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<br />o <br />o <br />('") <br />,::> <br /> <br />7 <br /> <br />00 <br /> <br />During the three years of experimental stocking, specific sites were identified. The three <br />stocking sites originally selected for the stocking effort were chosen based on a high <br />occurrence of nearby backwater or secondary channel habitat, and characteristics known or <br />suspected to be highly important to the survival of the species. The three sites were kept <br />approximately 25-30 miles apart, so that monitoring efforts could easily detect any distinctive <br />movement patterns or downstream displacement of stocked fish. Stocking sites are located <br />at river mile 136.6 (Mixer Site, New Mexico), river mile 117.5 (Upper Utah Site), and river mile <br />79.6 (Bluff, Utah Site). These sites were modified from the original stocking plan for access <br />purposes. A fourth site was added in October 1994 at RM 158.6. <br /> <br />The Bluff Site was selected because this area has accounted for the only documented <br />razorback sucker captures in the mainstem San Juan River. The Mixer Site has a relatively <br />large amount of clean cobble and gravel substrates (Bleisner and Lamarra 1993). that should <br />support larger standing crops of algae and invertebrates that comprise the diet of juvenile and <br />adult razorback sucker (Bestgen 1990, Minckley et al 1991). This area is also <br />geomorphologically very complex and provides numerous slow velocity areas. The Upper Utah <br />Site above Aneth, Utah, provides a high degree of channel braiding. This is an intermediate <br />location between the Bluff and Mixer sites and may provide communication between the <br />separately stocked populations. The Upper Utah and Mixer sites should have less angling <br />pressure than the Bluff Site, due to limited accessibility by road. The fourth stocking site at <br />RM 158.6 was later added to help improve retention of stocked razorback sucker in the San <br />Juan River. <br /> <br />Based upon the information gained during the monitoring of the experimentally stocked <br />razorback sucker, the Service now proposes to stock fish at the most upstream site, Hogback <br />Diversion Dam at RM 158.6. Releasing the fish at this site would provide almost 90 miles of <br />river for the fish in a reach of the San Juan having suitable habitat. The majority of recaptured <br />fish in the experimental stockings were found between RM 140 and 50. <br /> <br />D. INTERRELATIONSHIPS WITH OTHER PROJECTS OR PROPOSALS <br /> <br />The proposed plan has been formulated to complement and support the ongoing research effort <br />for the Implementation Program. The Program itself was established to foster such research <br />and coordinate the numerous activities ongoing and proposed for the San Juan River Basin <br />with potential to impact the endangered fish species. Other activities that may occur in the <br />Basin include, but are not limited to, the U.S. Army Corps of Engineers' permitting <br />responsibilities for dredge and fill activities in waters of the Untied States through section 404 <br />of the Clean Water Act, each respective State and Tribal resource agency's responsibilities for <br />management and protection of resident fish and wildlife resources, and other Federal, State. <br />and Tribal land management entities with responsibilities within the Basin. <br /> <br />II. ALTERNATIVES <br /> <br />A. NO ACTION <br /> <br />Under a No Action alternative, the augmentation plan would not be implemented. Although <br />