Due to an increased number of heatwaves, beaches in Florida have seen a rise in female sea turtles emerging from their eggs. This is due to the sex of a turtle being determined by the temperature the eggs are incubated at. If the temperature is above 27.7ᴼC then the eggs will produce a female turtle. If temperatures fluctuate, a balanced ratio of male and female sea turtles will be hatched.
…the sex of a turtle being determined
by the temperature the eggs…
The National Oceanic and Atmospheric Administration (NOAA) has claimed that the rising temperatures, caused by climate change, are heating up the sand that the turtles nest in, increasing the probability of a female turtle being born.
Over the past four years, scientists at a turtle hospital in Florida have been monitoring sea turtles and they have not found any male turtles, as all the sea turtles they have tested have been female.
This phenomenon is also occurring in other parts of the world, as Australia is experiencing a higher ratio of female turtles hatching in the north of the Great Barrier Reef, as 99% of green sea turtles born in this area have been female. In cooler areas of the reef there has been a 65% to 69% ratio of female turtles.
On the dark-coloured sandy beaches of Cape Verde, off West Africa, 93% of all sea turtles hatched were female, whereas on beaches that have lighter coloured sand this percentage was at 70%. This is because darker-coloured sand will absorb more sunlight, meaning that it will heat up much quicker, making the conditions necessary to produce female turtles.
…local populations could become extinct
due to the inability to reproduce…
Scientists have issued a warning that this increased number of female turtles could have a detrimental effect on the populations of sea turtles, as local populations could become extinct due to the inability to reproduce. In some cases, the reduced genetic diversity could lower the sustainability of the turtle populations.