HOUSTON, Sept. 6 (Xinhua) -- Laboratory tests have shown that oil found on two barrier island beaches in the U.S. state of Louisiana during Hurricane Isaac is a match with oil from BP's 2010 Macondo well explosion in the Gulf of Mexico, U.S. media reported Thursday.
Tests run by researchers at Louisiana State University confirmed that oil found on Elmer's Island and Grand Isle matched the biological fingerprint of oil that spewed from BP's Macondo well, according to the website of Christian Science Monitor.
The oil found on both islands "were good solid matches on Macondo oil," Ed Overton, the LSU chemist who did the tests, was quoted as saying.
Experts had speculated that Hurricane Isaac, the first hurricane to hit the Gulf of Mexico since the the April 2010 oil spill, might stir up some of the estimated one million barrels of crude oil that remains.
Isaac struck the Gulf Coast last week, dumping heavy rain across southern Louisiana, Mississippi and Alabama and pushing in storm surge that led to widespread flooding.
On Tuesday, scouts found a large tar mat on the beaches of Elmer's Island, prompting state officials to close 13 miles (20.8 kilometers) of coastline and restrict fishing along that shoreline. Elmer's Island, a wildlife refuge, was among the hardest hit areas during the BP spill.
Overton said the discovery of buried oil after Isaac does not mean that oil is everywhere like it was following the 2010 oil spill. The difference between the amounts of oil being exposed now by Isaac and what the Gulf saw in 2010 is "night and day," he said. He also warned of the difficulty for cleanup crews to find and remove buried oil.
BP said on Wednesday it would try to clean up the oil exposed by Isaac.
The 2010 blowout of BP's Macondo well in the Gulf of Mexico triggered an explosion that killed 11 rig workers and unleashed the worst oil spill in U.S. history.