NHDES today issued an official cyanobacteria advisory for Lake Kanasatka. We delivered multiple samples from several areas on the lake yesterday, which NHDES analyzed today. The samples ranged from a high of 500,000 cells/ml and too numerous to count, to a low of 6,000 cells/ml. The state threshold for issuing an advisory is 70,000 cells/ml, and there are still specs/flurries, coloration, and cloudiness being observed in the water today. While the high winds today are likely breaking it up somewhat, danger of accumulating cyanobacteria and high cell counts remains.


Most prevalent strains of cyanobacteria in these samples are varieties of Dolichospermum. In addition, Woronichinia cells were present.


The conditions sampled on Sunday are indicative of accumulations that can happen anywhere around our lake, depending on wind, weather, waves, boat traffic and other conditions. The blooms happen out in the lake and then are pushed around and can accumulate and disperse rapidly. Signs of a bloom include bright green scum, brown scum, whitish or greenish striations or paint chips on the surface, or lots of specs or flurries or general cloudiness in the top of the water column. As the cyanobacteria dies, it may release toxins. Often foam will collect on top of the water or along the shore. Toxins may still be present in the water after immediate signs of the bloom are gone.


Please remain vigilant and advise anyone, especially children and pets, to avoid consuming or coming in contact with the water where any conditions are present. Conditions in your location can change rapidly, and bloom accumulations are still imminent at this time. Please refer to FAQs and the links provided in previous posts for more information, and contact the Rapid Response Team or Water Quality Chair (links on Kanasatka.org website) with any questions or if you see anything of concern.


This advisory will remain in effect until NHDES confirms that cell concentrations of the blooms have subsided. Their protocol is to test weekly, or sooner if we see significant improvements in conditions.

September 14, 2021|Categories: News|

Established to promote the conservation of the quality of the environment of the area in the watershed of Lake Kanasatka, including the conservation of the natural resources of the land, water, marshland, woodland and open spaces, as well as the plant and animal life therein, and the protection of the water quality of Lake Kanasatka and its tributaries against pollution.

Friends of Lake Kanasatka, organized by Lake Kanasatka

As mentioned on our Facebook page, the Lake Kanasatka Watershed Association is taking donations in the name of one of our founders, Ted Hilton, to raise funds for a Water Management Plan. This plan will preserve the ecology of the lake, protect its wildlife, ensure the water quality, and keep Kanasatka pristine for generations to come.

You can make a secure online donation at:


or mail your check to LKWA, PO Box 774, Center Harbor, NH 03226.

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