Singapore — Rising temperatures at Australia’s Great Barrier Reef are causing more green turtles to be born female, which could lead to the species dying out, a new scientific study has found.
As the gender of green turtles is determined by temperature, the hotter weather caused by climate change induces warmer incubations of eggs, and that has led to a greater number of female hatchlings.
The study published last week revealed that more than 99% of the juvenile and sub-adult population on the northern part of the reef were female, and 69% were female on the southern reef.
The two populations were genetically distinct.
"We’re now seeing on those northern beaches virtually no males being born," said Worldwide Fund for Nature (WWF)-Australia CEO Dermot O’Gorman.
"That really rings alarm bells for the long-term survival of those northern green turtle population."
The study was carried out by the National Oceanic and Atmospheric Administration, California State University, and WWF Australia.
O’Gorman said urgent measures were needed to tackle climate change.
The Queensland Department of Environment and Heritage Protection had been testing various measures to lower the temperature of the sand, where the turtles laid their eggs.
Options included providing shade or inducing artificial rain to cool the beach, said chief scientist Colin Limpus.
"Protecting some of the big breeding males from threats like nets and bycatch is going to be really important going on into the future as well," said O’Gorman.
The Great Barrier Reef, covering 348,000km², was listed as a World Heritage site in 1981 as the most extensive and spectacular coral reef ecosystem on the planet.