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APPENDIX I - BIOLOGICAL RESOURCES pond for a number of years. The pond supports a lush inshore aquatic vascular plant stand that extends out to a depth of approximately four feet. Maximum lake depth at several sounding points ranges between 6.5 and 8.5 feet. A sparse shoreline riparian vegetation, consisting primarily of scattered willows, persists under heavy browsing pressure by cattle. The Mokelumne River is one the many Sierra foothill streams whose present flow is controlled by water releases from foothill reservoirs. Water level and flow rate during the November 1991 survey appeared to be at a yearly low (Figure 4.7-6(B). Much of the shoreline vegetation seen here would presumably be covered by high flows during the rainy season, then reappear and rejuvenate during the following dry season. The Mokelumne River is also instrumental in maintaining the woodland riparian area by periodically overflowing its bank. Major overflows help to restock the permanent pond with fish. The river's passage along the undisturbed riparian frontage of the project site provides viewers with one of the last glimpses of what the majority of the foothill stream riparian zones once looked like in San Joaquin County. That is, an extensive, wide riparian woodland complex, unlike the narrow swath of riparian trees and bushes commonly seen today along the river's course in the County. Wildlife Fish Interviews with the previous property owner revealed that the permanent pond was never purposely stocked, receiving all the fish species it presently supports from the Mokelumne River when the river periodically overflowed (Brovelli, 1991). Five hauls with a 100 x 6 foot, 1/4 inch mesh beach seine resulted in the netting of eight species in this habitat. The pond supports bluegill(Lepomis macrochirus), redear sunfish (Lepomis microlophus), warmouth (Lepomis gulosus), black crappie (Pomoxis nigromaculatus), largemouth bass (Micropyerus salmoides), mosquito fish (Gambusia affinis), brown bullhead (Ictalurus nebulosus) and golden shiner (Notemigonus crysoleucas). All species exhibited at least two distinct year classes, indicating that each was successfully reproducing in the pond. This group contains no native California fish species. Amphibians Only two amphibians, the native Pacific tree frog (Hyla regilla) and the introduced bullfrog (Rana catesbeiana)were observed on the site in November. The area possibly supports one or more species of salamander, but the onset of winter rains is needed to stimulate the activity of such species above ground. 11