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<br />(".) <br />C-, <br />" <br />..... <br />CD <br />C'J <br />...."', <br /> <br />resulted in preparation of an Augmentation Plan (Ryden 1997), and initiation of efforts in 1997 to stock <br />about 75,000 subadult razorback sucker in the San Juan River over a 5-year period, under guidelines of <br />the draft Genetics Management Plan (Crist 1997). <br /> <br />From 1997 through 1998, a total of 4,164 razorback sucker was stocked as part of the Augmentation <br />Plan, well below the anticipated amount of 15,000 fish per year. Finding larvae for the augmentation <br />program and then securing grow-out facilities in which to rear them limited the number of suitably sized fish <br />available for stocking. In 1998, the SJRIP developed its own grow-out ponds on Navajo Nation property <br />(Ojo Pond) near Farmington, New Mexico, and additional ponds followed (Avocet Ponds in 1999 and <br />Hidden Ponds in 2000), Annual collection ofIarvae in Lake Mohave and attempts to obtain excess juvenile <br />fish from a razorback sucker rearing program at Lake Mohave became standard procedure. In 1999, <br />about 65,000 larvae were obtained from Lake Mohave and stocked into Ojo and Avocet ponds. <br /> <br />As augmentation of razorback sucker began (1997), experimentally stocked razorback sucker were <br />recaptured during the course of adult monitoring studies, In 1997, a male razorback sucker group was <br />captured in what appeared to be a spawning aggregation. Larval collections that concentrated on finding <br />young razorback sucker in late spring were initiated in 1998; two larval razorback sucker were found that <br />year, and additional larvae were captured in 1999. This confirmed that stocked razorback sucker grew <br />and reproduced, As the larger number of stocked fish stocked attains reproductive size, the limitation of <br />small adult population size should be eliminated or at least diminished. <br /> <br />Preparation of a Colorado pikeminnow Augmentation Plan was also approved in 1997, but it was <br />postponed because of the success of experimental stocking ofYOY in 1996 and 1997, As noted above, <br />100,000 YOY Colorado pikeminnow were experimentally stocked each year in 1996 and 1997 to <br />determine habitat use and availability. Survival of those stocked fish appeared to be very good (Ryden <br />2000a, Trammell and Archer 2000), and this was one of the first successful attempts to augment Colorado <br />pikeminnowpopulations (Tyus 1991, Masslich alld Holden 1996). The YOY Colorado pikeminnow <br />became acclimated to the riverine environment relatively quickly and moved around, both upstream and <br />downstream (Tranunell and Archer 2000). This study showed that even when the river of concern, such <br />as the San Juan River, did not have the classic types of backwaters found in the Green River, stocked <br />YOY Colorado pikeminnow could still find acceptable habitat, avoid predators, and grow as well as their <br />wild counterpartS. <br /> <br />In addition to successful experimental stocking, a small recruiting population of Colorado pikeminnow <br />persists in the San Juan River, and there was concern that additional augmentation may dilute the genetics <br />of the wild stock. Therefore, a Colorado pikeminnow Augmentation Plan was not completed. <br /> <br />September 2000 <br /> <br />3-59 <br /> <br />Program Evaluation Report <br />