August 17, 2012

Blue-green algae absent in much of lake


---- — PLATTSBURGH — Blue-green algae sightings in Lake Champlain have diminished in most places over the past few weeks, but hot spots persist in the northeastern corner of the lake.

Algae blooms were identified along the New York shoreline near Port Henry and Westport earlier this summer and caused a few area beaches to close, but conditions have stabilized since then.

“We really haven’t seen much in the way of algae blooms in the main lake since early July,” said Mike Winslow, staff scientist for the Lake Champlain Committee, which oversees a volunteer lake-monitoring program. “There have been no further reports (of blue-green algae) in the Westport-Port Henry area.”

No other sightings have been reported along the New York shoreline, including from monitoring stations located at Cumberland Bay State Park and Wilcox Dock in Plattsburgh, he added.

However, they continue to surface in Missisquoi Bay, a shallow section of the lake on the Vermont side that traditionally harbors blue-green algae blooms in late summer.

“We have had reports of very thick but transient blooms in Missisquoi Bay, but they don’t seem to be wide blooms,” Winslow said. “Missisquoi can be tricky. Conditions are right for that area to start taking off.”

Monitors from the bay have reported no blooms one day, followed by thick ones the next, and nearly dispersed blooms a short while later.


Although there has been no scientific record to verify his thoughts, Winslow believes the blooms at various times in different parts of the lake may have a connection to the different types of toxin-producing blue-green algae that live in Lake Champlain.

The species that typically forms blooms in the main lake is different from the species usually found in Missisquoi Bay and may do well in the cooler conditions of early summer, he surmises. The type found in the bay may thrive in warmer, shallower water.

“We see that same scenario in the Great Lakes, as well,” he noted.

Some sampling of blue-green algae in Missisquoi Bay is still being done to determine whether it is toxic. However, for the most of the lake, testing has been eliminated in favor of the visual monitoring program.

Toxin conditions in blue-green algae can change rapidly, making a sample useless days after it is taken.

The Lake Champlain Committee has between 40 and 50 volunteer monitors who report to Winslow on a weekly basis. Last year, between 10 and 15 volunteers searched for algae blooms across the lake.

Weekly updates can be found on the Lake Champlain Committee website, as well as the Vermont Department of Health website.


Although all blue-green algae does not include potentially dangerous toxins, officials are still advising that people avoid contact with anything that resembles blue-green algae.

As a bloom develops, fuzzy green pinhead-size balls may appear in the water. The actual bloom often looks like thick pea soup with patches of turquoise blue as cells break down and release their pigments.

Contact with blue-green algae can cause skin irritation and gastrointestinal irritation. Some species produce toxins that can affect the liver, and others can impact the central nervous system.

Young children and pets are highly vulnerable. At Point au Roche State Park in Beekmantown several years ago, two dogs died after ingesting lake water contaminated with toxic blue-green algae.

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