Reservoir floodplains support distinct fish assemblages

River Research and Applications
By: , and 

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Abstract

Reservoirs constructed on floodplain rivers are unique because the upper reaches of the impoundment may include extensive floodplain environments. Moreover, reservoirs that experience large periodic water level fluctuations as part of their operational objectives seasonally inundate and dewater floodplains in their upper reaches, partly mimicking natural inundations of river floodplains. In four flood control reservoirs in Mississippi, USA, we explored the dynamics of connectivity between reservoirs and adjacent floodplains and the characteristics of fish assemblages that develop in reservoir floodplains relative to those that develop in reservoir bays. Although fish species richness in floodplains and bays were similar, species composition differed. Floodplains emphasized fish species largely associated with backwater shallow environments, often resistant to harsh environmental conditions. Conversely, dominant species in bays represented mainly generalists that benefit from the continuous connectivity between the bay and the main reservoir. Floodplains in the study reservoirs provided desirable vegetated habitats at lower water level elevations, earlier in the year, and more frequently than in bays. Inundating dense vegetation in bays requires raising reservoir water levels above the levels required to reach floodplains. Therefore, aside from promoting distinct fish assemblages within reservoirs and helping promote diversity in regulated rivers, reservoir floodplains are valued because they can provide suitable vegetated habitats for fish species at elevations below the normal pool, precluding the need to annually flood upland vegetation that would inevitably be impaired by regular flooding. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Reservoir floodplains support distinct fish assemblages
Series title River Research and Applications
DOI 10.1002/rra.2641
Volume 30
Issue 3
Year Published 2014
Language English
Publisher Wiley
Contributing office(s) Coop Res Unit Atlanta
Description 9 p.
First page 338
Last page 346
Country United States
State Mississippi
Other Geospatial Arkabutla Lake, Sardis Lake, Enid Lake, Grenada Lake
Online Only (Y/N) N
Additional Online Files (Y/N) N