As government and BP officials struggle to stem the massive oil spill in the Gulf of Mexico, the seafood industry—from fishermen to grocers and restauranteurs—is bracing for a major financial blow from expected shortages of oysters, shrimp, crab, tuna and other seafood.

However, most economic damage is expected to be regional—Louisiana’s seafood industry is worth $2 billion, reports the New Orleans’ Times-Picayune.

“The Gulf is second in the country in terms of (seafood) landings—behind Alaska—with nearly 1.3 billion pounds in 2008,” said Tim Fitzgerald, senior policy specialist for the Environmental Defense Fund’s Oceans Program. “However, almost 60 percent of this total can be attributed to menhaden, which is used primarily for reduction to fish meal and oil, not seafood.”

Menhaden is used in some fish-oil supplements.

EDF reports that just 10 percent of the shrimp eaten in the United States comes from the Gulf of Mexico. In fact, 80 percent of all seafood consumed in the U.S. comes from overseas, and of that amount 90 percent is farmed salmon and farmed shrimp. (Much of the domestic 20 percent comes from Alaska.)

Some oyster grounds and other fishing habitats along the Gulf Coast have been closed as a safety precaution. Oysters cannot flee oily water and neither can newly spawned larvae of shrimp and crabs, making them most vulnerable to contamination.

“The spill will have direct impacts on the surface layers of the sea,” where baby fishes are, says Doug Rader, EDF’s chief oceans scientist. “Many species use the currents for dispersal, riding the top meter or so.” The oil spill also will directly impact beaches “as foraging grounds for surf fish and shore birds,” he says.

Scientists expect that the coastal area’s intricate ecosystem could experience consequences from the spill for years to come.

The Coast Guard told the Associated Press on Saturday that they’re not sure how much oil has spilled since the April 20 explosion on the BP Deepwater Horizon drilling platform, but a previous estimate was at least 1.6 million gallons—which would fill about 2½ Olympic-sized swimming pools—and the leak is ongoing.

No previous oil spills in the Gulf have been that large.

“The comparison is that there is no comparison,” Anne Rheams, executive director of the Lake Pontchartrain Basin Foundation, told the New Orleans’ Times-Picayune. “You're talking about multiple habitats with multiple species depending on those habitats.”