Researchers map oil in Gulf of Mexico

Researchers map oil in Gulf of Mexico

A Florida State University researcher and his team have through a comprehensive analysis of oil in the Gulf of Mexico have analyzed the percentage that occurs naturally and how much came from the 2010 Deepwater Horizon spill. Their data creates a map, showing where the active natural oil seeps are located.

Offshore oil and gas in the Gulf of Mexico is a major source of oil and natural gas in the United States. The western and central Gulf of Mexico, which includes offshore Texas, Louisiana, Mississippi, and Alabama, is one of the major petroleum-producing areas of the United States.

The research was recently released online by the Journal of Geophysical Research Oceans and is also the basis for a paper with researchers at Columbia University published today in Nature Geoscience.

In total, 4.3 million barrels were released into the Gulf from the oil spill versus an annual release of 160,000 to 600,000 barrels per year from naturally occurring seeps, according to the new results.

The catastrophic blowout of the Deepwater Horizon drilling rig in 2010 caused the largest oil spill in U.S. history, releasing an estimated 206 million gallons of crude oil into the gulf before it was capped 87 days later.

This information gives us context for the Deepwater Horizon spill, said FSU Professor of Oceanography Ian MacDonald. Although natural seeps are significant over time, the spill was vastly more concentrated in time and space, which is why its impact was so severe.

Among the findings was that dispersants were able to eliminate about 21 percent the oil that floated on the surface of the Gulf of Mexico after the spill, but at the cost of spreading the remaining oil over a 49 percent larger area.

Using this new set of data, scientists will be able to go to a controlled area where they already know oil exists and perform controlled observations.

Researcher Ajit Subramaniam, an oceanographer at Columbia University's Lamont-Doherty Earth Observatory, used the data set to focus on natural oil seeps and discovered something unusual, phytoplankton, the base of the marine food chain, were thriving in the area of these natural oil seeps. The results published in Nature Geoscience show that phytoplankton concentrations near the oil seeps were as much as twice as productive as those a few kilometers away where there were no seeps.

This is the beginning of evidence that some microbes in the Gulf may be preconditioned to survive with oil, at least at lower concentrations, Subramaniam said. In this case, we clearly see these phytoplankton are not negatively affected at low concentrations of oil, and there is an accompanying process that helps them thrive. This does not mean that exposure to oil at all concentrations for prolonged lengths of time is good for phytoplankton.

It's giving us a basis for all of these other experiments, MacDonald said. It's really revolutionizing how we look at the Gulf. It also gives scientists the exact geographic points where oil from the spill was located, so researchers can go to the Gulf floor and explore the area to see if there has been any environmental effect.

Earlier studies have also analyzed the pollutant caused by the spill. UCF chemistry professor Andres Campiglia, thanks to research he began a decade ago, now has the ability to do what other researchers couldn't: detect these forgotten PAHs. The Gulf of Mexico Research Initiative recently awarded Campiglia a $1.5 million grant to track down the environmental fate of those PAHs.

Researchers map oil in Gulf of Mexico