The HABs Surveillance Program

Harmful Algal Blooms (HABs)



  • Most algal blooms are harmless. However, exposure to toxins and other substances from certain HABs can make people and animals sick.
  • Although most algal blooms are harmless, some types, called blue-green algae or cyanobacteria, can produce toxins that can be harmful to people and animals, especially dogs.
  • Over the past few years, HABs have appeared with increasing frequency in Owasco Lake. Typically they bloom later in the summer and early fall on warm, calm days.
  • In 2017, HABs were identified in all eleven Finger Lakes for the first time. HABs are appearing in fresh and salt water bodies world-wide.
  • We must face this clean water crisis. But it won’t be easy. Read on to learn how to protect yourself, and how you can help.


The Department of Environmental Conservation created a powerful GIS-based, interactive map for both trained samplers and the public across New York State. The map is live during the HABs season, which typically occurs between July and October.

  • Each year, HABs Program OWLA volunteers monitor their assigned shoreline zones once a week starting in early July through early October.


Follow safety guidelines from the Cayuga County Health Department to keep people and pets safe.

Symptoms or health concerns related to HABs should be reported to the Cayuga County Health Department Website or by calling 315-253-1560.


  • Here is a sample of the Reporting Form people can report a suspected bloom to the DEC for review. If confirmed as a HAB it goes on the map.
  • Photos can also be uploaded with the form.


Go to: to access archived HABS data for Owasco Lake and elsewhere in the Finger Lakes region and state-wide.



HABs (Harmful Algal Blooms) can come and go hourly.  This makes updating the public on current conditions difficult to impossible.  Weekly summaries of HAB patterns on our lake helps increase our knowledge of when, where, and under what conditions HABs are most likely to occur.

The single most important strategy for keeping ourselves safe from HABs is to avoid discolored or scummy water.

What can you do to HELP?

Protecting Owasco Lake is essential to the maintenance of our community character and the improvement of our economic future. We encourage everyone to help the Owasco Watershed Lake Association personally and/or financially. By this commitment you will help keep Owasco Lake clean and safe.