Cyanobacteria Warnings Issued For Henniker, Bedford Ponds

CONCORD, NH — The New Hampshire Department of Environmental Services has issued two cyanobacteria alerts warning swimmers in Bedford and Henniker to stay away from two local ponds due to concentrated levels of the bacteria. At Sebbins Pond in Bedford, stated officials found samples above the state recommended maximum threshold of 70,000 cells/ml or greater of cyanobacteria. The cyanobacteria were identified as Woronichnia, Anabaena (Dolichospermum), Microcystis, Coelosphaerium, and Oscillatoria. At Keyser Pond in Henniker, the cyanobacteria were identified as Anabaena (Dolichospermum) and was also over the recommended state level.

As a result, the New Hampshire Department of Environmental Services (NHDES) has issued warnings for both ponds.

"This warning is not based on a toxin evaluation and is intended as a precautionary measure for short term exposure," according to the alert. "NHDES advises lake users to avoid contact with the water in areas experiencing elevated cyanobacteria cell conditions, typically where lake water has a surface scums or streaks. NHDES also advises to keep pets and small children out of any waters that have green-turbid water, surface scums or other blue-green flecks in the water column."

When a cyanobacteria warning has been issued, NHDES returns to affected waterbodies on a weekly basis until the cyanobacteria standards are again met. Cyanobacteria are natural components of water bodies worldwide, but blooms and surface scums may form when excess phosphorus is available to the water. Some cyanobacteria produce toxins that are stored within the cells but 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, nausea, vomiting, and diarrhea. Chronic effects include liver and central nervous system damage.

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

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. Call NHDES to report a cyanobacteria bloom at 603-848-8094.

Submitted by Amanda McQuaid.