Nitrogen availability is hypothesized to play a central role in cyanoHAB progression, as well as production of the N-rich toxin microcystin. Recent work implicated reduced N substrates like ammonium and dissolved organic N (DON) in promoting greater bloom biomass and longevity. To examine the relative importance of oxidized and reduced N substrates to phytoplankton during different bloom stages, we measured concentrations and natural abundance δ15N isotope values of dissolved N substrates and phytoplankton biomass throughout the entirety of the 2020 cyanoHAB in Western Lake Erie. This is the first data on DON concentrations and isotope values in Western Lake Erie. We measured nitrate concentrations and isotope values to compare with DON and also with particulate organic matter (POM) 15N isotope values. This dataset is described and analyzed in the publication, "Patterns in sources and forms of nitrogen during a freshwater cyanobacterial harmful algal bloom".
Kharbush, Jenan J., Robinson, Rebecca S., Carter, Susan J. In revision. Patterns in sources and forms of nitrogen during a freshwater cyanobacterial harmful algal bloom. Limnology and Oceanography.