Scientists say that climate change is drastically altering the nature of the green sea turtle population near the Great Barrier Reef. This is because the sex of a turtle hatchling is determined not by chromosomes, but by the incubation temperature of sandy nests along the beach. At about 85 degrees Fahrenheit (29.4 degrees Celsius), turtle nests produce relatively equal numbers of male and female hatchlings. Cooler temperatures produce more males, while warmer sand causes the embryos to develop as females. Warmer nests in certain areas have caused more than 99 percent of green sea turtles to hatch female.
"She" needs a "he" to survive:
- A 2018 study in the journal Current Biology found that ongoing warming has led to an abundance of female turtles at a major nesting area called Raine Island. Sand temperatures have been climbing there since the 1960s.
- Determining a turtle’s sex is not easy. Without external genitalia, you can’t just flip over a turtle and take a look. You either have to make an incision to see the organs, or examine plasma or hormone levels.
- Australia isn’t the only place where female turtles are taking over. Researchers in Florida have noticed a preponderance of female loggerhead turtles in recent years.