Importance of benthic production to fish populations in Lake Mead prior to the establishment of quagga mussels

Lake and Reservoir Management
By: , and 

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Abstract

Limnologists recently have developed an interest in quantifying benthic resource contributions to higher-level consumers. Much of this research focuses on natural lakes with very little research in reservoirs. In this study, we provide a contemporary snapshot of the food web structure of Lake Mead to evaluate the contribution of benthic resources to fish consumers. In addition, we document the available food to fishes on soft sediments and changes to the invertebrate community over 2 time periods. Benthic invertebrate food availability for fishes is greater in Las Vegas Bay than Overton Arm. Las Vegas Bay is dominated by oligochaetes, whose biomass increased with depth, while Overton Arm is dominated by chironomids, whose biomass did not change with depth. Diet and isotopic measurements indicate the fish community largely relies on benthic resources regardless of basin (Las Vegas Bay >80%; Overton Arm >92%); however, the threadfin shad likely contribute more to largemouth and striped bass production in Overton Arm versus Las Vegas Bay. A 2-time period analysis, pre and post quagga mussel establishment and during lake level declines, suggests there is no change in the density of benthic invertebrates in Boulder Basin, but there were greater abundances of select taxa in this basin by season and depth than in other basins. Given the potential of alterations as a result of the expansion of quagga mussel and the reliance of the fishery on benthic resources, future investigation of basin specific, benthic processes is recommended.

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Publication type Article
Publication Subtype Journal Article
Title Importance of benthic production to fish populations in Lake Mead prior to the establishment of quagga mussels
Series title Lake and Reservoir Management
DOI 10.1080/07438141.2010.541328
Volume 26
Issue 4
Year Published 2010
Language English
Publisher Taylor & Francis
Contributing office(s) Nevada Water Science Center
Description 13 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Lake and Reservoir Management
First page 293
Last page 305
Country United States
State Nevada
Other Geospatial Lake Mead
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