Keep Lights Out for Loggerheads

 

Conservation groups say that South Carolina coastal residents’ support needs to increase to raise awareness and educate visitors to “Keep Lights Out for Loggerheads.”

Nesting season for the state reptile is May through October – occurring on the beaches of South Carolina’s barrier islands. From May through August, loggerhead sea turtles (Caretta caretta) come ashore to deposit approximately 120 eggs in a nest cavity in the dry sand dune system.  Sixty days later, loggerhead hatchlings emerge from the nest at night and head to the ocean.  Nests hatch from July through the end of October.  During the nesting season, loggerheads may be disoriented by artificial lights.  Disorientation happens when artificial light from man-made sources leads turtles away from the ocean.

To date in South Carolina, 34 disorientation events of loggerhead hatchlings have been reported to the S.C. Department of Natural Resources (DNR) Marine Turtle Conservation Program.

DNR officials say that these disorientation events may have affected as many as 4,080 hatchlings (based on the average of 120 eggs in a nest).  The causes of these disorientations include streetlights, gas station hood lights, city sky glow, exterior lights on commercial establishments, high density dwellings and beach front homes, including pool lights.  People on or near the beach carrying flashlights or lanterns, bonfires, and landscape lighting can also disorient loggerhead hatchlings.

When loggerhead hatchlings emerge from their shells, they are attracted to the blue and green wavelengths of light which are naturally reflected off the ocean. They use this natural light cue to navigate from the nest to the ocean.  This same mechanism is used by adult females when nesting. If an artificial light source on the beach is brighter than the natural light, the hatchlings will head towards this artificial source.  These artificial lights can be a direct source such as a beach front home’s exterior flood light or a street light. The artificial light can also be indirect, light pollution that creates a sky glow effect.

When a hatchling sea turtle is attracted away from the ocean towards a direct or indirect source of light, biologists describe this as a disorientation event.  Hatchlings become disoriented and crawl away from the ocean towards the brightest light. During this disorientation event, hatchlings are more susceptible to nocturnal predators.  While crawling the wrong way on the beach, hatchlings exhaust valuable, limited energy stores needed to swim offshore.  Hatchlings need energy once they reach the ocean to swim towards floating Sargassum seaweed found as far as 60 miles offshore. They use the seaweed as camouflage to protect them from predators.  The seaweed is also home to small crustaceans that loggerhead hatchlings eat to replenish their energy.

Loggerheads are listed as threatened under the Endangered Species Act and are protected by federal and state laws. The loggerhead nesting population in the southeastern United States is continuing to decline, and it has been recommended that this species be reclassified from threatened to endangered. If a sea turtle hatchling is disoriented by artificial light, the maximum federal fine for harming a threatened species is $25,000. County and local lighting ordinances exist to protect sea turtles. South Carolina’s lighting ordinances can be downloaded from http://www.dnr.sc.gov/seaturtle/volres/ordinances.pdf.  Violating local or county lighting ordinances carry fines up to $500.  As coastal development continues to increase, the number of disorientation events will also rise. If sea turtle friendly light fixtures and bulbs are used, this increasing trend can be reversed.  Sustainable development allows for sea turtles and people to coexist in the beachfront communities.

What You Can Do to Help Sea turtles in South Carolina

• Obey local and county lighting ordinances.
• Do not shine lights on a sea turtle or take flash photography.
• Turn out all interior and exterior lights (flood and deck) visible from the beach, dusk to dawn, from May through October.
• Close blinds and drapes on windows that can be seen from the beach or ocean.
• No flashlights, fireworks or bonfires on the beach.
• Encourage your local and county administrations to enforce their lighting ordinances.
• Do not disturb a nesting sea turtle and observe her only from a distance.
• When boating, lookout for sea turtles both inshore and offshore.  Sea turtle mortality from boat interaction is on the rise.
• Fill in large holes dug on the beach at the end of the day because adult and hatchlings sea turtles can become trapped in them.
• Remove tents, chairs, and other items from the beach and dunes at the end of the day that could obstruct a sea turtle when nesting.
• Adopt-a-Nest (www.seaturtle.org/nestdb/adopt).

If you encounter sea turtle hatchlings on the beach or an emerging nest, it is unlawful to disturb them and it can be harmful.

• Do not stand or sit on the sand dunes. It is unlawful to walk on the dunes.
• Do not approach any sea turtle hatchlings, and give them plenty of space.
• Do not handle or hold sea turtle hatchlings.
• Do not carry, guide or help sea turtle hatchlings to the ocean.
• Do not shine any lights on the hatchling regardless of the color of the light. Do not turn on your cell phone.
• Do not take any pictures of the hatchlings; flash photography is harmful to the hatchling.
• Any disturbance to a sea turtle nest or emerging hatchlings is unlawful and may harm the animal.

PHOTO CREDIT: Joseph Fritsch