How Climate Change Is Affecting Sea Turtles’ Gender

Something very strange is happening in the deep blue sea, and it’s all thanks to a little thing called climate change. As a result of a combination of rising ocean temperatures and “a seemingly idiotic genetic quirk called temperature-dependent sex determination (TSD),” male sea turtles will soon be vastly outnumbered by females.

This certainly does not bode well for the continuation of the species, but don’t worry, humans will probably be gone by the time this happens given our inability to confront climate change as a pressing reality.

Vice magazine:

A study published on Sunday in Nature Climate Change [explains that] TSD gives the turtles a baseline temperature of 84.2 degrees, at which there are 50/50 odds of being male or female. Beyond a certain threshold of heat, too few males will exist to sustain the population.

The study, Effects of Rising Temperature on the Viability of an Important sea Turtle Rookery, didn’t involve any radical new biological revelations about the turtles’ genes or physiology. It just required extensive geographical analysis, cross referenced with thousands of data points about climate and population numbers…

The authors of the study found that In the short term, turtle numbers are actually going to increase. The study looked at one species: loggerheads, on the island chain of Cape Verde off Africa’s west coast, and modeled what’s going to happen to them during 150 years of irrevocable temperature increase. The good news is that the increasing number of female turtles—who do the risky work of carrying the eggs to the island of their birth and laying them in hidden nests—will increase the overall number of turtles for the next 30 years.

Then, the males will start to seriously decrease in numbers. Professor Graham Hayes spoke to The Guardian about the long-term effects. “Once you get 100 years or more into the future, then things start to look serious. You have so few males left that it’s likely to be a problem. There will be heaps of females but not enough males to fertilize all those eggs.” Then they, y’know, go extinct.

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—Posted by Natasha Hakimi Zapata