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1 <br />Box 2. Opportunities for effective management of genetic resources in <br />endangered fish stocks in the Upper Colorado River Basin. <br />(These opportunities are listed by priority; Modified from <br />Riggs 1990). <br />1. Conserve endangered fish populations or stocks in the upper basin <br />for their genetic potential for recovery, applicable legal mandate, <br />and social or cultural values. <br />2. Facilitate natural recruitment of endangered fishes in the upper <br />basin to develop self-sustaining populations. <br />3. Maintain natural genetic diversity of endangered fish stocks in <br />situations where supplementation with captive-reared fish is <br />necessary in the upper basin. <br />4. Employ breeding strategies that will result in genetic diversity <br />similar to wild stocks where stocking of captive-reared endangered <br />fish is intended to complement natural recruitment. <br />5. Augmentation or restoration stocking of endangered fish will <br />supplement or reestablish stocks in waters where little or no <br />recruitment occurs by native or naturalized populations. <br />6. Thorough evaluation of the success of experimental endangered fish <br />stocking will be made prior to any large-scale augmentation or <br />restoration stocking. <br />Since the goal of recovery is to develop self-sustaining populations or <br />stocks, strategies 1 and 2 will be used to recover the endangered fish <br />stocks in the upper basin. Strategy 1 is the preferred strategy where <br />management opportunities 1 and 2 in Box 2 are employed. This strategy <br />will be used in the recovery of the Colorado squawfish and humpback chub <br />since these stocks are presently considered to be stable. Strategy 2 <br />will be used for recovery of the razorback sucker and bonytail where <br />management opportunities 3 through 6 in Box 2 will be used. Strategy 3 <br />may be used as a last resort to maintain the species in the wild. <br />However, endangered fish stocks in the upper basin that are in jeopardy <br />of extinction will be maintained in refuges as broodstocks that are <br />genetically managed until the limiting factors in their natural <br />environment can be eliminated or reduced. <br />III. CRITERIA FOR IDENTIFICATION AND CHARACTERIZATION <br />OF ENDANGERED FISH STOCKS <br />and <br />FOR DETERMINING THE STATUS AND TRENDS OF STOCKS <br />Individuals of natural animal populations are rarely distributed randomly and <br />their distributions may range from essentially continuous to highly clumped <br />6 <br />1 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />1 <br />fl <br />