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Updated: Jun 17, 2026
Sampling, Sorting, and Characterizing Microplastics in Aquatic Environments with High Suspended Sediment Loads and Large Floating Debris
Published on: July 28, 2018
Distribution of selenium, mercury, and methylmercury in surficial Missouri River sediments
Brenda M Pracheil1, Daniel D Snow, Mark A Pegg
1School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583-0962, USA. bpracheil2@unl.edu
Abstract:
Sediment deposition into Lewis and Clark Lake, an impoundment of the Missouri River, has caused substantial storage capacity reductions. Current proposals to hydrologically flush sediment would disturb river and reservoir sediment that may contain heavy metals. We quantified existing concentrations of selenium (Se), mercury (Hg), and methylmercury (MeHg) in surficial sediments upstream of and in Lewis and Clark Lake. We found elevated levels of Se (range 0.12-9.62 microg/g) and Hg (range 0.021.55 microg/g) at several sites throughout the study area; however, few sites contained levels of MeHg above detection limits. Sites with highest MeHg concentrations were found in Lewis and Clark Lake and ranged from below detection limit to 0.79 ng/g. We conclude that further investigation of sediment-sequestered contaminants in Lewis and Clark Lake should be conducted.
