Cyanobacteria Facts and Actions

What is cyanobacteria?

Cyanobacteria are a phylum of microscopic organisms found naturally in all types of water. These single-celled bacteria live in fresh, brackish, and salt water and photosynthesis to create their own energy from the sun. They are able to multiply quickly in warm, nutrient-rich (high in phosphorus and nitrogen) environments creating blooms that spread across the water’s surface.

A bloom occurs when large quantities of cyanobacteria rise from the sediment on the bottom of a waterbody and form mats on the surface. Blooms are becoming more and more common in New England lakes. The frequency of these blooms is directly related to the amount of nutrients that are entering lakes in stormwater runoff from fertilizers, poorly maintained septic systems, road salts and sands, manmade beaches and shoreline erosion. Water temperatures are also on the rise. Drought conditions with occasional intense rain storms that flush nutrients from the land into the lakes- together create the perfect growing environment for cyanobacteria leading to blooms. Blooms are most common in lake summer and early fall, but can occur anytime.

Why worry about cyanobacteria blooms?

Blooms can be harmful to people, animals, or the environment.

There are many species of cyanobacteria- some of those species can create HABs (Harmful Algae Blooms) from microcystins or cyanotoxins. HABs cannot be predicted. There are 5 species of cyanobacteria that live in fresh water that are known to be the most likely to turn toxic, but there are no predictors on when they will produce toxins. When these toxins are present in the water they are fatal if consumed by dogs and other wildlife. There is little treatment for animals that have consumed toxic cyanobacteria- there livers cannot process the bacteria and it quickly leads to total liver failure- symptom can start in as little as 15 mins or can take several days. Do not let children or pets near any algal blooms!

You cannot tell if a bloom is toxic by looking at it, so assume it is and stay away from the water. Use the contact sheet below if you suspect a bloom. Please also report all suspect blooms to Wolfeboro Police through dispatch.

Check out the flyer below from our friends at the Lake Winnipesaukee Association on how to identify cyanobacteria blooms and who to contact if you see a suspected bloom.

For even more information check out the resource page from the Vermont Department of Health here.

If you use lake water inside your home. DES and EPA advise that you do not use that water during an Advisory. If you “treat” lake water for inhouse use please see this Fact Sheet from the EPA about efficiency.

A variety of information mentioned in the presentation is available through the Cyanobacteria HAB page of the NHDES website, including:

• Healthy Swimming Mapper: Shows all active cyanobacteria Warnings/Alerts in the state and is searchable by waterbody or location.
• Bloom report form: If you see something unusual or suspect a bloom may be present, stay out of the water and report the bloom through this form. The form also includes photos of blooms in New Hampshire as well as how to collect and deliver a sample.
• Links to sign up for weekly updates of all Warnings in the state, or to be notified of a Warning/Alert on a specific waterbody.