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endangered fish (see Goals section above), capture rates of YOY Colorado pikeminnow during ISMP annual seine surveys were examined to see if Colorado pikeminnow relative abundance increased during the predator removal period. To assess depletion effects from removal efforts without the confounding factors of potential immigration and emigration, trend in catch rate was examined in one backwater that remained isolated from the main channel during several seasonal removal efforts. The best backwater for this was a backwater near Horsethief Wildlife Area at rm 154.5. It contained relatively high numbers of fish, was sampled in all seasonal efforts, and had no inflow from irrigation return. RESULTS General Total numbers of nonnative fish captured and removed varied greatly among individual backwaters and among seasons. During the three-year effort, 3,758 largemouth bass and 10,432 green sunfish were removed (Table 1). Other sunfishes (total number in parentheses) included black crappie (27), smallmouth bass (27) and bluegill Lepomis macrochirus (630). Other nonnative fish included 3,551 black bullhead, 2,807 white sucker, 101 channel catfish, and 6,642 common carp. Only two northern pike were captured. Crews were more effective capturing centrarchids when the electrofishing barge was used than when the electrofishing boat was used. The barge allowed access to shallow-water areas and could be dragged or carried to backwaters partially isolated from the channel. These habitats contained pond-like features (vegetation, branches, and other structure) typically favored by various species of sunfish (Sigler and Miller 1963). Also, the hand-held probes allowed netters to most effectively shock microhabitats associated with structure (branches, beaver lodges, rip-rap blocks, root-wads, etc.). The boat was primarily effective at removing adult carp along rip- rapped banks. The number of backwaters shocked using the barge was 21-25 in five of 7