Pollution leads to the birth of more female sea turtles

Contaminants seem to exacerbate similar effects caused by climate change

Pollution may be compounding the risks of climate change for green sea turtles. Because sea temperature determines the sex of the reptiles, warming temperatures are causing more females to be born. In the Great Barrier Reef, hundreds of females are born for every male. But researchers have found that pollution may skew the sex ratio toward females even further.

Studying green sea turtles (Chelonia mydas) in Australia, researchers found that some heavy metals and organic contaminants mimic the function of the hormone estrogen, tending to redirect developing embryos toward females. That raises concerns about the ability of the turtles, listed as endangered by the International Union for Conservation of Nature, to persist.

“As the sex ratio gets closer to 100% females, it will get harder and harder for adult female turtles to find a mate,” said Arthur Barraza, a researcher at the Australian Rivers Institute at Griffith University and first author of a new study in Frontiers in Marine Science. “This becomes especially important as climate change will continue to make nesting beaches warmer and more female-biased.”

Read more from Frontiers here.

Header Image: Researchers found exposure to certain contaminants can redirect developing embryos toward females. Credit: Griffith University