Gulf of Mexico becomes science laboratory for dispersants

President Barack Obama requested $2 million in supplemental federal funds for dispersant research associated with the oil spill in the Gulf of Mexico. Record volumes of dispersants have been used on the gulf's surface and in the subsea at 5,000 ft of water. Most previous research on dispersants involved laboratory testing, but the spill resulted in scientists monitoring the effects of chemical dispersant on a much grander scale.

Lisa P. Jackson, administrator of the US Environmental Protection Agency, testified on July 15 before a subcommittee of the Senate Committee on Appropriations about the request for funding dispersant research.

Dispersants played a big role in the Macondo oil spill response efforts. Scientists and others are studying the effects that dispersants might have on marine life. Federal officials and Louisiana state officials granted BP authorization to use approved dispersants to break down the oil into smaller drops.

In May, EPA and the US Coast Guard issued a directive requiring BP to implement a monitoring and assessment plan for subsurface and surface applications of dispersants. Federal authorities on May 26 asked BP to significantly decrease the overall volume of dispersants being used.

“Since that directive, we have seen the total volume of dispersants used fall by almost 70% from their peak levels,” Jackson said. EPA set up an extensive network to monitor the air, water, and sediments for the presence of dispersants and crude oil components.

The next phase of EPA’s testing will assess the acute toxicity of multiple concentrations of Louisiana sweet crude oil alone and combinations of Louisiana sweet crude oil with dispersants.

NOAA vessel joins the hunt for possible underwater oil plumes

The National Oceanic and Atmospheric Administration is sending its own research ship, the Gordon Gunter, to study reports of oil plumes suspended in the Gulf of Mexico.

NOAA’s Gunter was in the gulf already sampling plankton to establish baseline conditions for the deepwater oil spill off Louisiana. On May 28, NOAA expanded the Gunter’s mission to use its sonar equipment to define any underwater plumes.

Researchers from various universities have reported underwater oil plumes, and their findings need to be put into context. Some oceanographers suggest increased microbes are growing in response to the spill, which could tip the marine system out of balance. They warn that too many microbes robs oxygen from the seawater, creating an uninhabitable hypoxic area, or "dead zone" threatening marine life.

Still, documentation of these reported plumes has yet to be provided by the broad scientific community. BP PLC Group Executive Tony Hayward says there is “no evidence” of masses of oil suspended in seawater.

Meanwhile, NOAA scientist Charlie Henry told reporters weeks ago that a sample of water from these so-called plumes would look just like normal seawater. Hydrocarbons are present, but the oil is in tiny droplets.

“Layers of oil are totally untrue,” Henry said of some media reports regarding initial reports from university research vessels about underwater plumes of oil (OGJ Online, May 17, 2010).

If potential plumes are identified, the Gunter will deploy an underwater vehicle, Gulper, provided by the Monterey Bay Aquarium Research Institute “to take discrete water samples at various depths to allow precise characterization of any oil, dispersants, or other substances,” NOAA said.

Record volumes of chemical dispersants have been used on the spill, and any potential long-term dispersant effect on marine life remains unknown.

Threats to fisheries or marine life must be taken seriously, but first these reported underwater oil plumes have yet to be substantiated.