Unprecedented numbers of dead sea turtles wash ashore
A tally of sea turtles found dead or dying on the beaches along Louisiana, Mississippi, and Alabama found April to have the highest numbers ever recorded in a single month, 188 as of April 28, since records began in 1986. The average annual number of sea turtles found stranded in these three Gulf states 1986-2009 is 97, but reached 600 last year due to conditions resulting from the BP oil spill.
“The health of the Gulf and local sea turtles has been impacted by the BP oil spill and now ‘business as usual’ shrimping operations are jeopardizing critically endangered Kemp’s ridley sea turtles,” said Chris Pincetich, Ph.D. with the Sea Turtle Restoration Project.
The National Marine Fisheries Service declared an Unusual Mortality Event in mid-March when over 30 dead sea turtles arrived in two weeks. Federal and state investigators are working to determine causes of the sea turtle strandings. Oil poisoning, harmful interactions with shrimp trawl nets, or a combination of the two are suspected.
No new protections have been put in place for endangered sea turtles since the BP spill despite ongoing Endangered Species Act review and petitions for emergency action from the conservation group the Sea Turtle Restoration Project.
Of the 188 sea turtles found, 168 were Kemp’s ridleys. This species breeds and nests entirely within the Gulf of Mexico and was pushed to the brink of extinction in the early 1980s when lingering effects of the massive Ixtoc oil spill combined with a growing shrimp trawl fleet reduced the entire nesting population to less than 600 females.
Estimates calculated earlier this year by the National Marine Fisheries Service show Gulf of Mexico commercial shrimping killed 5,365 sea turtles in 2009. The species hardest hit with an estimated 4,168 killed was the critically endangered Kemp’s ridley sea turtle that reproduces exclusively in the Gulf.
“Based on available data, Gulf shrimping is the leading killer of sea turtles in the U.S.,” says Pincetich. “The chronic effects of living in BP oil are certainly making things worse for Gulf sea turtles.”
“Skimmer trawls must be required to use Turtle Excluder Devices (TEDs), or they should be outlawed. Tow times are almost impossible to enforce and we cannot rely on voluntary compliance, given the record of Gulf shrimpers,” said Carole Allen, STRP’s Gulf Office Director. “Research shows that even short periods of forced submergence may kill a sea turtle.”
The Louisiana Department of Wildlife and Fisheries reported that skimmer trawls were operating illegally in closed areas during the time the increased sea turtle strandings occurred. Skimmer trawls have come under increased scrutiny for not being required to use TEDs. Louisiana state law prohibits local law enforcement from inspecting TEDs.
Graphs (C) Sea Turtle Restoration Project, 2011.