State REMOVES Cyanobacteria Advisory for Governors Lake in Raymond, NH

Concord, NH – The New Hampshire Department of Environmental Services (DES) has REMOVED a cyanobacteria advisory for Governors Lake that was issued on 05/27/2020. Cyanobacteria advisories are issued when concentrations exceed 70,000 cells/ml. Cyanobacteria were identified as Anabaena/Dolichospermum, Microcystis and Woronichinia. In some locations, concentrations were estimated up to 2 million cells/ml (and too numerous to count at the main beach). Samples collected on 6/9/2020 revealed that concentrations had lowered, ranging from 4,000 to 39,500 cells/ml. Highest concentrations are still observed at the main beach. The cyanobacteria were found mixed within the pollen accumulations. While the bloom has mostly dissipated, NHDES advises that lake-goers look out for green 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 May 27, 2020 and was removed on June 10, 2020.

Visit the NHDES Beach Program website for photos and more information about cyanobacteria at https://www.des.nh.gov/organization/divisions/water/wmb/beaches/index.htm

Updates on advisories and warnings may be obtained at http://www4.des.state.nh.us/WaterShed_BeachMaps/WaterShed_BeachMaps.aspx

Follow the Beaches twitter feed: https://twitter.com/NHDES_Beaches

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 HAB@des.nh.gov.