Measured concentrations in octanol-water phase partitioning of microcystin congeners. This dataset is associated with the following publication: McCord, J., J. Lang, D. Hill, M. Strynar, and N. Chernoff. pH dependent octanol–water partitioning coefficients of microcystin congeners. JOURNAL OF WATER AND HEALTH. IWA Publishing, London, UK, 16(3): 340-345, (2018).

From 2017-2019, the Upper Midwest Environmental Sciences Center (UMESC) analyzed microcystin concentrations in samples collected from three different studies. The first study was on the movement and distribution of invasive carp (Bighead Carp, Silver Carp, Grass Carp) in the upper Mississippi River between lock and dam 16 and lock and dam 19. Samples were collected from May through October of 2017 and 2018 from backwaters, impounded areas and main channel areas in this reach of the Mississippi River. The second study was a nutrient and metal amendment study performed on natural phytoplankton communities from Lake Erie and Lake Michigan. This was a laboratory study where natural phytoplankton communities were incubated for 72 hours with amendments of ammonium, phosphate and metals (iron, zinc, molybdenum, nickel and manganese). After 72 hours, communities were sampled for microcystin concentration (among other metrics not reported here). The third study was a nutrient diffusing substrate study, where periphyton were grown on suspended substrates that leached nutrients or metals. After two weeks of deployment periphyton was collected from the substrates, diluted in purified water and then analyzed for microcystin concentration. Microcystin concentrations for all experiments were estimated using enzyme-linked immunosorbent assay (ELISA) test kits. We used a Bayesian method to calibrate the absorbance data from the kit and report here on both the microcystin concentrations of the samples analyzed, but also report the raw absorbance data from both samples and calibration standards so that others could recreate the microcystin analysis using other methods if they so choose.

Water samples were collected by charter boat captains and Stone Lab scientists in order to track the water quality of Lake Erie. Samples were analyzed for chlorophyll a (an indicator of algae biomass), microcystins (a group of toxins produced by cyanobacteria), total phosphorus and nitrogen (indicators of maximum biomass potential), dissolved nitrate, phosphate, and silicate (nutrients available for algae), and total suspended solids (mass of all particulates in the water). These data are available in .xlsx format.

In 2015-2018, the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency Great Lakes Restoration Initiative investigated the biodegradation of microcystins in source waters and sand filters from drinking-water plants in the Western Lake Erie Basin. Four source waters and three sand filtrate samples were collected from the intakes and sand filters of Lake Erie drinking-water plants and transported to the USGS Ohio Water Microbiology Laboratory, where investigators set up microcosms to enrich for and identify indigenous bacteria capable of degrading microcystins. Quality control samples were set up in the microcosms to check analyses and included positive controls, negative controls, and replicates. Microcystin biodegradation was quantified by the disappearance of the toxin as compared to control cultures in microcosm and microplate experiments, and by the presence of a gene within microcystin-degrading bacteria that encodes for an enzyme involved in the initial steps of biodegradation. Bacteria were isolated from microcosms enriched with microcystin-LR (MC-LR) and MC-LR concentrations were measured over time by ELISA (table 1). Isolates were selected from the microcosm experiments for further growth testing in microplate experiments with various enrichment media and MC-LR over 96 hours (table 2). Biofilm formation potential for the isolates were also measured and data is shown in table 3. Isolate absorbances of ten potential microcystin degraders were incubated in a microplate with MC-LR as the sole carbon source (table 4) and concentrations of MC-LR in microplate wells were measured over time (table 5).

Physical and serum chemistry effects in mice due to a single oral dose of ten microcystin congeners at a variety of dose levels to determine health effects and a no observable effect level. This dataset is associated with the following publications: Chernoff, N. Comparative toxicology of microcystin congeners. U.S. Environmental Protection Agency, Washington, DC, USA. Chernoff, N., D. Hill, J. Schmid, J. Lang, T. Le, A. Farthing, and H. Huang. The comparative toxicity of ten microcystin congeners administered orally to mice: Clinical effects and organ toxicity.. Toxins. MDPI AG, Basel, SWITZERLAND, 12(6): 403, (2020). Chernoff, N., D. Hill, J. Schmid, J. Lang, A. Farthing, and H. Huang. Dose-response study of microcystin congeners MCLR, MCLA, MCLY, MCRR, and MCYR administered orally to mice. Toxins. MDPI AG, Basel, SWITZERLAND, 13(2): 86, (2021).

Multiple linear regression models were developed using data collected in 2016 and 2017 from three recurring bloom sites in Kabetogama Lake in northern Minnesota. These models were developed to predict concentrations of cyanotoxins (anatoxin-a, microcystin, and saxitoxin) that occur within the blooms. Virtual Beach software (version 3.0.6) was used to develop four models: two cyanotoxin mixture (MIX) models and two microcystin (MC) models. Models include those using readily available environmental variables (for example, wind speed and specific conductance) and those using additional comprehensive variables (based on laboratory analyses). Many of the independent variables were averages over a certain time period prior to a sample date, whereas other independent variables were lagged between 4 and 8 days. Funding for this work was provided by the U.S Geological Survey – National Park Service Partnership and the U.S. Geological Survey Environmental Health Program (Toxic Substance Hydrology and Contaminant Biology). The resulting model equations and final datasets are included in this data release while an associated child item model archive includes all the files needed to run and develop these VB models.

Data from NLA 2012 was used to assess biovolume results for cyanobacteria (phytoplankton) in relation to both landscape and in lake factors. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.

Data from NLA 2012 was used to assess biovolume results for cyanobacteria (phytoplankton) in relation to both landscape and in lake factors. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.

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(1) qPCR and RT-qPCR for cyanotoxin producing genes, and (2) some water quality parameters. This dataset is associated with the following publication: Duan, X., C. Zhang, I. Struewing, X. Li, H. Allen, and J. Lu. Cyanotoxin-encoding genes as powerful predictors of cyanotoxin production during harmful cyanobacterial blooms in an inland freshwater lake: Evaluating a novel early-warning system. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, NETHERLANDS, 830: 154568, (2022).