Members of a Japan-based group working to protect sea turtles warned Monday that a serious tumor-causing illness is apparently spreading among the reptiles, with three cases having been identified in Japan since last summer.
The cases were found in Okinawa, Shizuoka and Kochi prefectures.
The illness, fibropapillomas, can be fatal when tumors block the turtle's mouth and eyes, obstructing the animal's movement and food intake. Experts believe the illness is caused by a virus.
A dead turtle found on Iriomote Island, Okinawa Prefecture, last summer had numerous tumors around the neck and legs and was diagnosed with severe fibropapillomas.
Experts, however, could not determine the cause of death.
Another dead turtle was found on a beach in Omaezaki, Shizuoka Prefecture, in September with lesions on its legs. A third turtle, still alive, was caught in a fishing net in November off Kochi.