NBC, msnbc.com and news services
VENICE, La. - As President Barack Obama arrived in Louisiana Sunday to monitor efforts to battle the massive Gulf Coast oil leak, federal officials closed impacted waters to commercial and recreational fishing for at least 10 days.
Scientists were sampling the waters, and the federal government said all seafood harvested so far appeared safe.
Earlier Sunday, Interior Secretary Ken Salazar told NBC that the potential environmental outlook is "a very grave scenario."
"A lot of oil could spread" since stopping the three leaks from the well that blew up and then sank nearly two weeks ago could take three months, he told NBC's "Meet the Press".
BP, which operates the well, was more optimistic, telling NBC's "TODAY" show on Sunday that a temporary fix — domes that will be placed over the leaks until they can be cut off — was nearly ready to be deployed. The domes will have piping to send the spewing crude up to tankers for collection.
"We're forecasting (it) to be complete in eight to ten days," Doug Suttles, BP's chief for exploration and production, said of the first dome.
Obama arrived in New Orleans at midday and then drove to Venice, La., where he was due to speak after touring the area.
There has been little success stemming the flow from the ruptured well on the sea floor by skimming the oil, burning it or dispersing it with chemicals.
Long tendrils of oil sheen made their way into South Pass, a major channel through the salt marshes of Louisiana's southeastern bootheel that is a breeding ground for crab, oysters, shrimp, redfish and other seafood.
Adding to the gloomy outlook were warnings from experts that an uncontrolled gusher could create a nightmare scenario if the Gulf Stream current carries it toward the Atlantic.
'Slow version of Katrina'
There is growing criticism that the government and oil company BP PLC should have done more to stave off the disaster, which cast a pall over the region's economy and fragile environment.
Venice charter boat captain Bob Kenney lamented that there was no boom in the water to corral the oil, and said BP was "pretty much over their head in the deep water."
"If they weren't, they would have cut the oil off by now," he said.
"It's like a slow version of Katrina," he added. "My kids will be talking about the effect of this when they're my age."