Sea turtles still in peril, but many populations are climbing
It’s a dangerous business being a sea turtle. Eggs and hatchlings get eaten by racoons, dogs, and other predators. Those that make it to the water risk death from fishing hooks and nets, and even plastic bags that look like tasty jellyfish.
No wonder six of the seven species of sea turtle (including the loggerhead, above) are in danger of extinction. But thanks to conservation efforts, more sea turtle populations are increasing than decreasing, according to the first comprehensive global assessment. Scientists analyzed 299 published nesting site surveys, with an average length of 16 years.
After aggregating the data for 17 regions, they found that populations have been on the upswing in 12 regions, they report today in Science Advances. The greatest boost was among green turtles in the southwest Indian Ocean, where numbers have increased an average of 18% per year. In general, the researchers credit the protection of nesting grounds, safer fishing gear, and an international ban on the trade of sea turtle products, such as their meat and skin. Yet sea turtles are becoming scarcer in the five other regions analyzed, with the worst declines in leatherback turtles in the eastern Pacific Ocean. Their numbers are dropping by 16% per year, perhaps because of less abundant food or more deaths from fishing.
The scientists say the global picture is encouraging, but incomplete. Most surveys weren’t long enough to detect a trend, and sufficient published data were available for only 17 of the 58 regions in which sea turtles live. So in addition to protecting turtles, the team says, it’s also important to keep monitoring.