BILOXI — A worst-case scenario for the Gulf region, now that the initial wave of oiling is over, is that the effects will persist for years.
Stopped after 172 million gallons entered the Gulf, according to the government estimate, the gusher is the largest off-shore oil spill in U.S. history. More than 11 million gallons were burned and 1.8 million gallons of dispersant were used to sink untold amounts. Scientists believe 44.7 million gallons remain unaccounted for.
If you consider the volume, Ronald J. Kendall, chairman of environmental toxicology at Texas Tech University, told the New York Times earlier this month, we could see re-oiling for years to come.
The economic effect has been estimated as high as $23 billion.
Every oil spill is different, but the thread that unites Valdez in 1989, the Ixtoc in Mexico in 1979, the Amoco Cadiz in France in 1978 and two Cape Cod spills in the late 1960s and early 1970s is just how long oil can linger in the environment, hidden in out-of-the-way spots, the Times reported.
Sea otters digging in sediment for food are still being exposed in Alaska based on liver studies, fiddler crabs three decades after the Cape Cod spill move erratically and are slow to react to predators and Mango groves along the shores in areas of Mexico are less thick.
Dig a deep plug out of a marsh oiled four decades ago near West Falmouth, Mass., and it smells of diesel, officials said.
In the Gulf, on top of everything else, the EPA has said that cleanup efforts have damaged the environment.
Absolutely nothing you do to respond to an oil spill is without impacts of its own, said Lisa Jackson, administrator of the EPA, whether its burning, vacuuming or digging.
One good hurricane
Even with the well stopped, one good hurricane could push remaining oil into the marshes of Mississippi.
In practice, the use of dispersants that had never been tested so far beneath the surface has made the oil much more difficult to track. And marine biologists still arent convinced the chemicals are safe for sea life.
Dr. Mark Peterson, fish and marsh ecologist at USMs Gulf Coast Research Lab, said theres likely another type of oiling thats going on.
Hundreds of thousands of gallons of dispersant have broken the crude into oil particles too small to see with the eye.
It doesnt get rid of it, kill it or absorb it, Peterson said. It just makes it too small to see and can only be detected with chemical analysis.
But how often this microscopic oil is being deposited on the marsh is hard to know, he said.
It could be possible that its coming in all the time, the tiny, almost molecular-sized droplets, he said.
The ecology of the Gulf of Mexico is specially adept at breaking down oil, but how it will do with an amount the size of the BP spill is unknown.
Gathering concrete data is expensive and the Gulf region has been chronically underfunded for scientific research for decades.
BP once promised $500 million toward Gulf research. In mid-July, only $30 million had gone to universities in the Gulf region.
Mike Carron with Northern Gulf Institute said the person he deals with at BP believes BP will make good on the promise and distribute the rest, however, that person isnt the decision-maker.
Carron said theres still a threat of underwater oil moving ashore.
It will be a year or two before we know how many whale sharks are damaged, or how many dolphins have died, he said. Some of the threat is to microscopic animals, some is to reproductive systems.
It will be two years before scientists can get a reading on juvenile fish.
Whale sharks sink when they die, and the worst of the spill was in the middle of their summer feeding range.
As of July 27, the number of animals killed during the spill or injured and captured alive was 4,417 birds, 730 turtles, 69 dolphins and one sperm whale. But federal wildlife and fisheries experts said many more died in deep water, uncounted.
NOAAs Steve Murawski said that in the long run, there could be a decline in the populations of predators that eat oiled animals.
While the early concern was mammals and turtles that need to come to the surface to breath, whales, dolphins and sea turtles also feed in the deep ocean canyons where oil was sunk near the source of the gusher.
The visibly oiled birds are only a small part of our concern, said Rowan Gould, acting director of U.S. Fish and Wildlife Service. What concerns us most is what we cannot see.
Millions of birds that range across the western hemisphere, winter in the marshes along the Gulf and forage the same water that has oil in it now. This winter, they will return and likely be exposed, even with projects designed to attract them elsewhere.
Birders reported oil on the feet of Least terns and shearwaters nesting in high numbers on the beach south of Beauvoir in early July. Things dont look good for Coastal breeding populations in Louisiana and Mississippi because the spill hit in the spring.
The American Bird Conservancy complained that boom failed to protect important bird colonies.
Mark LaSalle, director of Pascagoula River Audubon Center, said they still dont know how much oil it takes to have an impact on a bird. There are no set levels or known impacts at each level. But they do know that eating oil damages a birds gut, whether its coated or not.
And for humans, OSHA has looked at 1,048 BP samples, raw data on oil-cleanup workers for exposure to a chemical that injured Valdez workers 2-butoxyethanol.
OSHA found most had no exposure to the chemical, and all exposure levels detected were well below occupational limits.
But Dr. Riki Ott, a marine toxicology expert who worked at the scene of the Valdez oil spill, told a packed Sierra Club meeting in Mobile that she thinks public health officials down-play health problems because they cant document unsafe levels of chemical exposure.
Our federal government standards are set up for 40 hour work weeks where you have time to clear your body, she said. Constant exposure was what made Valdez fishermen sick, she said.
Symptoms of the Gulf spill might be written off as food poisoning, heat stroke and staph infections.
And Ott said it likely wont be just cleanup workers having health problems. People at the beach need to watch for wicked sore throats, burning eyes, ear bleeds. Thats what they saw in Valdez. And most at risk are little children.
But because there are so many unknowns and no real precedent in an region whose environmental research has been critically underfunded, a great deal will likely remain speculation.
(Information from The New York Times, the Associated Press, WKRG television in Mobile, Mother Jones magazine and National Public Radio and Huffington Post contributed to this report.)