Changes in fish communities following concrete lining of the Coachella Canal, southeastern California

The fish community of a 3.4-km section of the concrete-lined Coachella Canal, Imperial County, California, was comprised of six species, with an absolute density of 0.039 fish/m² and estimated biomass of 4.367 g/m². When compared to studies conducted in the canal prior to lining, or in other unlined areas, these data suggest reductions in species diversity (-14.3 to -62.5%), density (+8.9 to =83.8%), and biomass (-30.1 to -91.2%). These data support speculations that numbers of river-adapted fish would remain relatively high in a concrete-lined canal, but lentic and cover-oriented fishes such as centrarchis would decline.