GENERAL

What happened?
On April 20th, 2010, the oil exploration platform Deepwater Horizon suffered an explosion and consequently caught fire approximately 50 miles southeast of Venice, Louisiana, causing it to sink. The circumstances surrounding the explosion are currently being investigated by the Minerals Management Service (MMS). The explosion and subsequent sinking of the platform severed the well head, causing what is known as a blowout. The well head, located 5,000 ft below the ocean surface on in an area known as the Mississippi Canyon. As of April 29th, NOAA estimates approximately 5,000 barrels per day (equivalent to 210,000 gallons per day) are being released through the severed well.

For a map of the spill location and oil trajectory, visit:
http://response.restoration.noaa.gov/book_shelf/1884_cumlative4_29_trajectories.pdf

For up to the date information about the blowout, visit:
http://www.incidentnews.gov/incident/8220

Why is this event different than a typical oil spill?
The Deepwater Horizon blowout is different than most commercial oil spills because oil is being released continually, rather than over a short duration. In a typical oil spill, the release happens over a short period of time, usually hours, while in the Deepwater Horizon blowout, it may take weeks to months to cease the flow of oil in from the well.

Has the spill made landfall yet?
As of late April 29th, portions of the spill have begun to make landfall in Louisiana, and is expected to reach Mississippi on Saturday, Alabama on Sunday and Florida on Monday. The following graphic shows the expected trajectories for Saturday, May 1st.

Link to full-size map: http://www.flickr.com/photos/uscgd8/4564199216/sizes/l/

What percentage of domestic fossil fuels are obtained from the Gulf of Mexico?
The Gulf of Mexico provides approximately 44% of the nation’s crude oil and over 55% of liquid natural gas.

ENVIRONMENTAL

What endangered species are at risk from this spill?
The inshore Gulf of Mexico is home to many threatened and endangered species, including the Gulf Sturgeon, Smalltooth Sawfish, Dusky, Night and Tiger Sharks, Nassau and Warsaw Grouper, as well as five species of sea turtles (Kemp’s Ridley, Hawksbill, Green, Loggerhead and Leatherback). Although many marine mammals frequent the Gulf of Mexico, they typically remain offshore in deeper waters.

How will this affect the many bird species that inhabit the Gulf of Mexico?
The Gulf of Mexico is home to many nesting and sea birds, many of whom can potentially be affected by the Mississippi canyon spill, including the brown pelican, which was only removed from the endangered species list in 2009. Other species that may be potentially affected include beach nesting terns and gulls (Caspian Tern, Royal Tern, Sandwich Tern, Least Tern, Laughing Gull, Black Skimmer, Beach nesting shorebirds, American Oystercatcher, Wilson's Plover, Kentish (Snowy) Plover, Reddish Egret, and large wading birds (Roseate Spoonbill, Ibises, Herons, Egrets).

For more information about the potential effects of this spill on birds in the gulf, visit:
http://www.birdlife.org/news/news/2010/04/gulf-oil-spill.html

What effects would landfall of the spill have?
The Gulf coast contains approximately 60% of the marsh land in the U.S., and is important habitat for numerous species. This marshland is already threatened by subsidence, oil and gas exploration related damage (i.e., trenching for pipelines), and wetlands loss due to development. Landfall of the spill will result in oiling of coastal marshlands, potentially resulting in significant effects on flora and fauna.

ECONOMIC AND SOCIETY

How will this affect the commercial fishing industry?
The extent to which this affects the commercial fisheries will depend upon the amount of oil spilled and efficacy of cleanup efforts. The Deepwater Horizon spill will likely affect the Menhaden fishery, where the Gulf of Mexico provides up to one-third of the nations Menhaden, which is a common source of fish oil and fish meal. The Gulf of Mexico is also important spawning site for Atlantic Bluefin Tuna, whose larvae spend most of their time at the surface, and are susceptible to oil slicks. The affect of the spill on the commercial fishing industry has yet to be determined, however, the large extent of the spill is likely to significantly restrict fishing activities in the area.

How important is the Gulf of Mexico to the U.S. shellfish industry?
The U.S. obtains approximately 70% of its shrimp and oysters from Gulf of Mexico waters. If these species are exposed to oil, they may become tainted and may curtail the harvest, significantly impacting the U.S. supply.

How has this affected Gulf of Mexico Oil Production?
As of April 30, current oil production in the Gulf of Mexico has not been affected. However, President Obama’s Press Secretary David Axlerod announced that there will be no more drilling on new leases until the cause of the blowout has been determined. It should be noted, however, new drilling on currently owned leases has not been affected.

RESPONSE

What is being done to respond to the spill?
Presently, two simultaneous response methods are being used:

The first response method is to stop the release of oil. This is being attempted through the use of remotely operated vehicles (ROV) to activate anti-blowout devices at the wellhead. If this is not successful, other strategies are being prepared, including capturing the oil directly above the leaking pipeline using a large containment chamber and pumping the oil to barges on the surface. A final, permanent solution that is in progress, but will take several months to complete, is to drill relief wells in the same oil reservoir to relieve pressure.

The second response method being used is to remove or disperse the oil that has already been released to prevent it from reaching shore. There are many potential methods available, including in situ burning, sorbents, herding, chemically dispersing, booming off sensitive areas, and mechanical removal. In situ burning, dispersants and booms are currently being used as the primary removal tools.

What is in situ burning?
An in situ burn is the burning of oil at or near the site of the spill. This is done by containing large portions of the spill and igniting them. This is effective at removing large quantities of oil from the water column, but there are risks. These burns create a lot of smoke and residual product, and environmental trade-off should be examined.

What are Dispersants?
Dispersants are a chemical used to break up oil spills and disperse them into the water column.  While this is effective at breaking up surface slicks to prevent oiling of birds and beaches, it transfers the oil into the water column and can increase the risk for underwater species.

Dispersants are most effective when the following conditions exist:

• Deep water: the deeper the water, the more the dispersed oil can dilute, the less dangerous it becomes.
  
  
• Wind & Waves:  These chemicals need to mix with the oil on the surface.  This is done through waves and winds creating turbulence.
  
  
• Oil Type: Oils that are more viscous are the ideal candidates for dispersants, as they have a tendency to stick together on the surface. Crude oils (what is being spilled from the well) and fuel oils for ships are dispersant candidates.

To learn more, visit the following link:
http://www.itopf.com/spill-response/clean-up-and-response/dispersants/

What are booms?
Since oil floats on the surface, it can be directed through the use of booms.  Booms are long floating barriers used to contain oil to a certain area, or to protect areas from spreading oil (beaches, wildlife reserves, water intakes, etc.).  These booms are effective in calm waters with little disturbance on the surface.  When employed with skimmers, they can be used to contain and remove oil from the water surface.

http://www.itopf.com/spill-response/clean-up-and-response/containment-and-recovery/

In what conditions can in situ burning be used as a response tactic?
In situ burning can be a very effective cleanup method. Under prime conditions removal efficiencies can exceed 90%, however, this method has many limitations including:

• Minimum thickness of oil required (1 mm for volatile, fresh crude, 10 mm for residual fuel oils)
  
  
• Oil must be contained to prevent spreading of burning oil
  
  
• The wind must not exceed 20 knots and seas should not exceed 2-3 feet
  
  
• There must be good visibility so that the burn can be monitored from aircraft