Laserfiche WebLink
<br />o <br />~, <br />~ <br />~1 <br /> <br />Colonel John N Reese <br /> <br />D R AFT <br /> <br />9 <br /> <br />0) <br /> <br />Arizona, New Mexico, Utah, and Colorado, as well as Federal representatives <br />from the National Park Service, the Bureau, and the Service) recommended that <br />the San Juan River be added to the Colorado squawfish recovery plan. The <br />updated Colorado squawfish Recovery Plan (August 6, 1991) states that the <br />species can be downlisted to threatened status when all recovery areas <br />(including the San Juan River from lake Powell upstream to the confluence of <br />the Animas River) have naturally self-sustaining populations. The San Juan <br />River is also iAcluded in the delisting criteria. <br /> <br />Razorbac~ Suc~er <br /> <br />Historical and Current Distribution <br /> <br />The razorback sucker, an endemic species unique to the Colorado River Basin, <br />was historically abundant and widely distributed within warmwater reaches <br />throughout the Colorado River Basin. Historically, razorback suckers were <br />found in the main stem Colorado River and major tributaries in Arizona, <br />California, Colorado, Nevada, New Mexico, Utah, Wyoming, and in Mexico (Ellis <br />1914; Minckley 1973). Bestgen (1990) reported that this species was once so <br />numerous that it was commonly used as food by early settlers, and further, <br />that commercially marketable quantities were caught in Arizona as. recently as <br />1949. In the Upper Basin, razorback suckers were reported in the Green River <br />to be very abundant near Green River, Utah, in the late 1800's (Jordan 1891). <br />An account in Osmundson and Kaeding (1989) reported that residents living <br />along the Colorado River near Clifton, Colorado, observed several thousand <br />razorback suckers during spring runoff in the 1930's and early 1940's. In the <br />San Juan River drainage, Platania and Young (1989) relayed historical accounts <br />of razorback suckers ascending the Animas River to Durango, Colorado, around <br />the turn of the century. Platania and Young (1989) also reported the 1976 <br />capture of two adult razorback suckers by VTN Consolidated, Inc., from an <br />irrigation pond adjacent to the San Juan River near Bluff, Utah. <br /> <br />In August 1990, the New Mexico Department of Game and Fish (lief Ahlm, <br />Fisheries Specialist, pers. comm.) interviewed two anglers from Aztec, New <br />Mexico, who claimed to have .commonly. caught razorback suckers in the Animas <br />River near Cedar Hill bridge in the 1930's and 1940's. When the two men were <br />shown a battery of photographs, including roundtail chub (Gila robusta), <br />humpback chub (Gila ~), bony tail (Gila eleqans), bluehead sucker <br />(Pantosteus discobolus), flannelmouth sucker (Catostomus latiDinis), razorback <br />sucker, and Colorado squawfish, they both immediately identified the razorback <br />sucker as the fish they had caught. However, prior to the 1976 capture by VTN <br />Consolidated, Inc., there were no scientifically verified reports of razorback <br />sucker captures in the San Juan River drainage. <br /> <br />The current distribution and abundance of razorback sucker has been . <br />significantly reduced throughout the Colorado River system (McAda 1987; McAda <br />and Wydoski 1980; Holden and Stalnaker 1975; Minckley 1983; Marsh and Minckley <br />1989; Tyus 1987). The only substantial population of razorback suckers <br />remaining, made up entirely of old adults (McCarthy and Minckley 1987), is <br />.found in lake Mohave; however, they do not appear to be successfully <br />recruiting. While limited numbers of razorback sucker persist in other <br />