Climate Changes Change Sex Of Great Barrier Reef Turtles

Climate Changes Change Sex Of Great Barrier Reef Turtles

Climate Changes Change Sex Of Great Barrier Reef Turtles

The research warned: 'With warming global temperatures and most sea turtle populations naturally producing offspring above the pivotal temperature, it is clear that climate change poses a serious threat to the persistence of these populations'. The embryos inside respond to the temperature, developing as male if colder and female if warmer. The research includes the study of two genetically different population of turtles on the reef.

After collecting 411 for analysis and release, they found a "moderate female sex bias" in turtles from beaches in the cooler, southern Great Barrier Reef, where about 65-69 percent were female.

The scientists calculated that the northern population has been delivering primarily females for more than 20 years, corresponding to rising temperatures in the region.

This unique biological trait of these creatures is what that has jeopardised their future in an increasingly warmer world as rising temperatures due to climate change are turning one of the world's largest sea turtle colonies nearly entirely female, a new study revealed. It could even mean the extinction of that group of animals, the biggest population of green sea turtles in the world. A couple of degrees below and you get mostly males; a couple of degrees higher and you get mostly females.

Conservationists concerned at growing number of female sea turtles on Australia's Great Barrier Reef
Climate Changes Change Sex Of Great Barrier Reef Turtles

"The disconcerting thing is that we can now see how changes in the climate could affect the longevity of this and other sea turtle populations around the world", Michael Jensen, NOAA marine biologist and the study's lead author, said in a statement.

This photo shows Raine Island, where the turtles lay their eggs. The results also raise new questions about the risks for marine turtles worldwide, as well as other temperature-dependent species including alligators and iguanas. Turtles don't wear signs of their sex as obviously as humans; researchers can't tell just by looking between their legs.

Unlike anatomical exams at nesting beaches used to determine the sex of individual hatchlings, the new study used an innovative combination of endocrinology and genetics to assess the sex of hundreds of turtles across a large foraging ground. That's not normal and it's not good for sea turtle populations. But the researchers found that if they brought blood plasma samples back to their lab, they could use hormonal differences to distinguish male and female turtles. Males breed far more often than females, but researchers don't know to what extent the handful remaining can make up for all their missing brothers.

Even in cooler beaches to the south, almost 70 per cent of young turtles were female. When eggs hatch from sand that averaged 29ºC (84ºF) over the incubation period, they produce a 50-50 mix of males and females.

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