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~ , <br /> <br /> <br />formed as the reservoirs were filling. Initial recruitment of native fish was high <br />' since the relative abundance of nonnative fishes was low. Low reservoir levels <br />may occur again as a result of maintenance draw-downs, drought, or other <br />reasons. Adult or larval native fish should be stocked into these reservoirs <br />' coincident with reservoir re-filling to take advantage of: <br />1. an absence or reduction of predators, allowing adults to successfully <br />' and naturally recruit young into the system or allow hatchery-produced <br />larvae to survive, grow quickly, and establish a population. <br />' 2. Rapid growth potential for longevity of the "big-river" fishes, resulting in <br />the establishment of a long-lived population even if later recruitment is <br />suppressed by nonnative predation. <br />1 3. a dramatically expanded population size, allowing for selection to <br />operate for a time on an abundant gene pool which is then available for <br />translocation elsewhere within the management area. <br />GENETIC CONCERNS <br /> <br /> <br />1 <br /> <br /> <br /> <br /> <br /> <br /> <br />Because populations of the "big-river" fishes have undergone rapid contraction in <br />terms of size and extent of populations, conservation of the remaining genetic <br />variability within each species is crucial. If a species lacks sufficient genetic <br />capabilities to adjust and adapt to shifts in conditions in available habitats, it <br />cannot re-establish aself-sustaining state despite human intervention. This plan <br />focuses on the perpetuation of the existing level of genetic variability through <br />maximization and conservation of variability in founder populations and on the <br />maximization of the variability in the progeny of those founders destined to be <br />returned to the wild. In order to maximize the number of individuals contributing <br />to the next generation, the LCRMP has identified four management options: <br />1. Maximize the number of individuals contributing to the next generation. <br />Where possible collect early life history stages from natural reproduction of wild <br />adults for rearing in protected areas. Collections over the entire spawning <br />season and from all spawning areas are needed to maximize the number of <br />breeding adults contributing to the collected wild progeny. <br />2. Stock suitable numbers of wild adults (tagged for identification) into isolated <br />bays from which nonnative fish have been eliminated and allow them to spawn <br />11 <br /> <br />