Harmful Algal Blooms

Harmful algal blooms (HABs), also known as cyanobacteria, are of concern because they can produce toxins that are harmful to people and animals. In addition, the blooms are unsightly and negatively impact recreation, tourism, and lakefront property values.

Surface water that is discolored with a paint-like or filmy appearance or floating scum should always be avoided as it is potentially harmful. The New York State Department of Environmental Conservation’s (NYSDEC) photo gallery contains images of these types of blooms as well as non-harmful blooms.

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 is notified if public water supplies are impacted by algal blooms.

There is a lot that is not known about what causes a harmful algal bloom to occur. It is known, however, that harmful algal blooms need the following: warm temperatures, sunlight, calm conditions, and nutrients. Nutrient pollution from human activities makes the problem worse, leading to more severe blooms that occur more often.

How to Report a Bloom

If the bloom is located on Owasco Lake, contact the Owasco Lake Watershed Inspection Program at 315-427-5188.

If the bloom is located on Cayuga Lake, notify the HABs Harrier Program at habshotline@gmail.com and include photos, location and date and time of the bloom.

If the bloom is present on another waterbody contact the New York State Department of Environmental Conservation (NYSDEC) at HABsinfo@dec.ny.gov. Here is further information on blooms.

How to Find Out Where Blooms Have Been Reported

The NYSDEC HABs Notification Page features a map that illustrates where blooms have been reported within Cayuga County and New York State.

The Owasco Lake Watershed Inspection Program’s website displays a map that highlights the results of the Owasco Lake HAB Monitoring Program.

The Community Science Institute’s website displays a map that highlights the results of the 2019 Cayuga Lake HABs Reporting Page.

For further information on HABs, consult the following websites

If you have additional questions, contact the Cayuga County Health Department at 315-253-1405 or cchealth@cayugacounty.us.


The Water Bulletin: The Newsletter of the Community Science Institute, Fall 2020

Harmful Algal Blooms Flyer (Short Term)