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occasions were completed in the White River and Green River and four were completed in the Yampa river in 2002. Additional Green River sampling included one day of effort in Split Mountain Canyon (Task 4). The fourth sampling occasion on the Yampa River covered approximately half of the river miles that were completed during each of the previous three sampling occasions because boat access was limited by low water. We need to further evaluate the usefulness of captures for abundance estimation from the last sampling occasion conducted on each river system because of the possibility of fish movement out of some reaches and the inability to sample much of the rivers at lower flows experienced at post-runoff. We will determine if Colorado pikeminnow started their spawning migration based on declining capture rates relative to prior sampling occasions and on state of reproductive readiness offish when captured. In 2002, sampling occurred mid-April through mid-July (Task 3, Table I). Electrofishing effort included 182 hours on the Green River, 178 hours on the White River, and 166 hours on the Yampa River. Effort had to be estimated for three samples on the Green and five samples on the White because of data recording errors. Effort for twenty-three Yampa River samples was estimated from the VVP in the other boat because a replacement VVP lacked a time recorder. Two electro fishing boats were used in all reaches on all three rivers. Sampling effort on the Yampa and Green rivers included less than an hour using the block and shock method in backwaters and flooded tributaries. Green River Colorado pikeminnow captured in 2002 during all sampling occasions totaled 110 (n = 738 in 2000 and 396 in 2001). A total of 185 Colorado pikeminnow were captured in the White River in 2002 (n = 315 in 2000 and 239 in 2001), and 33 were captured in the Yampa River (n = 81 in 2000 and 141 in 2001). In 2002, there were seven Colorado pikeminnow recaptured in the Green River, (n = 83 in 2000 and 36 in 200 I), 22 in the White River (n = 26 in 2000 and 26 in 200 I), and none in the Yampa River (n = 6 in 2000 and 21 in 2001). Recaptures reported are for fish captured only in that year, not fish marked in previous years. Abundance estimates for each year will be based only on recaptured fish that were marked during previous sampling occasions in each year. Fourty-eight razorback suckers and one razorback x flannelmouth sucker hybrid were also captured; most were from the Green River between Split Mountain and Ouray Bridge on the Green River. Another 34 razorback suckers too small to PIT tag were also captured and released in the Green River. Two razorback suckers were captured in the White River. The primary shortcoming of2002 efforts was that extremely low flows precluded sampling in most canyon reaches as planned in Task 4. One day of sampling was completed at Split Mountain Canyon; LodDIe and Whirlpool canyons were sampled in a different project. VII. Recommendations: Complete 2003 field work and write the final report. FY 2002 Annual Report 22i Page - 3