Latest microcystin numbers from Grand Lake St. Marys (from 5/6/2026).
This is three weeks out from the “spike” we saw. Algae biomass is still high, but it is lower than the biomass from three weeks ago – about 75% of the levels we saw then (a 25% decrease).
We are hopeful that we see a continued downward trend.
Information courtesy Dr. Stephen Jacquemin, Wright State University-Lake Campus. Learn more about conditions currently affecting water quality here: https://lakeimprovement.com/may-2026-water-quality/
Monitor GLSM microcystin levels here: https://lakeimprovement.com/microcystin-levels/