Turtle fishing is big business. However, the practice by fishermen of harvesting out turtles, keeping the healthy ones, and then discarding those that appear diseased is leading to a wider species loss through promoting the spread of disease. In a sense, the fishermen are creating conditions where stocks of turtles run down faster thereby accelerating the loss of their own trade.
This finding has come about after researchers began studying incidents of green turtle fibropapillomatosis disease. A herpesvirus is believed to be the causative agent of the disease. The viral disease manifests as pink tumors which appear on the turtles’ flesh. The disease affects the turtles’ vision and impedes their movement. By not being able to swim properly, many turtles die of starvation.
Over a two-year period in the waters around Turks and Caicos islands, it was found that some 13 percent of green turtles had the disease. The incident rates are steadily rising and the University of Exeter research group think that the practice of fishing healthy turtles and casting back infected ones, resulting in more infected turtles being present in higher numbers is leading to an accelerated spread of the virus. Although the turtles are classified as an endangered species, fishing is a common practice and the turtles are regularly eaten by the inhabitants of the islands.
Turtles are also popular for a dish served up to holidaymakers seeking Caribbean sun on the islands, which are a British Overseas Territory. The two island groups are located in the North Atlantic Ocean, southeast of the Bahamas, north of Hispaniola, and about 1,000 kilometres (620 miles) from Miami in the U.S.
The researchers argue that a new approach to conservation is required. Discussing the situation in more detail, Dr Tom Stringell, from the University of Exeter’s Centre for Ecology and Conservation, explained in a research brief: “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.”
Dr. Stringell added: “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.”
The findings are published in the journal Frontiers in Marine Science, in a paper called “Fisher choice may increase prevalence of green turtle fibropapillomatosis disease.”
