photo credit USF
So, we've been hearing that all the oil that was "supposed" to be on the surface has likely been pushed down to smother the seafloor thanks to dispersants like Corexit. This is bad news considering much of bottom life is at or near the base of the food chain and is sedentary, meaning creatures cannot move to a less contaminated environment.
"Tiny deep-sea creatures are showing a "strong toxic response" to hydrocarbons, an ingredient of oil, according to preliminary results released Tuesday by the University of South Florida (USF)."
Sediment samples were taken from an important ecological site near the Deepwater Horizon wellhead.
"By shining ultraviolet light on the samples, the team indirectly detected hydrocarbons in the sample that seem to have the same fluorescent fingerprints as oil from the wellhead, which was capped July 15."
The team also took healthy specimens of bacteria and phytoplankton and exposed them to water samples from the surface and from the deep. The Phytoplankton, which have a slight natural glow, showed "enormous reduction" in light upon exposure to the deep-water samples. The bacteria showed similar results when exposed to the surface samples. It is not yet clear why they show opposite reactions.
"It's possible, for example, that different species have different reactions to the toxic effects of oil and chemical dispersants,” says David Hollander, a USF chemical oceanographer.
Hollander emphasized that his team's observations are preliminary: "I hope they don't get misconstrued as scientific fact."
Full article here (National Geographic)