Pj. Braaten et Cs. Guy, STRANDING OF PENTAGENIA-VITTIGERA FOLLOWING FLOW REDUCTIONS IN THE LOWER MISSOURI RIVER, Journal of freshwater ecology, 12(3), 1997, pp. 493-494
During a nine-day period in December 1995, water levels in the lower M
issouri River declined 1.65 m as a direct result of upstream flow regu
lation for navigation. We observed numerous aquatic invertebrates, pre
dominately Pentagenia vittigera, on a mud flat downstream from a wing
dike in the lower Missouri River. The estimated number of P. vittigera
stranded on this single mud flat was 6,400 individuals. Based on an a
nalysis of December discharge and water levels from 1980-1994, it appe
ars that the rate of water level declines and subsequent stranding of
P. vittigera were rare events; nonetheless, rapid decreases in dischar
ge associated with the transition between the navigation and non-navig
ation seasons can negatively impact P. vittigera.