Three months. That’s all it took to wipe almost every member of a species of turtles off of the map.

It all started in mid-February when canoeists paddling down the Bellinger River in New South Wales, Australia, came across several dead and dying turtles.

Since then more than 400 dead turtles have shown up. Dozens more sick turtles were also recovered, each of which was lethargic, emaciated and covered in infected lesions in their eyes, skin and even internal organs.

None of the infected turtles survived.

The 60-kilometer river is the only home to the Bellinger River snapping turtle (Elsaya georgesi), a rare but little-studied species that has already been on the decline for years due to pollution and predation by invasive foxes. Scientists now fear that this mysterious, as-yet-unidentified disease has reached 90 percent of the turtle’s habitat and could cause the species’s imminent extinction.

Is there hope? So far 17 apparently healthy turtles have been captured and brought into safety. University of Western Sydney zoologist Ricky Spencer says the 10 males and seven females—all that could be located by a multiagency team of wildlife experts—will spend up to the next eight months in quarantine where they will be monitored daily for signs of the disease. If they stay healthy, they could later form the core of a captive-breeding program that could, in theory, save the species from extinction even if it completely disappears in the wild.

Along with starting a captive-breeding program, the other big challenge is to identify the disease and determine how to stop it. The process could take years. Although other diseases and certain bacteria have been known to affect turtles—especially their fragile eyes—Spencer says there are no other known turtle diseases that produce such extensive lesions “throughout internal and external organs.”

At this point of the year, the Bellinger River turtles would typically enter their winter hibernation period, so it’s hard to know how many may be alive but hiding underground. Even though few turtles have been seen over the past few weeks, Spencer asks the public to report any sightings of sick or dead animals to state wildlife authorities, to not touch any turtles they do see and to limit human activities on the river to minimize the risks of spreading the disease further.

The next few months will be full of questions. Will the captive turtles survive and breed? Will the disease be identified in time to keep it from spreading? Will any hibernating turtles wake up in a few months or has this unknown disease already taken its toll?

Right now answers, and turtles, are in short supply.

Healthy Bellinger River snapping turtle photo by Sally Tsoutas, courtesy of the University of Western Sidney. Diseased turtle photos via the NSW Office of Environment and Heritage

Previously in Extinction Countdown: