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to avoid extremely low flows, trips in 2002 were scheduled two weeks earlier than 2001 trips. A total of]2 sites were sainpled throughout the canyons including the four long- term trend sites at RM 185, 174.4, 160.4, and 145.7. A total of293 individual humpback chub were collected in Desolation/Gray canyons by trammel netting, electro fishing, hoop netting and minnow trapping. Trammel nets yielded the highest catch of humpback chub. Tranunel net catch rates increased between trips, while electrofishing catch rates remained similar (not tested for significance). Average total length of chubs caught was 240.5 mm with a range of71-409 mm. Six humpback chub were recaptured during the second trip that had been tagged during the first trip. Long term recaptures (from previous years) were observed during both trips. IV. Study Schedule: a. Initial year: 200 I b. Final year: 2003 V. Relationship to RIPRAP: Green River Action Plan: Mainstem V.B Conduct population estimate for humpback chub V .B.]. Desolation/Gray VI. Accomplishments ofFY02 Tasks and Deliverables, Discussion of Initial Findings and Shortcomings: Two sampling trips were conducted through Desolation/Gray canyons on June 1-8 and June] 5-22. A third sampling trip was scheduled for June 29-July 6 but was not conducted. A total of] 2 sites were sampled throughout the canyons including the four long-term trend sites at RM 185, 174.4, ]60.4, and 145.7. The other sites were located at RM 202, ]82, 174.2, ]66.8, ]58.7, ]55, 153.5, and 147.5. Four "wild card" sites from previous ISMP monitoring were included within the twelve sites. In general, sampling occurred during the peak and descending limb of the hydro graph. Sampling had been scheduled during this time to take advantage of higher flows. In 2001, flows dropped rapidly and catch rates from the last trip were low. In 2002, we attempted to take advantage of the flows by moving the project forward two weeks. However, f10ws dropped more rapidly than 2001 and the third trip was canceled to avoid extreme damage that can be done to equipment (boats and motors) and additional safety risks involved with low water in Desolation and Gray canyons. Flows were 5600-4700 cfs during the first trip and 3170-1810 cfs during the second trip. The third trip would have occurred during flows of 1250-1040 cfs (all flows determined by USGS gage #09315000, Green River at Green River gage). Trammel nets were utilized to target the adult component of the Desolation/Gray humpback chub population. Past research indicates that trammel nets provide the greatest FY 2002 Annual Report 22k Page - 2