What: Undergraduate students from UC Davis professor Peter Moyle's fish biology class will catch and release fish in Putah Creek. They will be looking for Sacramento perch, a native fish that has been extinct in the creek for 50 to 100 years. Moyle's students have been sampling the fish populations since the 1970s, creating years of findings that convinced a judge this spring to order that more water be released so native fish could live in the creek. In early September, nearly 300 Sacramento Perch were planted in Putah Creek to take advantage of the restored flows. This is the first sampling to see how the perch are faring. When: Saturday, Oct. 12, 8-11 a.m. Where: Putah Creek, near UC Davis Picnic Grounds Background: Once native to Putah Creek, Sacramento perch are being reintroduced. Moyle calls their long-term survival a "long shot," but recent court-awarded water flows in Putah Creek may favor the Sacramento perch. "The most probable cause of their decline has been competition for spawning sites with introduced species like black crappie and bluegill," Moyle says. "The big test will be whether or not the fish can spawn in the creek." Working closely with Fred Meyer, a biologist from the California Department of Fish and Game, Moyle obtained the perch from Lagoon Valley Reservoir (near Vallejo). On Sept. 3, Moyle, graduate student Michael Marchetti, and undergraduates Pat Crain and Ross Burnett planted 116 reservoir fish in the ponds at the picnic grounds and 130 at Russell Ranch. Also, an additional 50 perch from Marchetti's behavior research program were planted at the picnic grounds. In both places, fish were planted in the quiet-water habitats they prefer. Fish planted ranged in size from 2 inches long to over 12 inches long and in age from one to four years. Directions: From I-80, turn north on Highway 113 toward Woodland. Take the Hutchison Drive exit, and turn left (west) at the top of the ramp. Turn left on Hopkins Road; drive past the university airport. The road dead-ends at the picnic grounds on the banks of Putah Creek.