Harmful Algal Blooms

The Issuenutrients
Cyanobacteria (blue green algae) have naturally been present in the lake for centuries. A combination of factors allow the algae to grow into blooms that can harmful to human health and  degrade our water quality:

  • Phosphorus and nitrogen inputs (nutrients) from the surrounding watershed feed the algae.
  • Hot, sunny, and calm weather creates ideal cyanobacteria growing conditions.
  • Zebra and quagga mussels don’t filter blue green algae out of the water.
  • Nutrients originate in the watershed and have many sources. Reducing nutrients from the watershed is the only strategy we have to prevent another bloom.

What to look for:
Use visual cues to identify harmful algae blooms. They can appear like pea soup, spilled paint, globs, and parallel streaks. The color is typically blue-green to green to yellow, but can also be brown, red or purple.

Its important to remember: If you see a bloom, avoid it! Blooms can move up and down the water column, and can be pushed by wave and wind action. They can appear quickly in the lake when the conditions are just right. Please use your visual indicators before recreating in the water – stay safe and avoid it.

How to report it:
Help by collecting information on blooms:

  • Location (GPS coordinates, address, or geographic description of the area )
  • Photos
  • Description – Was it streaky, globby, threadlike, like spilled paint, like pea soup, scummy, silky, or have small leaves? What color was it?
  • How large of an area did it cover?
  • How long was it there?

Report Suspected Blooms to HABs@canandaigualakeassoc.org.  

Shoreline Monitoring Program
To help us increase our understanding of the blue green algae dynamics in Canandaigua Lake, in 2018 CLWA lauched a Volunteer Shoreline HAB Monitoring Program. Sixteen CLWA volunteers will be out performing weekly suveillance, looking for and sampling harmful algal blooms. Findings will be reported to the public on our website, facebook page and in our email blasts.

Week one (July 29-31): No blooms Reported
Week two (Aug 5-7): No Blooms Reported
Week three (Aug 12-14): No Blooms Reported


Additional Resources:

hab brochure pic

HAB Brochure Canandaigua Lake

dogs and habs pic

 Dogs and HABs Fact Sheet


On October 20, 2015, the Canandaigua Lake Watershed Association and the Canandaigua Lake Watershed Council co-hosted a community discussion on the September blue green algae event.  A panel of experts each presented a powerpoint, followed by a question and answer session. The experts discussed the science behind blue green algae and the sequence of events on Canandaigua Lake. Video and presentations are below.

Kevin Olvany – Blue Green Algae presentation

Scott Kishbaugh – Canandaigua Presentation

Dr. Greg Boyer – Introduction to HABs

October 20, 2015 Canandaigua Lake Watershed Association – Blue Green Algae Presentation [HD] from Finger Lakes TV on Vimeo.