Comparing western Lake Erie Microcystin Congeners Between Small-HAB and Large-HAB Years.

Session: 41a. - Great Lakes Harmful Algal Blooms Research from Watershed Influence to Ecosystem Effects

Thomas Bridgeman, Dept. of Environmental Sciences, University of Toledo, [email protected]
Dilrukshika Palagama, University of Toledo, [email protected]
David Baliu-Rodriguez, University of Toledo, [email protected]
Jennifer Thornburg, University of Toledo, [email protected]
Brenda Snyder, [email protected]
Dragan Isailovic, Univeristy of Toledo, [email protected]

Abstract

Blooms of cyanobacteria, mainly Microcystis aeruginosa, in western Lake Erie vary extensively between years due to environmental factors such as tributary nutrient loading and weather patterns. Variations in the size of the annual bloom and in ambient nutrient ratios are reflected in bloom toxicity and in the total concentration of microcystin (MC) toxins that are produced. While total MC concentrations are frequently measured in Lake Erie, the specific MC congeners present are seldom quantified and it is unknown whether the relative prevalence of congeners varies between years with bloom size and toxicity. In this study we used an HPLC-Orbitrap MS system to quantify the 4 most abundant MC congeners over a summers with a small bloom (2016) and a large bloom (2017) at 8 sites ranging from nearshore hyper-eutrophic to offshore mestrophic. We compare the concentrations and ratios of congeners between year, sites, and with ELISA total MC results

1. Keyword
harmful algal blooms

2. Keyword
Microcystis

3. Keyword
mass spectrometry