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i 1 <br />'~ 0.8 <br />~' 0.6 <br />a 0.4 <br />V <br />~ 0.2 <br />~ 0 <br />~'}--~J---- -~ $ -~--------- <br />------- -a- :~ --- <br />1 2 3 1 2 3 4 1 2 3 <br />( 1998 { 1999 { 2000 { <br />Year and Sampling Rotation <br />FIGURE 3.-Mean CPE (fish per net hour; bars represent ± 1 SE) of roundtail chub <br />in Black Rocks, 1998-2000. <br />Fish Condition -Captured fish were removed from the nets and watched for a short <br />period to assess general health. Of the more than 500 humpback chubs handled during this <br />study (many handled more than one time) only two mortalities were documented. These two <br />fish were removed alive from the trammel nets, but had trouble orienting in the live well and <br />eventually died even though extra efforts (salt baths and movement of the fish to push water <br />through their gills) were made. All the remaining fish appeared healthy at release -correct <br />orientation and brisk swimming ability. No mortalities were recorded in the 50 humpback <br />chubs held overnight in live cages and all of these fish appeared healthy upon release. In the <br />majority of cases, recaptured fish also appeared healthy. However, two chubs (one roundtail <br />chub in 1999 and one humpback chub in 2000) exhibited severe fungus infections when they <br />were recaptured. These fish were treated with extra salt baths and were able to swim briskly <br />when released. However, their ability to survive the fungus infection is unknown at this time. <br />Movement <br />A total of 14 humpback chubs were recaptured in Black Rocks that had originally been <br />tagged in Westwater Canyon. All fish were originally tagged before 1998. In addition, three <br />6 <br />