Five Years On, USF Researchers Revisit Gulf Oil Spill

Apr 21, 2015

On April 20, 2010, a wellhead a mile below the surface of the Gulf of Mexico exploded, killing 11 workers aboard the Deepwater Horizon oil platform.

In the subsequent leak, more than 200 million gallons of oil spilled out. On the Gulf’s surface, the oil covered up to 68-thousand square miles – an area roughly equal to the size of Florida.

But the spill, which went on for 87 days until the leak was finally capped, ended up stretching across four dimensions – not just from the Gulf coast to the depths beneath the platform about 100 miles from Florida’s Panhandle, but across time as well.

So on the fifth anniversary of the Deepwater Horizon explosion, researchers from the University of South Florida College of Marine Science and the Florida Institute of Oceanography gathered to discuss their past, current and future work related to the disaster.

USF College of Marine Science Professor David Hollander examines a piece of equipment before sending it out to collect oil spill data in the Gulf of Mexico.
Credit C-IMAGE Consortium

David Hollander became one of the most recognizable faces of USF’s efforts. The professor of Chemical Oceanography was one of the first researchers to find evidence of oil deep on the ocean’s floor.

"There’s still significant oil in the bottom, it’s repeatedly soiling the coastline when storms come up, so it’s apparently located also adjacent to the beaches, there’s still oil in the marshes," Hollander said.

Also resting on the ocean floor appears to the be the remnants of what researchers call a "dirty blizzard" of oil, dead plankton and other organisms, and sediment pushed into the Gulf when freshwater was released from the Mississippi River to try to keep the oil plume away.

Some scientists, as well as oil well operator BP, have claimed that just because wildlife and plants haven't died in huge numbers, the lingering effects of the spill aren't as bad or widespread as feared. Hollander disagrees, pointing to studies published earlier this year that at least three percent of the oil could still be on the ocean floor.

"The overwhelming number of samples that were collected, both in the water and in the sediments, were not at lethal concentration, but actually sub-lethal concentrations," Hollander said. "The map of the sediments reflected 1,200 square miles which were actually quite severely impacted - not just a three kilometer ring around the wellhead."

To break it down further, Hollander puts it this way: lethal concentrations of oil are like opening a can of paint and inhaling the fumes; sub-lethal concentrations are like painting an entire room, closing all the doors and windows and then falling asleep. Either way, you’re going to be sick; it’s just a matter of how bad and for how long.

"The concentrations that you were breathing were substantially lower but the impacts, albeit protracted, can be identical or even more expressed," he said. "In organisms, if they don’t die, they’re still alive, their behavior could be changed, their reproduction could be changed, their growth could be changed."

Researchers collect samples from inside a fish to see what effect the Gulf spill has had on it.
Credit C-IMAGE Consortium

As part of the investigation of the spill’s ongoing effects, the researchers have been collecting samples of multiple species of Gulf wildlife, such as red snapper and golden tilefish, and looking at their livers and bile to determine how they’re processing the oil still present in their environment.

"The fish are still eating contaminated food sources, albeit at lower concentrations and are slowly getting back to what would be considered the baseline condition," Hollander said.

That baseline data, showing pollution levels in Gulf water, sediment and wildlife, could help determine further effects of the BP spill, as well as any future spills. 

It's also the next major project for C-IMAGE (Center for Integrated Modeling and Analysis of Gulf Ecosystems), a USF-led international coalition of scientists from 19 institutions in five countries including Mexico, the Netherlands, Germany and Canada.

"We don’t have a good baseline, because five years in the course of science is very short," Eckerd professor of marine science and chemistry David Hastings said. "In the course of political events and other things, it’s a long time, but for us in the scientific community, five years is a very short amount of time, so we still really don’t know what the long-term impacts are."

In addition to collecting that information, USF Marine Science researchers will also join a group of international scientists later this summer in work involving a similar disaster that took place over 700 miles from the Horizon site almost 40 years ago.

The group will travel to the site of the Ixtoc-1 oil well in the Gulf, about 60 miles northwest of Campeche, Mexico. In 1979, the well suffered a blowout like the Deepwater Horizon, causing a similar major oil spill.

USF College of Marine Science professor Steve Murawski believes the lessons they learn at that site can help paint a picture of the possible future for the area near the Horizon.

"By doing these comparative studies," Murawski said, "we can actually forecast into the future what the deep waters around Deepwater Horizon will look like 35 years from now in terms of the toxicity and any impact on the environment."

A researcher collects water from the Gulf to determine its toxicity.
Credit C-IMAGE Consortium

"We are academics doing research, but we’re not doing academic research," Murawski added. "We’re doing research that actually is supposed to help the policy decision and policy making apparatus in the United States, and so, we’re trying to focus this research on practical things that we need to know in terms of actually assisting this industry and assisting society in making these tough choices."

And since USF is also a institute of learning some of this research has been done – and will continue to be done – by College of Marine Science students, like Kristina Deak, a first year PhD candidate studying biological oceanography.

Speaking on the deck of the USF research vessel Weatherbird II, Deak talked about how the immune systems of fish were affected by the oil spill.

"Unlike humans and mice where there are actually tests available where we can test it pretty easily if their immune system has changed, with fish we don’t have those tests," she said. "So you have to go into their DNA and look at the genetics of the fish, so for my masters, which I just finished, I was able to identify these genes for the first time in the organisms, and on my PhD, I’ll be developing an assay to actually measure in real time how these genes are changing."

"It’s incredible," Deak added. "We’re able to actually work on a real-life problem and develop new tools that will help us in the future. So we’re actually at the forefront of this new field, which is a great opportunity for people just starting out in science – this is something that’s going to shape all of our careers."

The USF College of Marine Science has received more than $33 million in spill-related research grants over the last five years. C-IMAGE also received a $20 million grant for its investigation of the Ixtoc spill site from the Gulf of Mexico Research Initiative last year.

You can see a list of frequently asked questions assembled by C-IMAGE by clicking here.