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<br />,~ <br />~ <br />00 <br />,..... <br />{..) <br />c..; <br /> <br />When the 7-year research plan was initiated, its ultimate goals were (1) to identifY the physical, chemical, <br />and biological factors that limit endangered and native fishes and (2) to provide options for conserving and <br />restoring the endangered fish community (Bureau et al. 1992). Specific objectives included: <br /> <br />I. Collect detailed information on the relative abundance and distribution of fisheries in the <br />San Juan River Basin, with emphasis on areas downstream of Navajo Dam. <br /> <br />2. Characterize physical habitat for fisheries in the San Juan River and the relationship <br />between flow and physical habitat. <br /> <br />3. Detennine the biological response of fish populations to the reoperation of Navajo Dam. <br /> <br />4. Detennine habitat use and needs of the Colorado pikenrinnow and razorback sucker in the <br />San Juan River. <br /> <br />5. Characterize water quality in the San Juan River and identifY critical quality issues that may <br />affect recovery of endangered species. <br /> <br />6. IdentifY interactions between native and nonnative species. <br /> <br />7. IdentifY and test management options which could improve reproduction and recruitment <br />of target species. <br /> <br />As noted in the objectives, the 7-year research plan included investigation of the entire native fish <br />community, rather than just the two endangered fish species. The rOlUldtail chub was also identified as a <br />target species. Although it was not listed as endangered, it was considered for listing in several parts of the <br />Colorado River Basin and was rare in the mainstem San Juan River and other areas. In addition, the <br />studies comprising the 7-year research plan were developed to examine the entire San Juan River, from <br />Navajo Dam to Lake Powell, and investigate all life history phases of the fishes (larvae, young, juvenile, <br />and adult). A major aspect of the 7-year research plan, and of the SJRIP, was evaluation of the biological <br />effects of reoperation of Navajo Dam to mimic a natural hydrograph. Reoperation primarily involved <br />releasing higher flows during spring runoff and lower flows during the rest of the year. Many of the studies <br />were designed to investigate the biological and habitat changes that occurred with the more-natural flow <br />pattern. In addition, adaptive management was included as an important component of the 7 -year research <br />plan. This meant that as new needs for research or management become evident, additional studies or <br />management actions would be implemented, even though the initial plan may not have foreseen those needs. <br /> <br />To meet these objectives, a biological studies series was formulated, and sampling began in 199 I. Table <br />2. I shows the various studies that were implemented on the San Juan River in response to the 7-year <br />research plan, as well as the 1987 to 1990 studies. Four core biological studies were <br /> <br />September 2000 <br /> <br />2-5 <br /> <br />Program Evaluation Report <br />