Massive amounts of oil at bottom of Gulf of Mexico: Report

Samantha Joye of the Department of Marine Sciences at the University of Georgia told ABC News that her research team was "finding it everywhere that we've looked".

"The oil is not gone. It's in places where nobody has looked for it," she said this week.
In August, scientists from Woods Hole Oceanographic Institution reported they had measured an underwater plume of drifting oil from the BP disaster stretching at least 35 km. The finding proved the need for rethinking clean-up operations after deepwater drilling accidents, they said.

On a blog last week, Joye described a centimetres-thick "layer of flocculent, sedimented oil" about 25 km from the ruptured BP wellhead that exploded April 20. The disaster is the worst oil spill in US history. The gusher was finally contained by late July.

The sample from the layer would be sent for analysis to see if it matches the oil that came from the BP well, Joye wrote. The oil blanket covered newly killed shrimp and other marine creatures, she said.

The underwater plume found by the Woods Hole scientists in June was at least 35 km long, 200 metres high and two kilometres wide.

Finding hidden underwater oil masses will likely become a major part of the legal case that the US government is developing against BP and its subcontractors who are responsible for the spill, according to Steve Murawski of the National Oceanic & Atmospheric Administration (NOAA).

BP and its subcontractors have spent billions of dollars cleaning up the months-long spill from the April explosion of the Deepwater Horizon drilling rig.

But most of the efforts have been focussed on surface oil. BP has argued that underwater oil is quickly broken down by microbes.

The oil gusher was finally blocked in August with a cement plug in the damaged well head. Engineers are still working on a second seal, the so-called bottom kill, which entails pumping cement directly into the oil reservoir through a relief well.