PORTLAND (AP) – New England’s largest red tide bloom in decades continued to plague the region’s shellfishermen, as Maine’s governor followed Massachusetts’ lead by declaring it an economic emergency for the industry on Friday.

The toxic algae bloom has closed clam flats from Downeast Maine to Martha’s Vineyard, and Maine Gov. John Baldacci said problems could persist through the summer and maybe even into the fall.

“This says to me that the difficulties that are facing the shellfish industry now will continue and the economic impacts will grow,” he said. “Therefore, it’s imperative that we work to find any avenue to assist folks who are impacted.”

The red tide extends from the Schoodic Peninsula in Maine to Massachusetts’ Buzzards Bay, but it has not extended into Rhode Island waters, a state scientist there said Friday.

“There’s no indication that this area is growing at this point in time,” said Joe Migliore of the Rhode Island Department of Environmental Management’s Office of Water Resources.

The toxic algae bloom contaminates shellfish like clams and mussels, making them unsafe for people and animals to eat. But it does not pose a risk to people who eat lobsters, scallops and finned fish.

This has been the worst red tide outbreak in New England since 1972, and the region’s shellfishermen and seafood retailers are suffering.

Baldacci’s announcement came a day after Massachusetts Gov. Mitt Romney declared a similar emergency. Both governors are asking the federal government for disaster funding for the shellfish industry.

Sens. John Kerry and Edward Kennedy and other members of the Massachusetts congressional delegation urged the U.S. Commerce Department and the Small Business Administration to expedite Romney’s request.

“Massachusetts relies heavily upon the fishing industry,” Kennedy said in a statement Friday. “We must do all we can to address this crisis.”

The algae bloom started in Maine and moved southward over the past two months.

The publicity surrounding the red tide created wary consumers at a time when short supply is sending prices for steamers and clams shooting upward.

“It’s wicked bad for business,” said Peter Aikens Jr., who had to increase the prices at Petey’s Summertime Seafood and Bar in Rye, N.H.

Steamers, hard-shelled clams and mussels are still available in New England, but the high price and bad publicity hurts. So far, Rhode Island has not had any problems, and shellfish flats are still open in Maine’s Cobscook Bay area.

In Rye, N.H., Aikens said he’s paying $129 for a gallon of clams, $30 to $40 more than usual. That cost is reflected on his menu, where he’s raised prices three times already this season. An order of steamers now costs $14.99, up from $11.99 at the beginning of the season.

“People get mad, they don’t understand,” he said. “People think you’re gouging them.”

The problem is manageable for the time being for most retailers and restaurants. But it will intensify if the red tide closures remain in effect around the Fourth of July, a time of traditional lobster and clam bakes in New England.

Laura Ingalls, manager of Two Lights Lobster Shack in Cape Elizabeth, said many customers have been making inquiries about whether it’s safe to eat fried clams. She has offered assurances that the clams come only from safe areas.

“We only serve fresh clams, and we try to serve Maine clams,” he said. “All of our clams are certified and come from flats that have been tested for red tide.”

Great Eastern Mussel Farms in Tenants Harbor, Maine, also has been busy assuring seafood market managers and wholesalers that its mussels and clams are safe to eat.

The Department of Marine Resources isn’t letting anything harvested in a red tide area on the market, said David Preston, Great Eastern’s quality assurance manager. “When people see mussels and clams in the market, they should be safe,” he said.