For Immediate Release
Posted: October 09, 2020


Amanda McQuaid, Harmful Algal Blooms Coordinator
(603) 271-0698 |

State REMOVES Cyanobacteria Advisory for Lake Kanasatka in Moultonborough, NH

Concord, NH – The New Hampshire Department of Environmental Services (NHDES) has REMOVED a cyanobacteria advisory for Lake Kanasatka that was issued on 9/29/2020. This was the second advisory posted after one in August had been removed (8/12-8/26). Periodic surface scums of cyanobacteria were forming in isolated locations recently. However, there have been no new sightings of blooms this week and most recent samples, collected on 10/6/2020, revealed that lake water had very few colonies of cyanobacteria. Such accumulations are common in the fall in New Hampshire lakes, when temperatures rapidly change and the lakes experience “fall turnover.” Lake debris, cyanobacteria and algae can get caught in the surface waters. NHDES advises lake-goers to look out for surface accumulations in the future. Please continue to monitor your individual shoreline for changing conditions.

This advisory was not based on a toxin evaluation and was intended as a precautionary measure for short term exposure. Cyanobacteria are natural components of water bodies worldwide, though blooms and surface scums may form when excess nutrients are available to the water.  Some cyanobacteria produce toxins that are stored within the cells and released upon cell death. Toxins can cause both acute and chronic health effects that range in severity.  Acute health effects include irritation of skin and mucous membranes, tingling, numbness, nausea, vomiting, seizures and diarrhea. Chronic effects may include liver and central nervous system damage. Be cautious of lake water that has a surface scum, changes colors, or appears to have green streaks or blue-green flecks aggregating along the shore.  

The advisory went into effect on September 29, 2020 and was removed on October 9, 2020.

If you notice anything resembling cyanobacteria, please refrain from wading, swimming or drinking the water. Keep all pets out of the water and contact NHDES immediately. Please call NHDES to report a cyanobacteria bloom at (603) 848-8094 or email