By SHAILA DEWAN
Published: Thursday, July 15, 2010 at 5:16 a.m. GAINESVILLE, Fla. — The Kemp’s ridley sea turtle lay belly-up on the metal autopsy table, as pallid as split-pea soup but for the bright orange X spray-painted on its shell, proof that it had been counted as part of the Gulf of Mexico’s continuing “unusual mortality event.” Under the practiced knife of Dr. Brian Stacy, a veterinary pathologist who estimates that he has dissected close to 1,000 turtles over the course of his career, the specimen began to reveal its secrets: First, as the breastplate was lifted away, a mass of shriveled organs in the puddle of stinking red liquid that is produced as decomposition advances. Next, the fat reserves indicating good health. Then, as Dr. Stacy sliced open the esophagus, the most revealing clue: a morsel of shrimp, the last thing the turtle ate. “You don’t see shrimp consumed as part of the normal diet” of Kemp’s ridleys, Dr. Stacy said. This turtle, found floating in the Mississippi Sound on June 18, is one of hundreds of dead creatures collected along the Gulf Coast since the Deepwater Horizon oil rig exploded. Swabbed for oil, tagged and wrapped in plastic “body bags” sealed with evidence tape, the carcasses — many times the number normally found at this time of year — are piling up in freezer trucks stationed along the coast, waiting for scientists like Dr. Stacy, who works for the National Oceanic and Atmospheric Administration, to begin the process of determining what killed them. Despite an obvious suspect, oil, the answer is far from clear. The vast majority of the dead animals that have been found — 1,866 birds, 463 turtles, 59 dolphins and one sperm whale — show no visible signs of oil contamination. Much of the evidence in the turtle cases points, in fact, to shrimping or other commercial fishing, but other suspects include oil fumes, oiled food, the dispersants used to break up the oil or even disease. … Studies show that dispersants, which break down oil into tiny droplets and can also break down cell membranes, make oil more toxic for some animals, like baby birds. And the solvents they contain can break down red blood cells, causing hemorrhaging. At least one fresh dolphin carcass found in the Gulf was bleeding from the mouth and blowhole, according to Lori Deangelis, a dolphin tour operator in Perdido Bay. … Shrimpers emerged as a prime suspect in the NOAA investigation when, after a round of turtle necropsies in early May, Dr. Stacy announced that more than half the carcasses had sediment in the airways or lungs — evidence of drowning. The only plausible explanation for such a high number of drowning deaths, he said, was, as he put it, “fisheries interaction.” Environmentalists saw the findings as confirmation of their suspicions that shrimpers, taking advantage of the fact that the Coast Guard and other inspectors were busy with the oil spill, had disabled their turtle excluder devices. … But there has also been illegal activity. In Louisiana, agents have seized more than 20,000 pounds of shrimp and issued more than 350 citations to commercial fishermen working in waters closed because of the oil spill. In Mississippi in June, three skimmer boats were caught exceeding legal tow times — one just hours after the shrimper had been given a handout explaining that the maximum time had been reduced, Lieutenant Armes said. As for the piece of shrimp that Dr. Stacy found lodged in the turtle’s throat during the necropsy, it, too, pointed to shrimpers. A turtle is normally not quick enough to catch shrimp, Dr. Stacy said. Unless, of course, it is caught in a net with them. …
