Advertisement
  1. News

Study finds dispersants did not help oil degrade in BP Deepwater Horizon spill

A plane sprays dispersant as it passes over an oil skimmer in the Gulf of Mexico near the coast of Louisiana after the BP Deepwater Horizon oil spill. [Associated Press]
Published Nov. 9, 2015

WASHINGTON — The chemical sprayed on the 2010 BP oil spill may not have helped crucial petroleum-munching microbes get rid of the slick, a new study suggests.

And that leads to more questions about where much of the Deepwater Horizon oil spill went. If the new results are true, up to half the oil can't be accounted for, said the author of a new study on the spill in the Gulf of Mexico.

After the 172 million gallon spill, the chemical dispersant Corexit 9500 was applied by airplane on the slick to help it go away and help natural microbes in the water eat the oil faster. The oil appeared to dissipate, but scientists and government officials didn't really monitor the microbes and chemicals, said University of Georgia marine scientist Samantha Joye.

5 YEARS AFTER SPILL: Gulf of Mexico is resilent, but scarred

So Joye and colleagues recreated the application in a lab, with the dispersant, BP oil and water from the gulf, and found that it didn't help the microbes at all and even hurt one key oil-munching bug, according to a study published Monday in the journal Proceedings of the National Academy of Sciences.

"The dispersants did a great job in that they got the oil off the surface," Joye said. "What you see is the dispersants didn't ramp up biodegradation."

In fact, she found the oil with no dispersant "degraded a heckuva lot faster than the oil with dispersants," Joye said.

Joye's team chronicled nearly 50,000 species of bacteria in the gulf and what they did to the water with oil, and water with oil and dispersant.

RELATED: Despite concerns, dispersant use continued on gulf oil spille

One of the main groups of oil munchers are fat little sausage-shaped bacteria called marinobacters, Joye said. They eat oil all the time and comprise about 3 percent of the bacteria in normal water. But when there's oil, they eat and multiply like crazy until they are as much as 42 percent of the bacteria, Joye said.

But when the dispersant was applied, they didn't grow. They stayed around 3 percent, Joye said.

Instead, a different family of bugs called colwellia multiplied more, and they don't do nearly as good a job at munching the oil, Joye said. She theorized that for some reason the dispersant and marinobacters just don't work together.

So if the oil wasn't degraded by the bacteria, the question remains: Where did it go? Joye guesses it might still be on the floor of the gulf.

Outside scientists Jeff Chanton and Ian MacDonald of Florida State University said the study seemed to make sense. Chanton called the results important and surprising.

The National Oceanic and Atmospheric Administration welcomed the study and will evaluate to determine how well dispersants work in the future, said agency spokeswoman Keeley Belva.

ALSO IN THIS SECTION

  1. Check tampabay.com for the latest breaking news and updates. Tampa Bay Times
    The driver of a Ford F250 truck took evasive action but collided with the pedestrian, officials say.
  2. Hernando County sheriff’s sergeant  Louis “Lou” Genovese died Saturday after struggling for weeks with an undisclosed medical condition, according to the Sheriff's Office. He was 41. HERNANDO COUNTY SHERIFF'S OFFICE  |  Hernando County Sheriff's Office
    Sergeant Louis “Lou” Genovese, a deputy since 2006, was 41.
  3. FILE - This June 2, 2017, file image made from video shows the Trump National Doral in Doral, Fla. President Donald Trump said on Twitter on Saturday, Oct. 19, 2019, he is reversing his plan to hold the next Group of Seven world leaders' meeting at his Doral, Florida, golf resort. (AP Photo/Alex Sanz, File) ALEX SANZ  |  AP
    The chief of staff called Trump’s sudden change of course — announced by the president on Twitter Saturday evening — “the right decision.”
  4. An Army carry team transfers the remains of Staff Sgt. Aaron R. Butler at Dover Air Force Base in Delaware on Friday. Butler died Wednesday of injuries sustained from an IED in Afghanistan.
    The soldiers were with the 1st Armored Brigade Combat Team and were in a Bradley fighting vehicle. They were not immediately identified.
  5. Hernando County community news Tara McCarty
    News and notes from Hernando County
  6.  Tampa Bay Times
    No information was released about the individual who died.
  7. Jeffrey D. Senese was inaugurated as Saint Leo University's 10th president. Pictured, Monsignor Robert Morris (left), Class of 1979, and a member of the board of trustees, and D. Dewey Mitchell, chair of the university’s board of trustees, bestow the presidential medallion on Senese. Renee Gerstein and William Speer, Saint Leo University
    New and notes on local businesses
  8. Dr. Manjusri Vennamaneni (center) was awarded Businesswoman of the Year by the Indo-US Chamber of Commerce. With her are Matt Romeo, President of PrimeCare (left), and Dr. Pariksith Singh, CEO, Access Health Care Physicians. Vince Vanni
    News and notes on local businesses
  9. Scientology’s international spiritual headquarters in downtown Clearwater is anchored by the Flag Building, on left. An elevated walkway connects the building to the Fort Harrison Hotel, the church’s first purchase in the city in 1975. LUIS SANTANA  |  Times
    The mysterious deals could reshape downtown Clearwater.
  10. Clearwater City Council members react to Tampa Bay Times reporting showing companies tied to members of Scientology bought 101 acres of downtown commercial property in three years. Times  |   (2017)
    We showed the politicians a map of the land now owned by buyers tied to Scientology. Here’s what they said.
Advertisement
Advertisement
Advertisement