Reuters) - With the failure this weekend of BP's "top kill" attempt to plug its leaking Gulf of Mexico oil well, fears are growing that the economic and environmental impact of the nearly six-week-old spill can only spread.
Here are some facts about effects of the worst ever U.S. oil spill, triggered by the April 20 explosion of the Deepwater Horizon rig:
THE SCALE OF THE CATASTROPHE
"This is probably the biggest environmental disaster we have ever faced in this country," top White House energy adviser Carol Browner said on Sunday.
"There could be oil coming up 'til August." Browner told CBS's "Face The Nation," "We are prepared for the worst."
Louisiana, the nearest state to BP's gushing undersea well that is 42 miles out in the Gulf of Mexico, has been the most impacted by the spill so far.
Louisiana Governor Bobby Jindal said this week that more than 100 miles of Louisiana's 400-mile coast had so far been impacted by the spilled oil.
State officials have reported sheets of oil soiling wetlands and seeping into marine and bird nurseries, leaving a stain of sticky crude on cane that binds the marshes together.
Billy Nungesser, president of Plaquemines Parish, saw dying cane and "no life" in parts of Pass-a-Loutre wildlife refuge.
"Oil debris", in the form of tar balls and surface "sheen", has also been reported coming ashore since the April 20 accident in outlying parts of coastal Mississippi and Alabama.
In the week of May 17, Coast Guard officials found tar balls on some beaches in the Florida Keys, raising fears that the so-called Loop Current that runs from the Gulf of Mexico through the Florida Straits may have already brought oil from the spill far to the southeast. But laboratory tests subsequently showed the tar balls were not from the BP spill.
FISHERIES
The U.S. government has declared a "fishery disaster" in the seafood-producing states of Louisiana, Mississippi and Alabama due to the oil spill. This makes them eligible for federal funds to offset the impact on fisherman and their communities of the oil pollution in their fishing grounds.
Louisiana's $2.4 billion seafood industry supplies up to 40 percent of U.S. seafood supply and employs over 27,000 people. The state is the second-biggest U.S. seafood harvester and the top provider of shrimp, oysters, crab and crawfish.
NOAA on Friday extended the area closed to fishing in the Gulf of Mexico as a result of the spill to 25 percent of Gulf U.S. federal waters, an area covering 60,683 square miles (157,168 square km), up from 20 percent previously.
It is taking this step as a precautionary measure to ensure that seafood from the Gulf will remain safe for consumers.
