Turtle hatchlings being led astray

Sea turtle hatchlings are so drawn to light that they will even flock to a white plastic foam cooler left on the beach.

So imagine what they're up against trying to find their way to the ocean -- flashlights, lanterns, bonfires, beachfront landscape and pool lights, streetlights and sky glow from city lights. Even with lights out along the beaches, more turtle hatchlings are getting disoriented trying to find their way to the ocean.

This year, turtle watch volunteers in South Carolina reported disorientation among hatchlings at 34 nests along the coast. The disturbances might have involved more than 4,000 loggerhead turtles, a federally protected species whose numbers are said to be in a long-term decline and at risk of extinction.

The most notorious happened on Hilton Head Island in September, when a man proposing to his girlfriend placed 150 candlelight luminaries on the beach and killed 60 or more loggerhead hatchlings. But 19 incidents were reported on Charleston County beaches, including eight on Cape Island, a remote barrier island far out in the Cape Romain National Wildlife Refuge.

"Cape Island is the densest nesting beach in three states and they're being disoriented by city glow from Georgetown," said DuBose Griffin, S.C. Department of Natural Resources sea turtle coordinator. Georgetown is 25 miles from the beach.

The 34 incidents are half again more than the 23 reported in 2008, but that's partly due to more emphasis on reporting among the volunteer watch groups, she said.

Overall, the number of nests in the state his year dropped to 2,170 from a banner year in 2008, when 4,500 nests were found. That's not unusual. The number of nests varies widely year to year, and low years tend to follow banner years, Griffin said.

The hatchlings navigate their way to the sea by reading colors in the ambient light on the water. Any bright glow distracts them. Even a white sneaker can turn them aside. On Isle of Palms, where most beachfront owners keep lights dim and turtle watch volunteers caution renters who don't, there were five incidents of hatchlings becoming disoriented this year.

It's not just the houses on the beach causing trouble, said Bev Ballow, of the island watch group. It's streetlights and glow from streets and shopping centers in Mount Pleasant.

"The turtle tracks go round in circles, back into the dunes. Once they get back in the dunes, you can't find them; they get into heavy brush and the ghost crabs get them. You can see where the tracks end right at the ghost crab hole," she said. "People have to be out there at night to assist the turtles getting to the ocean without scrambling all over the beach."

On Sullivan's Island, Ballow has seen turtles turn to the dunes following the sweep of the lighthouse beam. "They're going zip-zip, zip-zip, zip-zip," she said.

But Folly Beach volunteers found no evidence of hatchling disorientation this year, following a year with a few incidents, said watch group co-leader Shannon Teders. The city has tightened enforcement of lighting laws and covered its street lights.

Nearly all the turtles hatched in the Lowcountry are loggerheads, the beloved totem creature of the coast -- a long-lived turtle that grows to the size of a kitchen table. As a threatened species, the turtle has drawn a residents' army of volunteers keeping watch on nests up and down the coast. But three nests in the state this year were of the larger and rarer leatherback turtle; one was a green turtle nest.

Overall, more than 200,000 turtles were estimated to have hatched as of Wednesday; about 9,300 were lost. But the numbers are deceptive because few of the turtles that make it to the water are thought to survive to be adults. The season lasts through October; most nests have now hatched.

Volunteers find turtles in pools, Griffin said. On Edisto Beach, hatchlings year-in and year-out are killed trying to cross Palmetto Boulevard, the beachfront road. The problems are just going to get worse, with nesting numbers expected to climb over the next five or 10 years as turtles hatched after protections were put in place reach maturity and nest, she said.

"The biggest problem is noncompliance with lighting ordinances. As development continues and municipalities don't keep their communities dark, we're going to continue to have these disorientations," she said.

Reach Bo Petersen at bpetersen@postandcourier.com or 937-5744.