Due to warming climates, 90% of green turtles at the Great Barrier Reef are hatching female.
Due to warming climates, 90% of green turtles at the Great Barrier Reef, the largest green turtle colony, are hatching female.
Like many turtles, green sea turtles’ development is affected by the temperature of the sand surrounding the eggs. Eggs that are laid in cooler environments, less than 28.5°Celsius, tend to produce more males than females, and warm nests, greater than 30.3°Celsius, are known to hatch more females than males. If this trend continues, this could lead to the green sea turtle’s extinction.
It’s likely that the surplus of females has gone unnoticed because of the difficulty of determining a green turtle’s sex. Because sexual dimorphism isn’t completely recognized in green turtles until early adulthood, it’s difficult to determine the sex until the animal is fully grown, at least 20 years old.
Researchers are currently examining the effect of rising temperatures on green sea turtle populations along the coasts of Hawaii and on the island of Saipan in the western Pacific.
Sources: (Frazier, 1971; Hersh, 2016; Hirth, 1997; Märzhäuser, 2018; Witzel, 1982)