With increasing concerns about freshwater cyanobacteria blooms, there is a need to identify which waterbodies are at risk for developing these blooms, especially those that produce cyanotoxins. To address this concern, we developed spatial statistical models using the US National Lakes Assessment, a survey with over 3,000 spring and summer observations of cyanobacteria abundance and microcystin concentration in lakes across the conterminous US. We combined these observations with other nationally available data to model which lake and watershed factors best explain the presence of harmful cyanobacterial blooms. We then used these models to estimate the cyanobacteria abundance and probability of microcystin detection in 124,500 lakes across the CONUS. This dataset includes the compiled data used to generate the models and the dataset used to generate prediction for a much larger population of lakes. The data package includes two tabular data files, two tabular metadata files, and one methods document.

This dataset is the evaluation of eutrophication in rivers based on quantitative polymerase chain reactions (qPCRs) of phytoplankton. The qPCR data of 2017, 2018, and 2019 are included in the current dataset. The 2917, 2018, and 2019 physicochemical and biological data generated by the USGS are also included in the current file. This dataset is associated with the following publication: Zhang, C., K. McIntosh, N. Sienkiewicz, E.A. Stelzer, J.L. Graham, and J. Lu. qPCR-based phytoplankton abundance and chlorophyll a: A multi-year study in twelve large freshwater rivers across the United States. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, NETHERLANDS, 954: 175067, (2024).

Cyanobacteria are common in inland water bodies. Many strains are known to produce potent toxins (cyanotoxins) which can impact human and animal health in sufficient concentrations. Lake Elsinore and Canyon Lake are two impaired lakes in California with frequent cyanobacteria blooms that are not monitored for toxin production. These data document the liquid chromatography triple quadrupole mass spectrometry (LC/MS/MS) results for 21 cyanotoxins and algal toxins in 13 cyanobacteria samples collected during bloom events from Lake Elsinore and Canyon Lake (CA, USA) in July, August, and September 2016.

The dataset including qPCR, phytoplankton counts and water quality parameters are used for the evaluation of phytoplankton identification and quantification and assessment of eutrophication. This dataset is associated with the following publication: Zhang, C., K. McIntosh, N. Sienkiewicz, E.A. Stelzer, J.L. Graham, and J. Lu. Using cyanobacteria and other phytoplankton to assess trophic conditions: A qPCR-based, multi-year study in twelve large rivers across the United States. WATER RESEARCH. Elsevier Science Ltd, New York, NY, USA, 235: 119679, (2023).

qPCR and RT-qPCR. This dataset is associated with the following publication: Lu, J., I. Struewing, L. Wymer, D. Tettenhorst, J. Shoemaker, and J. Allen. Use of qPCR and RT-qPCR for monitoring variations of microcystin producers and as an early warning system to predict toxin production in an Ohio inland lake. WATER RESEARCH. Elsevier Science Ltd, New York, NY, USA, 170: 115262, (2020).

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.

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.

This data set includes qPCR data for the microcystin producing planktothrix (mcyApla) gene and the microcystin producing cyanobacteria (Hep) gene for samples collected from Grand Lake St. Marys and downstream waterways in 2023.

Data release including concentrations of cyanotoxins and phytoplankton community composition data for water samples collected from the Lake Mattamuskeet National Wildlife Refuge in North Carolina during 2015.