This Species of Sea Turtle Is Almost All Female, Signally a Major Problem
One thing is clear; the future is looking female for green sea turtles born Australia’s Great Barrier Reef. Only about 1 percent of baby green sea turtles hatching are male now, a sad outcome of global warming, according to a new study.
In sea turtles, warm temperatures produce significantly more female hatchlings. Vice versa, cooler temperatures produce more males. Higher temperatures from global warming have made it so “virtually no male turtles are now being produced” in the green sea turtle population in the northern Great Barrier Reef, according to the findings of the study.
“That’s really ringing alarm bells for the long-term status of the region,” Dermot O’Gorman, the CEO of World Wildlife Fund Australia, told NBC News. The WWF-Australia helped with the study as part of an initiative looking at turtle health and conservation.
The outcome of global warming on sea turtle populations has been evident for decades. Only now have researchers had the funding to scientifically prove it.
In turtles that were born on the reef’s warmer northern nesting beaches, 99.1 percent of juveniles, 99.8 percent of sub-adults, and 86.8 percent of adult-sized turtles were female, according to the researchers.
The northern Great Barrier Reef is home to one of the "largest green turtle populations the world," according to the study. Green sea turtles take about 25 years to reach the onset of sexual maturity and they are protected by the Endangered Species Act.
And sea turtles aren't alone; other reptiles that have their sex determined by the temperature of their nesting environments include most other turtles, as well as alligators, crocodiles and some lizards.
“As far as I’m aware, this is one of the first times that kind of our worst fears are coming true and that there are populations that are being exposed to such high temperatures that they are basically unisexual,” said Clare Holleley, a senior research scientist with the Australian National Wildlife Collection.