A microscopic image of Alexandrium fundyense red tide algae. (Photo: Woods Hole)
Massive red tide may hit New England: scientists
UNITED STATES
Thursday, February 25, 2010, 23:00 (GMT + 9)
Scientists from the National Oceanic and Atmospheric Administration’s (NOAA) Gulf of Maine Toxicity (GOMTOX) project are warning state authorities of a noteworthy algal bloom in New England that could cause red tides next spring and summer and lead to the closing of shellfish beds.
The naturally occurring algae Alexandrium fundyense generates a toxin as it swims in the water and divides continuously, creating red tide. The alga also generates dormant cells, or cysts, that sink to the ocean bottom at the end of blooms.
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Maps showing the concentration of Alexandrium cysts buried in Gulf of Maine seafloor sediments over four years. (Map: Woods Hole Oceanographic Institution) |
Late last year, a survey measured the highest amount of cysts ever seen by GOMTOX: over 60 per cent higher than the amount observed just before 2005’s infamous red tide. The cyst bed also appeared farther south, such that this year’s algal bloom may impact Massachusetts Bay, Georges Bank and other areas earlier in the season than in past years, reports Associated Press.
The algae’s toxins can accumulate in mussels and clams and cause paralytic shellfish poisoning (PSP) in humans who eat them, although fish, lobster, scallops and shrimp remain safe to consume. State agencies then close shellfish beds to prevent illnesses, which caused USD 20 million in losses to the Massachusetts shellfish industry alone in 2005 and similar troubles in 2008 – losses that could be topped this year, Physorg.com reports.
Woods Hole Oceanographic Institution (WHOI) oceanographers Dennis McGillicuddy and Don Anderson along with North Carolina State University (NCSU) Professor Ruoying have been developing a computer model to calculate the strength and whereabouts of algal blooms in the Gulf of Maine. It is difficult to forecast red tides because weather phenomena cannot be predicted months in advance.
"Our research has shown that cyst abundance in the fall is an indicator of the magnitude of the bloom in the following year," GOMTOX member McGillicuddy told. "However, even if there is a large bloom offshore, certain wind patterns and ocean currents in the late spring and summer are needed to transport it onshore where it can affect coastal shellfish."
Managers say a regional-scale advanced warning plus updates closer to and during red tide season can help state agencies prepare to monitor them and appraise public health risks. Warnings also allow shellfish farmers and fishers the chance to change the timing of their harvest and the seeding of aquaculture beds and restaurants to purchase seafood from new suppliers.
"Red tide is a chronic problem in the Gulf of Maine, and states have limited resources to handle it," said Darcie Couture, director of Biotoxin Monitoring for the Maine Department of Marine Resources. "When we get this information about the potential severity of a red tide season, and the dynamics of the bloom once the season has started, it gives us an advantage in staging our resources during an otherwise overwhelming environmental and economic crisis."
Related articles:
- Maine requests federal aid for shellfish industry
- Red tide leads to shellfish bans
By Natalia Real
[email protected]
www.seafood.media
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