Reach-scale comparison of habitat and mollusk assemblages for select sites in the Clinch River with regional context

Journal of the American Water Resources Association
By: , and 

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Abstract

Several hypotheses, including habitat degradation and variation in fluvial geomorphology, have been posed to explain extreme spatial and temporal variation in Clinch River mollusk assemblages. We examined associations between mollusk assemblage metrics (richness, abundance, recruitment) and physical habitat (geomorphology, streambed composition, fish habitat, and riparian condition) at 10 sites selected to represent the range of current assemblage condition in the Clinch River. We compared similar geomorphological units among reaches, employing semi-quantitative and quantitative protocols to characterize mollusk assemblages and a mix of visual assessments and empirical measurements to characterize physical habitat. We found little to no evidence that current assemblage condition was associated with 54 analyzed habitat metrics. When compared to other sites in the Upper Tennessee River Basin (UTRB) that once supported or currently support mollusk assemblages, Clinch River sites were more similar to each other, representing a narrower range of conditions than observed across the larger geographic extent of the UTRB. A post-hoc analysis suggested stream size and average boundary shear stress at bankfull stage may have historically limited species richness in the UTRB (p < 0.001). Associations between mollusk assemblages and physical habitat in the UTRB and Clinch River currently appear obscured by other factors limiting richness, abundance, and recruitment.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Reach-scale comparison of habitat and mollusk assemblages for select sites in the Clinch River with regional context
Series title Journal of the American Water Resources Association
DOI 10.1111/jawr.12218
Volume 50
Issue 4
Year Published 2014
Language English
Publisher American Water Resources Association
Contributing office(s) Tennessee Water Science Center
Description 19 p.
First page 859
Last page 877
Country United States
State Tennessee, Virginia
Other Geospatial Clinch River
Online Only (Y/N) N
Additional Online Files (Y/N) N