As part of the mitigation for construction of the Los Vaqueros Reservoir in the upper Kellogg Creek Watershed, the Contra Costa Water District removed non-native fishes from managed stock ponds on the watershed. We found six species of fish in 7 of 90 ponds. Several ponds with fish were drained during the fall low water period each year from 1998 to 2001. Water was pumped out of ponds and fish were removed with seines, throw nets, and dip nets. Ponds later recharged from groundwater springs. California red-legged frog (Rana aurora draytonii) adults were observed in ponds within weeks of recharge. Reproductive success for California red-legged frogs increased dramatically after predatory fish removal. Two ponds never had more than 2 juvenile California red-legged frogs prior to fish removal, but had > 450 juveniles after fish removal.
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