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<br />. <br /> <br />o <br /> <br />587 <br /> <br />3. Determine Habitat Ouality. Determine habitat quality for each habitat mapping unit utilized in <br />Objectives 1 and 2. Habitat quality will quantifY specific physical and biological features of riffle, run <br />and low velocity habitats. This objective is a continuation of 1996 work. <br /> <br />4. Correlate Habitat Utilization to Availabilitv. Correlate and compare detailed radio tracking data and <br />y-o-y captures (habitat utilization) to habitat availability. This is a continuation of 1996 work.. <br /> <br />5. VeritY Soawning Bar Conditions. VeritY physical habitat conditions and complexities within the <br />documented squawfish spaWning bar and for other potential spaWning locations. Utilizing data <br />collected in 1995 and 1996, including identification of other locations exhibiting similar characteristics <br />to the documented spawning bars, detailed sampling of the most comparable sites will be completed. <br /> <br />6. Analyze Razorback Sucker Habitat Availability. Analyze potential Razorback habitat availability <br />based upon habitat utilization from experimental stockings. Work will be closely correlated with the <br />radio tracking data collection effort. <br /> <br />Methods: <br /> <br />1. Habitat mapping (San Juan River and Colorado River). The documentation of habitat types within <br />the San Juan River from RM180 to RM--2 will be continued during FY97. Two separate videographic <br />flights will be mapped as part of this year's effort. Emphasis will be on winter low flow and summer <br />base flow. Habitat mapping will be accomplished by directly delineating habitat boundaries in the field <br />utilizing color prints from airborne videography taken a few days prior to the field investigation. <br />Mapping methodologies (habitat types) will be the same as previous studies. Special emphasis will <br />be placed on the Lake PoweIVSan Juan River interface. Processing of the data in the GIS system <br />produces coded polygons for which the surface area is computed and stored individually. The surface <br />areas of major habitat types (eg., riffle, run, slackwater, eddy, backwater, etc.) and an index of habitat <br />complexity (Shannon-Weiner) will be summarized by river mile and geomorphic reach. Our <br />objectives are to continue with a program designed to determine the spatial, temporal (baseflow <br />comparisons from year to year), and discharge-related variations in habitat abundance and complexity, <br /> <br />2. Digitize and process data utilizing GIS. Upon completion of each habitat mapping program <br />(Objectives 1 and 2), the field maps will be rectified and digitized into ArcCAD. <br /> <br />3. Detennine Habitat Ouality. Habitat quality characterization is intended to describe the physical and, <br />chiefly, biological characteristics of low velocity habitat types within the San Juan River. The <br />distribution and productivity of these types of habitats may influence the distribution of various life <br />stages of fishes which utilize them. Backwater habitats will be sampled at 18 sites in the lower six <br />geomorphically defined reaches (3 sites per reach). Samples will be collected in April, August, <br />September and October. The intent will be to assess the condition and productivity of these habitats <br />just prior to runoff and then after runoff during the period when storm evertts are most intense and <br />sensitivity of squawfish YOY to disturbances is greatest. Additional samples may be collected in <br />backwaters where UDWR finds stocked YOY Colorado squawfish and requests such sampling. As <br />a control, six backwaters will be selected in the lower Colorado and Green Rivers (12 total) to <br />compare the biological productivity of backwaters in known Colorado squawfish nursery areas with <br />San Juan backwater habitats. Habitat quality will consist of measuring physical (water depth, <br /> <br />47 <br />