New reports have revealed that an increasing amount of sea turtles on Australia’s Great Barrier Reef have herpes and it’s all down to human pollution.
The animals have contracted a turtle-specific herpesvirus that causes fibropapillomatosis – a condition in which disfiguring tumours grow on the eyes, flippers, tail, shell or internal organs.
While the tumours are benign, they can still be life threatening for the sea creatures, making them more vulnerable to other infections.
“The tumours are benign but can grow up to 30 centimetres in size and block the turtles’ vision, says Karina Jones of James Cook University in Townsville, Australia. “This means they can’t find food or see predators or boats.”
“Severely affected turtles are quite skinny and have other pathogens affecting them – that’s why they die.”
The unpublished results of surveys by Jones’s team this year show that herpesvirus is most prevalent within a narrow stretch of Cockle Bay at Magnetic Island, a popular tourist destination in the middle of the reef.
It’s been estimated that half of the turtles in this hotspot have fibropapillomatosis, compared with less than 10 per cent of turtles sampled across the rest of Cockle Bay.
The definite cause remains unknown, but environmental contaminants are at the top of the suspect list. “We see these tumours in turtles in very localised hotspots around the world where there is heavy human activity,” says Jones.
Turtles that live in a healthy marine environment can still carry the virus, however it often lies dormant with no obvious symptoms.
Karina explained: “We think there must be some external trigger that causes the tumour development,”
Over the last two decades, Doug Mader of the Turtle Hospital in Marathon, Florida, says he has gone from treating six to eight turtles per month to the same number per week and he agrees that human pollution is probably to blame.
“It is thought that pollution may weaken their immune systems, thus rendering them more susceptible to disease,” he says.
The next step for the experts is to pin down the contaminates that are responsible for the horrible disease.
Karina said: “The field is very challenging because there are so many questions to ask,” and continued “But it’s always good to ask the big questions.”
Let’s hope the problem is solved soon!