Use of benthic invertebrate community structure and the sediment quality triad to evaluate metal-contaminated sediment in the upper Clark Fork River, Montana

Environmental Toxicology and Chemistry
By: , and 

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Abstract

The upper Clark Fork River, above Flathead River, is contaminated with large amounts of As, Cd, Cu, Pb, Mn, and Zn ores from past mining activities. The contaminated area extends from the Butte and Anaconda area to at least 230 km downstream to Milltown Reservoir. Both the upper Clark Fork River and Milltown Reservoir have been designated as U.S. Environmental Protection Agency Superfund sites because of metal-contaminated bottom sediments. We evaluated the impacts of past mining activities on the Clark Fork River ecosystem using benthic invertebrate community assessment, residue chemistry, and toxicity testing. Oligochaeta and Chironomidae generally accounted for over 90% of the benthic invertebrate community in the soft sediment depositional areas. Taxa of Oligochaeta and Chironomidae were predominantly pollution tolerant. Higher numbers of Chironomidae genera were present at stations with higher concentrations of metals in sediment identified as toxic by the amphipod Hyalella azteca in 28-d exposures. Frequency of mouthpart deformities in genera of Chironomidae was low and did not correspond to concentrations of metals in sediment. Total abundance of organisms/m2 did not correspond to concentrations of metals in the sediment samples. Chemical analyses, laboratory toxicity tests, and benthic community evaluations all provide evidence of metal-induced degradation to aquatic communities in both the reservoir and the river. Using a weight-of-evidence approach-the Sediment Quality Triad - provided good concurrence among measures of benthic community structure, sediment chemistry, and laboratory toxicity.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Use of benthic invertebrate community structure and the sediment quality triad to evaluate metal-contaminated sediment in the upper Clark Fork River, Montana
Series title Environmental Toxicology and Chemistry
DOI 10.1002/etc.5620131213
Volume 13
Issue 12
Year Published 1994
Language English
Publisher Wiley
Contributing office(s) Columbia Environmental Research Center
Description 14 p.
First page 1999
Last page 2012
Country United States
State Montana
Other Geospatial Upper Clark Fork River