The turtle population across the Great Barrier Reef is full of females, according to a new study. The study found out that the sea turtles dwelling in the Great Barrier Reef are mostly females. More than 99 percent of the turtle populations of the northern, warmer area of the Great Barrier Reef are females, and this has baffled the scientists. As per the study, the increasing seawater temperature due to climate change has resulted in this unexpectedly high number of females in one of the world’s largest turtle populations. Researchers are worried about this bizarre gender difference as this could lead to the collapse of turtle pollution in future.
The latest study was carried out by a group of international scientists led by research biologist Michael Jensen US National Oceanic and Atmospheric Administration (NOAA). Jensen and his team analyzed more than 400 turtles living in the warm waters of Great Barrier Reef. They found out that about 99.8 percent of the adult green sea turtles present in the northern warmer sea area of the Great Barrier Reef were females and almost 99.1 percent of a slightly younger juvenile group of turtles were also girls.
When the scientists studied the effect of warmer temperatures on turtle population, they found out that, the warmer the sea water, the more are the chances of production of female turtle offspring. That means, when the eggs of the turtle come under the influence of warmer sea water, there is high chance that a female turtle would take birth. As per the scientists, the incubation of eggs of sea turtles is dependent on the temperature of the sand. Warmer sea waters have warmer sand and this result in female hatchlings. Similarly, cooler sea waters result in cooler sands, hence, male hatchlings are produced. In NOAA’s website, it is mentioned that when the temperature is 27.7 degree Celsius or cooler, then males are born and if the temperature is 31 degree Celsius or warmer, then female turtles are born. And, within 27.7°C and 31°C, a mix of female and male baby turtles take birth.
Jensen said that the rising sea temperatures due to climate change are shifting the ratio of male to female. “All sea turtles affected by temperatures this way are subject to this change as beaches where they nest become warmer,” he told. The study further informed that extreme incubation temperatures not only produce female-only hatchlings but also result in high mortality of developing clutches. So, as it is predicted that the average global temperature will increase to 2.6 C by 2100, surely, the sea turtle populations are in danger. Having an all-female turtle population will definitely lead to dwindling turtle populations in future.