The Lake Improvement Association recently committed $5,000 for toxic algae research led by Dr. Stephen Jacquemin, Professor of Biology at Wright State University Lake-Campus. 

The project’s overarching objective is to determine whether the reduction in toxicity, but not biomass, measured in Grand Lake St. Marys during 2021 was linked to a shift to non-toxic algal strains, changes in external loading, or shifts in internal nutrient availability and recycling.

Project Key Points:

  • Low rainfall in 2021 led to anywhere from a 50 to 90+% reduction in monthly streamflow compared to decadal averages
  • The load reductions resulted in reduced algal bloom toxicity but not reductions in biomass (surface Microcystis scums)
  • Throughout 2021, concentrations of microcystins stayed low (4 ug/L or less) compared to average microcystins in August (~60 ug/L), even when biovolume increased in June and July to normal levels for Grand Lake (~375 ug/L phycocyanin)
  • It is unclear whether the low toxicity represents a shift to non-toxic algal strains or potentially toxic strains that are simply not expressing toxin genes
  • A major limitation to our understanding and modeling of harmful algal bloom (HAB) proliferation and toxicity is that existing models do not forecast years wherein there are large blooms but relatively low toxicity, like GLSM experienced in 2021
  • This research presents an opportunity to investigate drivers of HAB toxicity, independent of cyanobacterial biovolume in Grand Lake St Marys
  • It will help us understand why the lake functions as it does and how we can use conservation tools to improve the health of the watershed

This commitment from the LIA is part of a larger proposal for research that has been submitted to the Ohio Water Resources Center. Official notification of decisions for funding is expected in the next few months.