A recent study published in the scientific journal Nature Climate Change, shows that continual warming climate could cause greater numbers of sea turtles to be born female. The publication warns that when the sands become too warm, the sea turtle eggs grow too warm. Without enough male sea turtle, the entire population could be at risk for extinction.
“Sea turtles are unusual in that the gender of the offspring is not driven by sex chromosomes, as in humans,” said Professor Graeme Hays, one of the lead authors of the study. Rather, the sex of sea turtle’s is determined by the sand’s temperature where the female turtle decides to bury her eggs.
Scientists have long known that the reproductive process in reptiles is extremely sensitive to shifts in temperature. For species of sea turtles, once the temperature goes above about 84 degrees Fahrenheit (29 degrees Celsius), more female turtles are born. At about 87 degrees Fahrenheit (30.5 degrees Celsius), populations become completely female.
“It will be the end of the story without human intervention,” said co-author Graeme Hays from Deakin University in a report by the Sydney Morning Herald. At temperatures higher than about 91 degrees Fahrenheit (33 degrees Celsius), embryos fail to survive. Sand temperature depends strongly on its color, Hays said.
“The darker the sand, the more heat it absorbs from sunlight. So blacker sand would be much warmer than lighter colored sand.”