Green turtles of the Great Barrier Reef
The effects of global warming will be complex and unexpected, as the disappearance of male turtles shows.
The north of the Great Barrier Reef is home to one of the largest green turtle populations in the world. Scientists estimate that more than 200,000 nesting females make their home in the region.
In an unexpected consequence of global warming, more and more of these turtles are becoming female.
The sex of green turtle hatchlings is determined by the temperature of the eggs during incubation – warmer temperatures lead to females, while cooler temperatures result in males.
As average temperatures rise, fewer and fewer of the hatchlings are male.
A recent survey found that more than 86% of adult turtles in the region are female. Among young turtles the split is even more pronounced: more than 99% are female.