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Current Status and Recovery Efforts: The Lake Mohave population of razorback sucker has been studied extensively (Burke et al. 1992, Buth et al. 1987, Marsh 1994, Marsh and Minckley 1989, Minckley 1983, Minckley et al. 1989, 1991, Pacey and Marsh 2000). It represents the largest population of razorback sucker in the lower basin with 4,000 wild individuals still occurring there in 2003. These wild adults are expected to disappear from the lake through natural mortality in the next decade (Marsh pers comm.). However, 70,000 subadult razorback sucker have been stocked into Lake Mohave by USBR and the Service since 1992 in part as a result of section 7 consultations. These fish are beginning to enter the population and replace the aging wild fish. The Lake Mohave Native Fish Work Group, a group made up of State and Federal agencies and university personnel, developed this stocking program. The goal of the group is to establish an adult population of 50,000 fish using wild larvae produced in Lake Mohave, to provide a genetic refugium for this species in the lower basin. Applicable Recovery Goals and Management Strategies: ' Recovery Goal. Maintain genetic refugia in the lower basin and/or self-sustaining population while moving towards recovery. ' Downlisting Criteria: 1. Genetic variability of razorback sucker in Lake Mohave is ' identified, and a genetic refuge is maintained over a 5-year period. 2. Two self-sustaining populations (e.g. mainstem and/or ' tributaries) are maintained over a 5-year period, starting with the first point estimate acceptable to the Service, such that for each population: a. the trend in adult (age 4+ ;> 400 mm TL) point estimates does not decline significantly, and b mean estimated recruitment of age-3 (300-399 mm TL) ' naturally produced fish equals or exceeds mean annual adult mortality, and ?s. Razorback Sucker 25