Saturday, July 31, 2010

Blobs in crab larvae characteristic of dispersant

Reported by: Shelley Brown, Weekend Anchor
Contributor: Tammie Mills, Photographer
Last Update: 7/30 11:24 pm

New findings back up the concern the dispersant BP used so widely may do more harm than the oil itself.

Researchers at Tulane say it appears they've detected a Corexit sort of fingerprint in the orange blobs found lodged in the bodies of tiny blue crab larvae collected from marshes that stretch from Texas to Florida. Researcher Erin Grey said the results, while not conclusive, are likely. She's waiting on two other independent tests.

On May 20, 2010, EPA administrator Lisa Jackson said, "this is unprecedented volumes of dispersants used so far" when talking about the chemical dispersant known as Corexit being used to break down oil in the Gulf of Mexico.

That's what UNO's Martin O'Connell, Ph.D, who studies aquatic organisms that move through the water, says is the problem. That the volume of the EPA's pre-approved dispersant used to break down the oil probably turned it into small droplets, making it easy for a mix of oil and dispersants to finds its way under a shell.

He said, "something with a shell, a small shell, a shrimp or a crab.. it kind of gets stuck in some places, and if it can survive the actual toxicity and shed that shell, the oil can be released. If they can't survive though it's stuck there then there's a problem."

O'Connell said most components of oil won't bio-accumulate, meaning oil likely won't reach the food chain. As for Corexit, he said, "no one really knows."

"If you're a small fish and you eat 1,000 of these small crab larvae and all of them have oil or Corexit droplets in them they could get into the fish.. that little fish could be eaten and so on and so on," said O'Connell.

New Orleans attorneys, Stuart Smith and Mike Stag represent fishermen and cleanup workers who have left boats because they're sick. The attorneys have hired experts to test air and water quality samples, including Dr. William Sawyer, a toxicologist out of Florida, who said, "some of these chemicals are in great excess.. of risk-based lethal levels.. that the current hydrocarbon levels are capable of sterilizing our fisheries and estuary production zones."

O'Connell shares similar concerns:

He said, "I think they should be more concerned that we might be losing whole cohorts of these animals when they're very small, and we won't see the impact in the adults but three or four years from now. When we're expecting adult crabs coming into Lake Ponchartrain, there might not be as many out there."

Since so many fish and crabs feed on crab larvae, some scientists fear the oil and dispersant droplets threaten to kill critical areas in the Gulf of Mexico food web.

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