A Bellinger River snapping turtle. Image Credit: © Gary Bell/OceanwideImages.com

Mysterious illness wiping out turtles

  • BY Natalie Kyriacou |
  • May 05, 2015

A mysterious and deadly virus is setting the Bellinger River snapping turtle on a bleak trajectory toward extinction

ONCE AN UNTOUCHED wilderness of hills, valleys and waterfalls, the Bellinger River National Park is now a graveyard for river turtles infected by a mysterious and deadly illness.

Hundreds of sick and dying Bellinger River snapping turtles (Myuchelys georgesi) - which only inhabit this region - have been washing up on the banks of the river, on the mid-north coast of NSW, alarming local scientists and authorities.

First detected in February, the illness has been sweeping its way across the river system, devastating the native freshwater turtle population. With the threat of extinction looming heavily on this rare species, local wildlife services are furiously working to identify the cause - likely a pathogen - and find a cure.

"Right now, we must wait and see what the pathology tells us, but if we sit on our hands, we will drive another vertebrate to extinction and ignore a looming ecosystem breakdown of the Bellinger River," says zoologist Dr Ricky Spencer from the University of Western Sydney. "There are other rivers on the north coast of NSW, where species of turtle only exist. Is the Bellinger River a preview of what is to come?"

Mystery illness renders turtles blind

While very little is known of this infection, its symptoms are disturbing. Turtles have been witnessed clambering on to rocks, where they plunge their head underwater and drown themselves as the virus takes hold. Other specimens have been seen with their entrails pouring out of their shells.

According to Ricky, sick turtles display symptoms of blindness and growths around their eyes, as well as appearing to be extremely lethargic and emaciated.

About 75 per cent of the turtles' range has been affected, says Ricky, while mortality rates are extraordinarily high, reaching 100 per cent in affected areas.

"A minimum of 350 snapping turtles have been killed, though this number is likely to be far more than that, as February floods washed away a lot of dead animals," he says.

Population numbers of the turtle peaked in 2007, reaching up to 4500, but they are now in rapid decline. Ricky says that it is impossible to know the current turtle population, though they should have a clearer assessment in spring.

Conservation efforts turn towards related species

In the meantime, authorities have shifted their focus toward breeding programs to try to repopulate the rapidly depleting river and preserve closely related species.

An incident management team has been established by the National Parks and Wildlife Service in an effort to respond to the crisis, while signs advising people not to touch sick or dead turtles have been erected along the river's edge. 

"We don't even know if it is a virus yet," Ricky says.

"The first thing we must do is identify and repopulate the turtles that aren't affected and get animals out of the river for safekeeping and potential breeding stocks," says Ricky.

"It gives us a window into the health of the entire ecosystem around the Bellinger River, and suggests something is very wrong."

 

Anyone who finds either sick or dead turtles is urged to call NSW Environment Protection Authority on 131 555