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computer. The data stored for each signal by the receiver included the <br />following: <br />1. date, <br />2. time (h/min/sec), <br />3. channel or frequency, <br />4. power level of signal, <br />5. antenna (combined, individual), and <br />6. signal code. <br />Data downloaded to the notebook computer were in ASCII . TXT format which then were <br />processed, edited, and converted to database files for manipulation and analyses. <br />The other SRX_400 receiver (version 4.01/W5A), was not programmed for <br />datalogging, and was used to search for radio-tagged fish from boats between and <br />outside the range of the fixed, land-based stations. An aluminum boat with a 65- <br />horsepower jet drive facilitated up- and downstream travel to monitor movements <br />of transmitter-tagged fish following release. River reaches were searched for <br />radio-tagged fish at least weekly between the time fish were implanted with <br />transmitters (May and June) and September of each year, and more frequently <br />during the spawning season (see Appendix; Table K-8 for a summary of tracking <br />effort). Searches for radio-tagged fish were made less frequently between <br />October and May. Because the study area to be searched was extensive, several <br />miles of river had to be covered on a given day. For this reason, when contact <br />was made with a radio-tagged fish, it was only for about 10-15 minutes. Only the <br />general location (river mile) and general habitat type that each fish was <br />occupying at the time of contact was recorded. <br />Antennas. Nine- and four-filament aerial directional antennas (148-152 <br />Mhz) were used for surveillance at remote stations; three-element antennas (AF <br />Antronics, Inc.°) were used from boats. The stationary, dipole underwater <br />antenna used in the Redlands fishway consisted of an 8-cm end portion of the <br />inner solid copper wire of a coaxial cable (58 0) exposed and positioned 15-cm <br />above the floor of the fishway. Smaller - sized, multi - filament antennas used with <br />the high-band frequency did not compromise signal reception or gain. <br />Field Sampling <br />The fish community between Delta (RM 57) and immediately upstream of the <br />Redlands Diversion Dam (RM 3.9) was sampled twice each year from 1996 through <br />2000 during late-July or early-August and again between mid-September and early- <br />October with two electrofishing craft. One was a 5-m long, aluminum <br />16