ABSTRACT 



Non-urban were more favorable than urban stream sections as habitat 

 for trout and held more trout. The major habitat difference was amount 

 of instream solid overhead hiding cover. Urban land modifications had 

 created unnaturally straight, narrow channels with high, unstable banks 

 with little of the undercuts and woody debris that provide shelter for 

 fish. Urban and non-urban sections did not differ significantly with 

 respect to water velocity, dissolved nitrate, or amount of pools or 

 water turbulence. Per unit stream length, non-urban sections averaged 

 54% more trout larger than 20 cm (8 inches) and 74% greater total trout 

 biomass than urban sections. 



In both urban and non-urban areas, trout abundance as kg/ha was 

 generally below the level predicted by the Wyoming Habitat Quality 

 Index (HQI). This could have been due to effects of angling or other 

 unmeasured factors, to measurement errors or to inapplicability of the 

 HQI method to the areas studied. There is evidence that altering the 

 HQI method to consider solid overhead hiding cover and pool-turbulence 

 hiding cover as separate variables rather than as a total cover index 

 will enhance predictiveness. 



Implications for urban stream fishery management are discussed. 



