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I I I I I I I I I I I I I I I I I I I represent ball traps but also serve as irrigation reservoirs. The ponds are interconnected by underground pipe. Water suppling the ponds is a mixture of water coming from Lake Powell and the cities treated waste water plant. A pumping facility is located adjacent to the northern pond which pumps water to a sprinkler irrigation system. The ponds have a total surface area of approximately 3.4 acres and are a little more than 2 meters in depth. They each have plastic liners and are equipped with spray aerators. Fish were stocked into the southern pond on May 16, 1996. Monitoring or sampling was integrated and supported by other activities in the area. Fish were collected by seine and by trammel net. Water parameters were measured using a hydrolab. Water Quality Measurements In general, water quality was fairly good. Parameters did have some significant, but expected shifts, dependent upon season, irrigation demand, and the volume and source of water. The aeration system is probably critical to the fish's survival during the summer months. It contributed to water column mixing and has a significant influence on dissolved oxygen levels. Vertical measurements taken during the summer suggests that some stratification occurs near the pond's bottom. Here DO concentrations dropped to 2.7 mgll which probably represents the lowest detection range of the equipment used. Observed temperatures ranged from 12.1 to 26.2 degrees C. Conductance varied between 946 to 1364 umobmlcm and pH ranged from 7.8 to 9.3. Surface and mid-water column concentrations were always above 5.0 mg/L and normally nearer 8 to 10 mg/L. Data is provided in the Appendix. Fish On May 16, 1996, the pond was stocked with 296 razorback suckers that were raised from Green River brood stock in 1993. These fish had been designated as surplus and held in high concentrations which slowed growth and development. Their average length was 115 mm and they weighted 17 grams. In July, the ponds were partially drained for maintenance reasons. The ponds were drawn down to less than a meter depth and floating algae covered about 50 percent of the surface. Several dead suckers were observed. Twenty-four fish were captured using a 15-m seine. Their average length was 194 mm (Table 1). It was discovered that fish had moved into the northern pond, apparently though the adjoining pipe. We also collected numbers of tiger salamander newts. We attempted and had difficulty capturing fish in early March of 1997. Water temperatures were still cool and fish were dormant and not active. Eleven of the fish captured in trammel nets averaged 350 mm. Efforts were made again in early May which produced more than 130 fish. Fish were quite active at that time and were easily caught with trammel nets. None of the fish exhibited any sexual dimorphism which would be characteristic of active spawners. A subsample of82 fish averaged 359 mm in length and an average weight of641 grams. The range of lengths and weights were pronounced (Table 1, Figure 1). 2