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|Title:||An analysis of freshwater mussels (Unionidae) in the lower Ohio River at two beds near Olmsted, Illinois : 1992 studies|
|Authors:||Payne, Barry S.|
Miller, Andrew C.
Shafer, Deborah J.
Stream ecology--Ohio River
|Publisher:||Environmental Laboratory (U.S.)|
U.S. Army Engineer Waterways Experiment Station.
|Series/Report no.:||Technical Report ; EL-94-2|
|Abstract:||A survey to assess community characteristics, density, population demography of dominant species, and the likelihood of finding endangered species of freshwater mussels (Unionidae) was conducted in the lower Ohio River near Olmsted, IL. Data will be used to analyze impacts of construction and operation of a new lock and dam at River Mile (RM) 964.4 on the Ohio River. Species diversity (2.36) and evenness (0.80) were higher upriver than downriver of Lock and Dam 53 (1.55 and 0.51 at three farshore sites at RM 967). Based on quantitative samples taken upriver of the lock, five species individually comprised more than 10 percent of the community. These species and their percent abundance were as follows: Fusconaia ebena (21 percent), Truncilla donaciformis ( 16 percent), Quadrula pustulosa (12 percent), T. truncata ( 12 percent), and Obliquaria reflexa (10 percent). Fusconaia ebena and M. nervosa comprised a greater fraction of the community downriver than upriver of Lock and Dam 53. Quadrula pustulosa, Q. quadrula, Q. metanevra, and O. reflexa had greater relative abundance upriver than downriver of Lock and Dam 53. Density of native unionids (15.0 to 105.2 individuals/square meter) and Corbicula fluminea (229.4 to 653.8 individuals/square meter) varied significantly among nearshore, midshore, and farshore sites downriver of Lock and Dam 53. Biomass density differences were not nearly as clear (i.e., they were significant at the 0.1 but not 0.05 level) nor as substantial. The endangered species Plethobasus cooperianus was obtained in qualitative samples upriver of Lock and Dam 53 in 1992, but was not obtained in either quantitative samples (both beds) or qualitative samples downriver of Lock and Dam 53. Overall, the size structure of the F. ebena population downriver of Lock and Dam 53 indicated two major cohorts: very recent recruits (presumably 1991) centered at 8 to 20 mm in length and a cohort of moderately large and old mussels centered at 60 to 70 mm in length. Drought, natural patterns of recruitment, and species introductions are natural factors that potentially affect native mussels in the lower Ohio River. Effects of construction and operation of the Olmsted Lock and Dam project can best be monitored by regularly monitoring density, diversity, and size demography of dominant native mussel populations in the lower Ohio River.|
|Gov't Doc #:||Technical Report EL-94-2|
|Rights:||Approved for Public Release; Distribution is Unlimited|
|Size:||130 pages/4.57 Mb|
|Appears in Collections:||Technical Report|
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|TR EL-94-2.pdf||5.11 MB||Adobe PDF|