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New HABs reported on east side of Canandaigua Lake: What should you look for?

Fall is officially here, and you never know what the weather will bring day-to-day. We’ve certainly had some cooler, rainy days mixed with stretches of calm, sunny weather. With this seasonal weather variability we can also expect to see variable lake conditions. 

Friday’s calm, sunnier conditions have brought a few reports of blooms on the east side of the lake. These are areas of moderate to dense surface streaking. Ontario Beach Park and Deep Run both had blooms along the shoreline today. This is a reminder to continue to use caution, especially if you have dogs swimming at the waterfront. See image from the Crystal Beach neighborhood below. 


The timing of blooms is in line with what we’ve seen in the season’s past. Cyanobacteria are trying to optimize the light to use for photosynthesis and they may hang at the surface on calm days. 

There are still a few more weeks left in the shoreline monitoring program and there will continue to be trained eyes on the lake well into the fall between paid watershed staff and volunteers. If you remember, in 2021 we had blooms late into October. 

As always, please continue to use your visual indicators when recreating in the lake – conditions may change daily, if not hourly, so look for signs of surface streaking of algae, surface scums, or green/discolored water. These areas should be avoided. 

The HABs and secchi disk monitoring programs are nearing an end for the season, but we are continuously thinking of ways to expand our monitoring networks in the future. If you are a CLWA supporter and would like to get involved in volunteering next season,  feel free to send us an email to [email protected] and we will add you to our training list for next year! 

What is a HAB?

Cyanobacteria, sometimes referred to as blue-green algae because of their color, are among the oldest organisms on earth, and they are ubiquitous in all water environments. Although we tend to think of them as being harmful, and they can be, they are also incredibly valuable to life on earth because they efficiently consume large amounts of atmospheric carbon dioxide and release oxygen during photosynthesis. Unfortunately, in highly dense concentrations as seen in blooms, they can produce several toxic compounds that are hazardous to people and animals. Although several algal species (called phytoplankton) contribute to the blooms we see in our lake, the most abundant and dangerous is a group (genus) called Microcystis. 

During the warmest summer months, there are conditions that exist that may promote the formation of HABs. They can appear very quickly and persist for hours or days, or they can disappear almost as quickly as they formed. Since previous research informs us that high levels of toxins may accompany the blooms, humans and our pets should avoid coming into contact with the water when an active bloom is observed. 

What should you look for?

Use visual cues to identify harmful algae blooms. They can appear like pea soup, spilled paint, globs, or surface streaks. The color is typically green, blue-green, or yellow, but can also be brown, red or purple. Visit the DEC photo gallery to learn more about identifying blooms.

Here’s what it looks like. Photo provided by Canandaigua Lake Watershed.


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