"So these waters already had a bacterial community in them, then they got a second input of hydrocarbons."
As the water came back over, he explained, the organisms that had already bloomed and eaten their preferred hydrocarbons immediately attacked and went after certain compounds.
Then they were fed a new influx of hydrocarbons.
"When you have these developed communities coming back over the wellhead, they consume the hydrocarbons much more quickly," Valentine said, "and the bacterial composition and hydrocarbon composition behaves differently. It changes at a different rate than when the waters were first exposed."
The model allowed the scientists to test this hypothesis and to look at some of the factors that had been measured: oxygen deficits and microbial community structure.
"What we found was very good agreement between the two," Valentine said.
"We have about a 70 percent success rate of hitting where those oxygen declines were. It means that not only is the physics model doing a good job of moving the water in the right place, but also that the biology and chemistry results are doing a good job, because you need those to get the oxygen declines. It's really a holistic view of what's going on."
There are valuable lessons to be learned from the study, the scientists believe.
"It tells us that the motion of the water is an important component in determining how rapidly different hydrocarbons are broken down," Valentine said. "It gives us concepts that we can now apply to other situations, if we understand the physics."
Mezic said that this should be a wake-up call for anyone thinking of drilling for oil.
"The general perspective is that we need to pay more attention to where the currents are flowing a
|Contact: Cheryl Dybas|
National Science Foundation