Oil Spill Wildlife Spotlight: Turtles

Oil Spill Wildlife Spotlight: Turtles

Susan Cosier
Published: 05/28/2010

Kemp's ridley, courtesy of the National Park Service

Among the plumes, tar balls, and ribbons of oil floating in the Gulf of Mexico swim sea and marsh turtles largely dependent on the region’s rich waters. Already officials have counted more dead turtles than they recover in a typical year, possible victims of the crude gushing into the Gulf. Some of the most vulnerable species are the Kemp’s ridley turtle, which breeds on the Gulf’s shores, and a subspecies of the diamondback terrapin turtle, a variety native to the area that’s just hanging on.

 
The oil can coat the turtles and get into their eyes. Turtles can also ingest and inhale the oil, says Donna Shaver, the sea turtle science and recovery chief for the Padre Island National Seashore in Texas. For 30 years Shaver has caught, released, and tracked Kemp’s ridley turtles, helping the population, which fell from about 40,000 nesting females counted in one day in 1947 to a record low of 200 in the 80s, gradually creep higher. Some scientists now estimate the population to be 8,000, and virtually all of the females return to the Gulf to breed and lay their eggs on the sandy beaches.
 
“For Kemp’s ridley, which is the most endangered of the sea turtles, most exist in the Gulf of Mexico,” she says. “This is troubling, what’s going on with the oil spill, and we hope that it won’t be a tremendous setback, but we just don’t know at this time.”
 
Like birds, the turtles are nesting this time of year, from May to July, hauling their 100-pound bodies ashore to lay about 100 eggs. When Shaver, a National Park Service employee, first started her conservation efforts after an oil spill off of Mexico’s coast, the researchers fished for hatchlings with nets. “We’d come up with a tar ball or a turtle; they looked very much the same,” she says. “Over the years since then it’s greatly diminished. We just don’t see that very often here.”
 
Now, with help from other Padre Island National Seashore biologists, Shaver removes the eggs from the nests to keep them safe from high tides, predators, and other threats until they hatch. When they release them, and the turtles paddle out to sea, the small, prehistoric looking swimmers eat and rest on seaweed and debris. Unfortunately, oil may accumulate there, too.
 
In Cedar Point Marsh next to Dauphin Island, diamondback terrapin turtles, which live where fresh and salt water mix, are also laying eggs. In an attempt to save the local dwindling population, researchers rear the hatchlings in a lab at the University of Alabama at Birmingham. Biologist Thane Wibbles, the lead researcher there, was ready to release the 1-year-old turtles, which are more likely to survive when they’re bigger, right when the rig exploded. “All of a sudden, boom, we get the largest oil spill in the history of the Gulf of Mexico,” he says. “They’re very susceptible to being inundated with oil if it comes into the bay at all. The salt marshes are directly behind that. Beaches are easy to clean up, but salt marshes are a completely different story.”
 
Still, he remains hopeful that the species will recover despite the new threat. “I’m an eternal optimist. The environment is potentially very resilient, but it typically over time has not had to weather these types of hits,” he says.
 
From the Texas coast, Shaver says she’s determined to help the turtles. “There’s an incident command system that’s set up for turtles, and we hope we can do everything we can to try to save them. We’re not giving up.”