Huge sea turtles slowly coming back from brink of extinction

SETH BORENSTEIN Associated Press Yahoo News 21 Sep 17;

WASHINGTON (AP) — Sea turtles are lumbering back from the brink of extinction, a new study says.

Scientists found more populations of the large turtles improving than declining when they looked at nearly 60 regions across the globe. That's a big change from a decade or two ago, experts said.

Long-living sea turtles have been pushed to endangered levels by hunting, accidentally being caught in fishing nets, habitat loss, plastics pollution and climate change, experts say.

But massive efforts to save the egg-laying turtles by changing fishing nets and creating protected and darkened beaches are working, said study lead author Antonios Mazaris, an ecology professor at Aristotle University of Thessaloniki in Greece.

"There's a positive sign at the end of the story," Mazaris said. "We should be more optimistic about our efforts in society."

The research was published Wednesday in the journal Science Advances.

There are seven different species of sea turtles, all but one endangered. The slow creatures live for several decades with some species weighing about 100 pounds and others well over 1,000 pounds.

Mazaris pointed to Hawaiian green sea turtles, once in trouble 40 years ago, as story of success. Maybe too much success.

"They have more turtles than they know what to do with," said Roderic Mast, a sea turtle advisory group co-chairman at the International Union for Conservation of Nature, which determines the global list of endangered species.

Tourists seeking sea turtles create traffic problems and fishermen complain the creatures get in the way, said Mast, who wasn't part of the study and is president of the Oceanic Society advocacy group. He added: "It's a good problem to have."

Mazaris and colleagues looked at 299 sets of turtle populations over different lengths of time around the globe, finding 95 of them increased, while 35 went down. The rest didn't change or there wasn't enough data.

There were increases in North and South America on the Atlantic coast but setbacks in the Asia Pacific region.

"The evidence is widespread and convincing," said Selina Heppell, head of Oregon State University's department of fisheries and wildlife, who wasn't part of the study.

Mast pointed to Kemp's ridley sea turtles as a good example of what's happening, especially in the United States. In the 1940s, there about 40,000 of them, mostly in the southern U.S. and Mexico. By the 70s, there were only 1,200 left.

The U.S. and Mexican governments changed laws, fishing practices and set aside dark, quiet areas for turtles to nest. That population is increasing by about 10 to 15 percent annually, Mast said. That's good, but he said they remain critically endangered.

"Sea turtles are bellwethers. They're flagships that we use to tell the story of what's going on in the oceans," Mast said. "And that's why people should care about turtles."


Sea Turtles Are Coming Back From The Brink of Extinction, Well Done Everybody
MICHELLE STARR Science Alert 22 Sep 17;

It's not often humanity gets to pat itself on the back for a positive effect on the environment, but researchers are hailing sea turtles as a "global conservation success story" as population numbers climb.

Six of the seven species of sea turtle are at varying threat levels on the International Union for Conservation of Nature Red List of Threatened Species. But research shows significant improvements that show promise for the future.

Humans have not been kind to turtles. They have been killed for their shells and meat, and their eggs harvested for food. Their nesting and foraging habitats have been destroyed, and they get tangled in fishing nets, or caught accidentally.

The hawksbill turtle and the Kemp's ridley turtle are both critically endangered, the green turtle is endangered, the loggerhead turtle, the leatherback turtle and the olive ridley turtle are all vulnerable. Only the flatback turtle isn't listed as threatened, but there's insufficient data for an assessment.

To gauge turtle numbers, the research team studied data on 299 nesting sites, monitored between 6 and 47 years. They found that 95 of those nesting sites had significantly increased numbers of nests, compared to just 35 that had significant decreases.

The team isn't 100 percent sure what's causing the upward population trend, but believes it's linked to protection of eggs - harvesting them is illegal in many countries, and heavily restricted in others.

There's also been a reduction in sea turtle bycatch, thanks to initiatives such as the development of a fishing hook that is much less likely to be swallowed by the turtles.

However, that doesn't mean the sea turtle is out of the woods, or even close. The researchers found that leatherback turtles continue to decline.

There are other factors that need to be taken into account, too. Counting the nesting sites before the eggs hatch will not include potential disasters affecting juvenile turtles.

Rising sea levels at Raine Island in Australia, the world's largest remaining green turtle nesting site, has killed many eggs before they could hatch, since the eggs can't survive underwater.

Many loggerhead turtle hatchlings died at Mon Repos in Australia earlier this year when sand temperatures became too hot for survival.

Sea turtles take a long time to reach sexual maturity, too. Hawksbill turtles take 3 years, loggerhead turtles take 12 to 30 years, and green turtles take anywhere between 30 and 50 years to sexually mature, so population rises we're seeing now could be thanks to conservation efforts some time ago.

Saving the sea turtles will continue to be an ongoing effort.

"Our findings highlight the importance of continued conservation and monitoring efforts that underpin this global conservation success story," the researchers wrote in their paper.

The research was published open access in the journal Science Advances.