Blue-Green Algae (Cyanobacteria)

Monitoring and Health Advisories - 2008 Season:

October 3, 2008 Update: As of this week, most areas of Lake Champlain were generally safe. There are, however, blooms still present in parts of Missisquoi Bay with toxin concentrations at the low alert level (more details & map with locations). The areas of densest algae accumulation in these areas of the lake will be moving around with the changing winds and weather fronts, so those recreating in these areas should watch for dense accumulations of algae and avoid these locations.

NEW! View photos of the August 2008 blooms

The 2008 season monitoring season is conducted by the University of Vermont with volunteers coordinated by the Lake Champlain Committee. Both groups receive funding from the Lake Champlain Basin Program.

What is Blue-Green Algae?

Photo credit: Quebec Ministry of Environment Blue-green algae (cyanobacteria) blooms may appear thick like pea soup, or look like green paint or grass clippings on the water. Although most of the lake has never had dense blue green algae blooms and most of those that do occur are harmless, blue-green algae can sometimes produce neurotoxins that can be dangerous if ingested in large enough quantities. In 1999, a dog died after ingesting toxic blue-green algae from Lake Champlain, followed by two more in 2000.

Blue-green algae can form when warm surface water temperatures and calm winds limit vertical mixing of the lake water. These conditions, together with abundant phosphorus, can contribute to blue-green algae growth patterns that produce neurotoxins and prompt local human health concerns. During the August 2001 heat wave, officials from the Vermont Department of Health posted a blue-green algae advisory for the Lake because of conditions which may lead to the formation of blooms. In August, 2002 another advisory was issued by the Health Department about blue-green algae blooms detected at testing sites in Missisquoi Bay and St. Albans Bay. The Montérégie Public Health Department also posted an advisory for the Quebec portion of Missiquoi Bay during July 2002. (see links below to complete advisories).

Monitoring for Blue-green Algae

Sampling blue-green algae scum. Since 2000, the LCBP has continued to fund blue green algae studies by the University of Vermont, the VT Department of Health, and Syracuse University in conjunction with the Federal Centers for Disease Control and Prevention. Scientists are monitoring Lake Champlain for blue-green algae blooms and measuring the environmental conditions that promote blue-green toxicity in Lake Champlain. For more information about this program, contact the University of Vermont's Rubenstein Ecosystem Lab at (802) 859-3086, or view the published technical reports here. The Quebec Ministry of the Environment is also testing for blue-green algae on Missisquoi Bay, continuing a project begun in 1999. Several beaches on Missisquoi Bay have been closed because of blue-green algae blooms over the past summers. In 2002, a Missisquoi Bay Phosphorus Reduction Agreement was signed between Vermont and Quebec.

Lake Users Should Use Caution

Use common sense when dealing with algae blooms. Do not allow your pets to eat clumps of algae that have washed up on the beach. To be safe, don't let your children play in clumps of algae or drink untreated lake water while swimming or playing in the water. Lake-shore residents with shallow drinking water intake pipes that might pump in blue-green algae should be cautious. No one should drink untreated lake water.

Contacts for questions about blue-green algae health concerns
Additional Links
Past Health Advisories (if still available online)

 
Lake Champlain Basin Program - 54 West Shore Road - Grand Isle, VT 05458
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