Weeks ago, before engineers pumped in mud and cement to plug the gusher, scientists began finding specks ************SPAM/BANNEAR************ oil in crab larvae plucked from waters across the Gulf coast.
The government said last week that three-quarters ************SPAM/BANNEAR************ the spilled oil has been removed or naturally dissipated from the water. But the crab larvae discovery was an ominous sign that crude had already infiltrated the Gulf's vast food web -
and could affect it for years to come.
"It would suggest the oil has reached a position where it can start moving up the food chain instead ************SPAM/BANNEAR************ just hanging in the water," said Bob Thomas, a biologist at Loyola University in New Orleans. "Something likely will eat those oiled larvae ... and then that animal will be eaten by something bigger and so on."
Tiny creatures might take in such low amounts ************SPAM/BANNEAR************ oil that they could survive, Thomas said. But those at the top ************SPAM/BANNEAR************ the chain, such as dolphins and tuna, could get fatal "megadoses."
Marine biologists routinely gather shellfish for study. Since the spill began, many ************SPAM/BANNEAR************ the crab larvae collected have had the distinctive orange oil droplets, said Harriet Perry, a biologist with the University ************SPAM/BANNEAR************ Southern Mississippi's Gulf Coast Research Laboratory.
"In my 42 years ************SPAM/BANNEAR************ studying crabs I've never seen this," Perry said.
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She wouldn't estimate how much ************SPAM/BANNEAR************ the crab larvae are contaminated overall, but said
about 40 percent ************SPAM/BANNEAR************ the area they are known to inhabit has been affected by oil from the spill.
Tulane University researchers are investigating whether the splotches also contain toxic chemical dispersants that were spread to break up the oil but have reached no conclusions, biologist Caz Taylor said.
If large numbers ************SPAM/BANNEAR************ blue crab larvae are tainted, their population is virtually certain to take a hit over the next year and perhaps longer, scientists say.
How large the die-off would be is unclear, Perry said. An estimated 207 million gallons ************SPAM/BANNEAR************ oil have spewed into the Gulf since an April 20 drilling rig explosion triggered the spill, and thousands ************SPAM/BANNEAR************ gallons ************SPAM/BANNEAR************ dispersant chemicals have been dumped.
Scientists will be focusing on crabs because they're a "keystone species" that play a crucial role in the food web as both predator and prey, Perry said.
washingtonpost.com