Gulfport, Mississippi (CNN) -- Gulf Coast states have seen drops in tourism linked to the BP oil spill in the Gulf, though it has not caused any beaches to close, tourism officials told CNN Wednesday.
More worrisome than the people who call to cancel are those who don't call to book their trip in the first place, said Kathy Torian, a spokeswoman for Visit Florida, the state's tourism bureau.
Hoteliers have a shot at dissuading worried would-be vacationers who call to cancel, she said. But they are unable to have any effect on those who opt not to book travel to the state in the first place, she said.
The stakes are high. Tourism in Florida is a $65 billion industry that employs more than a million people, Rep. Corinne Brown, D-Florida, told the House Committee on Transportation and Infrastructure on Wednesday.
"And so we are devastated," she said. "People are canceling. They're not coming to the hotels. They're canceling, not coming to Florida. So we're in lock-down devastation."
Florida has $2.5 million in its coffers for use in advertising and is making plans to use the $25 million promised this week by BP, Torian said.
Louisiana's coastal area, known more for sport fishing than for beachgoing, is also suffering.
Gov. Bobby Jindal toured part of Louisiana's vast coastal marsh Wednesday and found thick, oily sludge encroaching on the fragile ecosystem.
"We saw some heavy oil stranded in the wetlands. The oil is no longer just a projection or miles from our shore. The oil is here. It is on our shores and in our marsh," Jindal said at a news conference after the airboat tour in Plaquemines Parish.
According to NOAA, about 35 miles of Louisiana shoreline has been affected by oil.
The annual Seafood Festival in the town of Jean Lafitte the last weekend in July has been canceled so resources can be concentrated on the oil, CNN affiliate WWLTV reported. On Grand Isle, the annual Tarpon Rodeo is still on for July, but could be called off, local officials told WWLTV. Several other fishing rodeos have been canceled.
The good news is that the state on Wednesday reopened three oyster beds and parts of two others that have not been affected by the oil, the station reported.
The Louisiana Office of Tourism website assures visitors and potential visitors that there is no need to change travel plans, as the spill risk lies mostly east of the mouth of the Mississippi River and 75 percent of coastal fishing waters are west of there.
BP promised $15 million apiece to Louisiana, Mississippi and Alabama to help the states attract visitors.
Alabama tourism spokeswoman Edith Parten said her state has seen a small number of cancellations, but it has launched a $1.5 million ad campaign that it plans to supplement with BP's money.
"I think we are getting word out with the tourism campaign," she said.
In Mississippi, about half of the people who had made vacation plans along the state's coast before the April 20 spill have canceled them, said Ken Montana, president of the Mississippi Gulf Coast Tourism Commission.
And it gets worse, he said. "What's happening is we are not getting the phone calls to book," he said. "It's almost come to an 80 percent reduction in calls for future bookings."
The tourism commission has spent $600,000 of its own money for an advertising campaign set to begin Monday "to let people know we are open," he said. He predicted the state would begin using money from BP -- which he credited for moving quickly -- starting next week.
But he bemoaned the image that the disaster has conjured among many.
"The perception is that everybody has oil on the beach and we are all closed up," he said. "No beaches are closed, period."
All the state waters are open and open to all activities, he stressed.
For some, the ripple effects of the spill have yet to hit shore. Bob Mahoney, owner of Mary Mahoney's Old French House in Biloxi, Mississippi, said business at his seafood restaurant located 150 yards from the high-tide mark is pretty good.
"The truth of the matter is it hasn't affected me yet," he said. "I don't think it has."
But he has already seen the price for shrimp shoot up from $4.75 per pound last year to $6.75. At about 500 pounds per week, that adds up, he said.
And, the 63-year-old restaurateur said, "If the stuff starts starts hitting our beaches, I'm sure we'll be affected."
Whatever happens, though, he vowed to stay put.
"I ain't leaving Biloxi," said Mahoney, whose mother in 1964 founded the restaurant, which has survived other challenges. After Hurricane Katrina filled it with eight feet of water in 2005, he and other relatives rebuilt it in 55 days, he said.
Asked Wednesday in the congressional hearing how he planned to address the long-term issue of the psychological impact on the area -- the fact that people might not visit the Gulf Coast or eat its seafood because they fear contamination -- Lamar McKay, president and chairman of BP America, was stumped.
In testimony to the House committee, he told Rep. Anh "Joseph" Cao, R-Louisiana, "I don't have a specific answer for that, but I do want to let you know that our intent is to stand behind what we're saying, and it doesn't end when the cleanup ends."
CNN's Aaron Cooper, Tom Watkins and Jim Kavanagh contributed to this story.