Red tide is an algae that contaminates shellfish and can be dangerous to humans who eat the shellfish. It does not pose a risk to people who eat lobsters or finned fish, nor swimmers. Scallops also are not affected because people don't eat the part that absorbs the poison.
The red tide that has advanced southward from Maine over the past two months is the worst in New England since 1972. This is the first time Massachusetts has declared a state of emergency because of red tide.
Romney said he is seeking aid from both the U.S. Small Business Administration and the Department of Labor for shellfisherman and others affected by the algae. He said he didn't know how long it would take to get a response but that the request is being expedited.
Red tide is costing the shellfish industry about $3 million per week, Romney said. Retailers and shellfishermen say prices could rise.
The toxic algae, called Alexandrium, is called red tide because it colors the water a rusty color at extremely high concentrations, Anderson said. Each year, a bloom of the algae moves from the Gulf of Maine to Cape Ann, off Boston's North Shore.
Usually, the wind isn't right to push it westward into Massachusetts Bay, but this year, strong east and northeast winds, including from two May nor'easters, blew in a particularly heavy algae bloom that flourished in the bay's warmer waters.