Blue-Green Algae Blooms Spotted In Mallets Bay, In Late November

Dec 2, 2016

State officials identified a potentially toxic bloom of cyanobacteria – also known as blue-green algae – in Mallets Bay earlier this week, after they had stopped monitoring the lake for the blooms for the season.

State officials confirmed the report after James Ehlers, executive director of the nonprofit Lake Champlain International, notified VPR of the potential bloom.

Angela Shambaugh, an aquatic biologist at Vermont’s Department of Environmental Conservation, said late-November blooms aren’t unprecedented in Mallets Bay.

“It’s not unusual for Mallets Bay to have cyanobacteria blooms this time of year. We have them on record has happening several times back in 2006 and 2008 I believe, and there are other lakes in Vermont where cyanobacteria blooms occur periodically this time of year,” she said.

Shambaugh said cooler water temperatures and increased wind both reduce the chances of the potentially toxic algae blooms, but conditions this year still allowed a bloom in the final week of November.

Ehlers noted that even though swimming in Lake Champlain is mostly over for the year, duck hunters and their dogs are vulnerable to toxins from cyanobacteria blooms. The blooms can be especially harmful to dogs because they tend to swallow water when swimming.

Gov. Peter Shumlin signed a new law earlier this year that requires the Vermont Department of Health to maintain “a publicly accessible Internet site that provides information concerning the presence of cyanobacteria in areas known to be used for recreation, including swimming or boating.”

Cyanobacteria appeared in Mallets Bay on Nov. 30, 2016, much later in the year than is typical in Lake Champlain.
Credit Courtesy / Lake Champlain International

The law also requires the health department to “conduct public outreach describing the area affected and the nature of the public health hazard in the area.”

However, the Department of Health website created to track the blooms has been shut down for the year.

Visitors to the page are met with a message that says “the 2016 monitoring season has ended,” and provides no information about current or recent cyanobacteria blooms on Lake Champlain, despite the fact that state officials confirmed a bloom this week.

Shambaugh says the state’s process for identifying cyanobacterial blooms outside of the normal season doesn’t change much.

“We take the time to validate it and make sure that it is a bloom,” she said. “In this case, the email that went out originally [from the Vermonter who spotted the algae] notified the Town of Colchester as well, and the health department, with what was being observed, so in that respect the response to the public was already taken care of in that first initial conversation, because all the people that needed to know that this might be happening were in that original loop.”

Shambaugh says her understanding of the new state law is that it doesn’t require the public notification to be posted on the health department’s algae tracker website.

“I do not believe there’s any particular requirement as to where that information needs to go,” she said. “From our perspective, it’s most important to get it to the towns because those are the folks that have the responsibility to take on broader notification. They will post signs – they have the authority to post signs along the beaches and the water shores, so the health department works with them to get that public outreach underway.”

The Town of Colchester posted notification of the bloom online Thursday.