Speaker: Rachel Gabor
Seminar Title: Dissolved Organic Matter and Algal Blooms in Ohio Lakes
Abstract: Harmful algal blooms are a common water quality and public health concern in Lake Erie and smaller Ohio Lakes. Algae can act as a source, sink, and transformer of organic matter in aquatic environments, giving them a complex relationship with the overall carbon budgets of lentic ecosystems. In this seminar I will highlight 2 projects investigating the relationship between organic matter and algal blooms in Ohio. In the first project we ran research cruises across the Western Basin of Lake Erie before, during, and after the 2022 harmful algal bloom to quantify the distribution of carbon between inorganic and organic forms during these times. We found an increase in concentration of organic carbon and a shift to more labile, aliphatic molecules during more intense algal blooms. In the second project we tested an experimental algal bloom treatment, using nanobubbles of ozone to limit algal blooms. Because ozone is highly reactive with organic matter, the ozone treatment efficacy is impacted by the presence of organic matter and the treatment itself changes organic matter chemistry through both chemical reactions and inputs from dead algae. Experiments using this technology in mesocosms, rivers, and lakes have enabled us to begin the process of understanding the potential efficacy of this new technology.
Host: Andrea Grottoli
