Climate change and sea turtles

Editor’s note: This is part of a series for #SeaTurtleWeek highlighting some of the threats faced by sea turtles today. A different threat will be highlighted each day. For more information on other Sea Turtle Week activities offered by the Sea Turtle Preservation Society, please go to our website or visit us on Facebook and Instagram.

Climate change poses a major global threat to sea turtles as well as humans. Some of the impacts on sea turtles from climate change include sea level rise affecting nesting beaches, storm intensity and frequency near turtle nesting sites, and even the sex ratio of hatchlings.

The summer heat that often has both Florida’s residents and visitors complaining plays a critical role in sea turtle egg development. Many reptiles, including sea turtles, use temperature-dependent sex determination to assign the nest’s sex ratio. This means that the embryos are not male or female because of sex chromosome combinations but instead are influenced by the temperature of the environment during their development. 

In the case of sea turtles, research indicates that incubation temperatures below 81.86 degrees Fahrenheit will produce male turtle hatchlings. Temperatures above this will generate female hatchlings. It is typical for there to be a range of temperatures on a nesting beach and also within the same nest’s clutch. A recent analysis of 75 sea turtle rookeries worldwide showed the average ratio of females to males was roughly 3 to 1.

The rate of climate change far exceeds the abilities of animals, such as sea turtles, to adapt naturally to such dramatic environmental changes and threatens their future survival.

Corri Osborne contributed to this article.