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600 <br />500 <br />J <br />E <br />400 <br />X <br />_o <br />0 300 <br />C <br />0 <br />CU <br />U 200 <br />c <br />CU <br />a) <br />100 <br />Blue Springs -1 <br />Chut <br />...... <br />10 12 14 16 18 20 22 <br />River Kilometer <br />7/93 <br />.......... 6/94 <br />--- 7/03 <br />Figure 2. Dissolved carbon dioxide levels taken at various river kilometers in the Little <br />Colorado River during July 1993 (Mattes 1993), June 1994 (Robinson et. al 1994), and our <br />July 2003 reconnaissance trip. <br />The translocated humpback chub were exposed to various changes in water chemistry and <br />river discharge from their initial July 2003 capture near the LCR confluence and the <br />November 2003 monitoring trip. In the LCR, mean CO2 levels ranged from 86.5 to 216.5 <br />mg/L at the 1.9 RKM collection site and 16.2 RKM translocation site, respectively. <br />Although less pronounced, changes were also evident in dissolved oxygen (7.14 to 9.81 <br />mg/L), water temperature (25.8 to 23.62°C), conductivity (4,529 to 4,634 uS), and pH (7.80 <br />to 7.25). Although humpback chub were released under baseflow discharge and high <br />water clarity conditions, they were subject to a minor spate the following day (Figure 3). <br />Periodic flooding persisted until the November 2003 monitoring trip with two episodes <br />culminating in mean daily discharges of 7-8 times above baseflow (-6.4 m3/s near the <br />confluence). By the November monitoring trip, the LCR had returned to baseflow. Mean <br />Humpback chub <br />released ? <br />e Falls / <br />, <br />1 <br />10