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<br />WW <br /> <br />and released into the Colorado River in an attempt to reestablish <br />a population in this subbasin. <br /> <br />Procedures <br />We will assess survival, growth, and bioaccumulation of <br />selenium in razorback sucker larvae stocked in the restored sites <br />(Walter Walker state Wildlife Area and Adobe Creek) by conducting <br />concurrent in situ and on-site studies if fish are available. It <br />would be desirable to locate each study site close to one of the <br />monitoring sites in Task 1. The source of the fish has not been <br />identified, but it would be desirable to use fish from Green <br />River stock. <br />For the in situ studies, replicate test chambers will be <br />deployed at each site and stocked with equal number of larvae. <br />Survival will be monitored daily and the fish will be fed <br />plankton collected daily near the enclosures using light traps or <br />plankton nets. The plankton will be diluted to a known <br />concentration of plankters with site water and equal volumes of <br />this solution will be fed to fish in each enclosure. After all <br />the fish have been fed, the plankton solution will be filtered <br />and the plankton saved for selenium (and other inorganics) <br />residue analysis. Ammonia, conductivity, dissolved oxygen, and <br />pH will be measured daily in each enclosure. A composite sampler <br />will be used to collect 24-hour composite water samples for <br />selenium (and other inorganics) analysis. A subsample of the <br />composited water will also be analyzed for alkalinity, calcium, <br />chloride, conductivity, hardness, magnesium, pH, and sulfate. <br />The in situ tests will conducted for least 10 days, but it <br />would be desirable to keep the fish in the enclosures until they <br />attain stockable size. At the end of the test, the surviving <br />fish will be measured for total length and weight and saved for <br />selenium residue analysis. If the study extends beyond 30 days, <br />fish sampling will occur at 30-day intervals and water sampling <br />for selenium (and other inorganics) analysis will be done weekly <br />rather than daily. <br /> <br />7 <br />