LEADER 03297oam 2200409Ia 450 001 9910696708203321 005 20080717161733.0 035 $a(CKB)5470000002381794 035 $a(OCoLC)173495571 035 $a(EXLCZ)995470000002381794 100 $a20070928d2007 ua 0 101 0 $aeng 135 $aurcn||||||||| 181 $ctxt$2rdacontent 182 $cc$2rdamedia 183 $acr$2rdacarrier 200 14$aThe response of suspended sediment, turbidity, and velocity to historical alterations of the Missouri River$b[electronic resource] /$fby Dale W. Blevins 210 1$aReston, Va. :$cU.S. Dept. of the Interior, U.S. Geological Survey,$d2007. 215 $aiv, 8 pages $cdigital, PDF file 225 1 $aCircular ;$v1301 300 $a"Prepared in cooperation with the U.S. Environmental Protection Agency." 300 $aTitle from Web page (viewed on Sept. 28, 2007). 320 $aIncludes bibliographical references (page 8). 330 $a"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. 606 $aSediment transport$zMissouri River 606 $aRiver engineering$xEnvironmental aspects$zMissouri River Watershed 615 0$aSediment transport 615 0$aRiver engineering$xEnvironmental aspects 700 $aBlevins$b Dale W$01387539 712 02$aGeological Survey (U.S.) 801 0$bORE 801 1$bORE 801 2$bGPO 906 $aBOOK 912 $a9910696708203321 996 $aThe response of suspended sediment, turbidity, and velocity to historical alterations of the Missouri River$93501077 997 $aUNINA