When the Deepwater Horizon oil rig blew in 2010, it spewed some 200 million gallons of oil into the Gulf of Mexico. In order to break up the slick, another 1.84 million gallons of dispersant was added to the mix. This one-two punch of toxic chemicals devastated coastal ecosystems [pdf], but how would such a chemical bombardment affect underwater ecosystems like coral reefs? According to a new study, the
picture is no prettier.
Researchers at the Mote Marine Laboratory in Florida tested the effects of Deepwater Horizon-type oil and the dispersant used to clean it up, Corexit® 9500int, on coral larvae in the lab to replicate what may have happened following the spill. Larvae colonize reefs by sampling a surface, sticking to it and then changing into a polyp to get growing. They do this based on chemical cues in the water. Adding oil and dispersant, it turns out, severely hinders this sensitive settlement process.
Mutated shrimp from Al Jazeera’s video report
Al Jazeera‘s report on seafood in the Gulf Coast reads like a horror story: eyeless shrimp, fish with oozing sores, clawless crabs. Unfortunately these deformities are very real and disturbingly common two years after the Deepwater Horizon oil spill in 2010. Chemical dispersants used by BP to “clean up” the oil spill are the likely cause.
Deformities happen even in ordinary circumstances, but scientists and fishers are seeing them in unprecedented scales in Gulf marine life. For example, half the shrimp caught in a Louisiana bay lacked eye sockets, according to fishers interviewed by journalist Dahr Jamail.
“Some shrimpers are catching these out in the open Gulf [of Mexico],” [commercial fisher Tracy Kuhn] added, “They are also catching them in Alabama and Mississippi. We are also finding eyeless crabs, crabs with their shells soft instead of hard, full grown crabs that are one-fifth their normal size, clawless crabs, and crabs with shells that don’t have their usual spikes … they look like they’ve been burned off by chemicals.
Perhaps the most troubling line in the whole article is this: “Questions raised by Al Jazeera’s investigation remain largely unanswered.” When Jamail went knocking on doors at government and corporate offices, nobody wanted to talk. One scientist he interviews mentions the difficulty in getting funds to study the oil spill’s environmental impact. The Deepwater Horizon oil spill may be rapidly fading in our memories, but its impact on the ocean is not.
Image via Al Jazeera English
The oil stopped spilling from the Deepwater Horizon wellhead months ago, but the Gulf of Mexico’s environmental saga continues. Researchers have investigated the chemicals used to disperse the oil flow in the first place, and found that these “dispersants” didn’t disperse. The effects of this massive chemistry experiment, however, are still unknown.
“The dispersants got stuck in deep water layers around 3,000 feet [915 meters] and below,” said study leader David Valentine, a microbial geochemist at the University of California, Santa Barbara…. “We were seeing it three months after the well had been capped. We found that all of that dispersant added at depth stayed in the deepwater plumes. Not only did it stay, but it didn’t get rapidly biodegraded as many people had predicted.” [National Geographic]
In total, the response team pumped over 800,000 gallons of dispersants into the oil flow; dispersants break down oil into smaller droplets that can degrade more quickly. But the impact of the dispersants themselves has been up for debate. For the new study, scientists tracked the dispersants by following one of its ingredients: dioctyl sodium sulfosuccinate (DOSS).