Laserfiche WebLink
<br />.\ <br /> <br />wW <br /> <br />Restored sites in the floodplain of the Colorado River are expected to provide suitable habitat for <br />early life stages of razorback sucker and other listed fishes. These areas will be available as nursery <br />habitat for drifting larvae. They may also be used as grow-out areas for hatchery-produced larvae <br />destined for augmentation of wild populations. <br /> <br />Flows necessary to reduce elevated concentrations of selenium to acceptable concentrations in <br />water and food organisms and still maintain habitat that is attractive to and suitable for endangered <br />fish will be determined. Along with the biological effect concentration, this information is needed <br />for developing remediation and future adaptive management strategies to assess the suitability of <br />these restored sites as razorback sucker habitats. <br /> <br />IV, Study Goals, Objectives, End Product: <br />Goals/Objectives: <br />1. To determine if flows necessary to reduce elevated concentrations of selenium to acceptable <br />concentrations in water and food organisms and still maintain habitat that is attractive to and <br />suitable for endangered fish. <br /> <br />End Product: <br />Development of remediation techniques to alleviate selenium (and other inorganics) contamination <br />problems that may cause adverse effects on razorback sucker and other endangered fish recovery. <br /> <br />V, Study Area: <br />Channel area at Walter Walker State Wildlife Area (VVWSW A) along the Colorado River near <br />Grand Junction, Co. <br /> <br />VI. Study Methods/Approach: <br />A comprehensive baseline survey was completed to determine the present level of selenium (and <br />other inorganics) contamination at this site. Baseline data offish species composition and use of <br />this site has been collected. A water inlet control structure has been installed and is being operated <br />at the upper end ofthe dike surrounding WWSW A, Varying flows will be allowed through this <br />structure to determine what amount of water is necessary to dilute the ambient concentrations of <br />selenium in water and food organisms to a concentration that will not adversely affect the <br />endangered fIsh, Fish species composition and utilization will also be monitored to ensure habitat <br />is maintained that is still attractive to the endangered fish, This monitoring effort will be continued <br />after remediation measures have been implemented to determine if concentrations of these <br />contaminants have changed in response to these measures. In addition to selenium and other <br />inorganics, this monitoring program will also include measurements of general water quality <br />parameters, and water and sediment discharge into and out of the restoration site. <br /> <br />VII. Task Description and Schedule: <br />Objective l: <br />1. Operate water control structure at various flows and monitor fish species composition and use of <br />the flooded backwater; compare this fish use data with baseline data collected in 1995 &1996, <br /> <br />2 <br />