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HABITAT DESCRIPTION <br />Middle Creek is a small stream (1. 5m wide) with low gradient throughout <br />the study area. It flows through a narrow valley at Station 1 having a <br />r well-defined channel and a gradiant of 2%. Overhanging vegetation, stable <br />1 undercut banks and pools provide fish habitat at this station. Ouring <br />summer months an irrigation diversion just upstream withdraws a considerable <br />portion of the flow. Substrate at Station 1 is primarily cobble and gravel <br />in the riffle areas with sand and silt in pools. Below Station 1, Middle <br />Creek flattens out to a low gradient (0.5-0.6%), widely meandering pasture <br />stream. Foidel Creek and a small intermittent stream enter Middle Creek <br />i upstream of Station 2, which increases the flow in spring and summer. Lower <br />Middle Creek (Stations 2 and 3) has little woody riparian vegetation, few <br />i undercut banks due to sloughing and many abandoned beaver dams. Deep pools <br />provide the major fish habitat in this reach of stream. Substrate is pri- <br />marily sand and silt with gravel in riffle areas. However, riffles averaged <br />no more than 30% in the lower reaches. <br />• Fish Creek is a wide (4m or more), low gradient (0.2%) stream through- <br />out the study area. The stream is widely meandering but lacks woody riparian <br />vegetation or undercut banks at either station due to sloughing of the <br />banks. Deep pools afford the only major fish habitat at either station. <br />The substrate in the riffle areas is rubble and gravel' with sand and silt in <br />the pools. However, riffles averaged only 20% at both stations. <br />METHODS <br />Location and degree of cover of aquatic,macrophytes were mapped in 100 <br />sectionsat all stations except Station 1 on Middle Creek, where a SOm section <br />was mapped. Visual estimate technique was used to obtain extent of coverage. <br />Benthic invertebrates of Middle Creek and Fish Creek were collected <br />August 1-2, 1980. Two samples in the riffle sections of each station were <br />taken with a Surber square-foot bottom sampler <mesh size 700 um). Pool <br />habitat was sampled by taking two Ekman grabs. Each grab was placed in a <br />sieve bucket (mesh size 250 um) and rinsed of excess silt and debris. <br />Benthic samples were preserved in the field with 75i; ethanol and returned to <br />• <br />-3- <br />