Large lakes provide a variety of ecological services to surrounding cities and communities. Many of these services are supported by ecological processes that are threatened by the increasing prevalence of cyanobacterial blooms which occur as aquatic ecosystems experience cultural eutrophication. Over the past 10 years, Lake Erie experienced cyanobacterial blooms of increasing severity and frequency, which have resulted in impaired drinking water for the surrounding communities. Cyanobacterial blooms may impact ecological processes that support other services, but many of these impacts have not been documented. Secondary production (production of primary consumers) is an important process that supports economically important higher trophic levels. Cyanobacterial blooms may influence secondary production because 1) cyanobacteria are a poor quality food resource and 2) cyanotoxins may be harmful to consumers. Over three years at 36 sites across the western basin of Lake Erie, we measured 3 indices of secondary production: growth of a native unionid mussel, the size of young-of-year dreissenid mussels, and the mass of colonizing animals on a Hester-Dendy sampler. These indices were related to models with and without cyanobacterial data to assess whether cyanobacteria are associated with variation in secondary production in the western basin of Lake Erie. The results suggest cyanobacterial abundance alone is only weakly associated with secondary production, but that cyanotoxins have a bigger effect on secondary production. Given recent summer’s high cyanobacteria abundance, this impact on secondary production has the potential to undermine Lake Erie’s ability to support important ecosystem services.

Large lakes provide a variety of ecological services to surrounding cities and communities. Many of these services are supported by ecological processes that are threatened by the increasing prevalence of cyanobacterial blooms which occur as aquatic ecosystems experience cultural eutrophication. Over the past 10 years, Lake Erie experienced cyanobacterial blooms of increasing severity and frequency, which have resulted in impaired drinking water for the surrounding communities. Cyanobacterial blooms may impact ecological processes that support other services, but many of these impacts have not been documented. Secondary production (production of primary consumers) is an important process that supports economically important higher trophic levels. Cyanobacterial blooms may influence secondary production because 1) cyanobacteria are a poor quality food resource and 2) cyanotoxins may be harmful to consumers. Over three years at 36 sites across the western basin of Lake Erie, we measured 3 indices of secondary production: growth of a native unionid mussel, the size of young-of-year dreissenid mussels, and the mass of colonizing animals on a Hester-Dendy sampler. These indices were related to models with and without cyanobacterial data to assess whether cyanobacteria are associated with variation in secondary production in the western basin of Lake Erie. The results suggest cyanobacterial abundance alone is only weakly associated with secondary production, but that cyanotoxins have a bigger effect on secondary production. Given recent summer’s high cyanobacteria abundance, this impact on secondary production has the potential to undermine Lake Erie’s ability to support important ecosystem services.

Within New Jersey’s Raritan Basin Water Supply Complex, multiple lakes and reservoirs with persistent and recurrent cyanobacterial harmful algal blooms (cyanoHABs) discharge water which ultimately travels downstream in surface water to drinking-water intakes. Cyanobacteria and other water-quality data were collected as part of a collaborative study among multiple agencies, including the U.S. Geological Survey (USGS) New Jersey Water Science Center (NJWSC), New Jersey Water Supply Authority, New Jersey Department of Environmental Protection, and Montclair State University to evaluate the spatial and temporal variability of cyanotoxin occurrence and potential production, persistence, and transport from lacustrine sources to downstream fluvial systems used as a drinking-water source in the Raritan Basin Water Supply Complex, New Jersey. An advanced monitoring strategy using a combination of solid phase adsorption toxin tracking (SPATT) passive samplers, discrete water-quality samples, and continuous monitoring instrumentation, were used to help gain insight on rapidly changing water-quality conditions that affect cyanotoxin production and transport. Eight discrete sampling locations were chosen based upon existing USGS streamflow-gaging stations as well as one site located on Spruce Run Reservoir. Twenty discrete sampling events were conducted across the 8 river sampling locations and 24 sampling events from the reservoir sampling location from August 2020 through August 2021; events occurred twice per month except from December 2020 to April 2021, when samples were collected once per month. Each sampling event was spread over two days, with upstream sites sampled on the first day and downstream sites sampled on the second day. This sampling method mimicked the natural order of streamflow. To meet study objectives, certain types of data were collected, including streamflow, discrete water quality and turbidity samples, water-quality field measurements (water temperature, pH, dissolved oxygen, and specific conductance), nutrients (ammonia, orthophosphate, nitrate plus nitrite, total phosphorus, and total nitrogen), chlorophyll-a, cyanobacterial genes (cyanobacteria 16S cyanobacterial ribosomal RNA, and cyanotoxin synthetase genes for microcystin, saxitoxin, anatoxin-a, and cylindrospermopsin), cyanotoxins (microcystin, anatoxin-a, and cylindrospermopsin), and phytoplankton.

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.

In cooperation with the Texas Commission on Environmental Quality (TCEQ), the U.S. Geological Survey (USGS) utilized various field and laboratory methods to determine the presence and concentration of cyanobacteria, cyanotoxins, and taste-and-odor compounds in Texas water bodies. This data release documents the results from water-quality samples collected from 41 water bodies in Texas during 2016–19. Both qualitative and quantitative field and laboratory methods were performed. Analyses included phytoplankton taxonomy, measurements of phytoplankton biomass, and concentrations of cyanotoxins, taste-and-odor compounds, and photosynthetic pigments. Water-quality samples were also collected to provide supporting data and document existing conditions. These supporting data included dissolved solids, major ions, nutrients, and organic carbon. The study began in water year 2016 (WY16). A water year is defined as the 12-month period from October 1 through September 30 and is designated by the calendar year in which it ends. During water year 2016 and 2017, water-quality samples were analyzed for total and dissolved cyanotoxin concentrations (anatoxin, cylindrospermopsin, domoic acid, microcystin [total and 10 congeners], nodularin, okadaic acid, and saxitoxin), taste-and-odor compounds (methylisoborneol [MIB] and geosmin), chlorophyll a, pheophytin a, major ions (calcium, chloride, fluoride, magnesium, potassium, silica, sodium, and sulfate), and nutrients (nitrogen, phosphorous, and multiple species of each nutrient). In water year 2018 (WY18), analyses of cyanobacterial- and cyanotoxin gene concentrations were added to the study. In water year 2019 (WY19), the study design further expanded to include In-Situ Aqua TROLL sensors to compare the field values with the EXO2 multiparameter sonde. Each reservoir had one sampling site with the exception of three reservoirs at the beginning of WY2016. At those three reservoirs, only selected water-quality field properties were measured on site at 1-2 sampling sites —there were no water-quality samples collected at these sites. At all other sampling sites, water-quality field properties were measured every foot of the water column until the irradiance was 1 percent of the irradiance measured at the surface of the water column. Subsequently, water-quality field properties were measured every five feet to the bottom of the water column. Three rapid-assessment field kits were used to determine semi-quantitative values of three cyanotoxins (anatoxin, cylindrospermopsin, and microcystin) at each sampling site. Chlorophyll-a and pheophytin-a were analyzed by the Trinity River Authority Central Laboratory in Dallas, Texas. Cyanobacterial and cyanotoxin genes were analyzed by the USGS Ohio Water Microbiology Laboratory in Columbus, Ohio. The USGS Organic Geochemistry Research Laboratory in Lawrence, Kansas analyzed for cyanotoxins and taste-and-odor compounds. PhycoTech, Inc. determined phytoplankton taxonomy and biomass. Engineering Performance Solutions in Jacksonville, Florida analyzed for MIB and geosmin. Samples were analyzed for nutrients and major ions by the USGS National Water Quality Laboratory in Denver, Colorado. Water-quality field properties (water temperature, dissolved-oxygen concentration, pH, specific conductance, turbidity, chlorophyll density, chlorophyll fluorescence, phycocyanin density, phycocyanin fluorescence, irradiance, and Secchi depth) were also measured at each sampling site. Water-quality field properties and water-quality constituents are commonly referred to as “parameters” by analytical laboratories, and laboratory terminology for the datasets described in this data release were retained.

In cooperation with the Texas Commission on Environmental Quality (TCEQ), the U.S. Geological Survey (USGS) used various field and laboratory methods to determine the presence and concentration of cyanobacteria, cyanotoxins, and taste-and-odor compounds in selected Texas water bodies. This data release documents the results from water-quality samples collected from 12 water bodies in Texas during water year 2020 (WY20) and 2021 (WY21). A water year is defined as the 12-month period from October 1 through September 30 and is designated by the calendar year in which it ends. Both qualitative and quantitative field and laboratory methods were performed. Analyses included phytoplankton taxonomy, measurements of phytoplankton biomass, and concentrations of cyanotoxins, taste-and-odor compounds, and photosynthetic pigments. Water-quality samples were also collected to provide supporting data and document existing conditions. These supporting data included dissolved solids, major ions, nutrients, and organic carbon. Water-quality samples were analyzed for total cyanotoxin concentrations (anatoxin, cylindrospermopsin, domoic acid, microcystin [total and 10 congeners], nodularin, okadaic acid, and saxitoxin), taste-and-odor compound concentration (2-Methylisoborneo [MIB] and geosmin), chlorophyll a, pheophytin a, major ions (calcium, chloride, fluoride, magnesium, potassium, silica, sodium, and sulfate), and nutrients (nitrogen, phosphorous, and multiple species of each nutrient). Analyses of cyanobacterial and cyanotoxin gene concentrations are included. An In-Situ Aqua TROLL multiparameter sonde was deployed concurrently with a YSI EXO2 multiparameter sonde to provide two sets of field values that can be compared. Each reservoir had one sampling site. At each site, depth-integrated samples were collected using a peristaltic pump integrating through the photic zone. The photic zone is the depth when measured irradiance is 1 percent of the irradiance measured at the surface of the water column. Water-quality field properties were measured using the multiparameter sondes at 1-foot intervals in the water column through the photic zone (the upper layer of a water body where there is sufficient sunlight penetration to support photosynthesis), then at 5-foot intervals to the bottom of the water column. Three rapid-assessment field kits were used to determine semi-quantitative values of three cyanotoxins (anatoxin, cylindrospermopsin, and microcystin) at each sampling site. Chlorophyll-a and pheophytin-a were analyzed by the Trinity River Authority Central Laboratory in Dallas, Texas. Cyanobacterial and cyanotoxin genes were analyzed by the USGS Ohio Water Microbiology Laboratory in Columbus, Ohio. The USGS Organic Geochemistry Research Laboratory in Lawrence, Kansas analyzed for cyanotoxins and taste-and-odor compounds. PhycoTech, Inc. in St. Joseph, Michigan analyzed phytoplankton taxonomy and biomass. Taxonomic names within this data release are from PhycoTech's taxonomic naming convention and may differ from the taxonomic names listed in the Integrated Taxonomic Information System database (ITIS, 2022). Engineering Performance Solutions in Jacksonville, Florida analyzed for MIB and geosmin. Samples were analyzed for suspended solids, nutrients, and major ions by the USGS National Water Quality Laboratory (NWQL) in Denver, Colorado. Water-quality field properties (water temperature, dissolved-oxygen concentration, pH, specific conductance, turbidity, chlorophyll florescence (RFU & density), phycocyanin florescence (RFU & density), irradiance, and Secchi depth) were also measured at each sampling site. NWQL terms "parameter codes" and "parameter descriptions" were retained in the water-quality dataset when referring to water-quality field properties and constituents.

In cooperation with the Texas Commission on Environmental Quality (TCEQ), the U.S. Geological Survey (USGS) utilized various field and laboratory methods to determine the presence and concentration of cyanobacteria, cyanotoxins, and taste-and-odor compounds in Texas water bodies. This data release documents the results from water-quality samples collected from 41 water bodies in Texas during 2016–19. Both qualitative and quantitative field and laboratory methods were performed. Analyses included phytoplankton taxonomy, measurements of phytoplankton biomass, and concentrations of cyanotoxins, taste-and-odor compounds, and photosynthetic pigments. Water-quality samples were also collected to provide supporting data and document existing conditions. These supporting data included dissolved solids, major ions, nutrients, and organic carbon. The study began in water year 2016 (WY16). A water year is defined as the 12-month period from October 1 through September 30 and is designated by the calendar year in which it ends. During water year 2016 and 2017, water-quality samples were analyzed for total and dissolved cyanotoxin concentrations (anatoxin, cylindrospermopsin, domoic acid, microcystin [total and 10 congeners], nodularin, okadaic acid, and saxitoxin), taste-and-odor compounds (methylisoborneol [MIB] and geosmin), chlorophyll a, pheophytin a, major ions (calcium, chloride, fluoride, magnesium, potassium, silica, sodium, and sulfate), and nutrients (nitrogen, phosphorous, and multiple species of each nutrient). In water year 2018 (WY18), analyses of cyanobacterial- and cyanotoxin gene concentrations were added to the study. In water year 2019 (WY19), the study design further expanded to include In-Situ Aqua TROLL sensors to compare the field values with the EXO2 multiparameter sonde. Each reservoir had one sampling site with the exception of three reservoirs at the beginning of WY2016. At those three reservoirs, only selected water-quality field properties were measured on site at 1-2 sampling sites —there were no water-quality samples collected at these sites. At all other sampling sites, water-quality field properties were measured every foot of the water column until the irradiance was 1 percent of the irradiance measured at the surface of the water column. Subsequently, water-quality field properties were measured every five feet to the bottom of the water column. Three rapid-assessment field kits were used to determine semi-quantitative values of three cyanotoxins (anatoxin, cylindrospermopsin, and microcystin) at each sampling site. Chlorophyll-a and pheophytin-a were analyzed by the Trinity River Authority Central Laboratory in Dallas, Texas. Cyanobacterial and cyanotoxin genes were analyzed by the USGS Ohio Water Microbiology Laboratory in Columbus, Ohio. The USGS Organic Geochemistry Research Laboratory in Lawrence, Kansas analyzed for cyanotoxins and taste-and-odor compounds. PhycoTech, Inc. determined phytoplankton taxonomy and biomass. Engineering Performance Solutions in Jacksonville, Florida analyzed for MIB and geosmin. Samples were analyzed for nutrients and major ions by the USGS National Water Quality Laboratory in Denver, Colorado. Water-quality field properties (water temperature, dissolved-oxygen concentration, pH, specific conductance, turbidity, chlorophyll density, chlorophyll fluorescence, phycocyanin density, phycocyanin fluorescence, irradiance, and Secchi depth) were also measured at each sampling site. Water-quality field properties and water-quality constituents are commonly referred to as “parameters” by analytical laboratories, and laboratory terminology for the datasets described in this data release were retained.

In cooperation with the Texas Commission on Environmental Quality (TCEQ), the U.S. Geological Survey (USGS) used various field and laboratory methods to determine the presence and concentration of cyanobacteria, cyanotoxins, and taste-and-odor compounds in selected Texas water bodies. This data release documents the results from water-quality samples collected from 12 water bodies in Texas during water year 2020 (WY20) and 2021 (WY21). A water year is defined as the 12-month period from October 1 through September 30 and is designated by the calendar year in which it ends. Both qualitative and quantitative field and laboratory methods were performed. Analyses included phytoplankton taxonomy, measurements of phytoplankton biomass, and concentrations of cyanotoxins, taste-and-odor compounds, and photosynthetic pigments. Water-quality samples were also collected to provide supporting data and document existing conditions. These supporting data included dissolved solids, major ions, nutrients, and organic carbon. Water-quality samples were analyzed for total cyanotoxin concentrations (anatoxin, cylindrospermopsin, domoic acid, microcystin [total and 10 congeners], nodularin, okadaic acid, and saxitoxin), taste-and-odor compound concentration (2-Methylisoborneo [MIB] and geosmin), chlorophyll a, pheophytin a, major ions (calcium, chloride, fluoride, magnesium, potassium, silica, sodium, and sulfate), and nutrients (nitrogen, phosphorous, and multiple species of each nutrient). Analyses of cyanobacterial and cyanotoxin gene concentrations are included. An In-Situ Aqua TROLL multiparameter sonde was deployed concurrently with a YSI EXO2 multiparameter sonde to provide two sets of field values that can be compared. Each reservoir had one sampling site. At each site, depth-integrated samples were collected using a peristaltic pump integrating through the photic zone. The photic zone is the depth when measured irradiance is 1 percent of the irradiance measured at the surface of the water column. Water-quality field properties were measured using the multiparameter sondes at 1-foot intervals in the water column through the photic zone (the upper layer of a water body where there is sufficient sunlight penetration to support photosynthesis), then at 5-foot intervals to the bottom of the water column. Three rapid-assessment field kits were used to determine semi-quantitative values of three cyanotoxins (anatoxin, cylindrospermopsin, and microcystin) at each sampling site. Chlorophyll-a and pheophytin-a were analyzed by the Trinity River Authority Central Laboratory in Dallas, Texas. Cyanobacterial and cyanotoxin genes were analyzed by the USGS Ohio Water Microbiology Laboratory in Columbus, Ohio. The USGS Organic Geochemistry Research Laboratory in Lawrence, Kansas analyzed for cyanotoxins and taste-and-odor compounds. PhycoTech, Inc. in St. Joseph, Michigan analyzed phytoplankton taxonomy and biomass. Taxonomic names within this data release are from PhycoTech's taxonomic naming convention and may differ from the taxonomic names listed in the Integrated Taxonomic Information System database (ITIS, 2022). Engineering Performance Solutions in Jacksonville, Florida analyzed for MIB and geosmin. Samples were analyzed for suspended solids, nutrients, and major ions by the USGS National Water Quality Laboratory (NWQL) in Denver, Colorado. Water-quality field properties (water temperature, dissolved-oxygen concentration, pH, specific conductance, turbidity, chlorophyll florescence (RFU & density), phycocyanin florescence (RFU & density), irradiance, and Secchi depth) were also measured at each sampling site. NWQL terms "parameter codes" and "parameter descriptions" were retained in the water-quality dataset when referring to water-quality field properties and constituents.

In cooperation with the Texas Commission on Environmental Quality (TCEQ), the U.S. Geological Survey (USGS) used various field and laboratory methods to determine the presence and concentration of cyanobacteria, cyanotoxins, and taste-and-odor compounds in selected Texas water bodies. This data release documents the results from water-quality samples collected from 12 water bodies in Texas during water year 2020 (WY20) and 2021 (WY21). A water year is defined as the 12-month period from October 1 through September 30 and is designated by the calendar year in which it ends. Both qualitative and quantitative field and laboratory methods were performed. Analyses included phytoplankton taxonomy, measurements of phytoplankton biomass, and concentrations of cyanotoxins, taste-and-odor compounds, and photosynthetic pigments. Water-quality samples were also collected to provide supporting data and document existing conditions. These supporting data included dissolved solids, major ions, nutrients, and organic carbon. Water-quality samples were analyzed for total cyanotoxin concentrations (anatoxin, cylindrospermopsin, domoic acid, microcystin [total and 10 congeners], nodularin, okadaic acid, and saxitoxin), taste-and-odor compound concentration (2-Methylisoborneo [MIB] and geosmin), chlorophyll a, pheophytin a, major ions (calcium, chloride, fluoride, magnesium, potassium, silica, sodium, and sulfate), and nutrients (nitrogen, phosphorous, and multiple species of each nutrient). Analyses of cyanobacterial and cyanotoxin gene concentrations are included. An In-Situ Aqua TROLL multiparameter sonde was deployed concurrently with a YSI EXO2 multiparameter sonde to provide two sets of field values that can be compared. Each reservoir had one sampling site. At each site, depth-integrated samples were collected using a peristaltic pump integrating through the photic zone. The photic zone is the depth when measured irradiance is 1 percent of the irradiance measured at the surface of the water column. Water-quality field properties were measured using the multiparameter sondes at 1-foot intervals in the water column through the photic zone (the upper layer of a water body where there is sufficient sunlight penetration to support photosynthesis), then at 5-foot intervals to the bottom of the water column. Three rapid-assessment field kits were used to determine semi-quantitative values of three cyanotoxins (anatoxin, cylindrospermopsin, and microcystin) at each sampling site. Chlorophyll-a and pheophytin-a were analyzed by the Trinity River Authority Central Laboratory in Dallas, Texas. Cyanobacterial and cyanotoxin genes were analyzed by the USGS Ohio Water Microbiology Laboratory in Columbus, Ohio. The USGS Organic Geochemistry Research Laboratory in Lawrence, Kansas analyzed for cyanotoxins and taste-and-odor compounds. PhycoTech, Inc. in St. Joseph, Michigan analyzed phytoplankton taxonomy and biomass. Taxonomic names within this data release are from PhycoTech's taxonomic naming convention and may differ from the taxonomic names listed in the Integrated Taxonomic Information System database (ITIS, 2022). Engineering Performance Solutions in Jacksonville, Florida analyzed for MIB and geosmin. Samples were analyzed for suspended solids, nutrients, and major ions by the USGS National Water Quality Laboratory (NWQL) in Denver, Colorado. Water-quality field properties (water temperature, dissolved-oxygen concentration, pH, specific conductance, turbidity, chlorophyll florescence (RFU & density), phycocyanin florescence (RFU & density), irradiance, and Secchi depth) were also measured at each sampling site. NWQL terms "parameter codes" and "parameter descriptions" were retained in the water-quality dataset when referring to water-quality field properties and constituents.

This U.S. Geological Survey (USGS) data release contains results of a paleolimnological analysis of cyanobacteria occurrence in Moreau and Brant Lake in the Adirondack Region of New York based on a single sediment core collected in each lake in September, 2022. The data types include 1) lake sediment core data for lead-210 age dating, 2) akinete classification and enumeration data, 3) percent Carbon and percent Nitrogen data, 4) qPCR data for general cyanobacteria 16S and species-specific 16S genes (Dolichospermum, Microcystis, Planktothrix, and Gloeotrichia), 5) algal pigment data, 6) fluorescence characteristics of Water Extractable Organic Matter and stable isotopes. All data are reported as raw calculated values and are not rounded to USGS significant figures.