The relationships between microcystins (ELISA), chlorophyll a, the ratio of microcystins to chlorophyll a concentration, and residuals from the microcystins v. chlorophyll regression (Fig. 7A) with water temperature, pH, turbidity, and specific conductivity during the 9 August 2018 (black circles) and 7 August 2019 (white circles) HABs Grab for samples with greater than 1 μg/L of total microcystins.