Even before the BP oil spill, sea turtles were dying in the Gulf of Mexico in numbers that some term "appalingly high" because of another human activity: shrimp trawling.
The Associated Press reported today that the National Marine Fisheries Service (NMFS) is investigating the role of shrimping in the deaths of at least 35 sea turtles in recent days. The agency's action highlights an ongoing source of conflict between wildlife conservation and the Gulf fishing industry.
"Incidental take in fishing operations, or bycatch, is one of the most serious threats to the recovery and conservation of marine turtle populations," according to an NMFS website.
One government study estimated that 10 years ago, 86,000 sea turtles died annually in the Gulf of Mexico as a result of bycatch. Government-mandated changes in fishing gear have reduced mortality to an estimated 25,000 sea turtles a year, says Dr. Christopher Pincetich, a marine biologist with the nonprofit Sea Turtle Restoration Project (STRP).
Pincetich argues that many of those deaths are also preventable. "Thousands of sea turtles die each year because of lack of enforcement" of existing regulations, he says.
The primary regulation involves the proper use of a Turtle Excluder Device (TED) on shrimp nets. TEDs are essentially trap doors that allow turtles to escape the nets while keeping shrimp in. But advocates say that an unknown number of shrimpers have removed TEDs or closed the trap doors to minimize shrimp loss, even though it is illegal to do so.
Immediately after the Deepwater Horizon oil platform explosion started gushing oil into the Gulf last month, the shrimping season was opened early for a few days, to give shrimpers a chance to fill their nets before the oil slick inevitably led to the closure of fishing grounds.
"It is highly likely that shrimpers are taking advantage of the oil crisis," says Carole Allen, who directs STRP's Gulf office in Houston, adding that "probably few law enforcement officers have the time to board their boats" to check on the TEDs.
That concern was shared by at least one government official who says those suspicions were confirmed when the carcasses of drowned sea turtles began washing up on shore this week with no signs of oil contamination.
The threat posed by the massive oil spill is very real, says STRP's Pincetich. But it is not the only one that turtles face.
"The biggest threat to all sea turtles," he says, "is irresponsible, destructive fishing practices." He adds that for every pound of shrimp caught, trawls typically haul up 10 pounds of bycatch. "Much of the bycatch is injured, stressed, and thrown overboard to perish. And sea turtles drown when caught in nets for less than an hour."
Photo: Drowned turtle on a shrimp trawler courtesy Sea Turtle Restoration Project