One week after the dismissal of their initial “oil plume” findings by BP CEO Tony Hayward, USF researchers confirmed the presence of invisible hydrocarbons throughout the depths of the Gulf of Mexico on Tuesday.

Steve Murawski, chief scientist for the National Oceanic and Atmospheric Administration (NOAA), said USF and NOAA scientists collected 25 water samples on the R/V Weatherbird II last month.

David Hollander, a chemical oceanographer at USF’s College of Marine Science (CMS), said the deepest water sample at 1,000 meters had the highest concentration of hydrocarbons relative to shallower concentrations.

“If you have a gradient like that in a water column, chances are it’s not coming from the top – it’s coming from the bottom,” Hollander said.

These hydrocarbons are invisible to the naked eye, he said, much like sugar dissolved in water.

Hollander said the oil in the subsurface also appears to be degraded – a trait he thinks could be linked to BP’s use of dispersants on the oil. Because of this, he said it is more difficult to trace it back to its original source – a feat that would be made simpler with a pure sample of BP oil.

However, an attempt to obtain this sample earlier in the week was met with resistance.

“I was taken aback,” Hollander said. “The experience was a little unsettling. I was hoping for a little more cooperation.”

Ernst Peebles, a biological oceanographer at CMS, said the research team also discovered emulsified oil – described as “mousse” – which has a brown-orange color and often washes up as tar balls on the beach.

“The oil appears to be in layers,” he said. “The concentrations of hydrocarbons at depth are low, but are similar to the shallower water surrounding the larger visible particles.”

When the researchers originally designed the expedition, Peebles said they wanted to collect water samples from testing sites that would allow them to determine if the Florida Middle Grounds – “a marine protected environment” and fish sanctuary – would be at risk.

However, that risk and the affects the hydrocarbons will have on the environment have yet to be determined, said Dean of CMS William Hogarth.

He said Gov. Charlie Crist has asked BP for $100 million in aid so that Florida can begin to address the clean-up and ecological concerns that have resulted from the oil spill.