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as other contributing information (i.e., subjective information) such as the potential for catastrophic risk or the possibility of immediate extinction as old individuals die and are not replaced through recruitment. Priorities for placing endangered fish in refugia or developing broodstocks are determined through evaluation of distribution and relative abundance (i.e., catch-per-unit-of-effort) obtained during annual monitoring of wild stocks or from various ongoing field studies. Priorities for placement in genetic refuges or captive propagation by species or stocks within a species are established by participants of the Program's Biology Committee by a thorough evaluation of all available information including the distribution and relative abundance, natural spawning and recruitment, possibility of catastrophic risk that may result in elimination or extinction of a stock, status and trends, and the probability of the stock being extirpated from the wild. IV. GENETICS MANAGEMENT OF WILD STOCKS All presumptive stocks of endangered fishes must be protected since each may have unique genetic attributes that may be important to the recovery effort (Philipp et al. 1986; Rohlf 1991). As species decline to the point where they are listed as threatened or endangered, each remaining stock could play an important role in increasing the probability for recovery (Rohlf 1991). The need for management actions such as translocation and establishment of captive populations suggests that recovery effort may have been initiated too late for some endangered species (Tear et al. 1993). Natural propagation will be given the first priority in the recovery of endangered fishes in the Upper Colorado River Basin (Figure 1). However, captive propagation of some stocks will be needed. Broodstocks will be developed to produce progeny for stocking with genetic diversity similar to the wild stock or nearest neighbor for augmentation or restoration stocking. A. Stable Stocks. All naturally sustaining or stable stocks of endangered fishes in the Upper Colorado River Basin will be managed to prevent irreversible losses of genetic diversity that may result from management interventions or lack of action. Genetic conservation requires the maintenance of similar genetic diversity among wild and captive-reared endangered fish so that the risk of genetic loss or alteration is prevented or minimized (Lichatowich and Watson 1993). A systems approach (Box 3) incorporating four basic planning steps of (1) scoping and inventory (i.e., assessment of issues or problems and potential genetic risks), (2) strategic planning (i.e., identification of strategies to solve issues or problems facing the recovery effort, including captive propagation), (3) operational planning (i.e., implementation of strategies), and (4) evaluation will be followed in the planning process. Genetic management opportunities (Box 2) should be incorporated into recovery strategies. All viable stocks of endangered fishes in the upper basin will be identified and characterized following the criteria described in Section III.A. Rohlf (1991) emphasized that stocks should be inventoried and classified before situations arise that demand management decisions. The genetic diversity within and among populations of the endangered fishes 10 1 11 1