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14) Colorado squawfish use long-distance dispersal to best meet their life-stage specific <br />needs: larvae disperse downstream to warm nursery reaches where they remain and <br />grow until reaching adult size; adults disperse upstream to reaches rich in native forage <br />fish. <br />15) Population abundance in the Colorado River is relatively low: a total of 600-650 adults <br />and subadults was estimated for the period of study. <br />16) Compared to historical accounts, population abundance today appears low and <br />suggests the long-term trend of this population has been downward. <br />17) Maintenance of the population appears to depend on occasional strong year classes. <br />18) Two to three consecutive, strong cohorts of Colorado squawfish were produced <br />during the mid-1980's and recruited to the adult population in the early 1990's. <br />19) Frequency of strong year classes has been very low over the past 20 years. <br />20) Because of low and fluctuating adult numbers due to the infrequency of strong year <br />classes, the population appears vulnerable to extinction. <br />21) This population has the capacity to increase in abundance on its own without <br />augmentation if focused management activities are formulated, implemented, and <br />successful at boosting recruitment rates, perhaps through increasing the frequency of <br />strong year classes. <br />22) Prospects for the continued persistence and increased abundance of this population <br />likely will depend on identification of factors that limit spawning and hatching <br />success and survival of young, and most importantly, the effectiveness of recovery <br />actions aimed at addressing such factors. <br />RECOMMENDATIONS <br />1) Intensive, multi-year, scare-and-snare, mark-recapture efforts should be made <br />periodically to adequately monitor the status and trend of this and other upper basin <br />populations. A three-year effort period followed by a three-year non-effort period <br />would provide an abundance estimate every five years. Because the last effort for this <br />population ended in 1994, the next three-year effort period should begin in 1998. <br />vu