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METHODOLOGY Field Sampling Three different gear types, electrofishing, trammel nets, and trap nets, were used to collect sub-adult and adult fish in both Gardner and Hotspot ponds. Electrofishing was conducted from an outboard-powered, aluminum electrofishing jon boat, equipped with a 5.kilowatt generator and a Coffelt VVP-15 voltage pul sator to adjust the voltage and amperage transmitted to the water. The electrofishing boat used two spherical anodes (about 9-inch diameter) suspended from fiberglass booms in front and two 7-ft cathodes (0.25.inch diameter twisted cable) suspended from each side of the boat. The boat hull was also used as a cathode in conjunct i on with the droppers. Both the anode and cathode were stainless steel. Investigators used direct current and tried not to exceed 300 volts or 12 amps to minimize injury to fish, while maximizing electrofishing effectiveness. Trammel nets were 1.0- and 1.5-inch bar mesh, with a wall of 10- or 12-inch and 150-ft long. Two different size trap nets were used. The larger size was a series of two, 4 ft X 6 ft, rectangular hoops followed by five circular hoops that were each 4 ft in diameter. A center lead, 4 ft wide X 75 - ft long, was attached to a vertical, center brace of the first rectangular hoop. One-inch square mesh netting covered all the hoops and the center lead. The smaller trap nets were a series of two, 3 ft X 4 ft, rectangular hoops followed by five circular hoops that were each 3 ft in diameter. The center lead was approximately 3 ft wide X 50 ft long. Delta netting, 3/8-inch mesh, covered all the hoops and the center lead. Two tapered throats were attached to the first and third circular hoops of both the small and large trap nets. Sampl ing withelectrofishing, trammel, and trap nets occurred during April, June, and July of 1996 which coincided with pre-runoff, runoff, and post-runoff flow stages of the Colorado River, respectively. Electrofishingwas used primarily to collect fish from shorelines around the perimeter of each pond and shorelines of islands. Trammel nets were used to sample mid-water, pelagic habitat, and trap nets were set with one end of the center lead anchored to the shoreline with the hoops extending out into the pond. For each gear type, the numbers of fish by species and age category (sub-adult and adult) were recorded on field data sheets at the end of each sample effort. All Colorado squawfish collected were initially checked for a passive integrated transponder (PIT) tag, weighed (g), measured (total length [TL], mm), and muscle-plugged for contaminant analyses. . Colorado squawfish that had not been previously captured were PIT- tagged. All other native and nonnative fishes collected were fin.clipped to obtain recapture data to determine if fish moved between the two ponds. For Gardner Pond, the left pelvic fin was clipped for the first capture, the left pectoral fin for the first recapture, and the upper caudal fin for the second recapture. For Hotspot Pond, the right pelvic fin was clipped for the first capture, the ri ght pectoral fi n for the fi rst recapture, and the lower caudal fi n for the second recapture. All fish collections were accompanied with detailed information regarding pond location, date, time of day, water temperature, voltage and amperage output of electrofishing equipment. All fish were released alive. For electrofishing, effort was recorded in seconds whi ch was 1 ater converted to hours e 1 ectrofi shed. For trammel and trap nets, effort was recorded as total hours of fishing. 5