Avoid Areas of Lake Champlain that Contain Blue-Green Algae Blooms

For Immediate Release

Date: August 19, 2004

Contact: Dr. Bill Bress
State Toxicologist
Vermont Department of Health
802-863-7220

BURLINGTON - The Vermont Department of Health has declared an alert for several areas of northern Lake Champlain, due to the presence of blue-green algae blooms. Those areas are Missisquoi Bay, the Highgate shoreline and shipyard area, and North Hero State Park.

Blue-green algae has been identified in other sections of the lake, and the Health Department recommends people not swim or drink water from these areas:

Shelburne Pond in the town of Shelburne also contains blue-green algae blooms.

Tests of the blooms in several areas this week confirmed the presence of toxin-producing algae. Toxin levels in water bodies tend to be higher near the shoreline and at the surface of the water where animal and human contact is most likely. Common purification methods such as boiling, ultraviolet light and chlorination will not destroy the toxins formed in the blooms.

Avoid areas where blue-green algae is present for the following reasons:

Blue-green algae blooms were first observed on the Quebec side of Missisquoi Bay this summer. Since July the blooms have extended farther south, and strong winds over the weekend broke up and dispersed the blooms even further.

Public recreation areas along the affected northern shore have been posted with health alerts by town health officers. However, if anyone from the public sees blue-green scum on the water surface in public areas that have not been posted, call the local town health officer to report it. A listing of town health officers can be found on the Health Department website at www.healthyvermonters.info .

Town health officers post health alerts in public recreation areas if blue-green scum is visible, and will close public areas if algae toxin levels test above 1 part per billion of lake water.

Generally, lots of wind, cooler weather, rainfall, and cloudy days will cause algae blooms to die off. Some blooms die off after a few days or weeks, while others persist for a few months.

The algae alert system was developed by the University of Vermont in conjunction with the Health Department. The UVM Rubenstein Science Laboratory samples lake water on a regular basis until toxin producing algae are found. The amount found in samples determines the alert level.