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<br />18 <br /> <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 models of current and historic data suggest that <br />the LCR population of humpback chub has been in decline 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 mainstem temperature effects, Due to some <br />controversy over appropriate methods to estimate the abundance humpback chub in Grand <br />Canyon, an independent panel of experts has been convened to review current stock assessment <br />methods, A report from this panel will be available at the January 2004 AMWG meeting, <br />Associated with the 2003-2004 adaptive management experiment approved by the <br />Secretary oflnterior, a program of mechanical removal of non-native fishes near the confluence <br />of the Little Colorado was implemented in 2003, This work will continue in 2004 as <br />recommended, Early results suggest the efficacy of mechanical removal of non-native salmonids <br />is quite high (>50%), but that immigration of fish back into the removal reaches is substantial. <br />Therefore, frequent removal of non-native fishes is necessary to maintain low abundance, <br />Experimental Flows Update - (Under construction) <br />Humpback Chub - New Initiatives - (Under construction) <br /> <br />Data Acquisition. Storal!e and Analvsis (DASA): Based on results of the Remote <br />Sensing Initiative (Davis, et ai, 2003) and the success of several automated analysis projects <br />undertaken in FY200J, the GCMRC proposes to refocus many of its core monitoring data <br />acquisition and analysis efforts around a common theme entitled, automated core monitoring <br />technologies aDd applications. This approach envisions: (I) adoption of a suite of remote <br />sensing technologies that have either been proven or are very likely to produce terrestrial and <br />hydrographic data of sufficient accuracy to satisfy many of the scientific needs of the physical, <br />biological and cultural resource programs, as well as information requirements of resource <br />GCMRC FY2005-2006 Draft Annual Work Plan (November 10, 2003) <br />