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<br />00175~ <br /> <br />29 <br /> <br />Several research projects assessing food-fish linkages have been recently implemented. <br />These include: bioenergetics modeling (Peterson and Paukert, 2003) and diet and predation <br />associated with non-native trout removal project at the LCR (Coggins and Yard, 2003). <br />Following the aquatic protocol evaluation panel recommendations, it is proposed that an organic <br />mass balance project be used as an indicator of system-wide production and export. A request for <br />proposals will be developed during 2005 for this initiative. <br /> <br />Fisheries Resources <br />The Lees Ferry trout fishery has developed a stock assessment model using historic <br />angling data and catch effort data from past monitoring efforts. The model provides a three-to <br />five-year view of the state of this fishery resource and provides an opportunity to evaluate <br />management strategies associated with this fishery (Speas et aI., 2001). The monitoring program <br />that is in place through a cooperative effort between GCMRC and Arizona Game and Fish <br />includes the historic fixed sampling sites and new random, stratified sites based on shoreline <br />type. The program's design is intended to increase sampling areas to better characterize the trout <br />fishery as a whole. Recent data indicate that the fishery is strongly influenced by diel changes in <br />flows and that growth is likely density dependent: Th~: stable flows associated with ROD <br />operations has increased recruitment and the increased numbers of fish has resulted in smaller <br />fish (Speas et aI., 2001). <br />The downstream fishery program has approached the development of a long-term <br />monitoring program in a step-wise fashion to allow for analysis of historic data and to ensure that <br />new monitoring protocols address adaptive management program needs. Steps that have been <br />taken in the downstream fishery program include development of population estimates for <br />rainbow trout and brown trout in the mainstem and for humpback chub in the LCR and its <br />confluence with the mainstem. Stock assessment modds of current and historic data suggest that <br />the LCR population of humpback chub has been in dec:line for over a decade. This downward <br />trend in population abundance is based on an estimated chronic recruitment decline. Multiple <br />hypotheses exist for the apparent recruitment decline including dam operations, tributary <br />flooding, parasitism, predation/competition and main stem temperature effects. An independent <br />panel of experts was convened in 2004 to review current stock assessment methods. A report <br />from this panel was made available at the January 2004 AMWG meeting. The findings lend <br /> <br />GCMRC FY2006 Annual Work Plan (Draft February 15,2005) <br />