BOSTON – The U.S. Department of Commerce declared a disaster in the Massachusetts shellfish fishery Thursday due to the red tide outbreak off the coast, making the state eligible for funds to study the problem.

The decision will allow Congress to appropriate emergency funds for the shellfishing industry, which has been devastated by the toxic algae bloom that has closed clam flats from Downeast Maine to Martha’s Vineyard.

“We are taking action now because of the serious economic effects of this red tide disaster,” Commerce Secretary Carlos Gutierrez said. He said it is unclear how long the fishery disaster might continue or what the long-term economic impact might be.

Sen. Edward M. Kennedy, D-Mass., said he and other members of the state’s Congressional delegation will begin work to secure the funding. Once the money is appropriated, it would go to the affected states for distribution to the fishermen.

“We need to act quickly to get economic relief to families and communities as soon as possible,” Sen. John Kerry, D-Mass., said.

Gov. Mitt Romney also was informed of the declaration in a phone call Thursday morning.

“We’ll be working with our delegation in Washington to secure the necessary funding,” Romney said.

The U.S. Small Business Administration has also promised low-interest loans to aid those harmed by the red tide outbreak. A request for an emergency declaration from the Federal Emergency Management Agency is still pending.

Red tide has shut down the majority of shellfishing in Massachusetts in both state and federal waters.

The toxic algae bloom taints 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.

Maine and Massachusetts have declared states of emergency and asked for federal disaster relief for the shellfishing industry. According to Romney, red tide is costing the shellfish industry about $3 million per week.