Spatiotemporal Patterns and Ecophysiology of Toxigenic Microcystis Blooms in Lake Taihu, China: Implications for Water Quality Management

Whole lake monitoring of hypertrophic Lake Taihu, China, was conducted during the summers of 2009–2010, with the intent of identifying environmental factors influencing Microcystis bloom formation and promoting the growth of toxigenic strains (mcyE possessing). Low N:P ratios (replete N & P) appeared to select for toxigenic populations of Microcystis spp., whereas nontoxic Microcystis spp. strains were dominant in more nutrient limited regions of the lake. Chlorophyll a (Adj. R2 = 0.83, p mcyE) gene equivalents (Adj. R2 = 0.85, p a was identified as a more robust and useful metric for predicting microcystin concentrations than qPCR measurements enumerating the total Microcystis population based on c-phycocyanin (α subunit; cpcA) gene equivalents (Adj. R2 = 0.61, p Microcystis spp. was highly variable over time and space, and on average the population consisted of 36 ± 12% potentially toxic cells. On the basis of this study’s findings, a framework for the design and implementation of a water safety plan for Taihu water quality managers and public health officials is proposed.