Foreshadowing from Ixtoc Spill- BP oil spill is very unlikely to be harmless
This information is from the October issue of National Geographic.
The Ixtoc spill devastated local fisheries and economies. Wes Tunnell remembers it well. The tall, 65 year old coral reef expert at Texas A&M University- Corpus Christi earned his doctorate studying the reefs around Veracruz in the early 1970's and he kept studying them for a decade after the spill coated them with oil.
Tunnell wrote in an early report on the impact there and on Padre Island in Texas. In early June, after the new disaster had once again raised the question of how long the impact of a spill can last, he returned to Enmedio Reef to see if any Ixtoc I oil remained. It took him three minutes of snorkeling to find some.
"Well that was easy," he said. Tunnell stood in the clear, waist-deep water of the protected reef lagoon holding what appeared to be a three inc thick slab of sandy gray clay. When he broke it in two it was jet black on the inside, with the texture and smell of an asphalt brownie. Here on the lagoon side, where the reef looked gray and dead, the Ixtoc tar mat was still partially buried in the sediments. But on the ocean side of the reef, where winds and waves and currents were stronger, no oil remained.
The lesson for Louisiana, and the other Gulf states is clear, Tunnell thinks. Where there is wave energy and oxygen, sunlight and the Gulf's abundant oil-eating bacteria break it down fairly quickly. When oil falls to the bottom and gets entrained in low-oxygen sediments like those in a lagoon-- or in a marsh-- it can hang around for decades, degrading the environment.
Fisherman in the near by village of Anton Lizardo hadn't forgotten the spill either. "The Ixtoc spill about destroyed all the reefs," said Gustavo Mateos Moutiel, a powerful man, now in his 60's, who wore the trademark straw hat of Veracruzano fisherman. "Octopus gone. Urchins gone. Conch gone. Fish almost all gone. Our families were hungry. The petroleum on the beach was halfway up to our knees."
Though some species, such as Bay of Campeche Shrimps recovered within a few years, Moutiel, along with several other fisherman who had gathered on the beach said it took 15 to 20 years for their catches to return to normal. By then two thirds of the fishermen in the village had found other jobs.
Even in the turbulent, highly oxygenated waters of France's Breton Coast, it took seven years after the the 1978 Amoco Cadiz spill for local marine species and Brittany's famed oyster farms to fully recover, according to French biologist Phillipe Bodin. An expert on marine copepods, Bodin studied the long-term effects of the spill from the grounded tanker.
He believes the impact will be far worse in the generally calmer, lower-oxygen waters of the Gulf, particularly because of the heavy use of the dispersant Corexit 9500. BP has said the chemical is no more toxic than dish washing liquid, but it was used extensively on the Amoco Cadiz spill and Bodin found it to be more toxic to marine life than the oil itself.
"The massive use of Corexit 9500 in the gulf is catastrophic for the phytoplankton, zooplankton and larvae," he says. "Moreover, currents will drive the dispersant and the oil plumes everywhere in the Gulf."
In May, scientists in the Gulf began tracking plumes of methane and oil droplets drifting up to 30 miles from the broken well, at depths of 3000 to 4000 feet. One of those scientists was a University of Georgia biogeochemist Mandy Joye, who has spend years studying the hydrocarbon vents and brine seeps in the deep Gulf. She has found a plume the size of Manhattan, and its methane levels were the highest she had ever measured in the Gulf. As bacteria feast on spilled oil and methane, the deplete the water of oxygen; at one point Joye found oxygen levels dangerously low for life in a water layer 600 feet thick, at depths where fish usually live. Since waters in the deep Gulf mix very slowly, she said, such depleted z9ones could persists fo decades.
BP was using old DC-3's set up like giant crop dusters to spray Corexit 9500 onto surface slicks. But for the world's first major deepwater spill, the company also got permission from the U.S. Environmental Protection Agency and the Coast Guard to pump hundreds of thousands of gallons of dispersant directly into the oil and gas spewing from the well, a mile beneath the surface. That helped create the deepwater plumes.
"The whole goal was to keep the oil off the beaches, because that's what drives the economy," Joye said one day in June as she ran samples through her gas chromatograph aboard the R.V.F.G Walton Smith. The little research ship was bobbing in an oily sheen a few miles from the busted well. "But now you've got all this material in the water column that no one is seeing and that you can't get rid off. If the oil gets to the surface, about 40% evaporates. You can skim it, you can burn it, you can do something with it. But these tiny particles in the water column will persist for God knows how long."
Oceanographer Ian McDonald at Florida State University worries not only about the plumes but also about the sheer volume of the spilled oil. He believes it could have a major impact on the overall productivity of the Gulf-- not just on pelicans and shrimps in the Louisiana Marshes, but on creatures throughout the region everything from zooplankton to sperm whales. He's particularly concerned about the blue-fin tuna, which spawn only in the Gulf and in the Mediterranean; the tuna population was already crashing due to overfishing.
"There is a tremendous amount of highly toxic material in the water column, both at the surface and below., moving around in the most productive ocean basins in the world," MacDonald said.
What it looked like there (Video of Gulf birds, fish caught in BP oil spill):
More underground images of Gulf Oil Spill:
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