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Title: Effects of increased commercial navigation traffic on freshwater mussels in the Upper Mississippi River : 1993 studies
Authors: Miller, Andrew C.
Payne, Barry S.
Keywords: Freshwater mussels
Navigation--Mississippi River
Publisher: Environmental Laboratory (U.S.)
U.S. Army Engineer Waterways Experiment Station.
Series/Report no.: Technical Report ; EL-95-11
Abstract: In 1988, the U.S. Army Engineer District, St. Louis, initiated a monitoring program to analyze the effect of commercial navigation traffic on freshwater mussels (Mollusca: Unionidae), especially the endangered Lampsilis higginsi, in the upper Mississippi River (UMR). Preliminary studies were conducted in 1988, and detailed studies were initiated in 1989 and will continue until 1994. In August-September 1993, freshwater mussels were collected using qualitative and quantitative (0.25 sq m total substrate) methods in the main and east channel of Pool 10 near River Mile (RM) 635.2. The sampling program was reduced in 1993 because of high water throughout most of the UMR. Using quantitative methods, a total of 19 and 20 bivalve species were collected at nearshore and farshore sites in the main channel. Overall species diversity (H ') was similar at both sites, 1. 70 and 1.58 at the nearshore and farshore sites, respectively. In the main channel, 15.66 and 11.54 of the fauna showed evidence of recent recruitment at nearshore and farshore sites, respectively. Density (individuals/square meter) at the nearshore (64.5) and farshore site (56.1) was not significantly different (F = 1.85, P > 0.05). The endangered L. higginsi comprised 0.25 percent (one individual collected) and 0.11 percent (four individuals collected) using qualitative and quantitative methods, respectively, in the main channel. Six attributes of mussel beds were examined to judge their health: (a.) decrease in density of five common-to-abundant species, (b.) presence of L. higginsi (if within its range); (c.) live-to-recently-dead ratios for dominant species, (d.) loss of more than 25 percent of the mussel species, (e) evidence of recent recruitment, and (f.) a significant change in growth rates or mortality of dominant species. An examination of these six attributes, based on information collected to date, reveals that biotic conditions are stable at these beds.
Description: Technical Report
Gov't Doc #: Technical Report EL-95-11
Rights: Approved for Public Release; Distribution is Unlimited
Size: 67 pages/5.40 Mb
Appears in Collections:Technical Report

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