Description |
iv, 8 pages : digital, PDF file. |
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text txt rdacontent |
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unmediated n rdamedia |
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volume nc rdacarrier |
Series |
Circular ; 1301 |
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U.S. Geological Survey circular ; 1301.
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Note |
"Prepared in cooperation with the U.S. Environmental Protection Agency." |
System Details |
System requirements: PDF reader. |
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Mode of access: World Wide Web from the USGS web site. Address as of 7/17/08: http://pubs.usgs.gov/circ/2006/1301/pdf/circ%5F1301.pdf; current access available via PURL. |
Note |
Title from Web page (viewed on Sept. 28, 2007). |
Bibliography |
Includes bibliographical references (page 8). |
Summary |
"Median suspended-sediment concentrations in the lower Missouri River appear to have decreased by at least 70 to 80 percent from predevelopment conditions, although two semiquantitative sediment-settling observations made by William Clark and Edward Harris indicate even larger reductions in maximum concentrations. Regardless of the amount of reliability that might be ascribed to the Clark and Harris measurements, the decrease in suspended-sediment concentrations and increase in water clarity of the Missouri River is remarkable. Most of this decrease occurred after the closure of dams and massive bank stabilization activities that occured in the 1950s and 1960s. The ecological change that may have resulted from the decrease in suspended-sediment and turbidity has not been documented. However, numerous ecological changes can be postulated from fundamental principles of aquatic ecology (Horne and Goldman, 1994). For example, the greater range in velocities likely resulted in a greater range in turbidity and a greater variety of fish habitat. Also, increased water clarity may permit algal photosynthesis at low river stages providing a new energy source for the food chain and a niche for nonnative planktivorus fish. Increased water clarity should benefit sight-feeding fish, perhaps at the expense of native fish such as catfish, drum, and the endangered pallid sturgeon, that need little light to find food. Thus, the top end of the food chain also may be altered with a potential trophic cascade that could substantially alter the food chain and populations of many species. Conversely, drinking-water suppliers and other users who must remove river sediments benefit from the decrease in suspended material"--Conclusions and implications. |
Subject |
Sediment transport -- Missouri River.
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River engineering -- Environmental aspects -- Missouri River Watershed.
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River engineering -- Environmental aspects.
(OCoLC)fst01098286
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Sediment transport. (OCoLC)fst01110959
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Missouri River. (OCoLC)fst01240244
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Missouri River Watershed. (OCoLC)fst01264793
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Genre/Form |
Electronic books.
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Added Author |
Geological Survey (U.S.)
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Other Form: |
Blevins, Dale W. Response of suspended sediment, turbidity, and velocity to historical alterations of the Missouri River. Reston, Va. : U.S. Dept. of the Interior, U.S. Geological Survey, 2007 (DLC) 2007001224 (OCoLC)80358302 |
Gpo Item No. |
0620-A (online) |
Sudoc No. |
I 19.4/2:1301 |
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