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where m;,;+, is the number of fish captured in year i and i + 1, and n; and n;+, is the number of <br />fish captured in each sampling year. We estimated abundance of adult razorback suckers for all <br />pairs of years beginning in 1980 rather than using previously computed estimates from 1980 to <br />1992 because of corrections to capture histories that were discovered since the Modde et al. <br />(1996) analyses. We tested for trends in abundance over time for periods 1980-1992, 1990 to <br />1999, and the entire period (1980 to 1999) by regressing abundance estimates (as In) as a <br />function of time. No correction was made for years when no estimates were available. We <br />assumed these are the best available data, recognizing that mistakes in recording, non-detection <br />of PIT tags, and other factors may affect the capture histories used in these analyses. Future <br />efforts should ensure that accurate data recording and tag detection is a priority. <br />Survival estimates.-Jolly-Seber type models (recapture only and Barker's survival and <br /> <br /> <br /> <br /> <br />1 <br /> <br /> <br />population rate of change models) in program MARK (White and Burnham 1999) were used to <br />estimate survival rates of wild adult razorback suckers. The goal of these analyses was to <br />estimate probability of capture (p) and apparent survival rate (~) offish in the population <br />available for capture. We assumed that all individuals in the middle Green River population <br />were available for capture so that apparent survival rate ~, assuming tag loss of zero and site <br />fidelity = 1, can be considered an estimate of true survival S. The assumption of site fidelity was <br />not specifically evaluated, but can be considered so for the purposes of this analysis because <br />movement of fish in the middle Green River was thought restricted to the area encompassed by <br />our sampling (Tyus and Karp 1990). We used Barkers model to estimate lambda (7L), the <br />population rate of change, which is a joint function of survival, recruitment, and fidelity of the <br />animal to the study area. A ~, value less than one indicates a declining population, ~, > 1 <br />indicates an increasing population, and ~, =1 indicates a stable population. Global models that <br />9 <br /> <br />