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<br />C? <br />':~) <br />(~) <br />I-" <br /> <br />e,:, <br /> <br />0) <br /> <br />Alteration and loss of habitat have contributed to the decline of the Colorado <br />5quawfish and razorback sucker in the San Juan River. Recovery of these <br />species may be aided by assessing the quantity and quality of habitat needed <br />for recovery and by developing or enhancing habitat through management <br />techniques, such as instream flows, creation of backwaters, or other nonflow <br />activities, etc. The use of any of these management techniques will also be <br />considered in relation to successful implementation of other habitat <br />management techniques to provide a balanced contribution from each. <br />Initially, the habitat development and enhancement techniques described in <br />this section will be applied experimentally to determine if the squawfish and <br />razorback sucker will use developed habitat and if such techniques contribute <br />to recovery. Appropriate permits and NEPA compliance will be required. <br /> <br />Habitat management techniques will be tested in a variety of habitats, <br />including backwaters and side channels (low velocity habitats). spawning <br />habitat and may be used to open new habitat through the removal of instream <br />barriers, the construction of fish passages, or side channel modifications. <br />Testing should address the questions of quantity of specific habitats needed <br />and the problems associated with habitat quality. If lack of a specific <br />habitat type is limiting one or more life stages of the squawfish or the <br />razorback sucker, then increasing that habitat type may increase the abundance <br />of fish for the particular life stage. If lack of habitat quality is the <br />problem. the focus should be on improving, in selected locations, the quality <br />of existing backwaters and spawning habitat by improving flows, water <br />temperature. water chemistry and turbidity, decreasing the numbers of <br />predatory fish. etc. The role of Changing flows in creating important <br />ephemeral backwater habitat must also be determined. <br /> <br />3.3.1 Low Velocitv Habitats <br /> <br />Young-of-the-year Colorado 5quawfish are most often found in low velocity <br />nursery and feeding habitat. Theses habitats include backwaters and side <br />channels, and can be created by manipulating river flow or by side channel <br />modification to retain the characteristics typical of the river system. <br />Regulation structures such as Navajo Dam can be operated to control river flow <br /> <br />20 <br />