Sea turtles use light as a navigation tool, instinctively moving toward light at night. Sand dunes typically obscure the night’s natural light from their view, and this instinct to follow the light allows them to then find the sea. But when artificial lights shine above the sand dunes, sea turtles can become disoriented and wander inland to their death.
The Hillsboro Inlet Entrance Lighthouse in Pompano, Florida casts an extremely bright, 1,000-watt light onto the beach that attracts sea turtle hatchlings and lures them to their doom. The U.S. Coast Guard is currently evaluating the lighthouse and its effect on endangered sea turtles. It is unclear whether the lighthouse still serves a valid navigational role; its continued operation would likely only be cosmetic and historical. Unfortunately this issue has been inaccurately spun as a choice between sea turtles and a beloved, historic lighthouse. But in fact the lighthouse need not be at risk as long as simple steps are taken to give Florida’s turtles a fighting chance.
If the Coast Guard determines it is necessary to continue to illuminate the lighthouse, there are several easy steps it can and should take to help reduce the danger to sea turtles from the lighthouse.
1. Change the color from 1,000-watt tungsten halogen (bright white) to high or preferably low pressure sodium (yellowish tinge) for a more animal-friendly color.
2. Reduce the lumen output by using several 250-watt lamps or fewer.
3. Mask the portion of the lens room visible from the sand by rotating the metal shield blocking condominium bedrooms that is already in place.
4. Install a frosted, Plexiglas panel or filter curtain to dim the beam, only over the nesting beaches and only during turtle season.
5. Shield the bottom half pane of glass in the light enclosure such that stray light visible to the beach is eliminated.
6. Shield the bottom of the clamshell double lens so the lamp is not visible to the ground directly below and about 100-feet from the supporting structure.
7. Change the speed or direction of rotation so it is more suitable to sea turtle nesting.
8. Paint the ceiling and all structural elements in the lens room nonreflecting black.
9. Tinted glass or film with a visible light transmittance value of 45 percent or less could be applied to all glass windows and doors within line of sight of dry land.
For years, authorized volunteers who patrol the area have rescued disoriented hatchlings and moved them to darker beaches. Artificial light can also cause nesting mothers to head toward land instead of the sea where they and their young die of exhaustion, predation, entanglement, dehydration or even automotive strikes on coastal roads.
Please sign the Center for Biological Diversity’s petition to ask the U.S. Coast Guard to enact these simple measures necessary to save Florida’s endangered sea turtles, and for an even greater impact add your own two cents to the suggestions.
Photo of leatherback sea turtle courtesy Flickr Commons/jimmyweee.