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I I I I I I I I I I I I I I I I I I I Habitat analysis during the study included both qualitative and quantitative approaches, Qualitative habitat analysis involved a general reconnaissance of the entire study reach. The objectives of this generalized qualitative survey were to: 1) determine the range of habitats that existed within the study area; 2) identify significant physical changes to the Dolores River drainage since the 1981 survey (Valdez et at. 1982) i.e. presence of barriers to movement, dewatering, or point pollution sources and; 3) identify habitat features that required additional quantification, i,e, potential spawning area and nursery areas. Quantitative habitat analysis in 1990 included: 1) counting backwaters and potential spawning areas; 2) documenting physical attributes of potential spawning areas, and; 3) compiling and presenting USGS flow data for the Dolores River system, Backwater counts included all backwaters encountered while traversing any portion of the study area during a field trip. Criteria used to delineate a backwater were: 1) the length of the backwater exceeded the width at the mouth and; 2) surface area of the backwater was at least 15 m2. Density of backwaters was reported as number of backwaters per mile. Physical measurements of backwaters, including water depth, surface area and substrate type were made for all backwaters sampled. Surface area was estimated for all backwaters counted but not sampled, . A count of potential spawning areas was made within the study area in 1990 and 1991. Classification of these sites was based on the presence of deep pools in proximity to, and interspersed with, cobble-rime habitat (Sensitive Area Document; Biological Subcommittee, 1984). Further refinement of the number of potential spawning areas was made based on spawning sites described in the Yampa River, a system with habitat features similar to the Dolores River (Archer and Tyus 1984). Physical characteristics of these areas included: 1) suitable spawning habitat (graveVcobble/boulder bars with average depths of 0.3 to 3 m and velocities of 0.3 to 1 m/s), and; 2) suitable resting or staging habitat consisting of pools and eddies with average depth of 2 m and velocities of 0.3 m/s or less. Maps and detailed measurements of the physical attributes of these sites were made on three representative potential spawning areas in 1990 and 1991 under low flow conditions. Scaled maps were produced for each site showing channel configuration, water depths, surface macrohabitat features, substrates, and substrate embeddedness, Corresponding velocity data were provided for each site. 3.4 Water Quality, Macroinvertebrate and Sediment Sampling Six water quality and macroinvertebrate sampling sites were established within the study area (Figure 2). Twenty-five water quality parameters were measured at each site (Table 3). Water samples represented grab samples taken at one point in time and integrated across the channel at one location. All water samples were stored in coolers at 40C until processing. Water quality analyses were performed by ChemTech Laboratories of Murray, Utah (State of Utah and EP A Certification # E-56). Additional water quality parameters, including conductivity and salinity were measured afield using a Yellow Springs Instruments (YSI) temperature/conductivity/salinity meter or a Hydrolab Surveyor n. One sediment sample was collected at each water quality sampling site for analysis of Radium-226. A 5-cm diameter core sampler was used to collect one 8-cm sediment profile from the waters edge at each site, Samples were placed in a sealed container, stored at 40C, and analyzed by Core Laboratories, Inc" of Casper, Wyoming. Benthic macroinvertebrates were sampled using a modified Hess sampler (1 ft.2). Similar sample sites were selected where possible to minimize sample variation. Macroinvertebrate sample sites were located in cobble riffles, with velocities ranging from 0.3 to 0.6 m/s and depths of 25 to 36 cm. 5