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<br /> <br />The NfWG took a creative approach to develop its own low-cost, alternative rearing facilities (Mueller 1995). <br />Narrow coves along the lake's shoreline were physically blocked with nets or earthen barriers which provided <br />rearing sites. Some seasonal, ephemeral ponds were also used. Non-native fish were removed, providing <br />predator-free nursery areas where razorback suckers could be stocked and reared. In 1990,90 old adult razorback <br />suckers were captured from the reservoir and stocked into an isolated backwater prior to spawning. They did <br />successfully spawn, and the young survived and grew at the remarkable rate of 35-40 cm their first year. <br />However, only 150 offspring were produced, a rate not nearly adequate for the intended goal. <br /> <br />In conjunction with the spawning attempt, researchers were developing methods of monitoring spawning success. <br />It was discovered that larval suckers were phototactic and could be captured by the thousands (Mueller 1993). <br />This discovery presented a unique opportunity where we could use naturally spawned larvae as a source offish <br />for our rearing ponds. We no longer had to capture and stock spawning adults. Rather than limiting the genetic <br />variability to a few captive spawners, we could utilize the genetic variability of the entire reservoir population <br />by simply collecting naturally-spawned larvae throughout the entire 3-month spawning season. A volunteer <br />program was started in 1994 to collect naturally-spawned sucker larvae. Equipment is provided by government <br />agencies and volunteers go out at night and collect larvae. Lights are hung in the water to attract the 10 mm <br />larvae which are dip netted and taken to the hatchery where they are fed and grown out to a larger size for <br />stocking. In 1994, over 11,000 larvae were collected and that number has doubled each year. This past season <br />over 107,000 fish larvae were collected which have produced over 60,000 juvenile razorback suckers. <br /> <br />While we have developed a method of collecting adequate numbers of larval fish, overall production continues <br />to be restricted by available rearing space. The goal is to rear suckers to a length of30 cm before releasing them <br />back into the reservoir. This growth can be reached in one year by using warm backwater habitats and low <br />stocking rates. Under hatchery conditions we have a tendency to stock at higher numbers which retards growth. <br />It often takes hatchery fish 2 or 3 years to reach an adequate size compared to only I year under more natural <br />conditions. The program has adopted less conventional culturing approaches to increase production. Today the <br />NFWG has cooperative agreements with municipal golf courses in three differe~t cities where we use their ponds <br />as grow-out facilities. fish are stocked at numbers (500/ha.) low enough to avoid the need for feeding, while <br />providing rapid growth, and producing fish at low costs. This expansion has been a tremendous success in not <br />only producing additional fish, but also in drawing attention to restoration efforts. The program is being widely <br />embraced by the public, advertised by the golf courses, and has been incorporated into some local high school <br />curriculums. <br />As of last year, nearly 6,000 juvenile razorback suckers had been reintroduced back into Lake Mohave. This <br />number will dramatically increase during the next couple of years as hatchery fish become available. Research <br />indicates that approximately 50% of the fish are surviving (Marsh 1997). for the first time in 3 decades, young <br />adults are now commonly being captured with old adults. The ultimate goal is to establish a young adult <br />population of 50,000 suckers. The Bureau of Reclamation and fish and Wildlife Service are presently negotiating <br />an agreement to provide the necessary resources to insure that goal is achieved. <br /> <br />DISCUSSION <br /> <br />There have been some successful restoration projects within the Colorado River basin, however, they have been <br />generally limited to those species inhabiting springs, small tributaries, and headwater habitats. Stream <br />renovation is a common management practice in smaller, more confined habitats where restoration can be <br />accomplished by removing the threat ofhybridization by means of natural barriers and eradication of non-natives, <br />or by isolation (Rinne and Turner 1991). However, we have not been as successful in larger, more complex river <br />ecosystems. <br />