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SPRING, LATE-JUVENILE/ADULT COLORADO SQUAWFISH MONITORING Methods Late-juvenile/adult Colorado squawfish monitoring was conducted in the Green, Colorado, Yampa, and White rivers during April and May of 1988. Eight river reaches were sampled by the Utah Division of Wildlife Resources (UDWR) and 5 river reaches were sampled by the Colorado Division of Wildlife (CDOW: Table 1, Figure 1). Each river reach was divided into at least 2 sub-reaches to provide replicate samples--one shoreline of each sub-reach constituted one sample. Sampling was done by electrofishing along both shorelines of all reaches. Electrofishing crews began at the upstream end of each sub-reach and moved downstream at a steady pace. Backwaters, tributary mouths, and other habitat features were sampled once as the investigators proceeded downstream. Sampling time was measured to the nearest second on an elapsed time clock located on the variable voltage pulsator and converted to the nearest 0.1 hr for data analysis. All captured Colorado squawfish, humpback chub, and razorback sucker were measured to total length, weighed, and tagged with a unique-numbered colored tag before being released at the original capture location. Numbers of Colorado squawfish that were observed during the electrofishing collections but not captured were noted. Total numbers of northern pike, walleye, largemouth bass, smallmouth bass and green sunfish that were observed during sampling were also noted. Complete details on sampling design and data collection are provided in the ISMP Handbook. Table 1. River reaches sampled in the late-juvenile/adult monitoring program and codes used by ISMP. Sample Area Reach General Lead River Boundary Code Area Agency Green 335-327 1 Island Park UDWR 319-300 2 Split Mt.- Jensen UDWR 260-245 3 Ouray UDWR 115- 96 4 Green River town to Ruby Ranch UDWR 56- 40 5 Mineral Bottom UDWR Colorado 154-132 6 Loma to State Line CDOW 99- 86 7 Near Dolores River UDWR = 68- 49 8 Near Moab UDWR Yampa 105- 95 9 Above Juniper CDOW 80- 70 10 Maybell CROW 54- 49 11 Below Cross Mtn to Lily Park CDOW White 104- 95 12 Below Kenney Reservoir CDOW 21- 0 13 Mtn. Fuel Bridge to mouth UDWR 2