Changing Planet

Canada oks use of Corexit for oil spills—despite what we’ve learned in the Gulf

Co-authored by Erica Cirino

After Shell Oil’s Brutus oil well platform 90 miles south of the Louisiana coast spewed more than 88,000 gallons of crude oil into the Gulf of Mexico this May, Shell contracted Clean Gulf Associates and Marine Spill Response Corporation to clean up its mess. The two companies deployed workers in boats to control the movement of oil with floating booms, and then sucked up the oil with skimming machines.

The messy cleanup scene looked a lot like the 2010 Deepwater Horizon oil spill response effort. But this time, responders did not use dispersants, which—acting like strong detergents stirred by the movement of waves and wind—dissolve oil from the surface throughout the water. Instead, the Coast Guard and Shell agreed using on-water vessels and skimmers would be the most appropriate oil recovery plan.

Perhaps they did not want a repeat of the cleanup disaster caused by the use of dispersants after the Deepwater Horizon spill.

Some of the things lost in the Gulf and its communities following the 2010 Deepwater Horizon disaster. Credit: Carl Safina
Some of the things lost in the Gulf and its communities following the 2010 Deepwater Horizon disaster. Credit: Carl Safina
Oil floating on the surface of the Gulf of Mexico following the 2010 Deepwater Horizon disaster. Credit: Carl Safina
Oil floating on the surface of the Gulf of Mexico following the 2010 Deepwater Horizon disaster. Credit: Carl Safina

After BP’s well gushed more than 200 million gallons into the Gulf in 2010, cleanup teams sprayed 1.84 million gallons of a dispersant called Corexit 9500A onto the Gulf’s surface. As a result, it’s possible nearly a million sea creatures have perished in the years since. Scientists know thousands of marine mammals, sea turtles, and other sea creatures have died, in addition to an estimated 800,000 seabirds and shorebirds. Dispersants make oil especially harmful to bottom-dwelling organisms, which suck up the treated oil into their gills and mouths—resulting in death and disease.

Essentially, floating oil becomes dissolved oil. Embedded in seawater, it’s hidden from human sight, but not cleaned up.

“A mess; it was a mess. Applying dispersants to the oil was illogical. It was wasteful of spill response crews’ time and resources,” Carl Safina says of the Deepwater Horizon cleanup. Safina traveled to the Gulf in April 2010 to observe the spill firsthand. His observations from the trip are chronicled in his sixth book, A Sea in Flames.

Carl Safina wipes oil from his hands during his visit to the Gulf of Mexico following the 2010 Deepwater Horizon disaster.
Carl Safina wipes oil from his hands during his visit to the Gulf of Mexico following the 2010 Deepwater Horizon disaster.

The toxic effects of oil are believed to be exacerbated by the use of dispersant, and oil’s presence in the Gulf after the Deepwater Horizon disaster has caused abnormal growth, development and reproduction in many species, including mahi mahi, Gulf killifish and Bluefin and Yellowfin tuna. While its effects on most marine animals isn’t well understood, researchers have found that Corexit 9500A causes crude oil to become 52 times more toxic to marine plankton and that baby corals exposed to oil and dispersant had lower survival rates and difficulty growing on hard surfaces.

So when Canada’s government approved the use of dispersants in its amended oil-spill response outline last month, environmental advocates were not happy.

“It is sham,” says John Davis, director of ocean-advocacy organization Clean Ocean Action Committee. “[Corexit] doesn’t do anything to clean up an oil spill. It allows the toxicity in the oil to become more biologically available. The last thing you want is for oil to accumulate in the gills of a lobster.”

Before the updated regulations passed, several federal environmental statutes prohibited the use of dispersants to clean up oil spills because of the harm they wreak on wildlife, including the Migratory Birds Convention Act, the Fisheries Act and the ocean disposal provisions of the Canadian Environmental Protection Act.

Safety information on the use of Corexit advises the chemical be kept out of contact with eyes and skin, which it can severely damage. It can cause nausea and vomiting if ingested, as well as chemical pneumonia if it is inhaled into the lungs. Seeing that Corexit, like other oil dispersants, are sprayed, this is a real danger not only for animals but also for humans applying the chemical to the surface of an oil slick after a spill.

Canada hasn’t experienced as many major oceanic oil spills as the Gulf of Mexico. Yet that doesn’t mean future spills in Canada are impossible. And if they do occur, using Corexit and other dispersants could spell disaster for the areas rich array of marine wildlife, including whales, dolphins, porpoises, seals, sea lions, walruses, polar bears, seabirds, shorebirds, crabs, lobsters, mussels, clams and oysters.

“We know dispersants really don’t clean up oil, but hide it. We know dispersants can make oil more toxic, and that can kill wildlife,” says Carl Safina. “So keeping Corexit and other dispersants off Canada’s spill response plan would be advisable.”

Oiled pelican. Credit: Louisiana GOHSEP (Flickr)
Oiled pelican in Gulf of Mexico following the 2010 Deepwater Horizon disaster. Credit: Louisiana GOHSEP (Flickr)
Ecologist Carl Safina is author of seven books, including the best-selling “Beyond Words; What Animals Think and Feel,” and “Song for the Blue Ocean,” which was a New York Times Notable Book of the Year. His writing has won a MacArthur “genius” prize; Pew and Guggenheim Fellowships; book awards from Lannan, Orion, and the National Academies; and the John Burroughs, James Beard, and George Rabb medals. His work has been featured in The New York Times, The Los Angeles Times, The Washington Post, National Geographic, and elsewhere, and he hosted the 10-part “Saving the Ocean” on PBS. Safina is founding president of The Safina Center at Stony Brook University.
  • Michel Boufadel

    It is important to note that skimming of the oil cannot occur in agitated seas, as the oil would be below the booms, which themselves would rip due to the high current speeds (larger than 3 to 5 feet per second). In such a case, not using dispersant could result in the oil reaching the shorelines where the damage is likely larger.

  • Richard Davi

    Michel is correct. There are limitations to mechanical cleanup as well as safety considerations for cleanup responders in agitated seas. Dispersant do not “dissolve” oil. It breaks it up into smaller droplets, creating a greater surface area for microorganisms to attack it and break it down through natural processes. The use of dispersants just helps facilitate this process. For a well written explanation, go to the American Petroleum Institute’s website.

    • Ah, I think the trolls might have arrived. The American Petroleum Institute’s website is certainly not where I would go looking for an independent objective source, or “well-written explanation.” Breaking oil up into smaller droplets that allows oil to go into solution in seawater is pretty much the definition of dissolve. So yes, dispersants dissolve oil. It seemed to me that when BP kept using Corexit over the objections of the EPA it was to sink the oil to get it out of sight so estimates of volume would be difficult and contestable later when fines for damages would be assessed based on volume. Keeping the chemical composition secret when dumping it in the ocean commons was criminal in itself, whether or not it was legal. An explanation needs to be true, factual, objective, and unbiased, not just well-written. My bias is that I have learned not to trust the oil industry.

  • Sharon

    Knowing firsthand the lingering effects of Corexit on humans and wildlife, I too would not trust any explanation from the American Petroleum Institute, who is just out to support oil companies who, in turn, just want to get rid of the oil as quickly as possible with as little time, effort and $ as possible. Out of sight, out of mind is their motto. The problem is, some of the after-effects from Corexit are already there and others are unknown, and Big Oil is so powerful that they fund the research they base their “science” on. Shell did it the right way when they cleaned their recent oil spill, but our planet will pay the price for BP’s use of Corexit for its lifetime.

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