More female sea turtles born as temperatures rise

Male sea turtles are disappearing from Australia’s Great Barrier Reef. A new study of gender ratios found that 99 percent of immature green turtles born in the northern part of the reef are female. Among adult turtles, 87 percent are female, suggesting that there has been a shift in gender ratios over the last few decades.

A sea turtle’s sex is determined by its nesting environment. As sands warm, more females will hatch relative to males; if the sand temperature tops 84.7 degrees during incubation, only females will emerge.

The gender shift suggests that climate change is having a significant effect on one of the biggest green turtle populations in the world, said Michael Jensen, a marine biologist with the National Oceanic and Atmospheric Administration (NOAA) and lead author of the new study published in Current Biology.

Sea turtles are the “lawn mowers of the ocean,” according to Camryn Allen, an author of the new study and a marine biological researcher with the Joint Institute for Marine and Atmospheric Research (JIMAR) and located at NOAA in Hawai‘i. The turtles maintain coral reefs and are nutrient transporters. If they are lost, other species that depend on the same habitat will also be harmed.

Read more about it in the New York Times.