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FOR IMMEDIATE RELEASE:
DATE: June 19, 2020
CONTACT: Amanda McQuaid (603) 271-0698 (O), 848-8094 (C)

State REMOVES Cyanobacteria Advisory for Silver Lake in Hollis, NH

Concord, NH - The New Hampshire Department of Environmental Services (DES) has REMOVED a cyanobacteria advisory for Silver Lake that was issued on 06/09/2020. Cyanobacteria were identified as Microcystis and Woronichinia. Cyanobacteria advisories are issued when concentrations exceed 70,000 cells/ml. Samples collected on 6/19/2020 revealed that the bloom has currently dissipated and no cyanobacteria cells were found at the beach. Few cells of Microcystis were observed closer to the "boat Launch" area of the beach (2,500 cells/ml). While the bloom has dissipated, NHDES advises that lake-goers look out for green surface accumulations in the future. Periodic blooms do recur in this water body. 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 June 9, 2020 and was removed on June 19, 2020.

Visit the NHDES Beach Program website for photos and more information about cyanobacteria at www.des.nh.gov/organization/divisions/water/wmb/beaches/index.htm
Updates on advisories and warnings may be obtained at www4.des.state.nh.us/WaterShed_BeachMaps/WaterShed_BeachMaps.aspx
Follow the Beaches twitter feed:
twitter.com/NHDES_Beaches




NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

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