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8000 <br /> w 7000 <br /> m <br /> L <br /> 3 6000 <br /> L <br /> Y <br /> 5000 <br /> Y <br /> U <br /> 4000 <br /> L <br /> 0 <br /> N <br /> M <br /> 3000 <br /> 0 <br /> L <br /> 2000 <br /> E z 1000 <br /> 0 <br /> �i� 01 �� CP 00 O� O� O'' O� Oh OHO 01 O% O°� ti0 titi ti� ti' <br /> N ti� ti0 N _C ,y0 .ti0 1ti0 1ti0 ,LO .ti0 -0 1ti0 1y0 1ti0 -P ,LO <br /> Year <br /> Figure 7. Numbers of razorback sucker larvae collected in light traps in the middle Green River since <br /> 1993. <br /> In the San Juan River, 130,473 razorback suckers were stocked from 1994 through 2012. The <br /> number of endangered fishes stocked in the San Juan River is reported annually(see <br /> http://www.fws.gov/southwest/sjrip//). After stocking in the San Juan River began, river wide <br /> razorback sucker population estimates of 268 in October 2000 (Ryden 2001)have since grown to <br /> 1,200 in October 2004 (Ryden 2005), and to about 2,000 and 3,000 in 2009 and 2010, <br /> respectively (Duran et al. 2013). Additional mark-recapture data indicates increasing razorback <br /> sucker abundance estimates since 2009 (Durst 2014). However,because there is little to no <br /> documented recruitment in the San Juan River,this population increase should be attributed <br /> almost entirely to augmentation with hatchery-reared razorback suckers. <br /> Three razorback sucker stocked in the San Juan River near Farmington,NM, for the San Juan <br /> Recovery Program were captured between Moab, UT and the state line with Colorado in 2008. <br /> This demonstrates that exchange of stocked razorback sucker between the San Juan River and <br /> the Upper Colorado River is certain, and may have ramifications for recovery criteria. <br /> Researchers have confirmed that hundreds of razorback sucker are using both transitional inflow <br /> areas and fully lacustrine (lake-like)habitats in Lake Powell. Razorback sucker are spawning in <br /> the lake and there is now evidence that recruitment may be occurring (Service 2015a). While the <br /> role of Lake Powell in the recovery of razorback sucker is unclear, 75 individuals were detected <br /> in the San Juan arm of Lake Powell in 2011 (Francis et al. 2013). <br /> To summarize,the razorback sucker was facing extirpation in the Upper Colorado River basin <br /> approximately 20 years ago. To build population numbers in the Green, Colorado, and San Juan <br /> River subbasins, over a quarter of a million razorbacks have been stocked in these rivers. <br /> Stocking continues today and reproduction is occurring and increasing. Recruitment has also <br /> 20 <br />