Use of chemical dispersants may need re-evaluation, researchers say
By Max Paris, Environment Unit, CBC News
Underwater investigations near the site of British Petroleum's Gulf of Mexico spill in 2010 show lasting damage to deepsea coral, suggesting that oil may have been dispersed, but did not simply disappear.
The research was conducted by University of Pennsylvania biologist Charles Fisher using the U.S. navy's Alvin submersible. The corals his team studied were at a depth of 1,300 metres and 11 kilometres from BP's Macondo well, site of the spill.
During the days oil gushed from the well into the ocean, chemical dispersants were used extensively to keep oil slicks from washing up on the Gulf Coast and despoiling beaches, barrier islands and coastal swamps.
"I believe we have found that a good bit of the oil did end up in the deep sea," said Fisher. Despite the lack of light deepwater corals receive, they tend to be quite colourful, often exhibiting pinks and bright reds. The ones his team found on their first expedition in October 2010 were covered in a brown gunk. Normally, a coral would protect itself with a mucous.
"What we found out later, when we went back in December, we collected some of those corals and the tissue underneath the parts that were heavily covered were either dead, dying or gone," said Fisher.
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