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<br />I <br />I <br />;1 <br />I <br />I <br />'I <br />I <br />I' <br />;1 <br />I <br />l' <br />I <br />I <br />I <br />I <br />II <br />I <br />'1 <br />I <br /> <br />4.2. IDENTIFY. PROTECT, AND RESTORE HABITATS. <br /> <br />In order to determine full recovery potential of endangered fish species, <br />qualification and quantification of the historic and present river channel conditions <br />are necessary. Data on historic San Juan River channel conditions are available in <br />varying and limited forms; however, sufficient data exist to allow limited <br />comparisons with current channel conditions and dynamics. Initial tasks within <br />this objective are to identify historic and current river channel conditions. This <br />includes identification of geomorphically distinct river reaches and detailed habitat <br />mapping of these reaches. Included within this characterization is a determination <br />of overall changes from historic to current conditions. Research activities are <br />designed to evaluate physical habitat changes, both qualitatively and <br />quantitatively, as a response to different flow regimes. Activities are designed to <br />address both unregulated flows and those that can be provided by releases from <br />Navajo Dam. Modelling of flow and habitat relationships will be conducted to <br />allow for a definition of expected river channel conditions that are likely to occur as <br />a result of different flow regimes. Habitat use patterns by all life stages of <br />endangered. other native, and non-native fish species will be determined and <br />monitored to evaluate responses to different flow regimes. These data will be <br />incorporated into flow recommendations. Results of native fish community habitat <br />studies will be incorporated into management recommendations for the removal or <br />modification of instream structures that impede native fish movements or limit <br />range and creation or enhancement of required but unavailable or limited habitats. <br />To identify and provide for flow regimes necessary to recover the endangered fish <br />species and benefit the native fish community, an evaluation of the quality. <br />quantity, and sources of water is required. While Navajo Reservoir has been <br />identified as the primary origin, other sources, particularly the Animas River, will be <br />investigated. Analyses of stream channel conditions provided by both reservoir- <br />controlled flows and those occurring via inflow from tributary streams will be <br />conducted. Included within the provision of flows necessary to recover the <br />endangered fish species and manage the native fish community is the necessity to <br />protect these flows. Means of protection will be attained through Tribal, State, <br />and Federal regulatory actions. <br /> <br />4.3. IDENTIFY AND MANAGE THE NATIVE FISH COMMUNITY OF THE <br />SAN JUAN RIVER BASIN TO RESTORE THE ENDANGERED FISH <br />SPECIES <br /> <br />Protection and long-term management of the native fish community is best <br />accomplished through an approach that emphasizes an evaluation of historic and <br />current community structure dynamics. Specifically, identification of the spatial <br />and temporal distribution and abundance patterns of the native fish species relative <br />to man'caused alterations of the San Juan River is the focus of this objective. In <br />concert with research activities on physical environmental changes, fish <br />community data will provide necessary guidance for selection and implementation <br /> <br />8 <br />