Laserfiche WebLink
<br />EXECUTIVE SUMMARY <br /> <br />Current Species Status: The Colorado squawfish (Ptychocheilus lucius) was <br />listed as endangered on March 11, 1967. The original recovery plan was <br />approved on Mar~h 16, 1978. This is a' revision of that plan. The Colorado <br />squawfish population has declined from historic levels. This decline may be <br />due to various human-caused physical and biological changes in the Colorado <br />River system where the fish occurs. <br /> <br />Habitat Reouirements and Limitinq Factors: The present range of natural <br />populations of the Colorado squawfish is restricted'to the Upper Colorado <br />River Basin (Upper Basin) in Colorado, New Mexico, Utah, and Wyoming, although <br />hatchery reared Colorado squawfish have been reintroduced into the Salt and <br />Verde Rivers in Arizona. The decline in the numbers and distribution of <br />Colorado squawfish is due to physical changes in the river system, including <br />stream alteration and habitat fragmentation as a result of dam construction, <br />irrigation; dewatering, and channelization. Biological changes including <br />competition with and predation by introduced nonnative fish also are factors <br />in the squawfish decline. <br /> <br />Recovery Obiective: Delisting. Each Colorado Squawfish Recovery Area <br />(Recovery Area) can be delisted as recovery objectives are achieved. <br /> <br />Recovery Criteria: Each Recovery Area will remain 1 isted until such time as <br />their recovery criteria are met. The species can be downlisted or delisted <br />when all Recovery Areas have been downlisted or delisted. The Colorado <br />squawfish will be considered eligible for reclassification to threatened when <br />naturally self-sustaining populations are maintained in the Upper Basin in the <br />following Recovery Areas: <br /> <br />(a) the Green River subbasin including the Green River from its confluence <br />with the Colorado River to its confluence with the Yampa River, the <br />lower 220 km (137 miles) of the Yampa River, and the lower 240 km <br />(150 miles) of the White River; <br /> <br />(b) the Colorado River from Palisade, Colorado, to Lake Powell; and <br /> <br />(c) the San Juan River from Lake Powell upstream to the confluence of the <br />Animas River near Farmington, New Mexico. <br /> <br />(The Colorado squawfish may be downlisted separately by Recovery Area <br />with the Green River and Colorado River areas being downlisted <br />concurrently.) <br /> <br />The Colorado squawfish will be considered eligible for delisting when: <br /> <br />(a) downlisting criteria have been met; <br /> <br />iii <br />