Welcome to brain Stuff production of I Heart Radio. Hey brain Stuff, I'm more in vogel Bomb and this episode is a classic from our archives. Over the past few years, we've all seen changes to expected weather patterns. There have been more hurricanes in some areas, more droughts, and others
warmer winters. Here in Atlanta, where we produce this show, some of these effects of climate change are pretty obvious, but this episode is about one that's more subtle, if just as big, the difference in how some sea turtles are being born. Hey brain stuffling vocal bomb here. Australia's Great Barrier Reef is an enormous climate change experiment that's
not happening in the safe isolation of a laboratory. Instead, the warming waters off the east coast of the continent have a profound real world effect on thousands of miles of coral as well as the animals that live there. For decades, scientists have suspected that increases in ocean's temperatures would affect sex ratios in certain animals, and rese it shows that's exactly what's happening to the Pacific Green sea turtles. In most of Earth's creatures, gender is determined during the
fertilization process. That's not true of animals like turtles, crocodiles, and alligators, though, which rely on a concept called temperature dependent sex determination, or TDS to dictate the sex of their offspring. In the case of turtles, warming waters and sands are altering the TDS process During the breeding season. The turtles, which can grow to nearly five hundred pounds that's about two kims, with a shell diameter of four feet or one point two meters, flop ashore and bury
their eggs in the sand. The temperature of that sand determines whether baby turtles will wind up with blue or pink flippers. Figuratively speaking, if the incubation temperature is below eighty two degrees fahrenheit or thirty degrees celsius, the turtles will hatch as males. Above eighty eight degrees fahrenheit or
thirty one degree celsius, the babies will be female. A similar problem has been reported in loggerhead turtles on Florida beaches, since scientists have noticed a strong bias toward female turtles in some instances. Up to to see how varying temperatures might affect turtle populations. Scientists compared sex ratios of turtles near multiple breeding grounds around the Great Barrier Reef. They used blood tests and laparro scopy to determine the sex
of these animals. At the southern edge of the reef, near Brisbane, water temperatures are cooler and female turtles outnumber males by a ratio of two to one, about sixty five to sixty nine percent female. However, about one thousand, two hundred miles north, in the largest and most critical sea turtle rookery in the Pacific Ocean, warmer sea and air temperatures are having a dramatic effect of hatchlings are female.
Although each male can mate with more than one female during a breeding season, a severe imbalance in sex ratios doesn't bode well for temperature sensitive species like sea turtles. Furthermore, once the incubating sand becomes too warm, it outright kills the developing organism, further threatening turtle populations. The study was
published in January eighteen in the journal Cell Biology. The researchers write, our study highlights the need for immediate management strategies aimed at lowering incubation temperatures at key rookeries to boost the ability of local turtle populations to adapt to the changing environment and avoid a population collapse or even extinction.
Today's episode was originally produced by Tristan McNeil and is based on the article of Great Barrier Reef Green sea turtles are hatching female on how stuff works dot Com, written by Nathan Chandler. Brain Stuff is production of I Heart Radio in partnership with how stuff works dot Com and is produced by Tyler Clang. Four more podcasts my heart Radio, visit the heart Radio app, Apple Podcasts, or wherever you listen into your favorite shows.