Date of Award

Spring 5-7-2023

Document Type


Degree Name

Bachelor of Science (BS)


Marine Science


College of Science

First Advisor

George Boneillo


The harmful cyanobacteria Microcystis globally dominates eutrophic freshwater systems. Eutrophication leading to nitrogen and phosphorus loading into aquatic systems is increasing bloom propagation and shifting diatom/dinoflagellate dominated systems to cyanobacteria dominated systems. Understanding seasonal variability and environmental parameters combined with nutrient loading will allow for a better understanding of what factors are influencing Microcystis blooms. Biweekly plankton samples and environmental parameters were collected from Wall Pond from spring 2022-spring 2023. Results show that yearly plankton samples shifted from Microcystis dominated in the early summer to diatom dominated in the late summer-early fall then back to Microcystis dominated in late fall-early winter and then became dinoflagellate dominated in late winter-early spring. Results show that summer Microcystis blooms dominated due to increased temperatures and phosphorus, even though nitrogen was low. Microcystis bloomed in the late fall-early winter due to a hurricane that caused nutrient loading. Microcystis blooms dominated when N:P ratios were above Redfield ratio of 16. As N:P ratios and DIN concentrations decreased the system shifted from Microcystis dominated to dinoflagellate dominated. Bioassay results showed dual limitation of nitrogen and phosphorus.