Blue-green algae is the popular name for a group of tiny, single-celled organisms, or cyanobacteria. They occur naturally in lakes, streams, and oceans. Some blue-green algae produce toxins. Under certain conditions, blue-green algae can grow rapidly and cause a harmful “bloom,” which discolors the water or produces floating scums.

A harmful algae bloom (HAB) can cause health effects in people and animals. This may happen when a person’s skin touches the algae bloom, or when water is swallowed or droplets are inhaled. These blooms can also be a major hazard to drinking water supplies.

If you see an algal bloom, do not go in the water. Keep children and pets out of the water. This includes waterskiing and other recreational water sports because contaminated spray and droplets can be inhaled and cause problems. If you or your pets do go in water that has an algal bloom, wash yourself or your pets off immediately afterwards with tap water.

Do not use untreated lake water for drinking, brushing teeth, cooking, and bathing. Boiling the water will NOT kill the toxins produced by the blue-green algae. Instead it can actually elevate the toxin levels.

HABs can appear suddenly and without warning. Obey all beach closure signs at your local beach. The NYS Department of Environmental Conservation also updates a list of HAB notifications in the state on a weekly basis and in an archive

Dogs also swallow more water than humans while swimming and playing. Dogs are not bothered by water that looks bad or smells and will go in contaminated water.

Click here to visit the CDC's website for more information about pets and HABs.

For the General Public:

• Harmful Algal Bloom (HAB)-Associated Illnesses— Centers for Disease Control and Prevention
• Frequently Asked Questions about BGA–NYS Department of Health
• Harmful Algal Blooms—NYS Department of Environmental Conservation

Harmful Algae Blooms—NYSDOH

https://www.health.ny.gov/environmental/water/drinking/bluegreenalgae/