In a nutshell: higher prices for gas and seafood in the Midwest sooner, and later, questions about species of wildlife -- particularly migratory birds -- that make their way along the Mississippi River.

Photo by Petty Officer 3rd Class Casey J. Ranel | Coast Guard

Crews work May 8 to collect oil near and around the location where the Deepwater Horizon oil platform caught fire and sank.

That's the assessment of Robert Criss, a professor of earth and planetary science at Washington University who has expertise in hydrogeology and river systems. 

"Higher gas prices are probably inevitable," Criss said. "As far as hydrologic impacts, I don't see anything because the water is flowing the other way, and our migrating birds are mostly up here for the year. Some of the shore birds might still be moving north and their populations could be negatively impacted. Certainly next year there could be trouble for some of the migrating birds that use the Mississippi flyway, and it is, of course, one of the major flyways in North America."

Even as Midwesterners consider canceling fishing trips and summer vacations to the Gulf, the underwater gusher opened up by a BP drilling platform explosion three weeks ago continues to flow unchecked at a rate of 210,000 gallons a day off the coast of Louisiana. Company engineers have been unsuccessful in finding a way to plug the Deepwater Horizon well, their efforts hampered by the extreme depth of the leak, about a mile below the surface, and some state lawmakers are demanding a government takeover of the cleanup. (Click here to see video from BP showing the gusher.)

Criss said the oil spill has the potential to devastate wildlife in the Gulf states, but the impact on migrating waterfowl will depend on how long it takes to clean up the environmental mess.

"Come fall, they've got to run the gauntlet," he said. "If that oil's still down there, they will be moving back through it. Some stay in the area and others continue further to Central and South America."

The result could be reduced populations of long-distance migrators in the future.

Photo by Les Stone | Flickr

Washing an oiled Gannet at the International Bird Rescue Research Center in Louisiana May 1.

"Oil is really terrible for any kind of diving and wading birds," Criss said. "We saw that both in the Santa Barbara oil spill 40 years ago, as well as the Exxon Valdez. These animals get tarred up, and it's a death sentence for them. For one thing, they freeze. Their feathers and fur get matted down, and they can't survive that. The water is cold, and they can't keep clean or warm. And the animals lick or try to clean themselves and eat all this stuff. They end up poisoned while attempting to save themselves. It's just terribly sad."

In addition to the environmental impact, Criss said the Gulf region is still recovering from the catastrophic effects of Hurricane Katrina that hit the same area five years ago.

"It's going to wreck what's left of the economy in the New Orleans area," he said.

Criss said that offshore drilling platform leaks are particularly difficult to contain and the potential spillage is almost unlimited. Oil pipelines can be shut off and tanker spills are limited to the ship's capacities, but underwater "blowouts" gush until plugged.

The first major blowout in U.S. history was off the coast of California in 1969. A Unocal Corp. well spewed 3 million gallons of crude into the Santa Barbara Channel, devastating wildlife and coating 30 miles of sandy beaches with sludge. That spill spurred environmentalists and led to a host of legislative action.

"There's a pretty high probability that this will be worse than Santa Barbara, both ecologically and in the amount of oil," Criss said.

The current record for the worst U.S. oil spill goes to the Exxon Valdez tanker that hit a reef in Alaska's Prince William Sound in 1989, spilling its cargo of more than 10 million gallons of crude.

But there have been worse spills in the world: The IXTOC 1 blowout spewed 140 million gallons into the Gulf of Mexico over a period of nine months in 1979 before it was finally brought under control. Topping the list is the estimated 520 million gallons of crude that flowed into the Persian Gulf when Iraqi troops opened oil field valves in Kuwait during the 1991 Gulf War.

Criss said he doubts that the Deepwater Horizon leak will approach IXTOC, but the potential is always there, partly due to the geology of the Gulf of Mexico and its overpressured nature.

"If you drill down you encounter pressure on the fluids that are above hydrostatic. That enables the fluid to flow out really fast. They use heavy drilling muds with a density much higher than water to try and counterweight the pressures they find as they drill down," Criss said.

While the drilling industry has continued to make technological advances, there are always risks, he points out.

"This whole offshore oil industry has been pounding their chests for years. Yeah, yeah, we had problems in Santa Barbara, but -- thump, thump -- there have been no big problems in years,'' Criss said. "Well, here's the counter-example."