Toxic blue-green algae blooms have been spotted in three locations on Lake Champlain this week, the summer’s first outbreak.
More are expected, said Mike Winslow, staff scientist at the Lake Champlain Committee, a science-based advocacy organization that aims to protect Lake Champlain’s water health. Winslow said he is surprised it took so long for the blooms to appear given the warm weather early this summer.
The most significant bloom is in St. Albans, which was labeled as a high alert site by the state Department of Health. This includes two locations in the bay, the St. Albans boat launch and Bay Park. The other two locations are on Vermont 78 in Swanton and Malletts Bay in Colchester, which are on low alert.
Bay Park was closed last week because of the smell as a precautionary measure, said Steve Beauregard, director of public works for St. Albans Town. The boat launch is not closed.
Beauregard said the town tests the water every Monday for E. coli. The blue-green algae concentrations had not been tested as of Tuesday afternoon. If concentrations exceed a certain threshold, the areas are closed for recreational use.
According to the health department’s website, low alert means there are small amounts of blue-green algae and the area is open for recreational use. High alert means dense scum was observed in the water and the area is unsafe for recreational use.
Cyanobacteria, commonly known as blue-green algae, is a natural component in Lake Champlain. However, some types of these algae produce toxins that can cause skin irritation, gastrointestinal stress or kidney failure if swallowed, Winslow said.
The algae develop when the water is nutrient rich, warm and still, Winslow said. Wind pushes the algae to the shorelines where it is exposed to the sun and decomposes, which releases toxins that are potentially harmful.
There are no documented cases of human illness related to blue-green algae in Lake Champlain. However, several dogs have died allegedly after drinking lake water that was spotted with the algae, Winslow said.
Blooms are usually isolated events, Winslow said. Where the algae are not spotted, the water is safe for recreation.
“Just because it’s blooming in St. Albans doesn’t mean it’s blooming everywhere,” he said.
Winslow and his team report to local town officers who then decide to close areas along the lake.
The Department of Health provides a description of algae on their website. Water may appear cloudy and look like a thick pea soup. The blooms are generally green or blue-green in color, although they can be brown or purple, and a thick mat or foam may form when a bloom washes onto shore.
The Vermont Department of Health has created an interactive map of locations where algae blooms have been sighted on its website.
