Thanks to toxic oil spills, ocean pollution, poaching, and human development that disrupts their breeding grounds, the survival rate of leatherback sea turtles has been dwindling for quite some time. Now, university researchers have found that extremely hot temperatures brought on by climate change are causing even more problems for eastern Pacific populations of this endangered species.
When temperatures soar into the triple digits the way they have this past week, many humans seek relief in the ocean. Unfortunately for the sea turtle eggs buried on many of those same beaches, extreme heat is often fatal. Using a climate-forced population dynamics model, scientists were able to predict what might happen to sea turtles if global temperatures continue to climb. High egg and hatchling mortality associated with warmer, drier beach conditions emerged as the most significant cause of the projected climate-related population decline.
This means that increasing temperatures below the sand will make it harder for turtle eggs and hatchlings to survive. Additionally, temperature inside the nest affects turtles’ sex ratio, with most male hatchlings emerging during cooler, rainier seasons to join the predominantly-female turtle population. If actual climate patterns follow projections in the study, the already endangered eastern Pacific population of leatherback turtles will decline by 75 percent by the year 2100.
For the population to recover successfully, said Dr. James Spotila, the Betz Chair Professor of Environmental Science in the College of Arts and Sciences at Drexel University, “the challenge is to produce as many good hatchlings as possible. That requires us to be hands-on and manipulate the beach to make sure that happens.”
Spotila’s research team is already investigating methods such as watering and shading turtle nests that could mitigate the impact of hot, dry beach conditions on hatching success.
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