What If the Oil Leak Can't Be Stopped?

There is little good news to report on the oil spill in the Gulf of Mexico. Scientists say that the amount of oil spewing into the Gulf of Mexico could be vastly more than the official estimate.

Meanwhile, some contaminated waters may already have been snagged by a current that will pull oil out of the Gulf and up the East Coast. And new reports say a blanket of oil has reached freshwater wetlands at Louisiana's southeastern tip for the first time.

With these grim updates, what could we ultimately be facing?

"I think it's time to plan for the worst," said Matthew Simmons, former chairman of energy industry investment bank Simmons and Company. "BP is in total denial about this...This is totally unprecedented."

WIDE ANGLE: Get all the latest news and information about the massive oil spill threatening wetlands and wildlife on the Gulf Coast.

New analysis suggests that the official figure of 5000 barrels per day leaking into the Gulf may be a dramatic underestimate. Updated estimates range from between 20,000 to 100,000 barrels per day, based on analysis of images and the discovery of deep water plumes of oil by the a research vessel in the Gulf.

"There is very little information that is coming out of the government or NOAA about what is the true extent of the oil spill," said Eric Chassignet, head of the Center for Ocean-Atmospheric Prediction Studies at Florida State University in Tallahassee. "It is important for us to know how much oil is gushing out of the well."

WATCH VIDEO: As the Gulf oil spill approached the Louisiana Coast, James Williams discovered what experts were most worried about.

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One major concern remains keeping as much of the oil as possible away from marshes and estuaries along the shore. Louisiana Gov. Bobby Jindal showed reporters on Wednesday where oil was encroaching on remote wetlands, near where the mouth of the Mississippi River empties into the Gulf of Mexico.

"The more oil there is, the more likely it is that stuff is going to get washed up on shore," said Lawrence Rouse, an oceanographer at Louisiana State University, in Baton Rouge.

The spill will affect coastal wetlands, the sea floor, and the offshore water column, said Mark Carr of the Long Marine Laboratory at the University of California, Santa Cruz, and higher estimates for the amount of oil released mean the effects will be worse.

"There may be a threshold for some of these species that might not have been met by the lower volumes but may be with the higher volumes of oil," Carr said.

Wetlands remain a key concern, as crucial areas for the reproduction of numerous marine creatures from fish to invertebrates, he said.

But the ocean floor and the water column will be affected, too, Carr added. Species may be killed by the oil's toxicity or by the physical properties of oil mucking up their filtration systems or blocking nutrient and oxygen flow through the sediments. The effects will move up the food chain from plankton and small fish to large species like tuna or sharks.

Fisheries may be hurt even if the populations survive the spill. Commercial species may be so contaminated that they can't be sold for human consumption, he added.

Another concern with the spill is that it appears that a portion has been picked up by the Loop Current, which swirls through the Gulf of Mexico to the Florida Keys and back out to the Atlantic Ocean.

As the spill heads toward the Florida Keys, it may bring new problems.

"If it starts impinging on coral reefs then you have impacts to what are already highly endangered and otherwise fragile ecosystems," Carr said. "There are all these other human assaults on coral reef systems. When you add this on, the cumulative impacts may be beyond what they can handle. Oil on coral reefs is not a common phenomenon."

But Rouse noted that the current spreads and becomes more diffuse as it heads across the Atlantic, meaning that impacts on Europe would be minimal. Of greater concern is the area along the U.S. east coast, where it acts like a river.

Even there, "It is likely most of the stuff would stay in the current rather than wash up on shore," Rouse said. The current is offshore and more than 5000 feet deep. "But a hurricane, for example, could really disrupt things."