Algae bloom at Elm Brook Park in Hopkinton leads to state warning

Monitor staff
Tuesday, June 20, 2017

The state has warned of a possible algae bloom at Elm Brook Park in Hopkinton and has issued a cyanobacteria advisory, cautioning swimmers and pet owners to stay clear.

The New Hampshire Department of Environmental Services issued the advisory Monday, June 19, after samples revealed that the state threshold of 70,000 cells per milliliter of cyanobacteria was exceeded.

The heaviest bloom areas were observed near the boat ramp and appear either as a scum on the surface or small blue-green clumps suspended in the water column, said DES, although conditions could change. The department advises people to avoid contact with the water in those areas.

DES also advises pet owners to keep their pets out of any waters that have a surface scum or blue-green or bright green flecks, because animals can drink the water and become sick.

Department officials monitor the state’s public beaches and public waters for cyanobacteria. Once a cyanobacteria warning has been issued, NHDES returns to affected water bodies every week until the standards are again met.

Cyanobacteria, also known as blue-green algae, are natural components of water bodies worldwide, but blooms and surface scum may form when excess phosphorus is available to the water. Some cyanobacteria produce toxins that are released when the cell dies.

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, check the NHDES website.