First Study of Dispersants in Gulf Spill Suggests a Prolonged Deepwater Fate

Posted In Gulf Oil Catastrophe, News
Jan
27

dispersant-oil-spill
Plane Drops Dispersants on Oil Spill. Captions and Photo source: ©© NWF

By the Woods Hole Oceanographic Institution

To combat last year’s Deepwater Horizon oil spill, nearly 800,000 gallons of chemical dispersant were injected directly into the oil and gas flow coming out of the wellhead nearly one mile deep in the Gulf of Mexico.

Now, as scientists begin to assess how well the strategy worked at breaking up oil droplets, Woods Hole Oceanographic Institution (WHOI) chemist Elizabeth B. Kujawinski and her colleagues report that a major component of the dispersant itself was contained within an oil-gas-laden plume in the deep ocean and had still not degraded some three months after it was applied.

While the results suggest the dispersant did mingle with the oil and gas flowing from the mile-deep wellhead, they also raise questions about what impact the deep-water residue of oil and dispersant, which some say has its own toxic effects, might have had on environment and marine life in the Gulf.

“This study gives our colleagues the first environmental data on the fate of dispersants in the spill,” said Kujawinski, who led a team that also included scientists from UC Santa Barbara. “These data will form the basis of toxicity studies and modeling studies that can assess the efficacy and impact of the dispersants.

“We don’t know if the dispersant broke up the oil,” she added. “We found that it didn’t go away, and that was somewhat surprising.”

The study, which appears online Jan. 26 in the American Chemical Society (ACS) journal Environmental Science &Technology, is the first peer-reviewed research to be published on the dispersant applied to the Gulf spill and the first data in general on deep application of a dispersant, according to ACS and Kujawinski. Some previous studies had indicated that dispersants applied to surface oil spills can help prevent surface slicks from endangering marshes and coastlines.

Kujawinski and her colleagues found one of the dispersant’s key components, called DOSS (dioctyl sodium sulfosuccinate), was present in May and June, in parts-per-million concentrations, in the plume from the spill more than 3,000 feet deep. The plume carried its mixture of oil, natural gas and dispersant in a southwest direction, and DOSS was detected there at lower (parts-per-billion) concentrations in September.

Using a new, highly sensitive chromatographic technique that she and WHOI colleague Melissa C. Kido Soule developed, Kujawinski reports those concentrations of DOSS indicate that little or no biodegradation of the dispersant substance had occurred. The deep-water levels suggested any decrease in the compound could be attributed to normal, predictable dilution. They found further evidence that the substance did not mix with the 1.4 million gallons of dispersant applied at the ocean surface and appeared to have become trapped in deepwater plumes of oil and natural gas reported previously by other WHOI scientists and members of this research team. The team also found a striking relationship between DOSS levels and levels of methane, which further supports their assertion that DOSS became trapped in the subsurface.

Though the study was not aimed at assessing the possible toxicity of the lingering mixture, Kujawinski said she would “be hard pressed to say it was toxic”, it nevertheless warrants toxicity studies into possible effects on corals and fish such as tuna, she said. The EPA and others have already begun or are planning such research, she added.

David Valentine of UC Santa Barbara and a co-investigator in the study, said, “This work provides a first glimpse at the fate and reactivity of chemical dispersants applied in the deep ocean. By knowing how the dispersant was distributed in the deep ocean, we can begin to assess the subsurface biological exposure, and ultimately what effects the dispersant might have had.”

“The results indicate that an important component of the chemical dispersant injected into the oil in the deep ocean remained there, and resisted rapid biodegradation,” said Valentine, whose team collected the samples for Kujawinski’s laboratory analysis. “This knowledge will ultimately help us to understand the efficacy of the dispersant application, as well as the biological effects.”

Kujawinski and Valentine were joined in the study by Soule and Krista Longnecker of WHOI, Angela K. Boysen a summer student at WHOI, and Molly C. Redmond of UC Santa Barbara. The work was funded by WHOI and the National Science Foundation. The instrumentation was funded by the National Science Foundation and the Gordon and Betty Moore Foundation.

In Kujawinski’s technique, the target molecule was extracted from Gulf water samples with a cartridge that isolates the DOSS molecule. She and her colleagues then observed the molecule through a mass spectrometer, ultimately calculating its concentration levels in the oil and gas plume. This method is 1,000 times more sensitive than that used by the EPA and could be used to monitor this molecule for longer time periods over longer distances from the wellhead, she said.

“With this method, we were able to tell how much [dispersant] was there and where it went,” Kujawinski said. She and her colleagues detected DOSS up to around 200 miles from the wellhead two to three months after the deep-water injection took place, indicating the mixture was not biodegrading rapidly.

“Over 290,000 kg, or 640,000 pounds, of DOSS was injected into the ocean from April to July,” she said. “That’s a staggering amount, especially when you consider that this compound comprises only 10% of the total dispersant that was added.”

Kujawinski cautioned that “we can’t be alarmist” about the possible implications of the lingering dispersant. Concentrations considered “toxic” are at least 1,000 times greater than those observed by Kujawinski and her colleagues, she said. But because relatively little is known about the potential effects of this type of dispersant/hydrocarbon combination in the deep ocean, she added, “We need toxicity studies.”

“The decision to use chemical dispersants at the sea floor was a classic choice between bad and worse,” Valentine said.
“And while we have provided needed insight into the fate and transport of the dispersant we still don’t know just how serious the threat is; the ocean is a sensitive ecosystem unaccustomed to chemical irruptions like this, and there is a lot we don’t understand about this cold, dark world.”

“The good news is that the dispersant stayed in the deep ocean after it was first applied,” Kujawinski says. “The bad news is that it stayed in the deep ocean and did not degrade.”

Original Article, WHOI

Deep into the Unknown

New Questions Arise On Oil Dispersant Use

Seeking More Details on Oil Dispersants

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Resources

Federal

  • Deep Water Horizon Response is the official site of the incident in conjunction with BP, DOI, NPS, USGS, CDC, USFWS, NOAA and other branches of the US government (collectively called Unified Command). Information, including the latest news, photos, area plans, and volunteer information.
  • NOAA is a government program that uses science and research to protect life, property and natural resources. This NOAA site provides maps of the spill and related statistics, including a trajectory forecast map for the oil spill.
  • The Environmental Protection Agency provides data on Air, Land, and Water pollutants including sampling maps and contaminant levels.

Louisiana

  • Volunteer Louisiana is the official site for the State of Louisiana to get involved in the spill response.
  • The Louisiana Department of Wildlife and Fisheries provides maps of closures to fishing areas in LA.
  • The Louisiana Emergency Office has made Google Earth files of the spill available to the public here http://gohsep.la.gov/oilspill.aspx and also has current information on general closures of waterways, photos, and reports.
  • The Audubon Nature Institute site provides a number for citizens to call if turtles, manatees, dolphins, or other animals are in distress
  • The Oiled Wildlife Care Network is a CA based non-profit is advising folks in the Gulf of Mexico on best practices and provide resources on how people can help.
  • The Coalition to Restore Coastal Louisiana is a non-profit organization who strive to protect and restore coastal Louisiana. Volunteers are needed for numerous actions including: monitoring, oiled wildlife recovery, boat driving, or simple monetary donations.
  • The Greater New Orleans Foundation is a philanthropic organization in Louisiana and the surrounding region that joins with other non-profit, foundations and community and government officials to address the needs of the community. The Foundation has opened the Gulf Coast Oil Spill Fund.
  • The Louisiana Bucket Brigade is an environmental health and justice organization working with communities near oil refineries and chemical plants. They aid residents in these regions to reduce pollution and protect public health. The Brigade has formed an incident map where you can report observed signs of oil.

Alabama

  • The Alabama Coastal Foundation is an education based organization whose mission is to project the quality of Alabama’s coastal resources. They are currently training volunteers to help directly with the spill response.
  • The site by the Alabama Governor’s Office of Faith-Based and Community Initiatives gives basic phone numbers.
  • The Mobile Bay National Estuary Program is an organization funded by the EPA fighting the environmental challenged facing Mobile Bay. This site gives e-mail addresses and phone numbers to help and provides basic information.
  • The Mobile Bay Keeper is a group of citizens who are interested in preserving the Mobile Bay watershed as well as protecting the health of the individuals and environment in the Bay. Check out the latest information about the spill and learn how to become a member and donate to the cause.

Mississippi

Florida

  • The Florida Department of Environmental Protection is the lead agency in FL and this website provides the most thorough information in the state.
  • Volunteer Florida, the website of the Governor’s Commission on Volunteerism and Community Service and the State Emergency Response Team, lists volunteer opportunities by county.
  • The Escambia County site provides summary points of actions taken by BP and FL with a focus on the County.
  • The Pinellas County site is a concise list of related local websites and numbers for information.
  • The Gulf County site has current news on the spill as it relates to the county
  • Volunteer directly with the largest wild bird hospital in the United States, the Suncoast Seabird Sanctuary.

Organizations and other networks

  • American Birding Association
  • Audubon is a global leader in protecting birds and other wildlife and their habitats. They are partnering with other organizations.
  • The Sierra Club is a grassroots environmental organization that works to protect communities, wild places, and the planet. Updates on the oil spill, as well as volunteer and donation information.
  • The Nature Conservancy is a conservation organization with a mission to preserve and protect ecologically significant lands and waters for nature and people. Learn more about the oil spill and how to help out at http://www.nature.org/wherewework/northamerica/states/alabama/features/oilspill.html and check out their blog.
  • Sea Grant is nationwide network (administered through NOAA) of 32 university-based programs that work with coastal communities on environmental stewardship and the responsible use of our coasts. The Gulf of Mexico Sea Grant Programs provides resources to educators with research that may be impacted by the spill.
  • The National Wildlife Federation is America’s largest conservation organization whose mission is to protect and restore wildlife habitat, confront global warming and connect with nature. Get the latest information on the oil spill crisis and how to help.
  • The mission of Tri-State Bird Rescue and Research is to provide rehabilitation of injured, orphaned, and oiled native wild birds to return to their natural environment. Donate to their research.
  • Green Peace is an international organization that strives to save the planet from environmental threats such as global warming, destruction of forests and deterioration of the oceans. Follow their blog and learn how to take action.
  • Global Green USA is an international environmental non-profit organization with an office in New Orleans that strives to fight global climate change, eliminate weapons of mass destruction and create clean, safe drinking water for all. Follow their blog and get involved.
  • Matter of Trust is a non-profit organization focused on materializing sustainable systems by mimicking Mother Nature as well as concentrating on manmade surplus, natural surplus and eco-educational programs. Learn very simple ways to help the oil spill crisis.
  • The official Facebook page of Unified Command.
  • BP Gulf of Mexico response.