BP oil spill: an unexpected laboratory for deep-sea disaster

The Deepwater Horizon blowout, now into its fifth week, represents an unplanned environmental experiment on an enormous scale – one whose full impact on Gulf of Mexico ecosystems may not become clear for decades.

But scientists are scrambling to study the BP oil spill now, knowing that it is, in many ways, a unique event. Never before has a leak from such depths vented so much oil for so long. Scientists have many questions, from how the use of massive quantities of dispersants affects nature's ability to break down an oil to why oil plumes from deep-sea spills act in unexpected ways.

IN PICTURES: Louisiana oil spill

The information they gather could improve responses to future deep spills and provide a better sense of how they affect the ecology. Scientists, for example, know little about long-term effects that aren't severe enough to kill organisms, but can alter reproduction or behavior in fundamental ways, says Marshall Adams, a researcher with the environmental sciences division at the Oak Ridge National Laboratory in Oak Ridge, Tenn.

To the naked eye, "the oil can disappear, but we don't know the long-term effects on organisms and their population fitness," he says.

The open ocean is a particularly complex environment to understand, other researchers say. Research requires expensive ships, and many factors can affect the health of marine life at all levels of the water column, making it tough to single oil out from other stresses both human and natural.

But a concerted effort is afoot to use the BP oil spill as an opportunity to better understand deep water oil spills.

BP, which owns the exploratory well the Deepwater Horizon was working when the blowout occurred April 20, has offered $500 million over the next 10 years to underwrite research and monitoring efforts. Moreover, the National Science Foundation, which underwrites research by university-based scientists, has made quick-response grants available for gauging the spill's ecological effects.

Dispersants

For instance, scientists are trying to see if the wide use of chemical dispersants – more than 600,000 gallons so far – undercuts the ability of naturally occurring microbes to break down the oil.

On one hand, as dispersants break a slick into tiny oil droplets, more microbes get a chance to attack the oil, notes Qianxin Lin, a coastal ecologist at Louisiana State University in Baton Rouge. Microbes can attack oil droplet from every side. In a typical slick, they just nibble at the edges.

Yet dispersants also may also inhibit the chemicals microbes produce to gather and consume the oil, according to University of California at Santa Barbara researcher David Valentine. Armed with one of the rapid-response grants, he's heading to the Gulf to gauge the microbes' responses to dispersants.

Where does the oil go?

Scientists also want to know the amount of oil likely to come to rest on the sea bottom. On the surface, oil weathers, grows dense, and sinks. But in the BP oil spill, much of the oil never makes it to the surface.

Carefully controlled experiments a decade ago released small quantities of oil from a depth about half that of the Deepwater Horizon's Macondo well, and they revealed some surprises, notes Eric Adams, a scientist at the Massachusetts Institute of Technology who was involved in the work.

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