Identifying metabolic indicators of phytoplankton and comparing the temporal changes in algal community composition in two Lake Ontario areas of concern

Abstract

Freshwater algal blooms transition into harmful algal blooms (HABs) when cyanobacteria produce toxins that impact ecosystem health. The point at which algal blooms transition into HABs is not fully understood, but I believe that the transition can be predicted by combining molecular and community-level information. This study consisted of ten weeks of sampling in 2020 from August to October in Hamilton Harbour and the Bay of Quinte, two Lake Ontario areas of concern (AOCs). Phytoplankton genus composition was obtained via microscopy and water quality was assessed. Metabolomics were performed using liquid chromatography tandem mass spectroscopy (LC-MS/MS) to identify changes in metabolites over time. The results from this study identified taurine, serine, and glycine in large amounts in both locations and that phytoplankton community composition is primarily affected by nitrates, total phosphorus, and turbidity. These findings will improve our understanding of these AOCs as well as the behaviour of phytoplankton overall.