Comparisons of Water Quality and Biological Variables from Colorado River Shoreline Habitats in Grand Canyon, Arizona, under Steady and Fluctuating Discharges from Glen Canyon Dam
Glen Canyon Dam operations are known to affect mainstem Colorado River temperature and shoreline habitats for native fish. Options for ameliorating the impacts that operations have on young native fish include changing release volumes and/or changing the daily range of releases. Long-term alterations of operations that may produce a measurable biological response can be costly, particularly if the treatment involves reduced power generation. In September and October 2005, a series of two-week releases occurred that alternated between daily fluctuations that varied by 76 m3 s-1 and steady releases. The purpose of these short-term experiments was to study the effect of daily operations on water quality parameters and biotic constituents (phytoplankton, macroinvertebrates, and fishes) of associated shoreline habitats. Our results indicate that measured biological and physical parameters were, in general, unaffected by flow treatments. However, results should be interpreted cautiously as time within and between treatments was likely insufficient to affect measured parameters. These results lead to the recommendation that studies like this may be more amenable to laboratory experiments first and then applied to a large-scale setting, preferably for longer duration.
Citation Information
Publication Year | 2007 |
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Title | Comparisons of Water Quality and Biological Variables from Colorado River Shoreline Habitats in Grand Canyon, Arizona, under Steady and Fluctuating Discharges from Glen Canyon Dam |
DOI | 10.3133/ofr20071195 |
Authors | Barbara E. Ralston, Matthew V. Lauretta, Theodore A. Kennedy |
Publication Type | Report |
Publication Subtype | USGS Numbered Series |
Series Title | Open-File Report |
Series Number | 2007-1195 |
Index ID | ofr20071195 |
Record Source | USGS Publications Warehouse |
USGS Organization | Southwest Biological Science Center |