Within the next few weeks, the turtle will be released back into the river where it was first found, Cambodia's Sre Ambel River.
Mangrove turtles were thought to be extinct in Cambodia until WCS workers discovered a small population of the species on a nesting beach in 2001.
Cambodia's King Norodom Sihamoni ordered protection of the animal, giving it its local nickname, "royal turtle."
Mangrove turtles are considered the most endangered river-dwelling turtle in Asia. Just a decade ago, tens of thousands were thought to exist.
Now in many parts of its rangeincluding Cambodia, India, Malaysia, and Thailandonly a handful remain.
Conservationists attribute the declining numbers to poaching, habitat loss, and the use of fishing nets, which can snare turtles and cause them to drown.
"No matter where you look the number of nesting females is declining," Hendrie said. The Cambodia population, he pointed out, only has two to eight mature females.
The turtles spend most of their lives in mangrove-lined tidal estuaries, where rivers flow into the sea. During the breeding season, females swim upriver searching for sandbanks to lay their eggs.
The eggs are sought by poachers and considered a delicacy in many Asian countries.
WCS is working to safeguard nesting beaches by training local guards to protect them.
"Smuggling wildlife in Asia, as well as the rest of the world, is second only to the illegal trade in drugs and arms," said WCS spokesperson Stephen Sautner. "Asia clearly leads the way in both quantity and scope of trade, due mostly to demand from China for wildlife products."
The organization says that about 14 tons (13 metric tons) of live turtles are exported from Southeast Asia to East Asia each year.
Of the estimated 72 turtle species native to Southeast Asia, half are endangered.
Hendrie said protection efforts are getting better, but he's not sure if such improvement will outpace the crisis Asian turtles currently face.
"Some species are too close to the edge of extinction to probably survive this critical period," he said.
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