Hotter Sand Leads to All-Female Sea Turtle Populations on Florida Beaches

Climate change is affecting Florida’s sea turtles in an unusual way. It’s turning the population completely female. That’s not good news for an already threatened species. Male turtles are needed for reproduction.

Unlike mammals, the gender of turtles is not set through fertilization. The sex of a sea turtle is determined by how hot the sand is. The hotter the sand, the more likely the sea turtles will turn out to be female.

Heat waves have caused temperatures on the beach to rise. They've been so high that, for several years, all of the turtles born on some Florida beaches have been female. 

“The frightening thing is the last four summers in Florida have been the hottest summers on record,” the manager of the Turtle Hospital in the Florida Keys told Reuters. “Scientists who are studying sea turtle hatchlings and eggs have found no boy sea turtles, so only female sea turtles for the past four years.”

The National Oceanic and Atmospheric Administration says turtle eggs that stay at 81.9 degrees or lower will lead to male turtles. Temperatures above 88.9 degrees will lead to female turtles.

Scientists say if the trend isn’t reversed, there will be fewer sea turtles. Currently there are 6.5 million sea turtles in the world’s oceans. That's according to recent estimates. In some parts of the world, they’ve made a comeback. Laws protecting them have worked. 

In Georgia, officials last week reported an increase in the number of sea turtle nests. They found more than 3,960 along the coast. That breaks a previous record of 3,950 set in 2019. 

Photo from Reuters.