SALEM, N.H. — The New Hampshire Department of Environmental Services put out an advisory Thursday for people who swim and participate in other activities at Captains Pond in Salem. The department found a cyanobacteria bloom in the water.

This bacteria has potentially toxic effects that range in seriousness. People are advised to not come into contact with the water by swimming or drinking it.

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.

The department advises people to watch the shorelines for cyanobacteria when visiting a favorite lake. Lake water with these blooms may have a surface scum, changes colors, or the appearance of have green streaks or blue-green flecks aggregating along the shore.

The department regularly checks public beaches and waters for the bacteria. When a bloom is found, the department goes back to check the waterway every week until the bloom is under control.

Cyanobacteria is a natural component of water bodies worldwide. Blooms and surface scums may form when excess nutrients are available in the water.

The advisory will remain in effect until the department confirms that cell concentrations of the bloom have subsided.

Check the department’s website for updates at

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