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Other Non-natives Black bullhead, common carp and white sucker were abundant, channel catfish were uncommon, and northern pike were extremely rare (Table 1). About 43% of the 6,642 common carp removed were adults (>250 mm TL) and the rest were juveniles. Most adult carp (72%) were captured with the electrofishing boat. Numbers removed varied with removal period and no trend in total catch was evident. Channel catfish ranged in size from 147 to 640 mm TL, with 94% classed as adults (> 300 mm TL). Individuals between 360 and 499 mm TL made up 76% of all channel catfish captured. Results From Other Studies Fall ISMP seining results indicated that the highest catch rate of both largemouth bass and green sunfish in upper Colorado River backwaters was in 1998, one year prior to the initiation of this project (Fig. 8). For both species, seining catch rates were lower during the three years of the removal effort than in 1998 (Chuck McAda, unpublished ISMP data). Additional results from a more intensive seining effort associated with a non-native minnow removal project in the Grand Valley, conducted concurrently with this study, documented extremely low numbers of largemouth bass and green sunfish in backwaters (Trammell et al. 2002), and catch rate trends during 1999-2001 were not consistent with the electrofishing results presented here or the ISMP seining results. Catch rate of green sunfish (number seined per backwater), calculated from the results of Trammell et al. (2002), was highest in 2001, the last year of the electrofishing removal effort, suggesting no reach-wide depletion resulting from electrofishing removal. For largemouth bass, seining catch rate declined from 1999 to 2000 (none was captured in 2000) and then increased somewhat in 2001. This was consistent with ISMP seining catch rates but inconsistent with the electrofishing catch rates which were highest in fall of 2000. 17