Cyanobacteria Advisory for Mirror Lake

State Issues Cyanobacteria Advisory for Mirror Lake
in Tuftonboro, New Hampshire

Concord, NH- A cyanobacteria bloom has been observed on MirrorLake.
Samples collected on 8/6/19 exceeded the State threshold of70,000
cells/ml of cyanobacteria. Samples contained the cyanobacteria taxa;
Woronichnia and Microcystis and three varieties of
Anabaena/Dolichospermum. The bloom appears bright green and globulous.
Concentrations have been spotted accumulating along shorelines and at
the boat launch. Samples from the boat launch was over 1.3 million
cells/ml. Surface blooms can rapidly change and accumulate in various
locations around a waterbody. As a result, the New Hampshire
Department of Environmental Services (NHDES) has issued a
cyanobacteria advisory for those who use the waterbody for recreation.
Please continue to monitor your individual shorelines for changing
conditions and avoid contact.

NHDES monitors public beaches and public waters of the state for
cyanobacteria. Once a cyanobacteria advisory has been issued, NHDES
returns to affected waterbodies weekly until the cyanobacteria
standards are again met. NHDES advises lake users to avoid contact
with the water in areas experiencing elevatedcyanobacteria cell
conditions. NHDES also advises pet owners to keep their pets out of
any waters that have a cyanobacteria bloom.

This advisory is not based on a toxin evaluation and is intended as a
precautionary measure for short term exposure. Cyanobacteria are
natural components of water bodies worldwide, though blooms and
surface scums may form when excess nutrients are available to the
water. Some cyanobacteria produce toxins that are stored within the
cells and 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, tingling, numbness,
nausea, vomiting, seizures and diarrhea. Chronic effects may include
liver and central nervous system damage. Be cautious of lake water
that has a surface scum, changes colors, or appears to have green
streaks or blue-green flecks aggregating along the shore.

The cyanobacteria advisory went into effect on August 7, 2019 andwill
remain in effect until NHDES confirms that cell concentrations of the
bloom have subsided.

Visit the NHDES Beach Program website for photos and more information
about cyanobacteria
Updates on cyanobacteria advisories may be obtained
Follow the Beaches twitter feed:

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. Please call NHDES to report a
cyanobacteria bloom at (603) 848-8094.
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