After synthesizing existing knowledge to anticipate the potential ecotoxicological effects of the spill, and highlighting major gaps in scientific understanding, the scientists have created the first complete conceptual model for understanding both the Deepwater Horizon spill and analogous disasters in the future.
This new model accounts for how deepwater oil spills unfold and where the resulting ecological impacts accrue. It also emphasizes that the vast majority of the oil is retained at depth rapidly emulsified and dispersed due to the physics of the pressurized oil jetting from the tip of the wellbore and, among other response actions, calls into question the efficacy of dispersants.
"We have generally hailed the use of [chemical] dispersants as helpful, but really are basing this on the fact we seemed to have kept oil from getting to the surface," argues co-author Gary Cherr, director of UC Davis's Bodega Marine Lab. "The truth is, much of this oil probably was staying at depth, independent of the amount of surfactants we dumped into the ocean. And we dumped a lot of dispersants into the ocean all told, approximately one-third of the global supply."
Co-author Ron Tjeerdema, chair of the Environmental Toxicology Department at UC Davis, concurs. "The problem is, we really must address the downside of such compounds, particularly in light of the fact that the upside probably was not so great as it seemed at the time," he said.
Armed with a new foundation for research and policy implications, the NCEAS Gulf Oil Spill Ecotox Working Group is calling for further investigation into the long-term effects of deep-water oil spills.
"We now have a sense that the
|Contact: Sonia Fernandez|
University of California - Santa Barbara