Secchi Disk Program

On Canandaigua Lake, Dr. Bruce Gilman, Dept. of Environmental Conservation and Horticulture at FLCC, has been measuring secchi disk water clarity since the 1980’s at two mid-lake stations. For the last several years, Canandaigua Lake Watershed Association volunteers have also collected weekly secchi disk data at over 16 locations around the lake. This cooperative monitoring helps us learn about the factors that affect water clarity and overall lake health.

2017 Data for Water Clarity Monitoring

The below chart illustrates current data collected from the 2017 CLWA secchi disk volunteers. Data is updated weekly. Thanks go out to our long standing Volunteers: Dee Crofton, Gary Helming, Kevin Hefner, Scott Hill, Bruce Kennedy, Marty Lasher, Wade Sarkis, Lynn Thurston, Vickie Tucker, Bill Yust, and Steve Zumbo. We also welcome our NEW volunteers for 2017: Kathy Bromley & Greg Talomie, Amy Bowen, Rob Gray, Nadia Harvieux, Bill Mehls, Saralinda Hooker and Brian & Dolores Perkins!

For webOctober 9th, 2017

On October 6th,  the DEC Harmful Algal Bloom page added 9 waterbodies to the notification list. There are currently 68 waterbodies with blooms on the list.

Finger Lakes Sampling

DEC recently collected samples from all eleven Finger Lakes in order to learn more about the unique nature of harmful algal blooms in the Finger Lakes. While excessive nutrients (phosphorus and nitrogen) are recognized as a contributor to blooms, HABs have recently occurred in several Finger Lakes that have low nutrient levels. DEC’s Finger Lakes Hub staff and HABs monitoring partners worked together to collect large volumes of water from each lake, which were split and sent to multiple labs for analysis.

The Canandaigua Lake Watershed Council and CLWA collected and submitted two samples from Canandaigua Lake on September 26th for this study. Results will be published when they are received from the DEC.

Results from the September 25th sampling: 

Below are the results from samples that confirmed the presence of cyanobacteria HABs in the locations listed below. The bloom status is compared to the DEC Confirmed Bloom threshold of 25 µg/L Bluegreen Chlorophyll and a Confirmed with High Toxin Bloom threshold of 20 µg/L microcystin.

Location Date HABs Status BG Chl a (µg/L) Microcystin (µg/L) Visual Analysis
East Lake Road 9/25/2017 Confirmed with High Toxins 381 30 Mod. Microcystis, Trace DolichospermumDense Mougeotia, Mod. Zygnema, Fragilaria
East Lake Road 9/25/2017 Confirmed with High Toxins 45 22 Mod. Microcystis, Trace Dolichospermum

Monday, September 25th, 2017

With today’s high temperatures, we are seeing a heavier accumulation of algae throughout the watershed. Thank you to all that are sending in images, as it helps us assess the current conditions around the lake.

Water samples are being collected today for another round of analysis at SUNY ESF.  Results will be posted as soon as they are made available.

We urge you to use extreme caution when recreating in the lake. Please avoid all areas that show signs of streaking or have a spilled paint or pea soup appearance. Use these visual indicators before entering the water or letting your pets swim.  If you see anything suspicious, avoid it!

Please continue to email us photos for our image library, noting the location that you took the photo (closest address or GPS coordinates are great). Photos can be emailed to

For more information on blue green algae, please see our Harmful Algae Bloom brochure here, or visit the New York State Department of Health website and the New York State Department of Environmental Conservation website.

To report suspicious blooms contact:

Kevin Olvany
Canandaigua Lake Watershed Council Program Manager
(585) 396-3630

Kim McGarry
Watershed Technician
(585) 396-3630

Concerned about water clarity? 

See our quick blue green algae guide or visit the NYS DEC website and NYS DOH website fomore information on blue green algae.  If you have any questions or see a suspicious bloom, please email or

Interested in Volunteering? 


Secchi Disk volunteers use their own boats to go out on the lake and take weekly recordings. Findings are reported electronically, which makes real-time response to a possible critical condition possible. The additional data gathered by volunteers helps us supply more detail to the ongoing “picture” developing of Canandaigua Lake.

For more information, contact the CLWA office at (585) 394-5030 or email us.