Theresa Presser (Former Employee)

The Kootenai River Watershed is an international resource cooperatively managed by the U.S., Canada, and Tribal governments. In recent years, coal mining in the Canadian portion of the watershed has resulted in elevated concentrations of several constituents, including selenium, nitrate, and sulfate downstream (Storb et al., 2023). At increased levels, these mining byproducts can affect water...

This case-study of selenium pollution of Lake Koocanusa from coal mining in the upper Elk and Fording River watersheds relates to an overall goal of linking geologic source selenium dynamics to hydrological, biochemical, and ecological selenium dynamics. This type of approach enables a realistic understanding of the causes of uncertainty (for example, management alternatives for upstream selenium...

The sources, biogeochemistry, and ecotoxicology of selenium (Se) combine to produce a widespread potential for ecological risk such as deformities in birds and fish. Linking the understanding of source characteristics to a mechanistic, biodynamic dietary model of Se exposure on an ecosystem-scale improves the prediction of Se effects and its potential remediation.

Environmental sources of selenium (Se) such as from organic-enriched sedimentary deposits are geologic in nature and thus can occur on regional scales. A constructed map of the global distribution of Se source rocks informs potential areas of reconnaissance for modeling of Se risk including the phosphate deposits of southeastern Idaho and the coals of Appalachia.

Adverse effects of selenium (Se) on fish and waterfowl in wetlands receiving agricultural drainage occurred in the 1980s in the San Joaquin Valley of California. The identified mechanisms of Se enrichment helped resolve Se toxicity problems associated with irrigated agriculture in the arid West. Bioaccumulation of Se in ancient marine sediments is postulated as a primary pathway in source rocks.

The San Francisco Bay-Delta receives selenium (Se) internally from oil refineries and externally through riverine agricultural discharges. Predator species considered at risk from Se consume the estuary’s dominant bivalve, C. amurensis, an efficient bioaccumulator of Se. Modeling predicts site-specific ecological risk and derives a range of protective Se concentrations for use by decision-makers.

Selenium (Se) as a contaminant of ecosystems is bioaccumulative and causes reproductive effects in fish and wildlife. Ecosystem-scale Se modeling predicts Se bioaccumulation based on dietary biodynamics within site-specific food webs. The model can be used to forecast Se toxicity under different management or regulatory proposals or to translate a tissue guideline to a dissolved guideline.