Bacteria bloom at Turtle Pond leads to state warning

  • Hancock Town Beach at Norway Pond was closed on Friday, Aug. 5, 2016, due to visible cyanobacteria. (Brandon Latham / Monadnock Ledger-Transcript) Staff photo by Brandon Latham

Monitor staff
Wednesday, September 27, 2017

The state is warning that Turtle Pond in northeast Concord is suffering from a bloom of bacteria that could make it dangerous for swimmers.

The Department of Environmental Services says an elevated cyanobacteria cell concentration was observed in the pond, on Oak Hill Road, and that water samples collected at the boat launch on Wednesday revealed a dense bloom of microcystis.

The bloom appears as a green cloud and light green scum on the water, although blooms can come and go quickly.

This DES warning is not based on a toxin evaluation and is intended as a precautionary measure for short-term exposure.

NHDES advises lake users to avoid contact with the water in areas experiencing elevated cyanobacteria cell conditions, and advises pet owners to keep their pets out of any waters that have a surface scum or blue-green or bright green flecks. Pets that drink the water can get sick.

Once 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 too much phosphorus enters 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.

For more information, visit the NHDES Beach Program website https://www.des.nh.gov/organization/divisions/water/wmb/beaches/index.htm