NEW ORLEANS - As the one-year anniversary of the Gulf of Mexico oil-spill disaster approaches, the Center for Biological Diversity today released a report tallying the full impacts of the disaster on the region’s birds, sea turtles, dolphins and other wildlife. The report, titled “A Deadly Toll: The Gulf Oil Spill and the Unfolding Wildlife Disaster,” compiles federal data, scientific papers and media accounts to estimate the number of animals hurt by the spill so far. Using multipliers to calculate the true cost of the damage to wildlife species, the Center estimates that approximately 6,000 sea turtles, 26,000 dolphins and whales, 82,000 birds, and countless fish and invertebrates may have been harmed by the disaster. Based on the documented, ongoing effects of previous oil spills, pollution from the 2010 BP spill will continue to affect Gulf wildlife for decades.

“A year after the April 20, 2010, explosion that caused the well to leak oil for months, the ultimate toll on people and wildlife is still not fully understood,” reads the report. “But one thing is clear: The number of birds, sea turtles, dolphins and other animals sickened or killed and tallied as part of the government’s official count represents a small fraction of the total animals harmed by this disastrous spill.”

The government has reported the number of dead animals collected up to mid-February, but is not adding animals that are washing ashore this spring to the official tally because of the ongoing criminal and civil investigation of the spill’s effects. Data from previous spills, however, reveals that official mortality counts vastly underestimate true wildlife impacts, and that disasters like the BP blowout continue to harm wildlife for many years following the spill. To obtain an estimate of the true effects of the oil spill on wildlife, the Center added the number of animals that the media reported washed ashore this spring to the official federal tallies, then multiplied that number by accepted scientific multiplication factors of true mortality counts.

“The numbers of animals injured by the Gulf oil spill are staggering,” said Tierra Curry, a biologist at the Center. “No amount of mitigation money from BP could ever truly compensate for these horrendous losses.”

Government counts of wildlife harmed by the oil spill include 1,146 sea turtles, 128 dolphins and whales, and 8,209 birds from 102 species, including pelicans, black skimmers, clapper rails, northern gannets and sandwich terns. Since these counts were tabulated, media reports indicate at least 87 dead turtles have washed ashore and 390 additional dolphins and whales have been stranded. Although oiled birds continue to be found, the government has stopped reporting numbers.  

Scientists estimate that at least five times as many turtles die as wash up on shore, indicating that between 5,730 and 6,165 sea turtles have likely been harmed by the spill to date. All the sea turtles in the Gulf of Mexico — green, Kemp’s ridley, hawksbill, leatherback and loggerhead — are listed as federally threatened or endangered.

For marine mammals, scientists estimate that up to 50 times as many are killed as wash ashore, indicating that up to 26,000 marine mammals may have been harmed by the oil spill to date. Finally, scientists estimate that from four to 11 times more birds perish than are collected, with 10 times the number collected being a common rule of thumb to estimate true bird mortality. The BP disaster thus likely harmed more than 82,000 birds. Of particular concern are brown pelicans, which were removed from the endangered species list just five months before the BP spill. The government has collected 932 brown pelicans that were injured by the spill, indicating that more than 9,300 brown pelicans may actually have been harmed.

The oil spill also killed countless numbers of fish and invertebrates and pushed already-imperiled species closer to extinction. The spill occurred during peak spawning season for the severely overfished Atlantic bluefin tuna, which is currently being considered for Endangered Species Act protection in response to a May 2010 listing petition filed by the Center. The spill and the toxic dispersants used to break it up contaminated much of the total habitat for the country’s smallest seahorse, leading the Center to seek Endangered Species Act protection for the one-inch long dwarf seahorse on April 6.

Scientific studies show that oil spills affect wildlife for at least decades following the spill. Fiddler crabs in Massachusetts are still affected by a 1969 oil spill, and oysters and mangroves in the Gulf are still damaged by a 1979 spill. The 1989 Exxon Valdez spill is still harming fish, birds and whales.

“The BP Deepwater Horizon disaster is a tragic lesson that politicians are refusing to learn. Catastrophic oil spills will continue to threaten our nation’s wildlife as long as our country continues to push for more and more offshore drilling,” said Curry.