It’s that time of year again. Reports of potentially toxic cyanobacteria, also known as blue green algae, have started coming in to the state of Vermont, and Burlington officials closed part of North Beach because of the bacteria.
The Vermont Health Department’s cyanobacteria tracking map reports a “low alert” level of cyanobacteria at the Leddy Park beach area of Lake Champlain in Burlington.
Thursday morning, Burlington's Department of Parks, Recreation and Waterfront tweeted that North Beach is partially closed.
And now for the bad news... part of North Beach is closed due to Blue-Green Algae (cyanobacteria). Please respect posted signs.
— BPRW (@btvparks) July 7, 2016
Toxins from the cyanobacteria can also affect pets, and buildup of the bacteria has killed pets in Lake Champlain in the past. Last year, a dog died after swimming in the lake, though the Burlington Free Press reports that it it wasn’t completely clear if the death was caused by toxins from the bacteria.
Cyanobacteria thrives in water that has an excess of phosphorus. Water runoff from roads, parking lots, farms and the rest of the landscape carries phosphorus into Lake Champlain. When high phosphorus levels combine with mid- to late-summer heat, the warm, phosphorus-laden water allows cyanobacteria to thrive.
Federal officials at the Environmental Protection Agency officially signed off on new Lake Champlain pollution reduction targets for Lake Champlain, designed to bring phosphorus levels in the lake down to ecologically sustainable levels. The state of Vermont is now tasked with implementing policies to achieve the necessary pollution reductions.
Authorities in Vermont have closed beaches on numerous occasions in recent years because of cyanobacteria-related health risks, in both Lake Champlain and in Lake Carmi in Franklin County.
For the latest official information about cyanobacteria-related health risks, use the Vermont Health Department’s online tracking map.
Update 11:15 a.m. This post was updated, and the headline was changed, to reflect the partial closure of North Beach in Burlington.