One of the latest studies of the spill's lingering effects offers the most comprehensive understanding of the devastation to date. It's not necessarily that things are getting worse -- certainly many of spill's initial environmental consequences have improved thanks to ongoing cleanup efforts. It's just that with more research, scientists discover more adverse effects they didn't know about before.
Deepwater Horizon, owned by Transocean and leased to BP, exploded and sank in 2010, killing 11 crew and releasing nearly 5 million barrels of oil into the Gulf of Mexico -- the largest offshore spill in U.S. history.
"Things happen slowly in the deep sea," Charles Fisher, a marine biologist with Pennsylvania State University, told Newsweek. His study details oil spill effects recently observed on coral reefs near the Deepwater Horizon drilling rig.
Previously researchers had located only one of 14 local coral reefs that showed evidence of damage from oil contamination. Fischer's new study, which was published Monday in the online Early Edition of Proceedings of the National Academy of Sciences, details the discovery of two more contaminated coral reefs, suggesting a more extensive deep water impact that originally believed.
Fisher says coral reefs can offer a story of environmental damage, long after contaminated animals have died off or moved on.
"If fish or crabs or shrimp were swimming around in those areas [in 2010], we wouldn't have known," Fisher said. "But these corals stay there." Looking at them can give us an idea of what ocean conditions have been like throughout time."
In a essay published in response to the new report, scientists with BP suggested the conclusions of the latest study are premature -- and that researchers didn't consider the possibility that these reefs were affected by other sources of oil. But the paper's authors defended their research and doubled down on their conclusion that these reefs showed direct evidence of oil from the BP spill.