Panel of USF scientists present oil spill findings to the public
Last night in St. Petersburg, a panel of USF based marine scientists shared their findings on the impact of the BP Deepwater Horizon disaster.
Bob Weisberg is a Professor of Physical Oceanography at the University of South Florida, and a leading expert on the role of the Gulfâs loop current.
"It provides the connectivity between the Caribbean and southeastern United States. It flows into the Gulf of Mexico through the Yucatan, out through the Florida straights and then up the east coasts as the Gulf Stream. At the start of spill, it was as far north as the latitude of Tampa Bay, and in the process of going farther, and many of us though it would get as far north as the wellhead, which it has done many times in the past."
Weisbergâs group, the Ocean Circulation Group, used satellite imagery and observation of the Gulfâs pattern of currents to determine the potential path of the oil.
"But what happened, it happened on May 20th in fact, the loop current shed what we call an eddy. Once that happened, the connection between the wellhead and the Florida Straight was broken. Prior to that, some oil had gotten into the loop current, and a very small amount of oil did actually did flow through the Florida straights and up the east coast, but it was relatively minor because that connection was broken, so Florida really lucked out, and had that connection not been broken we would have seen oil in the vicinity of the keys and up the east coast."
Ernst Peebles is a Professor of Biological Oceanography at USF, specializing in research on coastal fisheries, and was part of the crew of the research vessel that identified subsurface oil in the Gulf. He gave an overview of the biological impact that the spill had on the gulf. He made a point that thereâs a disconnect between lab studies that determine water toxicity and what actually happens in nature.
"And there are some sub-lethal effects, that arenât necessarily detected or evident from laboratory studies. In nature, when an animal shows any kind of distress, it is preyed upon â in general â predatory fish arenât very polite to their prey when it starts to become impaired. So, a very sub-lethal, a very subtle change in behavior can have a sub-lethal effect. That type of dynamic, or response, isnât evident in the laboratory tests that people use to determine toxicity."
David Hollander is a professor in Chemical Oceanography at USF, whose work led him to discover oil on the floor of the gulf. He pointed out that, even without chemical dispersants, some oil was likely to remain deeper in the water column.
"This was like an aerosol can 21 inches in diameter that was able to spew out like that. What happens when pressure shoots out, it comes out as fine microdroplets. They burst out into very small particles, and thatâs a really important phenomenon, because independent of dispersant, the physical chemistry suggests that subsurface oil should form. And if itâs really small droplets, it should be stable for a pretty long time, and itâll stay there."
Along with Peebles, Hollander set out to track down sub-surface oil in the gulf, using models that Weisberg created to track the movement of underwater particles. Using sonar, along with other methods, they discovered what they believed to be a plume of oil about four hundred meters below the surface, all while BPâs CEO Tony Hayward, who has since been replaced, denied that subsurface oil could exist.
"There was a lot of pressure coming back from that cruise, and all of the sudden Tony Hayward comes out and says 'of course, there is no oil under the surface, oil doesnât stay underneath the water, oil floats' and that put a direct pressure on us as academics to really recognize whether this was oil or not."
Using carbon analysis of the water samples, they were able to come to a definitive conclusion.
"And so, at that point we really put it out, and we confirmed indeed that it was subsurface oil plumes at 400 and 1000 meters, and so we put Tony Hayworthâs statement to bed."
Hollander also was able to prove that the sub-surface oil did, in fact, come from the BP platform. He did this by comparing the chemical makeup of oil from the accident site to the samples of sub-surface oil they had collected.
"So really, the molecular compound specific approach is essentially the equivalent of a chemical fingerprint, and obviously the BP 252 Deepwater Horizon well is definitely the source of the subsurface oil."
Audience members were concerned about how these studies were funded, and if BP had anything to do with the research. During the question and answer period, Peebles addressed their concerns.
"The University of South Florida stepped up, and our foundation on the main campus gave us $500,000 to continue our work. We didnât have any strings attached because we didnât have any BP money, but there was still some government feedback we were getting, so the main campus was wise enough to give us money to continue our work to guarantee there were no strings attached."
USF is a member of the Florida Institute of Oceanography, which received $10 million from BP.
The event concluded with a panel of spokespeople from the various environmental organizations, who spoke about their activities in gulf restoration and how people can get involved.comments powered by Disqus