Graphic by Penelope Taylor ’20
BY CHEYENNE ELLIS ’20
A new study published in Current Biology has found a major shift in the gender ratio of green sea turtles around Australia’s Great Barrier Reef, according to VOA News. The results of this study indicate that 99 percent of sea turtles born in the northern part of the reef and 87 percent of adult sea turtles around the Great Barrier Reef are female, according to the New York Times. While this topic has been studied previously, the enormity of the situation, as well as the rapid progression, was unknown to researchers.
“We’re all trying to wrap our heads around how these populations are going to respond to those changes,” Dr. Jensen, a marine biologist with the National Oceanic Atmospheric Administration told the New York Times.
The cause of this latest phenomenon can be linked to climate change as the temperature increase is now impacting the sand of turtle nesting locations. If the sand reaches over 84.7 degrees, the young sea turtle population will be entirely female, according to the New York Times. Sarah Bacon, a biology professor at Mount Holyoke College, elaborated on this.
“In some animals, reproductive organ differentiation is triggered by the temperature at which the young are incubated in the nest,” she said. “Turtles are one group who use this method of sex differentiation. Warming of the turtle eggs in the critical window for sex organ differentiation could skew the sex ratio of the hatchlings.”
Although this study was conducted solely in the northern part of the Great Barrier Reef, researchers are afraid of what the data suggests about sea turtle populations and other animals whose gender depends on temperature throughout the world.
“The northern Great Barrier Reef is one of the largest genetically distinct populations of sea turtles in the world,” turtle scientist Camryn Allen told National Geographic. “What’s really scary, though, is to think about applying this problem to populations where the numbers already are extremely low.”
In light of this discovery, some Australian researchers have begun suggesting ideas to regulate the gender imbalance. One such idea involves placing tents over beaches to shade the sand, prior to turtle nesting season. Another involves using artificial rain as a mechanism to cool the nesting locations, according to VOA News. These solutions are all temporary, but will be able to stall the impending sea turtle extinction. These ancient creatures have faced temperatures changes before, but never at such a rapid pace, according to National Geographic. Temporarily interfering with their breeding habits will hopefully allow sea turtles enough time to adapt to the increasing temperatures.
In addition to irregular gender distribution, sea turtles are also at risk from a variety of other threatening circumstances. Young sea turtles who manage to escape predators face poaching, entanglement from plastic and fishing equipment, accidental consumption of plastic and difficulties in finding proper nesting locations due to artificial lighting, according to the Sea Turtle Conservancy. Similar problems have been noted in other marine species as well.
“Sea turtles are sentinels,” marine biologist Dr. Allen told the New York Times. “They’re telling us something is going on in the oceans and we need to pay attention.”