Oil sheen contained in Talbert Channel near site of last year’s major O.C. pipeline spill. Image by NOAA
A long-term study of the impacts of various oil spill clean-up strategies on marine mammals and birds off the coast of North Carolina is concluding that the best practice is a mixture of cleanup operations with different approaches to each species.
The study, to be published in February in the journal Science, found that while the preferred cleanup method was the oil-spilling operator’s best option for cleaning up the oil and dispersing it, this approach did not work if only the disperser or oil-spill treatment was applied at the spill site.
The study’s first analysis looked at how fish and crabs fared with each of three strategies: oil-spilling with little or no dispersing or oil-spill treatment applied at the site, oil-spilling plus a disperser at the site, and oil-spill plus a disperser and an oil-spill treatment deployed to the site. The second analysis looked at how birds fared with each of four strategies: oil-spill, oil-spill with little or no disperser applied at the site, oil-spill plus a disperser applied at the site, and oil-spill plus a disperser and an oil-spill treatment deployed.
“The dispersers are used to get oil into the ocean water while the oil-spill [or oil-spill treatment] is applied to the site to help disperse oil,” said Michael W. Leutert, a marine scientist at NOAA’s South Carolina Institute for Marine Science, which conducted the study. “This study provides scientific evidence that there is an optimum strategy for treating oil spills.”
The study did not examine how the birds fared with each strategy, but the result was consistent with previous studies showing that the best method of cleanup is the operator’s preferred strategy. The best strategy in this case was oil-spilling plus oil-spill and disperser. This strategy worked for all species, including mammals, turtles, and seabirds at the three study sites — Baffin Island, Cape Lookout, and Bluffton, at a range of distances from the oil spill.