All of Burlington’s Lake Champlain swimming areas are closed due to the presence of potentially dangerous cyanobacteria blooms that are occurring simultaneously.
The city’s Parks, Recreation and Waterfront Department announced the closures on Monday because of the blooms, which can release dangerous toxins that can be deadly to kids and pets. The swimming areas will remain off-limits until they subside and the beach owners — the state or city — determine that they are safe to enter. Officials will be testing and monitoring the blooms in the coming days.
According to the announcement, there are also small blooms near the Boathouse and Perkins dock areas where people can launch boats. The Department of Parks and Recreation suggests boaters use caution getting in the water.
Cyanobacteria occur naturally in the environment. Most of the time, the bacteria hang out in the sediment at the bottom of the lake, where they do not cause any harm, according to Mindly Morales, an environmental sciences and natural resources professor at the University of Vermont. But when the right combination of nutrient-rich runoff flows into the lake and warm temperatures arrive, the bacteria can surface and create the blooms.
According to the Vermont Department of Health, ingestion of cyanobacteria toxins can cause an array of health problems, from diarrhea and vomiting to liver damage and dizziness.
Not all cyanobacteria blooms are toxic, and it is impossible to tell if the blooms are dangerous without testing, according to the department.
The department did not respond to VTDigger’s query about toxicity of these particular blooms in time for publication.
It’s not unusual for beaches in the Burlington area to close during the summer due to cyanobacteria. But the number of simultaneous blooms caught Lake Champlain Basin Program director Eric Howe by surprise.
“The lake warmed up quickly this year and it’s unfortunate that this is happening across the lake because that means people don’t have other options of places to swim and recreate,” he said.
The region has generally seen cyanobacteria earlier in the season and more often, according to Howe.
“We’ve been monitoring blooms in the lake since the late 1990s,” said Howe. “We are seeing blooms earlier now than we did at the beginning of the monitoring program and they are starting to appear more frequently.”
