<
https://www.sciencealert.com/the-world-is-running-out-of-male-sea-turtles>
"Green sea turtles are already an endangered species, mainly due to humans
hunting them, harvesting their eggs, degrading their habitats, or entangling
them in garbage of some kind.
But they also face another, more insidious threat from people: the loss of male
hatchlings from the species.
You probably already know that this is partly caused by rising temperatures due
to climate change – but a new study has now unveiled another human-caused
problem driving this trend.
Certain pollutants may promote feminization in sea turtles, explains lead
author Arthur Barraza, a toxicologist with the Australian Rivers Institute at
Griffith University.
"Our research shows that the risk of extinction due to a lack of male green sea
turtles may be compounded by contaminants that may also influence the sex ratio
of developing green sea turtles, increasing the bias towards females," Barraza
says.
Green sea turtles (
Chelonia mydas) have a vast geographical range, inhabiting
tropical, subtropical, and temperate regions of the Atlantic, Pacific, and
Indian oceans, as well as the Mediterranean Sea.
Male hatchlings are now heavily outnumbered by females overall, although the
degree of imbalance varies in different parts of their range. In some warmer
places like the northern Great Barrier Reef, researchers say, hundreds of
female turtles are now born for every male.
That's because sea turtles use temperature-dependent sex determination, meaning
an embryo's sex is determined by sand temperatures around its egg in the nest,
with warmer sand favoring females. As temperatures rise around the world, male
hatchlings are growing scarce."
Via Rixty Dixet.
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
