title: Estimating microcystin levels at recreational sites in western Lake Erie and Ohio.
abstract: Cyanobacterial harmful algal blooms (cyanoHABs) and associated toxins, such as microcystin, are a major global water-quality issue. Water-resource managers need tools to quickly predict when and where toxin-producing cyanoHABs will occur. This could be done by using site-specific models that estimate the potential for elevated toxin concentrations that cause public health concerns. With this study, samples were collected at three Ohio lakes to identify environmental and water-quality factors to develop linear-regression models to estimate microcystin levels. Measures of the algal community (phycocyanin, cyanobacterial biovolume, and cyanobacterial gene concentrations) and pH were most strongly correlated with microcystin concentrations. Cyanobacterial genes were quantified for general cyanobacteria, general Microcystis and Dolichospermum, and for microcystin synthetase (mcyE) for Microcystis, Dolichospermum, and Planktothrix. For phycocyanin, the relations were different between sites and were different between hand-held measurements on-site and nearby continuous monitor measurements for the same site. Continuous measurements of parameters such as phycocyanin, pH, and temperature over multiple days showed the highest correlations to microcystin concentrations. The development of models with high R2values (0.81-0.90), sensitivities (92%), and specificities (100%) for estimating microcystin concentrations above or below the Ohio Recreational Public Health Advisory level of 6μgL-1was demonstrated for one site; these statistics may change as more data are collected in subsequent years. This study showed that models could be developed for estimates of exceeding a microcystin threshold concentration at a recreational freshwater lake site, with potential to expand their use to provide relevant public health information to water resource managers and the public for both recreational and drinking waters.
authors.affiliation: U.S. Geological Survey, Ohio Water Science Center, 6480 Doubletree Avenue, Columbus, OH 43229, USA. Electronic address: dsfrancy@usgs.gov.
authors.forename: Donna S
authors.initials: DS
authors.lastname: Francy
authors.affiliation: U.S. Geological Survey, Ohio Water Science Center, 6480 Doubletree Avenue, Columbus, OH 43229, USA.
authors.forename: Amie M G
authors.initials: AM
authors.lastname: Brady
authors.affiliation: U.S. Geological Survey, Ohio Water Science Center, 6480 Doubletree Avenue, Columbus, OH 43229, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Ecker
authors.affiliation: U.S. Geological Survey, Kansas Water Science Center, 4821 Quail Crest Place, Lawrence, KS 66049, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Graham
authors.affiliation: U.S. Geological Survey, Ohio Water Science Center, 6480 Doubletree Avenue, Columbus, OH 43229, USA.
authors.forename: Erin A
authors.initials: EA
authors.lastname: Stelzer
authors.affiliation: University of Toledo, Lake Erie Center, 6200 Bay Shore Road, Oregon, OH 43616, USA.
authors.forename: Pamela
authors.initials: P
authors.lastname: Struffolino
authors.affiliation: University of Toledo, Lake Erie Center, 6200 Bay Shore Road, Oregon, OH 43616, USA.
authors.forename: Daryl F
authors.initials: DF
authors.lastname: Dwyer
authors.affiliation: U.S. Geological Survey, Kansas Water Science Center, 4821 Quail Crest Place, Lawrence, KS 66049, USA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Loftin
mesh_terms: D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics*; D004784:Environmental Monitoring / Q000379:methods*; D057097:Harmful Algal Bloom; D060106:Lakes / Q000737:chemistry*; D052998:Microcystins / Q000032:analysis* / Q000235:genetics*; D046931:Microcystis / Q000201:enzymology / Q000235:genetics*; D009820:Ohio; D010453:Peptide Synthases / Q000235:genetics
chemical_list: D052998:Microcystins; D010453:Peptide Synthases
keywords: Cyanobacteria; Microcystin; Models