Search USGS⌕ Search
Home/Archive/USGS

USGS · 70030466

Spatial and temporal dynamics of microcystin in a Missouri reservoir

J.L. Graham·J.R. Jones·S.B. Jones·T.E. Clevenger
View original source ↗Export metadata ↓

Abstract

Environmental factors associated with spatiotemporal variation of microcystin (MC) in Mozingo Lake, a Missouri reservoir, were studied during summer 2001, and annual MC trends were characterized from May 2001-May 2002. MC increased during summer, ranging from 20 to 1220 ng/L. Seasonal patterns in MC corresponded with chlorophyll>35 ??m (Net Chl) and cyanobacterial biovolume associated with increased dominance by Microcystis and Anabaena. MC showed strong negative correlations with dissolved nitrogen (r=-0.95) and cations (r=-0.98), and strong positive correlations with Net Chl (r=0.91). Once the lake stratified, MC and Net Chl remained uniform throughout the photic zone and decreased significantly (p<0.05) in the aphotic zone. Field experiments indicated MC did not change independently of Net Chl in response to decreased light or increased nutrients; however, enclosure effects may have substantially influenced experimental results. Mozingo Lake MC was tightly coupled with seasonal lake processes, including stratification and nutrient loss from the epilimnion, and cyanobacterial community composition, abundance and distribution in the water column. MC was detected in all monthly samples suggesting the potential for problems associated with MC exists year round, but peaks in early fall presented the greatest concern in Mozingo Lake. ?? Copyright by the North American Lake Management Society 2006.

Explore related subjects

Lake and Reservoir ManagementArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J.L. Graham, J.R. Jones, S.B. Jones, T.E. Clevenger. 2006. Spatial and temporal dynamics of microcystin in a Missouri reservoir. https://pubs.usgs.gov/publication/70030466

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Integration of multiple methodologies as an indicator of cyanotoxin occurrence in Owasco Lake, New York

Cyanobacteria harmful algal blooms (cyanoHABs) pose environmental and public health risks in lakes with highly variable cyanobacteria and cyanotoxin distributions. We compared results from 3 independent monitoring programs to characterize spatiotemporal patterns in the stratified, mesotrophic Owasco Lake, one of the Finger Lakes in New York. Biweekly open-water samples collected at multiple depths in 2019 and 2020 were analyzed for phytoplankton community composition, chlorophyll a , cyanotoxins, and cyanotoxin synthetase gene targets. These data were examined alongside shoreline reports and microcystin measurements from 2 public water supply intakes. Open-water cyanobacterial biovolume was generally low but increased sharply during late summer Microcystis -dominated events. Microcystin was the only cyanotoxin detected and occurred infrequently; detections at drinking water intakes coincided with or followed open-water and shoreline bloom reports. The mcyE gene target was detected weeks before microscopy or cyanotoxin analyses indicated cyanoHAB development and persisted later. Relations among cyanobacterial biovolume, chlorophyll a , gene targets, and cyanotoxins were generally weak (the relations explained small proportions of the variability in the response variables), indicating ephemeral bloom dynamics and low overall biomass. Comparison across programs revealed a consistent sequence: early mcyE detection, shoreline bloom reports, open-water increases in cyanobacteria, sparse microcystin detections, and then detections at drinking water intakes. These findings demonstrate how genetic, chemical, and visual approaches can be combined across depths and monitoring entities. Routine genetic analyses in open water may provide early indications of toxigenic potential, support tiered monitoring frameworks, and inform management of recreational and drinking water risks in large lakes.

New York↗
USGS2025

Water quality-based risk assessment for zebra mussel establishment: A case study of single- and multiple-factor methods in northern temperate lakes

Most previous research has used an individual water quality parameter, such as calcium, to predict likelihood of zebra mussel establishment in lakes; we employed two multiple-factor methods, our own susceptibility index for zebra mussels in lakes (SIZL) and aragonite saturation state, to evaluate the risk of mussel establishment. Thirty sites in Voyageurs National Park (VNP) were sampled in 2023 for water quality conditions, including those that play a key role in mussel survivability. These results were combined with existing data sets to determine which lakes, and which locations within the larger lakes, are at greatest risk for zebra mussel establishment. Results for VNP indicate that physical lake characteristics and water quality conditions (both single- and multiple-factor methods) put the large, interconnected lakes in VNP at greater risk of zebra mussel establishment than the smaller interior lakes. All sampled interior lakes had alkalinity and calcium concentrations below thresholds conducive to zebra mussel establishment, although Mukooda and O’Leary lakes were identified as the most at-risk interior lakes. The area in the large lakes most at risk was Sullivan Bay in Kabetogama Lake, where water quality conditions were found to be conducive to zebra mussel establishment. Results from this study could be used by resource managers to focus additional inspections, decontaminations, and regulations to protect the most at-risk lakes. These multiple-factor methods may be useful in determining the risk of zebra mussel infestation in other water bodies.

Minnesota↗
USGS2025

Geochemical assessment of the suitability of converting a coal-fired power plant reservoir to a drinking-water reservoir

There is an increasing need for additional water storage in the United States, especially in arid regions. Alternatives like decommissioned power plant raw-water reservoirs would be cheaper to use than creating new reservoirs; however, the biogeochemical pollution risk of these reservoirs is not well understood. The San Juan Generating Station power plant and the associated reservoir will be used as a sediment-settling basin to store drinking water. To evaluate whether the reservoir is appropriate for this use, inorganic and organic constituents of concern were measured in reservoir sediment cores, pore water, and reservoir water in 2020. Forty-six percent of sediment arsenic concentrations measured in core subsamples (8 to 12 mg/kg) were slightly above the New Mexico residential cancer threshold for soil of 7.07 mg/kg. One sediment sample contained elevated total barium concentrations (6020 mg/kg). The organic compounds analyzed were either below detection limits or below regulatory thresholds. Reservoir water had one sample with arsenic greater than the drinking water standard (10 µg/L). Overall, the reservoir sediment inorganic and organic analyte concentrations are within acceptable ranges. The few samples that have elevated concentrations are not of a sufficient magnitude that dilution and/or treatment processes would preclude the use of the reservoir for water storage. Our findings show potential for use of former coal power station raw-water reservoirs as drinking-water reservoirs after plant closure.

New Mexico↗