- and potentially increases the chance of the disease spreading outside the local population.
Since the turtle harvesting industry in Turks and Caicos is rather small, the fishing practice is likely to have a negligible effect on the regional presence of the disease. But as green turtle populations continue to rebound globally, turtle fishing is likely to become more common.
"Monitoring this disease is therefore important for both wildlife conservation and future issues relating to food and human health," said researcher Annette Broderick.