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. . m long x 1 m deep and had a 1 mm mesh. Fish were identified and enumerated in the field and released. Fish too small or numerous to be identified in the field and sucker larvae were preserved for identification. Larvae were also collected in backwater and flooded vegetation areas at night using a flashlight to attract them to the water surface where they were netted with an aquarium dipnet. Larvae attracted to the surface of the water by the light source were netted and placed in a bucket of water. Larvae were preserved in formalin or alcohol for later identification. Dip netting was done only during 1999 in conjunction with the 24-hour drift net station. . . Post-larvaL- Presence, distribution and relative abundance ofYOY endangered fishes, and other native and nonnative fishes was investigated within the three monitoring sites using 4 m x 1 m seine nets of 3 mm mesh. All backwater and low velocity habitats within each monitoring reach were seined. At least three seine hauls were made in larger habitats and at least 50 percent of the surface area of smaller habitats were seined. Seine hauls were typically taken near the mouth of backwaters and near the middle and fmally at the shallower back end of the backwater. Fish were identified in the field when possible. All native fish were measured and released. Nonnative fish were counted, classified by life-stage and released. Samples containing fish too small and numerous to be identified or counted in the field were preserved and transported to the laboratory for identification. Physical measurements and attributes of seined habitats were also recorded. Measurements of habitat width, water depth and substrate characteristics were taken along three transects perpendicular to the axis of the backwater. These corresponded to the mouth of the backwater, one-third and two-thirds the length ofthe habitat sampled. Length and width of each seine haul were also recorded. . . . . . . 4 .