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i~ for successful spawning, with 160,000 fry shipped to Colorado from 1981 to 1988. Milt from wild greenbacks from Como Creek, Hunters Creek, Hidden Valley Creek and the Poudre River was also collected and used to fertilize ova from Bozeman females (Dwyer, 1988). This action also helped enhance the genetic diversity of the broodstock. An attempt was also made to establish a Poudre River greenback broodstock at the Saratoga NFH in 1984 and 1985. Eggs collected in 1984 did not survive, but 47$ of the eggs collected in 1985 survived to swim-up. None of the young accepted feed, and all died. Interestingly, eggs from the Poudre River population required much less time to develop and hatch than did those of the greenbacks from the Arkansas River drainage's Cascade Creek at the Saratoga NFH. At 8 C, eggs from the Poudre River fish required only 16 days to reach the eyed egg stage and 32 days to hatch, compared to 29 days to the eyed stage and 39 days to hatch for eggs from Cascade Creek (J. Hammer, Saratoga NFH, personal communication). New South Platte and Arkansas greenback broodstock were initiated at the CDOW Experimental Hatchery at Ft. Collins to replace the aging and unfunded USFWS broodstocks. During 1989, a total of 5,419 eggs were collected from Bear Lake, Como Creek, Hunters Creek and the Poudre River. in 1990, about 200 eggs were collected from Upper Hutcheson Lake. Fish were produced from all areas except the Poudre River, and eggs were collected again from the Poudre River in July 1992. Eggs were collected from the CDOW Experimental Hatchery broodstock in 1991 and 1992, with problems with asynchronous spawning experienced during 1992. Malachite green could not be used to control fungus in 1992, and all the 1989 year class of broodstock did not survive past the spawning season. Arkansas Drainage Broodstock. The Greenback Recovery Plan also calls for development of an Arkansas River greenback broodstock. To develop this broodstock, greenbacks from Cascade Creek were introduced into McAlpine Pond (privately owned) and Lytle Pond (on Ft. Carson Army Base). In 1984, eggs were collected from the greenbacks spawning in McAlpine Pond and in Lytle Pond and were sent to Saratoga NFH. Fry and catchable-sized greenbacks were produced at Saratoga NFH from 1987 through 1992. Due to FWS funding problems and the predominance of old adults within the Saratoga broodstock, the Arkansas River broodstock program was transferred from Saratoga NFH to the CDOW Experimental Hatchery. To facilitate establishment of the new broodstock at the CROW Experimental Hatchery, 3,200 eggs from South Apache Creek and 10,000 eggs from Saratoga NFH were shipped to the CDOW Experimental Hatchery in 1992. Following the collection of eggs at the Saratoga NFH in 1992, the remaining greenbacks at Saratoga NFH were lost due to water problems at the hatchery. Stockin 1 A wide range of stocking rates and methods have been used to re-introduce greenbacks into historic habitats. Early methods usually involved stocking low numbers (64 to 84) of adult and sub-adult greenbacks into renovated habitats during the fall of the year. Only small numbers of greenbacks were stocked due to the limited number of fish available from Como Creek. Unfortunately, colonization of the habitat was slow and genetic diversity was impaired due to the limited numbers of fish stocked. These problems undermined confidence in the ability to establish fishable populations The captive broodstock programs were initiated to allow more rapid establishment of new populations, to protect the small historic populations from over utilization as broodstock sources and to allow for genetic management. The captive broodstock program produced enough greenback fry to support stocking within each restoration site for at least three consecutive 14