Each of the six sea turtle species found in the United States are listed as endangered or threatened under the Endangered Species Act. Every day, sea turtles face a number of threats including pollution, boat strikes, hunting, accidental capture by fisheries, as well as the development of many coastal beaches that female sea turtles use for nesting sites.
But a growing threat to sea turtles is climate change. Rising sea levels and increased numbers of storms will likely limit the number of beaches that are suitable for nesting, and warmer temperatures could have a significant effect on sea turtle reproduction since the sex of sea turtle eggs is determined by the nest temperature. Warmer sands will result in more females, while cooler sands favor males. The magic temperature seems to be about 82°F, but this can vary depending on the species.
Temperatures are predicted to rise by 2.5-10°F in the next century, which could alter hatchling sex ratios especially in areas that are already warm like the Caribbean. In Florida, loggerhead nests are already producing more than 90% females, and further warming could mean that no males hatch from these nests at all.
In a new study, however, a group of researchers used screens to shade nests, and they found that it effectively reduced nest temperatures and produced a higher proportion of male hatchlings. By protecting beaches where males are more common and by applying artificial shading, if necessary, a healthy ratio of male and female sea turtles will be born.
Although shading may provide some relief to sea turtle populations already threatened with extinction, it is only a temporary solution to a much larger problem. To help take action against climate change, here are a few steps you can take at home and in your community.