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Sea Turtles Under Threat As Climate Change Turns Most Babies Female (futurism.com)
A new study published in the journal Current Biology found that as much as 99 percent of baby green sea turtles in warm equatorial regions are being born female. "The study took a look at turtle populations at nesting sites at Raine Island and Moulter Cay in the northern Great Barrier Reef, an area plagued with unprecedented levels of coral bleaching from high temperatures," reports Futurism. "The researchers compared these populations with sea turtles living at sites in the cooler south." From the report: Using a new, non-invasive hormone test, the researchers from the U.S. National Oceanic and Atmospheric Administration (NOAA) Fisheries Department and the Queensland Department of Environment and Heritage Protection found that while 65 -69 percent of the turtles from the southern region were female, between 86.8 and 99.8 of turtles tested in the northern region were female, depending on age. The sex of green sea turtles, along with some other species of turtles, crocodiles, and alligators, is not regulated by the introduction of sex chromosomes at key points during early development, as seen in humans and other mammals. Their sex is actually influenced by the temperature at which the eggs are incubated, with warmer temperatures more likely to lead to females. The difference between predominately male and predominately female hatchlings is only a few degrees, such as that formerly found between the cool, damp bottom of a sandy sea turtle nest and the sun-warmed top. The ages of the female turtles in the north suggest that this population has experienced temperatures that cause this imbalance since at least the 1990s. Given that the warmer temperatures seen in northern Australia have been distributed around the globe, experts predict that other sea turtle populations in warm regions are also following the same trend.
I wonder what ad-hoc excuse the denialists will come up with this time. A mythical "pause" in the rate of increase of female sea turtles? Sea turtles that live in a specific layer of the upper atmosphere that doesn't fit the trend exactly? Sun spot effects on sea turtle embryonic development? They found a male sea turtle once, so the trend doesn't exist?
Those who do not learn from commit history are doomed to regress it.
The abstract does not mention why this might be a problem. It says "results show a moderate female sex bias (65%â"69% female) in turtles originating from the cooler southern GBR nesting beaches" which indicates that there are southern beaches which are cooler. So uh, more females born, more eggs laid, more offspring, turtles spawn where turtles can spawn, and the range where they spawn changes but... what else changes?
I'm willing to accept that this might lead to too few males for a viable population, if somehow turtles are different from basically any other animal on earth, and one male can't service many females. However, the paper also says "Although increased breeding frequency, as well as polygynous behavior of male turtles, may help mitigate skewing offspring sex ratio [39], it is unknown how many (or what minimum proportion of) males is sufficient to sustain sea turtle populations."
IOW, your headline is FUD. Slashdot as usual.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
A cyclic warm period in that exact location just ended. Re-run the study in 5 years and let's see what happens. You can't predict a trend from a single data point.
"We receive as friendly that which agrees with, we resist with dislike that which opposes us" - Faraday