Sea turtles have crawled onto beaches to nest for millions of years. It was once easy for hatchlings to find the ocean after emerging from nests because the brightest horizon was always the ocean,
compared to the dark dune. Now, Florida’s coasts are lined with beachfront properties that can emit powerful, white light, which can cause sea turtles to crawl toward those lights (misorient) or crawl in circles on the beach (disorient). Based on consensus from a panel of sea turtle experts, around 100,000 sea turtle hatchlings are disoriented each year in Florida. They can end up in pools, decks, or even the road.
With grant funding from the National Fish and Wildlife Foundation, the Sea Turtle Conservancy (STC) is working to eliminate problem beachfront lighting and sea turtle disorientations in Southwest Florida. For Phase III of this project, STC is retrofitting beachfront properties in Pinellas, Manatee, Sarasota, Charlotte, Lee and Collier counties. Since 2010, STC has retrofitted lights on more than 200 beachfront properties, darkened more than 20 miles of beach and retrofitted thousands of bulbs and fixtures.
To quantify the brightness of a beach, STC staff takes light meter readings, measured in foot candles, before and after the lighting retrofit. At all properties retrofitted during Phase I of the NFWF grant, the amount of foot candles was reduced by 86 percent at 25 feet away from the building and 74 percent at the toe of the dune. The graph below illustrates how the amount of foot candles visible from the beach is decreased at large condominiums.
In general, a good sea turtle friendly lighting fixture directs
light down to the ground where it is needed for safety, shields the light source from being visible from the beach, and is outfitted with a long wavelength red or amber LED light bulb. The bulb cannot be painted or coated with an amber or red film. Sea turtle friendly lighting can be summed up with these three rules:
To learn about STC’s retrofit process, visit the Lighting and Dune Projects page.