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<br />Ww <br /> <br />IV. Description of past performance on this or similar project. <br /> <br />Not applicable. <br /> <br />V. Study Area <br /> <br />Two pilot projects will be implemented on the Colorado River. <br />pending are Adobe Creek and Walter Walker State Wildlife Area. <br />refugia ponds at Horsethief Canyon State Wildlife Area will be <br />reference site. <br /> <br />Sites <br />The <br />used as a <br /> <br />VI. Study Methods/Approach <br /> <br />Task 1. Monitoring of candidate sites. <br /> <br />Rationale <br />In order to determine the suitability of restored flood plain l1abitats for <br />use by razorback suckers and other listed fishes. tile degree of selenium <br />(and other inorganics) contamina~ion in several key ecosystem components <br />must be determined. Moreover, general habitat characteristics such 3S <br />water quality, sediment texture, and primary production should be assessed <br />in tl1ese sites. Tl1is information is needed for developing future adaptive <br />management strategies to assess the suitability of these restored sites as <br />razorback sucker habitats. <br /> <br />Procedure <br />A comprehensive baseline survey will be conducted to determine the present <br />level of selenium (and other inorganics) contamination and also fish <br />species composition in the two candidate restoration sites and the <br />reference site before water control structures are installed. This <br />monitoring effort will be continued" after remediation measures have been <br />implemented to determine if concentrations of these contaminants have <br />changed in response to these measures. Species composition will also be <br />monitored to determine what flows are necessary to reduce selenium levels <br />but still maintain l1abitat tl1at is attractive to the fisl1. In addition to <br />selenium and other inorganics, this monitoring program will also include <br />measurements of general water quality parameters. sediment texture, food <br />organisms, and water and sediment discharge into and out of each <br />restoration site. Tile baseline survey will be conducted in 1995. In <br />1996, a water inlet control structure will be installed at the upper end <br />of tile dike surrounding WWSWA. Varying flows will be allowed tl1rougl1 this <br />structure to determine what amount of water in necessary to dilute the <br />ambient levels of selenium to a level that will not adversely affect tile <br />razorback sucker. Fish species composition will continue to be monitored <br />to ensure that dilution flows will still maintain habitat that is <br />attractive to fish. The major components of the monitoring phase are as <br />follows: <br /> <br />A. Establish sampling sites in each candidate restoration site. The <br />number and location of these sites will be determined after a <br />thorough inspection of the candidate restoration sites. The use <br />of establisl1ed sampling sites will allow for detection of temporal <br />trends in contaminants and water and sediment quality. <br /> <br />B. <br /> <br />Establish sampling scl1edules at each site. <br />sampling will depend on the parameter being <br />budgetary and manpower constraints. <br /> <br />Tile frequency of <br />monitored and <br /> <br />C. Develop standardized procedures for sampling and analyses. <br /> <br />BC-l~-D <br />