Degraded Oil From BP Spill Coats Gulf Seafloor

A research team from Columbia University in New York returned this past weekend (Sept. 17 to 19) from a tour of duty in the Gulf of Mexico with new data to attempt to measure the location and magnitude of subsurface oil plumes, and their effects on the marine ecosystem, which have recently been the focus of much debate.

They found oil on the seafloor, evidence that it may be in the food chain, and signs that it may be hidden in large marine mammals. In spots, the "oily snow" — degraded oil and other organic material that clings to it — was up to 6 inches (15 centimeters) deep on the seafloor, said Columbia oceanographer Ajit Subramaniam.

Oil-Rig-Spills.Com"The idea that the oil is degraded and therefore doesn't matter is something we have to think about differently," Subramaniam said at a talk here today. "This is one of the first findings that showed degraded oil material collected on the seafloor."

When this gunk starts to pile up on the sea floor, the entire food web is at risk, the researchers said. The oceanographers also discovered discolored zooplankton, which eat the food chain's primary producers ­– phytoplankton – near oily clouds, Subramaniam said. The full analysis of the effects to the food chain, however, will take several months.

While the deep-ocean effects are largely out of sight, the Gulf's large mammals — including whales and dolphins — were also hit hard by the oil spill. Yet the true impact may take years to uncover.

"We really don't know much about the effect of the oil spill in cetaceans, because the effects are likely to be long term," said marine mammal expert Martin Mendez of the American Museum of Natural History in New York.

http://www.livescience.com/environment/gulf-oil-spill-underwater-plumes-10092...