As global temperatures continue to rise, a recent study highlights the dire situation loggerhead turtles in Cape Verde face.
The continued rise in global temperatures isn’t just a matter of discomfort for turtles—literally, it can lead directly to the extinction of their species.
This is because temperatures during incubation determine the gender of the hatchlings; so, warmer temperatures mean that more females are being born.
And with more and more female turtles being born, this gender disparity directly restricts the turtle population from growing.
A recent study by the University of Exeter, which focussed on the loggerhead turtle population on the Cape Verde islands, highlights the dire situation.
Cape Verde is where you can find one of the world’s largest nesting populations of loggerhead turtles—in fact, up to 15 percent of the global nesting total. Currently, according to Dr Lucy Hawkes, Senior Lecturer in Physiological Ecology at the University, 84 percent of the current hatchlings are female.
In the study, the research team came up with three climate change scenarios (low: 1.8°C, mid: 2.8°C, high: 3.4°C), and took into account both the current temperatures and hatchling data with projections from the Intergovernmental Panel on Climate Change (IPCC).
Based on a scenario with low future emissions and warming, by 2100, only 0.14 percent of hatchlings would be male. In the mid- and high-emissions scenarios, there would be no male hatchlings at all.
Lead author Claire Tanner said, "What surprised us was how even the low emissions scenario has detrimental effects for this population.
"What this shows is that now is the time to act on climate change—before it is too late to prevent the estimations seen in this paper," she added.
The researchers said that it might be possible for the loggerhead turtles to adapt to climate change by nesting earlier in the year, when it is cooler (ala natural selection).
However, the odds are against this due to the loggerhead’s long lifespan and the speed of climate change. It is likely that they would not be able to adapt fast enough.
The findings of the study was published in Volume 621 of the Marine Ecology Progress Series journal.