Bellinger River snapping turtles from the captive breeding program at Taronga Zoo have been returned to their true home.
The fact that ten turtles had been released was announced today by the NSW Office of Environment and Heritage to coincide with World Turtle Day, but it actually occurred quietly back in November.
Since then, the turtles have been monitored via tracking devices and it is known that nine of them have survived.
Watch them swim away in this video:
In 2015, a hitherto unknown virus wiped out most of the Bellinger River's unique turtle species, Myuchelys georgesi, and an emergency response team swung into action to rescue 17 healthy turtles to form an insurance population.
In the first year of the captive breeding program, 22 baby turtles hatched, followed by another 31 hatchlings last year.
It's estimated that before the disease outbreak, there were between 1600 and 4500 individuals living in the upper reaches of the river.
Surveys suggest that the Bellinger River snapping turtle population now numbers between 200 and 300 juveniles who somehow managed to survive.
But a resurgence of the virus is not the only threat faced by Myuchelys georgesi.
At a presentation by Riverwatch and its partners held at Bellingen Markets earlier this month, Gerry McGilvray from OEH said over the past four years an interloper, the Murray River short-necked turtle (Emydura macquarii), has become the Bellinger's dominant turtle species, outnumbering Myuchelys georgesi by a factor of four.
The two turtles are similar enough that they can interbreed to produce genetic hybrids.
Unfortunately for the snapping turtle, repeated hybridisation with the plentiful short-necked turtles could mean its unique and ancient genes gradually fade away.
A solution will need to be found before the juveniles in the Bellinger River reach their breeding age, which is at about eight to 10 years old.
Clearing Emydura macquarii from certain stretches of the river to allow Myuchelys georgesi to thrive may be the only way forward.
Another important aspect of ensuring that the Bellinger River snapping turtle makes a successful comeback is the health of the river.
OzGREEN's Riverwatch citizen science program has noted increased phosphate and reduced levels of dissolved oxygen at testing sites over the last few months, even in the Never Never sections of the Bellinger.
Sue Lennox said attention to the health of the vegetation on the banks is crucial in reducing contamination from fertilizers and animal waste.
Bellingen Landcare received a $100,000 grant in August to work with property owners improving the condition of the rainforest along the upper Bellinger River.
"Part of it is restoring the riparian zones so that nutrient run-off is trapped rather than coming into the rivers. That is something that will help river quality overall," Sue said.
"That's the key to the success of restoring the river health and the return of the turtles."