Water Quality Update for September 8, 2023

To follow up on the e-blast sent on Wednesday, it was an active week for CyanoHABs on Canandaigua Lake. Between Wednesday (9/6) and Thursday (9/7), trained volunteers reported 22 blooms. There were also several reports that came in from the general public. Watershed Council staff were also out documenting the extent of the blooms.

The areas impacted the most were the northeast shoreline, from Otetiana Point down past LeTourneau. Conditions were perfect for CyanoHAB formation- multiple days of 90-degree sunny weather with almost calm conditions. On Wednesday, there was a very slight subtle wind (1-2 mph) out of the west in the morning that helped to concentrate the cyanobacteria into blooms along the east side. One of our volunteers who is a sailor noticed the slight wind shift out of the east in the afternoon (the boats on moorings changed directions at the Yacht Club) and we started to get cyanobacteria concentrating into blooms on the west side.

The dots on the map pinpoint the volunteer reports, but there were more areas around the lake that also had blooms as reported by the public.

Since this was the first major cyanoHABs outbreak this summer, several samples were collected and sent to the Finger Lakes Institute in Geneva to help us better understand the levels of blue-green algae (measured by CyanoChlorophyll) to confirm bloom status. All samples collected came back above the bloom threshold of 25 micrograms per liter ( μg/L ). Below you will find a table of these results. More information is also available here.

We thank all our volunteers for mobilizing quickly in response to the situation!

With the change in temperature and some rains yesterday afternoon, we have only received a suspicious report this morning at 10:30 am from Crystal Beach showing some light “dots in the water”. Several other areas have reported clear conditions.

As we head into the weekend, please continue to use your visual indicators to look for signs of an active bloom situation – surface streaking, green, discolored water, or surface scums. Hot, calm days are more favorable for the rapid proliferation of cyanobacteria and resulting blooms. Please email HABs@canandaigualakeassoc.org with any questions.