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The Effect of Hypolimnion Reservoir Releases on Fish Distribution and Species Diversity
Author(s) -
Edwards Robert J.
Publication year - 1978
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1978)107<71:teohrr>2.0.co;2
Subject(s) - hypolimnion , canyon , downstream (manufacturing) , environmental science , water quality , fish <actinopterygii> , ecology , species diversity , fauna , hydrology (agriculture) , fishery , geography , eutrophication , biology , nutrient , geology , operations management , cartography , geotechnical engineering , economics
The fish faunas above and below Canyon Reservoir, Comal County, Texas, were surveyed to determine the effect of the impoundment upon the downstream community. Although 22 species were found above the reservoir, only 18 species were taken in the area downstream from the dam. Comparisons with pre‐impoundment surveys of this area, taken a quarter century ago, indicate that seven species, which were once present in the downstream area, are now absent. Species diversity indices demonstrate reduced diversity below the impoundment. Changes in downstream water quality, especially water temperatures, due to hypolimnion water releases, seem to be the most likely causal factors associated with this disruption of the natural stream community.