Water Quality Update for Friday, July 9, 2021

Cooler temperatures and a few rain events this week have kept water conditions quite nice! There have been no blooms observed by volunteers or watershed staff in our routine surveys this week. We received results from last week’s isolated blooms. As you may recall from last Friday’s update, volunteers observed blooms on Tuesday 6/29, and Thursday 7/1. Two samples were collected from the bloom on 7/1; one representing a typical bloom condition, and one from a “worst case” scenario, showing the heaviest concentrations of cyanobacteria. Samples were brought to our research partners at the Finger Lakes Institute in Geneva, and analysis was performed in their lab using a fluoroprobe- an instrument that measures chlorophyll with algal class determination. Profiles for Green Chlorophyll, Cyano Chlorophyll, Diatom Chlorophyll, Cryptophyte Chlorophyll, and Total Chlorophyll are part of this analysis, and the occurrence of and measurements for each are used to deem an active bloom. In New York State, a bloom is defined as having a cyano chlorophyll concentration of greater than 25 μg/L (micrograms per liter). Results from the three blooms reported last week are shared below.

As you can see, the two samples collected were above the bloom threshold. Within the day, blooms had dissipated, which reiterates the fact that water conditions can change very frequently. Secchi Disk reports from this week show the average weekly clarity has held in the 6.6 - 6.8 meter range for the last two weeks. After a nearly 10-degree average surface water temperature spike at the end of May / early June, our current average water temperature has been holding in the 68-70 degree range for the last few weeks.

As we know, conditions can change rapidly, and there is potential for increased cyanobacteria concentrations when the conditions are right. Please use your visual indicators to look for signs of active blooms. As recommended by the DEC, if you see it, avoid it. Volunteers and watershed staff will be continuing daily observations throughout July, August and September and we will communicate any significant changes in bloom activity through our weekly email updates, on our websites and through the Association's Facebook page. To report suspicious blooms, use HABS@canandaigualakeassoc.org. Enjoy your weekend!