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1 1 for egg and YOY life stages significantly decrease the time required to reach the target population size (from 52 to 30 years). In contrast, increasing survivorship values for 2- and 3-yr old squawfish only decrease the time to reach the target population sizes by 8-10 years. Both of these criteria suggest that prioritizing management activities to enhance early life-stage survivorship values will result in larger and faster increases in overall population sizes of Colorado squawfish. Population Monitoring 1 Monitoring; Genetic Ilariabift& OWN) Long-term monitoring of Ne N or at the very least a current estimate of Ne N would enhance our ability to quantify an appropriate management objective. The best approach would include estimates of both genetic and demographic data. Estimates of Ne N for salmon stocks have provided,greater opportunities to improve current management strategies for these fish (e.g. Waples 1990, 1991) and would be an appropriate and useful addition to the management of native Colorado River species. In addition, monitoring N?_N -would -provide the UBRIP the most direct measure of the basis for the management objective values. MonitorintDemogruPhic Parameiers The UBRIP currently conducts an interagency standardized monitoring program (ISMP). This program has generally focused on Colorado squawfish adults and young-of-the year (McAda 1987). To effectively monitor the population responses of species populations, this program should be continued for Colorado.squawfishand expanded to-include the other species. We estimated a target catch rate for adult Colorado squawfish needed to acquire the adult population size management objective (Table 9). These values give the UBRIP Empirical numbers that can be measured and assessed on a regular basis to determine if a stable age structure and recruitment of all life stages exists within each population and for Each species. Table 9. ISMP Target catch rates for adult Colorado squawfish based on N or each population. River Reach Existing Pop Estimate N. N./Pop Est ISMP catch rate (SE) Target rate (ISMP Pop Est/Nm Middle Green 1400 5477 3.91 1.09 (0.41) 4.26 Lower Green 1000 5477 5.48 3.08 (0.81) 16.88 Colorado 600 5477 9.13 0.59 (0.22) 5.39 In addition to enhancing the ISMP, population estimates of the census population for each species ' and population should be made on a regular interval. These estimates are particularly important for razorback sucker and humpback chub, because a quantified monitoring program is currently not in place for these species and little status information is available on them. Future ISMP should incorporate monitoring of all species as well as parameters needed to make population estimates for each population. 1 26