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= 15 1) in 2002, and 663 (SE = 107) in 2003, a reduction of 59% over the study period. Non- <br />overlapping confidence limits for abundance estimates in year 2000 compared to those in 2002 <br />and 2003 suggested statistically significant differences and a decline in Colorado pikeminnow <br />abundance over the study period. Regression analysis of loge abundance as a function of time (N <br />= 4) showed a negative relationship (loge abundance = 610.90 - 0.3018*year, 1-2 = 0.99, p = <br />0.003). Numbers of unique animals captured declined from 563 in 2000 to 97 in 2002, but <br />increased slightly to 143 in 2003. Abundance estimates for the middle Green River reach had the <br />best precision of all reaches studied, with CV's ranging from 9 to 18%. The relatively low CV's <br />were due to the relatively large number of captured and recaptured fish. <br />Colorado pikeminnow recruits in the middle Green River reach were moderately <br />abundant in 2000 and 2001 (estimates of 107 (SE = 20) and 133 (SE = 26), respectively) but <br />apparently declined in 2002 and 2003 (estimates of 22 (SE =15) and 43 (SE = 16), respectively); <br />confidence limits for estimates in all years overlapped. Estimates of Colorado pikeminnow <br />recruit abundance in the middle Green River were less precise than abundance estimates for <br />adults, with CV's that ranged from 19 to 70%. <br />Abundance estimates for adult Colorado pikeminnow in the Desolation-Gray Canyon <br />reach of the Green River and the lower Green River reach were lower than that observed in the <br />middle Green River reach. Abundance of adult Colorado pikeminnow was 699 (SE = 109) in <br />2001, 757 (SE = 165) in 2002, and 621 (SE = 129) in 2003, an 11% decline over the study <br />period. Overlapping confidence limits among pairs of point estimates did not suggest that any <br />were statistically significantly different. Regression analysis of loge abundance as a function of <br />time (N = 3) showed a slightly negative relationship (log, abundance =124.97 - 0.0592*year, <br />= 0.35, p = 0.595). Numbers of unique animals captured declined from 208 in 2001 to 99 and <br />28