In the three weeks since the April 20th explosion and sinking of the Deepwater Horizon oil rig in the Gulf of Mexico, and the start of the subsequent massive (and ongoing) oil leak, many attempts have been made to contain and control the scale of the environmental disaster. Oil dispersants are being sprayed, containment booms erected, protective barriers built, controlled burns undertaken, and devices are being lowered to the sea floor to try and cap the leaks, with little success to date. While tracking the volume of the continued flow of oil is difficult, an estimated 5,000 barrels of oil (possibly much more) continues to pour into the gulf every day. While visible damage to shorelines has been minimal to date as the oil has spread slowly, the scene remains, in the words of President Obama, a "potentially unprecedented environmental disaster."
Seawater covered with thick black oil splashes up in brown-stained whitecaps off the side of the supply vessel Joe Griffin at the site of the Deepwater Horizon oil spill containment efforts in the Gulf of Mexico off the coast of Louisiana Sunday, May 9, 2010. (AP Photo/Gerald Herbert)
A tugboat moves through the oil slick on May 6, 2010 in the Gulf of Mexico. (Michael B. Watkins/U.S. Navy via Getty Images)
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Oil burns during a controlled fire May 6, 2010 in the Gulf of Mexico. The U.S. Coast Guard is overseeing oil burns after the sinking, and subsequent massive oil leak, from the sinking of the Deepwater Horizon oil platform off the coast of Louisiana. (Justin E. Stumberg/U.S. Navy via Getty Images)
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Dark clouds of smoke and fire emerge as oil burns during a controlled fire in the Gulf of Mexico, May 6, 2010. The U.S. Coast Guard working in partnership with BP PLC, local residents, and other federal agencies conducted the "in situ burn" to aid in preventing the spread of oil. (REUTERS/Mass Communication Specialist 2nd Class Justin Stumberg-US Navy)
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The crew of a Basler BT-67 fixed wing aircraft releases oil dispersant over parts of the oil spill off the shore of Louisiana in this May 5, 2010 photograph. (REUTERS/Stephen Lehmann/U.S. Coast Guard)
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A pod of Bottlenose dolphins swim under the oily water Chandeleur Sound, Louisiana, Thursday, May 6, 2010 in the Gulf of Mexico. (AP Photo/Alex Brandon)
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Winds cause ripples to form on the water of grassy marsh wetlands in St. Bernard Parish, Louisiana, as work continues to try to protect it from the massive oil spill on May 9, 2010 in Gulf of Mexico. (Joe Raedle/Getty Images)
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A worker with one of the shoreline clean-up crews deploys a snare boom on the west side of the South Pass near Port Eades, Louisiana May 11, 2010. (REUTERS/Sean Gardner)
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A man holds a plastic bag with seawater and oil from the Gulf of Mexico oil spill south of Freemason Island, Louisiana May 7, 2010. (REUTERS/Carlos Barria)
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An oil-stained cattle egret rests on the deck of the supply vessel Joe Griffin at the site of the Deepwater Horizon oil spill containment efforts in the Gulf of Mexico off the coast of Louisiana, Sunday, May 9, 2010. (AP Photo/Gerald Herbert)
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Oily water is seen off the side of the Joe Griffin supply vessel at the site of the Deepwater Horizon oil spill containment efforts in the Gulf of Mexico on Saturday, May 8, 2010. (AP Photo/Gerald Herbert)
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A helicopter takes off from the helipad of the Development Driller III, which is drilling the relief well at the site of the Deepwater Horizon oil spill, in the Gulf of Mexico on May 11, 2010. (REUTERS/Gerald Herbert)
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Oil washes onto the sides of a 100-ton concrete-and-steel pollution containment chamber as the mobile offshore drilling unit Q4000 lowers it into the water at the Deepwater Horizon site on May 6, 2010 in the Gulf of Mexico . The chamber was designed to cap the oil discharge that was a result of the Deepwater Horizon incident. (Patrick Kelley/U.S. Coast Guard via Getty Images)
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The single cable supporting the 100-ton oil containment device being lowered to the sea floor disappears into Gulf waters off the side of the Q400 mobile drilling platform on Sunday, May 9, 2010. Efforts to contain the leak with the device were unsuccessful due to ice crystals forming in its domed roof. (AP Photo/Gerald Herbert)
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One of the New harbor Islands is protected by two oil booms against the oil slick that has passed inside of the protective barrier formed by the Chandeleur Islands, as cleanup operations continue for the BP Deepwater Horizon platform disaster off Louisiana, on May 10, 2010. (MARK RALSTON/AFP/Getty Images)
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Workers attempt to secure an oil boom into place in an effort to protect the coast line from the massive oil spill near Hopedale, Louisiana May 10, 2010. (REUTERS/Sean Gardner)
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Blobs of oil from the massive spill float on the surface of the water on May 5, 2010 in Breton and Chandeleur sounds off the coast of Louisiana. (Joe Raedle/Getty Images)
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Crews build a sand berm to protect the island from the potential of oil washing onshore, on Dauphin Island, Alabama May 10, 2010. (REUTERS/Brian Snyder)
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Unemployed commercial fishermen and their families wait in line to receive handouts from New Orleans Catholic Charities on May 5, 2010 in Hopedale, Louisiana. Many local fishermen have been temporarily shut down but have been hired by British Petroleum (BP) to lay oil booms in sensitive areas. (Sandy Huffaker/Getty Images)
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Captain Johnny Bourgeois and deckhand Chris Crappel (left) of Venice, Louisiana retie netting for shrimp trawling as they wait for the shrimp season to reopen in Venice, Louisiana May 9, 2010. Louisiana Department of Wildlife and Fisheries (LDWF) Secretary Robert Barham announced that the shrimp season in the territorial seas of the central coast of Louisiana from Four Bayou Pass to Freshwater Bayou were closed effective sunset Saturday. (REUTERS/Sean Gardner)
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Louisiana National Guard Private Dallas Bacon guides a dump truck as they use dirt to create an earthen barrier as they try to protect an estuary from the massive oil spill on May 10, 2010 in Lafourche Parish, Louisiana. (Joe Raedle/Getty Images)
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Louisiana National Guardsmen use Blackhawk helicopters to build a dam to protect the fragile wetlands known locally as "Bayou" near the town of Grand Isle, as work continues to protect the coastline from oil after the BP Deepwater Horizon platform disaster off Louisiana, on May 11, 2010. (MARK RALSTON/AFP/Getty Images)
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Mississippi River water (left) meets sea water and an oil slick that has passed inside of the protective barrier formed by the Chandeleur Islands, off the coast of Louisiana, on May 7, 2010. (MARK RALSTON/AFP/Getty Images)
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Oil from the Deepwater Horizon oil spill makes its way to shore on Chandeleur Islands in Louisiana on May 7, 2010. (AP Photo/The Dallas Morning News, Vernon Bryant)
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An aerial view of the northern Chandeleur barrier islands shows sheens of oil reaching land, Thursday, May 6, 2010 in the Gulf of Mexico. The islands rest 20 miles from the main Louisiana coastline. (AP Photo/David Quinn)
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Danene Birtell and Dr. Erica Miller of Tristate Bird Rescue and Research and Heather Neville rinse off an oiled brown pelican which was captured on a barrier island off the fragile Louisiana coast on Tuesday, May 4, 2010 at a triage center in Fort Jackson, Louisiana. (MIRA OBERMAN/AFP/Getty Images)
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This image provided by NASA shows the Mississippi Delta (top right) and the growing oil slick in the Gulf of Mexico on May 5, 2010. Photo was taken by International Space Station Expedition 23 flight engineer Soichi Noguchi. (AP Photo/NASA - Soichi Noguchi)
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Oil and oil sheen are seen moving past an oil rig, top right, in the waters of Chandeleur Sound, Louisiana, Wednesday, May 5, 2010. (AP Photo/Eric Gay)
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Steve Henne, of Marine Spill Response Corp., heads back to the Premier Explorer after a controlled burn in the Gulf of Mexico May 6, 2010. The U.S. Coast Guard working in partnership with BP PLC, local residents, and other federal agencies conducted the "in situ burn" to aid in preventing the spread of oil following the April 20 explosion on Mobile Offshore Drilling Unit Deepwater Horizon. Picture taken May 6, 2010. (REUTERS/Mass Communication Specialist 2nd Class Justin Stumberg-US Navy)
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An oil soaked bird struggles against the oil slicked side of the HOS Iron Horse supply vessel at the site of the Deepwater Horizon oil spill in the Gulf of Mexico off the coast of Louisiana Sunday, May 9, 2010. (AP Photo/Gerald Herbert)
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An aerial view of the oil leaked from the Deepwater Horizon wellhead, May 6, 2010. (REUTERS/Daniel Beltra)
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Dark clouds of smoke and fire emerge as oil burns during a controlled fire in the Gulf of Mexico May 7, 2010. (U.S. Navy photo by Mass Communication Specialist 2nd Class Justin Stumberg/Released)
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Bruce Padilla, left, and Adam Shaw, Louisiana oilfield divers, return through blackened seawater from watching a controlled oil burn in the Gulf of Mexico May 7, 2010. (U.S. Navy photo by Mass Communication Specialist 2nd Class Justin Stumberg/Released)
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Boom to protect Louisiana's fragile wetlands is put into place on Lake Machias on May 9, 2010, following a massive oil spill that is threatening the state's coastal islands. (Alex Ogle/AFP/Getty Images)
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Oil, scooped up with a bucket from the Gulf of Mexico off the side of the supply vessel Joe Griffin, coats the hands of an AP reporter at the site of the Deepwater Horizon oil spill in the Gulf of Mexico, May 10, 2010. (AP Photo/Gerald Herbert)
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Shrimp boats are used to collect oil with booms in the waters of Chandeleur Sound, Louisiana, Wednesday, May 5, 2010. (AP Photo/Eric Gay)
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Sunset, seen over wetlands outside of Venice, Louisiana on May 5, 2010. (REUTERS/Carlos Barria)
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Risers, the outer casings of oil drill pipes, are seen on the deck of the service vessel Joe Griffin as it prepares to head to Port Fourchon at the site of the Deepwater Horizon oil spill in the Gulf of Mexico on May 11, 2010. (AP Photo/Gerald Herbert)
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Capt. Demi Shaffer pilots the Joe Griffin as it enters the Gulf of Mexico carrying the containment vessel to the rig collapse site which will be used to try to contain the Deepwater Horizon oil, Wednesday, May 5, 2010. (AP Photo/Gerald Herbert)
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