Scientists cannot explain why the Bellinger river snapping turtle has been all but wiped out by a mysterious disease with a 100% mortality rate

This article is more than 5 years old

This article is more than 5 years old

A species of turtle has been pushed to the brink of extinction over the course of just one month after a mystery disease swept through its habitat in New South Wales, with alarmed scientists pinning hopes on a small band of survivors.



The Bellinger river snapping turtle, a species previously considered to be under no threat, has been virtually wiped out by a disease that causes them to become lethargic and then develop lesions on the eyes and throughout the body.

The turtle, only found in its eponymous river on the mid-north coast of NSW, is considered endearing by many conservationists because its face is set in a permanent grin.

But the jocular visages of the little creatures belie the serious threat the species now faces, prompting scientists from Australia and overseas to search for a reason for its sudden decline.

Dead turtles were first spotted beside the river by canoeists. Since then, more than 400 dead turtles have been recovered, with many others dying within a few days of being rounded up.

The disease cannot be treated, has a 100% mortality rate and has taken hold in 90% of the turtle’s habitat, raising fears that the animal may become extinct.

“There’s a real possibility they’ll become extinct, which is a tragedy really,” Dr Ricky Spencer, a zoologist at the University of Western Sydney, said.

“For this to occur over the period of a month is very alarming. It’s a mystery event never seen in Australia before. It may take years before we find out what’s happened here.

“What we do know is that it kills and it kills rapidly. Within a month, the turtles have gone from not threatened to endangered or critically endangered. The problem is that they only exist in the Bellinger river and nowhere else in the world, so a population crash here means extinction.”

Spencer has been working with the NSW office of environment and heritage, Taronga Zoo and the NSW national parks and wildlife service, as well as overseas scientists, to tackle the problem.

The team believe the turtles may have been attacked by a number of diseases after becoming vulnerable from a lack of food, but there is no established theory for the decline as yet.

A total of 17 healthy turtles have been taken into captivity, with scientists hoping that a successful breeding program will be able to bring them back from the brink.

“The captive breeding program will be very important,” Spencer said. “Hopefully the hatchlings will breed and we can release them back into a healthy part of the river at some point.”

The alarming decline, revealed on what is world turtle day, is the latest woe faced by a freshwater turtle species. According to the IUCN, 62% of the world’s freshwater turtle species are either threatened or endangered.

Freshwater turtles are considered crucial to the health of river ecosystems because they eat dead and decaying matter and help recycle nutrients.