Marine scientist Dr. Tracy Villareal will serve as chief scientist on a research cruise this August into the Gulf of Mexico to study the impacts of the oil spill on phyto- and zooplankton communities and map deepwater oil plumes.
When Tracy Villareal cruises around the belly of the BP beast out into the wide-open Gulf of Mexico, he’ll be on the hunt for deep oil plumes, tar balls and oil slicks.
He’s not sure where he’ll find them and exactly what he’s going to see. He and his fellow scientists and crew will be exploring and studying an unprecedented environmental disaster in the Gulf, and they will be looking for oil that is on the move and ever shifting.
“We are very concerned about the deep plumes that are reported,” says Villareal, a biological oceanographer at The University of Texas at Austin Marine Science Institute. “The plumes are dictated by subsurface current flows and not visible on the surface. We have models, but the real test is going out there and seeing if we can actually find them.”
Villareal is chief scientist on the R.V. Cape Hatteras, one of two ships embarking on a 27-day research cruise beginning August 21 that is funded by the National Science Foundation. The other vessel, the R.V. Oceanus, will be led by biologist Joe Montoya from Georgia Tech.
The two ships will act in concert to study both surface and deepwater oil. And they will need to be nimble, responding to each other's new discoveries out in the open ocean.
Villareal and his crew will begin their journey in the western Gulf and head eastward, all the while dropping a steel cable loaded with an array of sensors deep into the water. The scientists on board will get real time data on things like methane, nitrogen, oxygen and light absorption as far down as 1800 meters – all the way to the ocean floor.
“We’ll know we’ve found a plume when there is a sharp increase in methane and decrease in oxygen,” says Villareal. He says hydrocarbons disappear quickly from the plumes, but methane sticks around.
“The plumes will be very active and mobile, responding to the currents,” he says, “but it’s important that we try to get a good handle on them.”
By mapping the distribution of the plumes, the scientists want to resolve the issue of how far to the west and south the plumes are going and the extent to which the plumes are changing the basic ocean chemistry at depth. They’ll gather chemistry data from the sensors, but they’ll also reel in water samples bottled at various depths.
On the surface, the scientists will collect phytoplankton and zooplankton, and use large “neuston nets” to gather Sargassum (seaweed) and tar balls. There’s evidence that oil selectively impacts smaller phytoplankton, and Villareal wants to look at how the sizes of phytoplankton change across the Gulf and as they move into heavily oiled areas.
The researchers also hope to document the distribution of tar balls in the open ocean, so that others can better calculate when and where the gooey tar will show up on the coasts.
Villareal says that they don’t really know how the surface oil plumes will affect phyto- and zooplankton or how the microbes’ activity will change the deepwater chemistry. They don’t know how long it will take the deep plumes to disperse and to where they will go.
“These are the questions we want to answer so that we can gauge the impact of the oil spill on the larger Gulf of Mexico,” says Villareal. “The scale of this event will be manifest in all sorts of different processes. This is an incredible disaster, and we hope we can contribute something that’s meaningful and helps to bring some clarity to the issue.”
For more information contact: Tracy Villareal, 361-749-6732.
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