The Decline of the Pig-Nosed Turtle

The pig-nosed turtle–a freshwater species found in Papua New Guinea (PNG) and northern Australia–is a strangely cute little critter. It’s also evolutionarily important because not only is it the last member of its once widespread family (Carettochelyidae), but it also shares features with marine turtles and might represent a transition as turtles moved from freshwater to the oceans. In addition, the turtle is a key source of protein for people in PNG, particularly in areas where protein is scarce.

For years, researchers have suspected that the pig-nosed turtle has been declining in numbers, and the IUCN even listed the species as Vulnerable in 2000. But they had little more than anecdotes and suspicion until recently. A new study in Biological Conservation confirms their fears: the pig-nosed turtle in PNG is disappearing.

In Australia, the turtle suffers from habitat loss, but the problem in PNG is different—people eat the turtles and their eggs in large quantities. And so scientists not only surveyed adult turtles and their nests but also looked at turtle and egg sales in the local markets.

They found that female turtles had gotten smaller over the last 30 years; larger turtles were taken for food. In addition, local villagers intensively harvested turtle nests for eggs. And as eggs and turtles became rarer, prices increased in the markets.

“The level of harvest involved is unlikely to be sustainable,” the scientists write. And any management plan cannot be a simple one focused on eliminating hunting. The species will have to be managed more like a fishery. “We need to provide win win outcomes to both local and conservation communities,” the study’s lead author, Carla Eisemberg of the University of Canberra, told BBC News.

But there are several roadblocks to conservation: The local human population is growing. Tribal warfare has ended and people have now settled along the riverbanks, where they can more easily find turtles. And new technologies, such as modern fishing equipment, have also aided the turtle harvest. In addition, scientists are missing much of the information about the species’ life history that would let them design a conservation plan. And then it would take decades for the turtle to recover after such a plan was implemented.

Don’t expect the scientists to give up, however. The turtle is important both to them and to the local PNG people who depend on them for food. Surely the two groups can work together to let the pig-nosed turtle survive.

Sarah Zielinski | | READ MORE

Sarah Zielinski is an award-winning science writer and editor. She is a contributing writer in science for Smithsonian.com and blogs at Wild Things, which appears on Science News.