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<br />.0 <br />(":.'! <br />Co) <br />.. , <br />v <br />~ <br />W <br /> <br />16 <br /> <br />V. <br /> <br />ENVIRONMENTAL CONSEQUENCES <br /> <br />The proposed action is considered to pose no impacts to environmental resources in the <br />San Juan River other than aiding in the ultimate recovery of the razorback sucker through <br />the provision of much needed life history and distribution information. <br /> <br />Under the No Action Alternative, the proposed experimental stocking of razorback sucker <br />would not occur in 1996. However, the Implementation Program, with its attendant <br />commitment to research on and recovery of the endangered fish species of the San Juan <br />River would continue. The biological and hydrological investigations now underway would <br />continue; the analysis by the Bureau of Reclamation of the reoperation of Navajo Dam to <br />mimic the natural hydrograph of the San Juan River and provide releases from Navajo <br />Dam for the benefit of the endangered fish species would continue; research required in <br />the Biological Opinion for the Navajo Indian Irrigation Project would also continue. <br />Federal agencies would still be required to comply with the mandates of the Endangered <br />Species Act to insure that actions they propose to authorize, fund, or carry out are not <br />likely to jeopardize the continued existence of threatened or endangered species or result <br />in the adverse modification or destruction of critical habitat for listed species. <br /> <br />Because this proposal entails no modification of releases from Navajo Dam, the <br />manipulation of flows would be the same under the No Action Alternative or for the <br />proposed 1996 stocking. <br /> <br />If stocking of hatchery-reared razorback sucker were to proceed in 1996, follow-up <br />monitoring efforts would coincide with the four-month, 250-CFS experimental low flow <br />from Navajo Dam that has already been approved for the winter of 1996/1997. This <br />would allow for the collection of habitat use data during this test flow period that might <br />otherwise be unattainable given the paucity of radio-tagged fish presently remaining from <br />previous stockings. Also, differential overwinter survival can be studied and compared <br />to fish stocked in the fall of 1994/1995 (a normal winter base flow period for the San Juan <br />River) and to fish that have already had two full years to adapt to riverine conditions in ali <br />seasons. Muscle plugs taken from recaptured fish from both the fall 1994 and fall 1996 <br />stockings could provide comparative data on contaminant uptake by this species. In <br />addition, the stocking of fish currently being held at Wahweap could serve to dampen any <br />negative genetic impacts from previous stockings, since these fish are progeny from <br />different paired matings than the fish from all previous stockings, which were dominated <br />(97%) by progeny from a single paired mating. <br /> <br />The implementation of either of the options identified above would not place further <br />constraints on other resource uses in the basin than already exist The requirement for <br />federal entities to ensure that their actions are not likely to jeopardize listed speCies or <br />adversely modify or destroy critical habitat will continue to be adhered to for actions <br />regarding the razorback sucker regardless of this experimental program. The confirmed <br />presence of the experimental fish would not render analysis of impacts of proposed <br />