Caution signs around Baker Lake notifying the public of the presence of potentially harmful algae have been removed.
According to Richard Menger with Fallon County Environmental Health, the lake “has been deemed safe from cyanobacteria toxins” after blue-green algae blooms were observed and the lake was placed under caution Monday, July 29th. An advisory was issued by the Montana Department of Environmental Quality (DEQ) on Wednesday, July 31st, and was lifted on Tuesday, August 13th. The DEQ’s algal bloom map notes that the “bloom has dissipated”.
Menger explained that when blue-green algae dies, the algae sinks to the bottom of the lake where it decomposes and produces toxins such as microcystin and anatoxin-a, two toxins which Menger and the DEQ confirmed to be present in Baker Lake. Their presence in the lake is what lead to the cautionary state, and the concentration of the toxins in samples determines what level of caution the lake must be under, up to full recreational closure.
“Fortunately, this latest bloom did not create any dead zones that kill fish,” Menger wrote. “If I ever get fish kills, the lake would be closed to all water activities.”
According to the Minnesota Pollution Control Agency, blue-green algae can’t be completely eliminated and high water temperatures often can’t be helped, but harmful algae blooms may be reduced through the reduction of the amount of nutrients such as nitrogen and phosphorous entering the lake system.