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capturing all life stages of endangered fish (razorback sucker). This information will be critical in future efforts within the Basinwide Monitoring Program as well as the Levee Removal Program. Site manipulation will be integrated with the levee removal strategy to address specific hypotheses regarding floodplain and wetland ecology. This approach will be gradually implemented in each levee removal site. ' Nonnative versus Native Fish Enhancement. Emphasis will be placed on the determination of absolute and relative abundance changes of native and nonnative fishes as well as the interactions between native and nonnative species. Past and ongoing research ( Tyus, Crowl and Lentsch 1995) suggest that many nonnative species now present in the Colorado River System potentially limit native fish survivorship and recruitment through competition and/or predation. Channel catfish, northern pike, green sunfish and smallmouth bass all pose significant threats as predators of native species. Green sunfish, smallmouth bass and northern pike are known to inhabit littoral or lentil habitats in Midwestern lakes and reservoirs. Thus, the effects of development and management of floodplain wetlands must be assessed for nonnative as well as native fish species. First, we must determine which nonnative predators will use floodplain wetlands and whether increased spatial complexity provided by aquatic macrophytes (and the expected increase in YOY survivorship) will offset potential losses of native species due to nonnative predation. Second, we must determine if additional lentil habitat will result in a differential, long-term increase in the nonnative fish abundance due to increased spawning, growth and/or survivorship. If floodplain enhancement results in a differential increase in important nonnative predators (e.g., green sunfish, smallmouth bass, etc.) in the river system as a whole, we should expect long-term decreases in native fish populations due to increased predation. It is highly plausible to see a short-term enhancement of native fishes, followed by a long-term increase in nonnative fishes resulting in an overall, long-term decrease in the target native species. These 'lagged-time' predator effects are commonly observed and have been well documented in the'invasion ecology' literature. Prioritization. Selection and Well Defined Plan for Site Development. Site prioritization and scheduling has been a pervading issue in the habitat enhancement program. This strategy identifies and prioritizes sites of highest importance for restoration through a randomized block analysis design described in detail below. It should be noted, that while we have provided a ' matrix of the most feasible sites, with respect to our overall design, advantage should be taken of the existing hydraulic models and data available to determine the feasibility of inundating various sites (Tim OBrien, personal communication). Such endeavors are generally covered under the 'hydrology' section of the overall Floodplain Restoration documents. 6