If This Oil Spill Isn't Cleaned Up, Endangered Sea Turtles Will Get a Crude Awakening

Critically endangered Kemp's ridley sea turtles are expected to lay eggs on Texas’ Matagorda Island, parts of which are covered by as much as a foot of spilled crude oil.

(Photo: Reuters)

Apr 9, 2014· 1 MIN READ
John R. Platt covers the environment, wildlife, and technology and for TakePart, Scientific American, Audubon, and other publications.

A bale of critically endangered Kemp's ridley sea turtles is swimming through the Gulf of Mexico to nesting sites in Texas, unaware of the danger it may find when it reaches its destination.

The turtles are expected to land—and hopefully lay eggs—on Matagorda Island, off the coast of Texas, in the next two to three weeks. Thing is, Matagorda is a disaster site.

Crews there have been working around the clock to remove hundreds of thousands of gallons of oil that washed up on the island after a March 22 oil spill in Galveston Bay. That spill, caused when a barge carrying nearly a million gallons of oil struck another ship, released an estimated 170,000 gallons of crude into the bay and surrounding waters.

As of April 8, workers on Matagorda Island had removed 10 tons of oil-contaminated soil and debris, according to a report from Houston-based KHOU. In some places on the 24-mile beach, the oil was measured to be nearly a foot thick. The U.S. Fish and Wildlife Service told the Victoria Advocate that more than 110 dead, oiled animals had already been found on and around the island, including 11 dolphins and sea turtles from 19 other species.

Although Matagorda Island is not the primary nesting site for Kemp's ridley turtles—that would be Rancho Nuevo, Mexico, where almost all of the turtles lay their eggs—it is still an important site for the species. Cleaning up the island is especially critical because Kemp’s ridley turtles nearly became extinct in the 1970s owing to the animals being caught in shrimp trawling nets. Conservationists don’t know for sure the present-day total wild population of Kemp’s ridleys, but there are an estimated 7,000 to 9,000 breeding females.

"Part of the long-term recovery program for Kemp's ridley sea turtles involves promoting and trying to foster the establishment of other nesting sites for the species, particularly in Texas," says David Godfrey, executive director of the Sea Turtle Conservancy. "Over the years, as the nesting population has gradually begun to recover in Mexico, you've begun to see a number of turtles start to nest on other beaches. This gives the species a chance to take root at other nesting beaches so they're not vulnerable to having, literally, all of their eggs in one basket."

Oil could pose a big threat to the sea turtles, either by entrapping the reptiles, poisoning them, or coating their soft underbodies and affecting their ability to swim and breed. Even if most of the oil is cleaned up in the next few weeks, additional threats could linger, Godfrey says. The sea turtles forage year-round on the coast, where their diet of shrimp, crabs, and other crustaceans could carry toxins from the oil. "The toxicity bio-accumulates within species that are higher up the food chain, such as sea turtles," he says.

Tar balls also tend to persist in floating mats of sargassum, which hatchlings use as safe habitats. "Researchers studying hatchlings and year-old turtles in that kind of habitat where there have been spills find lots of tar within their mouths," Godfrey says. "They're likely eating the stuff, maybe even far away from where the spill occurred. That's true of all the little spills that are constantly happening all along the coast."