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outside of the nets. However, 3,800 m2 more habitat was seined inside the net due to our inability to seine in the deep water outside the nets. In White Wash, the percentage of adults was 18% inside and ! 10% outside the nets. No adult NNC were captured either inside or outside of the net on the single sample occasion when Red Wash was inundated. However, the significance of the block net experiment could not be adequately assessed due to the difficulties of seining the deep habitats, overtopping from ~ high water levels, and breaching from beaver damage and flash floods. Comparison with ISMP ~ The ISMP catch rates of Colorado pikeminnow in the lower Green River (ISMP reach 3) increased each year from 1997 to 2000 (Figure 10). However, catch rates remained below the long term mean, and well within the range of catch rates observed during ISMP sampling from 1986 to 1997. ~ Colorado pikeminnow captures in the middle Green River (ISMP reach 4), where no removal efforts took place, were also slightly higher from 1998 to 2000 than in 1997, and were also lower than the long term mean. In ISMP reach 3, catch rates for nonnative cyprinids in 1998 to 2000 were lower than the long term mean; however, catch rates were also very low in 1997 prior to removal efforts. Nonnative cyprinid catch rates in the middle Green River (ISMP reach 4) where no removal efforts were conducted were also , lower than the long term mean and declined each year from 1997 to 1999. However, CPE increased to above the long-term mean in 2000. 3.2 Colorado River NNC Removal Most Colorado pikeminnow captured in 1998 and 2000 in both treatment and control reaches 1 were age-0 (YOY}, ranging from 16-52 mm TL; however, in 1999 the Colorado pikeminnow appeared to be age-1 (Figure 11). In 1999, 85 Colorado pikeminnow were captured, primarily on the first trip (July 5- 9); ranging in size from 35 to 130 mm -larger than YOY Colorado pikeminnow caught on later trips in 1998 and 2000. These fish were likely part of the previous year class (age-1 ). In 1998, 60 Colorado ~ -11-