Heat, sun could limit red tide closures

Clams are for sale at Free Range Fish and Lobster in 2009 in Portland.
AP Photo/Robert F. Bukaty
Clams are for sale at Free Range Fish and Lobster in 2009 in Portland.
By Kevin Miller, BDN Staff
Posted July 12, 2011, at 7:56 p.m.

ELLSWORTH, Maine — Despite an unexpectedly large algae bloom that shut down clam beds in Down East Maine several weeks ago, the 2011 red tide season has been relatively mild and could end early thanks to the current spate of hot and sunny weather.

Darcie Couture, who directs the Maine Department of Marine Resources’ biotoxin monitoring program, said red tide blooms followed fairly typical patterns this year as they forced the closure of many of the traditionally hard-hit shellfish beds.

But the massive, widespread blooms that prohibited shellfish harvesting in large areas for lengthy periods in 2008 and 2009 never materialized. And if current conditions hold, most Maine waters could be largely free of the toxic algae weeks or even months earlier than normal.

“Optimistically, if things go well and if we don’t get any additional impacts from Canada, we could see closures lifted during the end of July or early August,” Couture said.

Red tide is caused by a type of algae native to Maine and many other coastal areas. During large-scale blooms that drift into near-shore waters, shellfish can absorb the algae into their tissues as they filter-feed, causing them to become toxic and even potentially fatal to humans.

The Maine Department of Marine Resources runs a comprehensive monitoring program that tests shellfish and closes affected areas to harvesting before the toxins reach dangerous levels.

That system ensures that any shellfish legally sold on the commercial market have been collected in clean areas and provides fishermen with up-to-date information so they can adjust their harvesting plans accordingly.

Severe red tide blooms — so called because they can sometimes give the water a reddish appearance, although not often in oceans this far north — are notoriously difficult to predict due to the role that weather is suspected to play in blooms.

But earlier this year, researchers with the Gulf of Maine Toxicity Project affiliated with the Woods Hole Oceanographic Institution forecast a moderate year for red tide in New England. That prediction appears to be holding true, Couture said.

Several areas in Maine, such as some of the waters between Harpswell and Phippsburg as well as Cobscook Bay, remain closed to harvesting of certain shellfish. But Couture said levels in many areas have stabilized or are dropping.

Couture said there is still a possibility that blooms in Canadian waters of Passamaquoddy could swing into Cobscook, extending closures there.

“Whether that hits us or not depends on specific wind direction and oceanography,” she said.

But while the algae that causes red tide need warm conditions to get going in early summer, the current hot and sunny conditions — with temperatures consistently in the 80s — could prompt the algae to become dormant, hastening the season’s end.

Meanwhile, in Washington, D.C., U.S. Reps. Mike Michaud and Chellie Pingree of Maine are co-sponsors of legislation that would re-authorize a program to further research red tide and develop strategies to respond to outbreaks.

“The shellfish industry in Maine experienced a severe economic crisis in 2009 as a result of the closure of nearly all of our shellfish beds,” Michaud said in a statement. “This bill will help Maine and other states develop regional action plans and a comprehensive national strategy to reduce the size and occurrence of harmful red tides.”

Members of Maine’s congressional delegation are also working on behalf of a budget item that would provide disaster relief funding to shellfish harvesters affected by the 2009 outbreak.

http://bangordailynews.com/2011/07/12/news/state/heat-sun-could-limit-red-tide-closures/ printed on September 20, 2014