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Can Sea Turtles Cope with Climate Change?

Adult male turtles may become less abundant as the climate warms, but the population sizes may actually increase because they breed more often than females. Credit: Kostas Papafitsoros

Adult male turtles may become less abundant as the climate warms, but the population sizes may actually increase because they breed more often than females. Credit: Kostas Papafitsoros

By Jacques-Olivier Laloë & Graeme Hays

Rising temperatures due to climate change are skewing gender ratios among turtles and increasing the mortality rate of hatchlings. Can they adapt?

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It is now widely accepted that warming temperatures are having profound impacts on a range of ecosystems and animal populations. Reptiles are particularly at risk because much of their physiology is intimately linked to temperature. Most reptiles are cold-blooded, with their body temperature driven by the external temperature.

Many reptiles also exhibit temperature-dependent sex determination (TSD), whereby the sex of an individual is determined not by genetics but by the incubation temperature of the developing eggs. In these species, when an egg is laid the developing embryo has no gender – it can develop into either a male or a female depending on the incubation temperature.

Sea turtles undergo TSD, with low incubation temperatures leading to the production of males and high temperatures resulting in females. Therefore, in the context of climate change, there are concerns that warming global temperatures might produce single-sex sea turtle populations and lead to the extinction of turtle species.

Since many sea turtle populations are already endangered, this topic has attracted major scientific and international attention, and in recent years there have been many breakthroughs in this field of research.

Female-Biased Populations

The discovery of TSD in sea turtles generated huge scientific interest in the 1980s. Soon, scientists...

The full text of this article can be purchased from Informit.