Red tide could hurt N.E. shellfish industry

Ocean survey leads to warning

A clammer raked for quahogs Tuesday in Brunswick, Maine. Researchers say indicators are in place suggesting a significant regional bloom of the toxic algae that causes red tide. A clammer raked for quahogs Tuesday in Brunswick, Maine. Researchers say indicators are in place suggesting a significant regional bloom of the toxic algae that causes red tide. (Pat Wellenbach/ Associated Press)
By Clarke Canfield
Associated Press / February 25, 2010

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PORTLAND, Maine - The New England shellfish industry faces the threat of widespread red tide outbreaks this spring and summer that could force the closing of hundreds of miles of clam flats and lead to clam shortages.

A survey of the ocean bottom off New England last fall provided evidence there will be a significant bloom of the toxic algae that causes red tide, federal and state officials said yesterday. This year’s bloom could be similar to those of 2005 and 2008 that shut down shellfish beds from Maine to Cape Cod for months.

Red tide has become more frequent and severe in recent years, resulting in tens of millions of dollars in economic losses. With more red tide being forecast, the outlook is bleak for clam diggers who have had to contend with major outbreaks in three of the past five years.

“It’s going to be devastating,’’ said Butch Taylor, owner of C&S Seafood in Cushing, which buys clams from more than 100 clammers in the midcoast Maine region.

Red tide is caused by naturally occurring algae that produce a toxin that shellfish absorb as they feed. Red tide taints clams and mussels, making them unsafe for people to eat, but poses no risk to people who eat other fish, lobster, scallops, or shrimp. Officials say that clams and mussels are safe, given the regulatory safeguards in place.

Red tide outbreaks have occurred periodically for decades, but some of the worst have occurred in the past five years.

Major blooms in 2005 and 2008 shut hundreds of miles of shellfish beds in Maine, New Hampshire, and Massachusetts. Last summer, nearly the entire Maine coast was shut down at one point.

Scientists survey the ocean bottom each fall to determine the abundance of microscopic cysts dropped by algae blooms that act like seeds for red tide outbreaks.

Last fall’s survey turned up a large number of cysts - 60 percent more than were observed prior to the huge red tide bloom of 2005 - indicating a large bloom is likely this spring.

The cyst abundance also appears to have expanded to the south, meaning any outbreak could affect areas such as Massachusetts Bay earlier in the season than in past years, scientists said.

The National Oceanic and Atmospheric Administration issued a warning yesterday about the outlook to give harvesters and aquaculture businesses time to prepare and restaurants time to make contingency plans for seafood supplies this summer.

When red tide strikes, clam prices usually go up, and retailers and restaurants turn to new suppliers to get product or simply hang out an “Out of Clams’’ sign, Taylor said. Restaurants serving fried clam rolls typically buy those clams in the spring and freeze them.

Although the conditions point to widespread red tide, researchers say ocean currents and wind patterns will ultimately determine where it shows up and how long it lasts.

Onshore winds will drive the red tide toward shore and force closing of clam flats. But when offshore winds are predominant, the algae tend to stay offshore, far from harvesting areas.

Once red tide settles into an area, it tends to stick around for years. But it is not clear why red tide settles in the first place.

“I think that’s the $64 million question,’’ said Darcie Couture, who is in charge of red tide monitoring for the Maine Department of Marine Resources.

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