Courtesy photo Officials with the New Hampshire Department of Environmental Services have issue a cyanobacteria advisory for Silver Lake in Hollis, shown here.

HOLLIS – Officials with the New Hampshire Department of Environmental Services do not want people to swim in a pair of local lakes because of a cyanobacteria advisory.

The advisory affects Silver Lake in Hollis and Franklin-Pierce Lake in Hillsborough.

On Saturday, the Silver Lake bloom appeared orange, yellow and blue-green. This is a common occurrence as colors may represent a mix of blue-green cyanobacteria, yellow pine pollen, and green algae appearing orange.

Samples collected from the Silver Lake beach and boat launch exceeded the state threshold of 70,000 cells per milliliter of cyanobacteria. Officials advise the public to avoid this water at this time.

At Franklin-Pierce Lake in Hillsborough, samples contained a mix of Anabaena/Dolichospermum taxa and were estimated as 680,000 cells per milliliter.

Toxins associated with cyanobacteria 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.

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