Investigating Drivers of Algal Bloom Succession in Lake Erie

Harmful Algal Blooms (HABs) are algae undergoing prolific, unregulated growth. A well-documented HAB taxa is the cyanobacterium Microcystis spp., which induces anthropogenic, ecological, and economic consequences due to the production of toxins and biomass which results in lake hypoxia. Microcystis spp. blooms are globally distributed in freshwater systems, with climate change and the aquatic continuum serving to further exacerbate bloom distribution, duration, and frequency. Thus, there is a need to elucidate the factors driving the ecological success of Microcystis spp., and the ecological “failures” of their competitors, such as diatoms. In Lake Erie, a seasonal pattern of algal bloom succession occurs: Microcystis spp. blooms dominate summer-fall, and diatom blooms dominate winter-spring. My dissertation assessed the drivers of these respective algal blooms and the factors contributing to their ecological success and succession across temporal, spatial and climatic scales.