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. R(2) = 0.83, p < 0.0001) was equally predicative of microcystin variance across the lake as fluorescence based real-time quantitative PCR (qPCR) measurements of microcystin synthetase E (mcyE) gene equivalents (Adj. R(2) = 0.85, p < 0.0001). Interestingly, chlorophyll 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. R(2) = 0.61, p < 0.0001). Overall, the lakewide composition of 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.
Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Institute of Marine Sciences, Morehead City, North Carolina 28557, USA. ottentim@email.unc.edu
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D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000032:analysis; D002681:China; D005798:Genes, Bacterial / Q000235:genetics; D057097:Harmful Algal Bloom; D060106:Lakes; D052998:Microcystins / Q000032:analysis; D046931:Microcystis / Q000235:genetics / Q000302:isolation & purification*; D009584:Nitrogen / Q000032:analysis; D010453:Peptide Synthases / Q000235:genetics; D010758:Phosphorus / Q000032:analysis; D010798:Phycocyanin / Q000235:genetics; D014873:Water Pollutants / Q000302:isolation & purification*; D014876:Water Pollution / Q000517:prevention & control; D060753:Water Quality
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D052998:Microcystins; D014873:Water Pollutants; D010798:Phycocyanin; D010758:Phosphorus; D010453:Peptide Synthases; D009584:Nitrogen