(ANTIMEDIA) Australia — Results from a new study published Monday in the journal Current Biology have shed light on a startling reality. Researchers say global temperatures are turning nearly all Great Barrier Reef sea turtles female.
“This is extreme — like capital letters extreme, exclamation point extreme,” Camryn Allen, co-author of the study and turtle scientist at the National Oceanic and Atmospheric Administration in Hawaii, told National Geographic. “We’re talking a handful of males to hundreds and hundreds of females. We were shocked.”
The sex of the green sea turtle is determined not by genetics, but by the temperature of the sand incubating the eggs. Hotter sand produces females while cooler sand allows for males. The new data shows that among the northern population of green sea turtles at the Great Barrier Reef (GBR), females now outnumber males 116 to 1.
In fact, researchers say, 99.1 percent of all juvenile turtles within this northern population was found to be female, with the figure rising to 99.8 percent for subadults. In contrast, the green sea turtle population at the southern end of GBR, where median temperatures are lower, is only 65 to 69 percent female.
Allen says the cause of this concerning trend is obvious. “If it’s not climate change, then what is it?” she asked the Washington Post.
Biologist David Owens, professor emeritus at the College of Charleston, agrees. “Climate change is clearly the culprit,” he told the Post.
Owens, who did not participate in the study but has worked with some of the researchers before, says the green sea turtle is not the only species being affected. Other temperature-dependent reptiles are having similar reactions.
“Many of the other species and populations my colleagues are studying are already showing 90 percent or more female populations,” he said.
Brendan Godley, sea turtle expert and professor of conservation science at the University of Exeter, told National Geographic the results of the new study are “groundbreaking” and that they “clearly point to the fact that climate change is changing many aspects of wildlife biology.”
Dermot O’Gorman, chief executive for the World Wildlife Fund Australia, also acknowledged the importance of the study while speaking with the Guardian. In doing so, he tied the study results to recent research highlighting the fact that mass coral bleaching events are now occurring with alarming frequency:
“We’ve had two years where we’ve had mass bleaching events on the Great Barrier Reef. That’s a very visible sign of the impact of climate change. But this is an invisible change. We can’t see the impact it’s having on a turtle population until a study like this shows some long-term trends.”
The study’s researchers say that if there’s any good news here, it’s that there still remains time to act on behalf of the green sea turtle due to their long lifespans and conservation efforts currently underway by the Australian government.
