Impact of dams on stream fish diversity: A different result

Diversity
By: , and 

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Abstract

Impoundments can drastically change the physical and biological characteristics of fluvial systems. Changes in the physical characteristics, such as reductions in flow, increased sediment deposition, and increased surface area, often influence the system’s biological components, including plant, macroinvertebrate, and fish assemblages. In addition to having direct effects on impounded waterbodies, impoundments can also have wide-ranging effects at the watershed scale, particularly on upstream tributary streams. The purpose of this study was to assess the magnitude of these effects. We analyzed historical data from 26 streams distributed across five sub-basins in the Bluff Hills region of the Yazoo Basin, MS, USA. All five major tributary rivers in this region are impounded by large (11,240–26,143 hectares) reservoirs for flood control. We compared fish assemblages in streams located upstream and downstream of the four reservoirs using PERMANOVA, and contrary to expectations, we found no significant differences between the upstream and downstream assemblages. We explore several possible explanations for this discrepancy and suggest that stream assemblage response to impoundment may be nuanced by the regional species pool, the history of stream conditions in the watershed, and the resistance of the streams to periodic disturbances.

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Publication type Article
Publication Subtype Journal Article
Title Impact of dams on stream fish diversity: A different result
Series title Diversity
DOI 10.3390/d15060728
Volume 15
Issue 6
Year Published 2023
Language English
Publisher MDPI
Contributing office(s) Coop Res Unit Atlanta
Description 728, 14 p.
Country United States
State Mississippi
Other Geospatial eastern Yazoo River
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