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<br /> <br />o <br />o <br />(~) <br />" <br />~.. <br />-.J <br /> <br />16 <br /> <br />Within the preferred alternative are several options concerning the source of stocked <br />fish. These options, either singly or in combination, would be both time and location <br />dependent in able for the augmentation plan to respond to conditions both at the <br />hatchery locations and in the San Juan River. For the purposes of this analysis, the use <br />of all sources has been considered as part of the alternative under review. <br /> <br />Because of the screening criteria to be in place prior to stocking regardless of the <br />source of the fish to be stocked, it is not expected that hatchery-reared razorback <br />sucker will expose wild fish to pathogens or diseases not already occurring in the wild <br />population. <br /> <br />Based on the length of river available to the stocked and wild populations of razorback <br />sucker and the extremely low populations of wild razorback sucker in the San Juan <br />River, it is not anticipated that competition for habitat or food will occur between the <br />stocked and wild fish. Indeed, it is expected that monitoring of the stocked fish may <br />allow researchers to gather more, critically needed, information concerning the wild <br />population of razorback sucker. <br /> <br />All experimental razorback sucker stock are Fl progeny of San Juan River arm of lake <br />Powell razorback sucker that were captured near Pi ute Farms Marina. These offspring <br />are fish from paired matings that took place at Ouray National Fish Hatchery in 1992. <br />Separate groups of these fish were raised at Colorado State University and Ouray <br />National Fish Hatchery (NFH) before being transferred to the Utah Division of Wildlife <br />Resources' Wahweap Warmwater Fish Hatchery (Wahweap) in the winter of 1992, and <br />the spring of 1993, respectively. ThElse fish were dominated (approximately 97%) by <br />progeny representing a single paired mating. All razorback sucker that were not used <br />for the experimental stocking study in the San Juan River in 1994 and 1995 were <br />stocked into lake Powell at Piute Farms Marina in August 1995. In late summer and <br />fall 1995, approximately 2000 razorback sucker were transferred to Wahweap from <br />Ouray NFH (900 fish) and Valley City NFH (1100 fish). These fish were also Fl <br />progeny from the 1992 paired matings at Ouray NFH, but represent different parental <br />lineage than those previously held at Wahweap. Three hundred of these fish were <br />utilized in the 1996 stocking efforts. <br /> <br />The potential to affect the genetic intElgrity of the wild population of razorback sucker <br />in the San Juan River will be addressed by the safeguards of the Genetics Management <br />Plan and the adherence to the sequential priority of stocks to be used. Razorback <br />sucker from the Green and Colorado rivers, lake Mohave, and the San Juan River arm <br />of lake Powell (the three sources for use in this augmentation effort) were studied to <br />determine if each system contained genetically differentiated or distinct stocks of <br />razorback sucker. Based on analysiS of allozyme variation and mitochondrial DNA, <br />distinct stocks of razorback sucker could not be identified. However the limitations of . <br />the study and possible bases for lack of differentiation are still in debate within the <br />scientific community. Questions have been raised concerning the applicability of <br />utilizing lake Mohave stock for augmenting the San Juan River population. However, <br />there are so few naturally occurring wild razorback sucker in the San Juan it may prove <br />to be impracticable and ultimately act to the detriment of the recovery of the species <br />