For Immediate Release
September 8, 2021

Contact

Amanda McQuaid
(603) 848-8094 | HAB@des.nh.gov

State Removes Cyanobacteria Advisory for Locke Lake in Barnstead, New Hampshire

The New Hampshire Department of Environmental Services (NHDES) has REMOVED a cyanobacteria advisory for Locke Lake that was issued on 8/4/2021. Cyanobacteria advisories are issued when cell concentrations exceed 70,000 cells/ml. Samples have been collected weekly since the onset of the advisory and conditions continue to improve overall. Samples collected on 9/8/21 contained Woronichinia, Microcystis and Dolichospermum. Most areas were generally clear with cell concentrations well below 5,000 cells/ml. However, a scum and bloom accumulation was still observed near the marina with a cell concentration of 700,000 cells/ml in one isolated location. Keep in mind that conditions can rapidly change. While the surface bloom has mostly dissipated, NHDES advises that lake-goers look out for clouds and 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 August 4, 2021 and was removed on September 8, 2021.

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.