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New Hampshire Department of Environmental Services

Media Center

DATE: September 5, 2019
CONTACT: Amanda McQuaid (603) 271-0698 (O), 848-8094 (C)

State REMOVES Cyanobacteria Advisory for Pine River Pond in Wakefield, NH

Concord, NH - The New Hampshire Department of Environmental Services (DES) has REMOVED a cyanobacteria advisory for Pine River Pond that was issued on 8/30/2019. Reports of dense, blue-green mats were described to be covering the bottom of the nearshore areas of the lake along Lord Road in Sanbornville/Wakefield. Green Mountain Conservation Group (GMCG) and Acton/Wakefield Watershed Alliance (AWWA) assisted NHDES with the sampling and communication on this event. GMCG shared microscopic images of the samples with NHDES. The first finding on 8/30 contained benthic mats of Oscillatoria and Lyngbya types of cyanobacteria. The second finding on 9/4 was a benthic mat of Anabaena and/or Cylindrospermum. The advisory was initially issued to warn the public of these cyanobacterial growths, however benthic mats of cyanobacteria will likely persist in these areas. These cyanobacterial mats are typically too dense to enumerate and do not often create surface blooms. However, at times, mats can become dislodged from the sediment and come to the surface as dense clumps of cyanobacteria. There do not appear to be any surface blooms and NHDES is removing the advisory for Pine River Pond at this time. Please avoid contact if you see dense clumps or patches at the surface of the water. Keep pets away as they may be more likely to consume cyanobacteria. Please continue to monitor your individual shoreline for changing conditions.

NHDES monitors public beaches and public waters of the state for cyanobacteria. Once a cyanobacteria advisory has been issued, NHDES returns to affected waterbodies weekly until the cyanobacteria standards are again met. NHDES advises lake users to avoid contact with the water in areas experiencing elevated cyanobacteria cell conditions. NHDES also advises pet owners to keep their pets out of any waters that have a cyanobacteria bloom.

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 30, 2019 and was removed on September 5, 2019.

Visit the NHDES Beach Program website for photos and more information about cyanobacteria at
Updates on advisories and warnings may be obtained at
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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.

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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