"They can sense the oil and move toward it," said UC researcher Terry Hazen, Ph.D. "So they're little oil-seeking missiles, sort of."
Last summer, Hazen led a team that spent months sampling the waters near where the Deepwater Horizon exploded last April 20. The disaster killed 11 workers and spilled more than four million barrels of light crude into gulf waters.
To keep large amounts from reaching the surface, BP deployed a huge quantity of a commercial oil dispersant called COREXIT. That created a plume of micron-sized petroleum particles.
"We found that there were some organisms down deep that are what we call psychrophiles or cold-loving micro-organisms," explained Hazen. "And they could degrade the oil that was there and degrade it fairly fast."
After months of sampling and study, Hazen and his team found some contamination in the water near the wellhead, but farther away at depths between 3,600 and 400 feet, the plume had disappeared.
"That doesn't mean it wasn't an ecological catastrophe though," said Hazen. "Certainly it caused the death of fishes, birds, plankton, turtles. The long-term effects we'll be studying for a very long time on those organisms."
Hazen acknowledges other researchers are still finding tar balls on Gulf beaches and even in water samples, but he points out there have always been tar-balls on Gulf beaches and much of that could be from oil that seeps naturally into the ocean every year.
Hazen's team began researching oil degradation four years ago, through a $500 million grant from BP.