Sept. 28, 2007 — Keep it low, keep it shielded and keep it long. To keep from luring sea turtles and their hatchlings to their deaths, thats what you should do with lights, wildlife biologist Claudia Lombard told St. Croix residents Thursday evening at the St. Croix campus of the University of the Virgin Islands. Lombard works with the U.S. Fish and Wildlife Service on St. Croix.
The more light that is visible to animals- not just turtles, but migrating birds and other animals as well- the more likely they are to become disoriented and die of exhaustion, Lombard explained. Low and shielded lights are self explanatory. The lower a light is to the ground, the more confined the area of illumination is. Shields above lights keep light focused only where it is wanted. Keep it long means use lights with longer wavelengths: Red, amber and yellow hues have little effect on turtles, but high wavelength; bright white light containing lots of blue and violet colors interferes with their navigating instincts, leaving them lost and disoriented. Hatchlings are especially vulnerable, Lombard said.
Hatchlings rely on vision to find the water, she said. They orient towards the brightest place but away from dark silhouettes. Hatchlings have a limited energy reserve for their initial frenzy of activity. The eggs yolk sack provides enough energy to crawl out of the nest, across the beach and as far as twenty miles out to sea to sargassum drifts to feed.
If they expend that energy going the wrong direction, they die of exhaustion before getting to food, she said.
What can you do as a home or business owner? Lombard had practical tips and an array of commercially available turtle-friendly lighting options to suggest.
What can you do? You can turn off unnecessary lights. And dont use decorative lighting, such as landscaping lighting, in areas that are visible from the beach, she said. Sometimes existing lights can be repositioned facing them away from the beach. And you can place vegetation buffers such as sea grape between the lights and the sea.
Sea grape also serves as a physical buffer to the turtles, Lombard said. When you put new lighting in, you can get more wildlife friendly options.
Lights with louvers directing the light downward look nice, and actually illuminate the area beneath the fixture better than regular lights. Shielded low pressure sodium Bollard fixtures are especially effective for large scale lighting situations and she said they are commonly used for security lighting around public buildings and college campuses.
On roads, light emitting diode (LED) fixtures embedded into roadways and at pedestrian crosswalks are a safe alternative to traditional road lighting.
Thats one alternative you see a lot in Florida these days, she said.
Lombard showed the names and pictures of a variety of specific commercial lighting products that reduce light pollution. She also shared several websites offering the products. At one: www.starrynightlights.com, she said you can purchase right from the website. These sites also have more information: www.myfwc.com.seaturtle/WildliveLighting/index.htm and www.turtlesafelighting.com.
Lombards talk was sponsored by the St. Croix Environmental Association and the V.I. Marine Advisory Service.
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