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The Laws That Saved Florida's Sea Turtles

Turtles dig the dark.
A hatchling loggerhead sea turtle on its journey to the ocean. (Photo: Wikimedia Commons)

A hatchling loggerhead sea turtle on its journey to the ocean. (Photo: Wikimedia Commons)

Here's a story you don't read every day: Once upon a time, a region had a problem for which there was a science-backed solution. Folks in the area adopted laws based on that science and now, decades later, they're reaping the benefits.

Where is this policy utopia? Florida. In the 1990s and early 2000s, many Florida cities adopted laws aimed at reducing light pollution on beaches. It was part of a larger effort to protect endangered sea turtles, which refuse to nest on beaches that are too well-lit at night, and whose hatchlings get confused and can't find the ocean if there are too many human-made lamps onshore. Now, a new study finds that hundreds of miles of Florida beaches are indeed darker now at night than they were in 1992, despite an uptick in the state's population, and, to be sure, these darker beaches house more turtle nests.

"That means some of the ordinances that have been put in place to have turtle-friendly beaches have been effective, so that's kind of nice," says John Weishampel, a biologist at the University of Central Florida who led the study. "Even though the light levels are going down, you can still see nesting females are responding negatively to light."

Last year, green sea turtles made nearly 28,000 nests; in 1989, there were fewer than 300 nests.

In other words, light laws work and need to stay. Luckily, most Floridians seem to like the laws, Weishampel says. "I would say Floridians generally appreciate the wildlife and they kind of like the idea of living next to this wilderness, the oceans. I don't think it's that big of a deal for them to turn off their lights during nesting season."

Over the past decade, Florida's green, leatherback, and loggerhead turtles have had remarkable comebacks. Last year, green sea turtles made nearly 28,000 nests on the beaches that the Florida Fish and Wildlife Conservation Commission surveys. In 1989, the commission counted fewer than 300 such nests. While it's difficult to prove any one turtle-saving law made the difference, experts think a combination of factors helped, including restricting development on beaches and requiring fishing boats to use turtle-friendly nets. Weishampel's study, published this week by the journal Remote Sensing in Ecology and Conservation, provides evidence lighting laws may have contributed too.

To conduct the study, Weishampel; graduate student Wan-Hwa Cheng; and Weishampel's high school-age son, Zachary, compared lighting data collected by satellite between 1992 and 2012 with annual turtle-nest data collected by the Florida Fish and Wildlife Conservation Commission. The data shows a strong, but not perfect, correlation between beach lighting levels and the numbers of turtle nests on beaches.

Are there any lessons policymakers can learn from Florida's success that they might apply to other species? "It might come down to how you sell it," Weishampel says. In Florida, there are advertising campaigns telling beach house-owners that "turtles dig the dark," along with plenty of cute turtle tchotchkes for sale, which build local affection for the slow-moving reptile. Perhaps it's time for some horseshoe crab stuffed animals?


Quick Studies is an award-winning series that sheds light on new research and discoveries that change the way we look at the world.