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Colorado River Subbasin: Razorback sucker Adults <br /> 3000 — <br /> 2500 <br /> 41 <br /> M <br /> m <br /> V2000 I - <br /> W <br /> u I <br /> m 1500 <br /> c <br /> a 1000 <br /> a <br /> 500 <br /> 0 <br /> 2004 2005 2006 2007 2008 2009 2010 2011 <br /> Year <br /> Figure 6. Preliminary population estimates of the adult razorback sucker in the Colorado River <br /> (Palisade,CO to the confluence of the Green River). Error bars represent the 95 percent confidence <br /> intervals(Service 2015a). <br /> Razorback sucker stocked in the Green and Colorado Rivers have been recaptured in <br /> reproductive condition and often in spawning groups. Larval captures in the Green, Gunnison, <br /> and Colorado rivers document reproduction. Survival of larvae through their first year remains <br /> rare, largely due to a decrease in the availability of warm, food-rich floodplain areas and <br /> predation by a suite of nonnatives when the flood plain nursery habitats are available (Bestgen et <br /> al. 2011). However, occasional captures of juveniles (just over age-1)in the Green and Colorado <br /> rivers suggest that survival of early life stages is occurring. Collections of larvae by light trap in <br /> the middle Green River have been generally increasing since 2003; in 2013, the largest collection <br /> of light trapped larvae occurred (7,376; Figure 7, Service 2015a). <br /> 19 <br />