Blue-Green Algae

Local Examples of Blue-Green Algae

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Blue-Green Algae

Blue-green algae blooms have been common in recent years during the latter half of the summer on lakes within Cayuga County. 

Blue-green algae, also known as cyanobacteria, are of concern as they can produce toxins that could pose a health risk to people and animals when they are exposed to them in large enough quantities.  Health effects could occur when the blooms are swallowed while swimming or through contact with the skin. 

Consuming water containing high levels of blue-green algae has been associated with effects on the liver and on the nervous system in laboratory animals, pets, livestock, and people.  Direct contact or breathing airborne droplets containing high levels of blue-green algal toxins during swimming or showering can cause irritation of the skin, eyes, nose and throat and inflammation in the respiratory tract. If you are experiencing symptoms from a potential blue-green algae exposure, you should contact your physician and the Cayuga County Health Department at 315-253-1405

Pet owners should keep their pets away from water experiencing algae blooms.  If animals ingest the toxins either through drinking or cleaning their fur after exposure, they can become sick quickly.

As a reminder, the Cayuga County Health Department encourages the community and visitors to: Know It, Avoid It and Report It.


Know It

Surface water that is discolored with a paint-like or filmy appearance or floating scum should always be avoided as they are potentially harmful.  Images of these types of blooms as well as non-harmful blooms can be viewed at   Weather influences where blue green algae blooms will occur.  During extended periods of calm and sunny days, blooms can accumulate at the surface in any location. Wind and waves may cause them to form along shorelines or in protected areas.  Shifts in wind direction can move a bloom form one location to another.  Periods of cool rainy weather can often lead to the disappearance of a bloom.

Avoid It

Always stay away from blooms in surface waters. Never swim, fish, boat, wade or eat fish caught in areas with blooms.  Bloom or no bloom, never drink, prepare food, cook, or make ice with untreated or improperly treated individual surface water supplies. During a bloom, individual surface water supplies should not be used for showering, bathing, or washing dishes even if treatment is provided. Public water supplies that draw water from surface water are treated, disinfected and monitored.  The public would be notified if public water supplies are impacted by algal blooms.

Reporting Information

Report a bloom

If you suspect that a bloom may be harmful, the Cayuga County Health Department asks that you report it to or  If the bloom is present on Owasco Lake, please report it to the Owasco Lake Watershed Inspection Program at (315) 427-5188 or (315) 237-2066. If you feel that you or animals are experiencing symptoms such as diarrhea, nausea, vomiting, irritation of the skin, eyes, or respiratory system due to exposure to a harmful bloom please contact your health care provider or veterinarian.

If you believe that you may have had physical symptoms after swimming in a blue-green algae bloom, please complete and return the electronic questionnaire below to Andrea Simmons, Director of Community Health Services by email: .

New York State Human Illness Questionnaire

If you prefer, please call us at 315-253-1560 during normal business hours and we will complete the form with you. 

Map of Blue-Green Algae Blooms.

Understanding Cyanobacteria and Cyanotoxins