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<br />'Bonytail.-Bonytai1 is the second highest priority species (Priority 2), River reaches to stock <br />bonytai1 in priority are: 1) middle Green River/Yampa River - in Dinosaur National Monument; <br />and 2) Colorado River - Palisade to Loma. All bony tail should be 200+ mm TL, i.e., age 2+. <br />Stocking should occur each late summer/fall for 12,000 bony tail per reach for 7 years. By <br />accepting the State of Colorado's stocking plan, the Pm gram has deemed that stocking bony tail <br />in the proximity of existing humpback chub populations is an "acceptable" risk regarding the <br />potential of hybridization between the species. <br /> <br />Colorado pikemimww.-Colorado pikeminnow is the last priority species (Priority 3). River <br />reaches to stock Colorado pikeminnow in priority are: 1) Colorado River - Rifle to Debeque; and <br />2) Gunnison River - Hartland to Redlands. All Colorado pikemim10w should be 150+ mm TL, <br />i.e., age 3+. Stocking should occur each late summer/fall for 1,340 Colorado pikeminnow per <br />reach for 9 years. <br /> <br />Humpback chub.-Humpback chub is not anticipated to be stocked. However, augmentation of <br />existing small populations may become necessary. Stocking to expand population of humpback <br />chub into the Yampa, Lodore, Whirlpool, and Split Mountain complex may be desirable in the <br />future for meeting recovery goal criteria. [Supplemental stocking of humpback chub is an option <br />to consider under Colorado's plan. Recovery goals do not assign specific numerical criteria to <br />smaller populations (e.g., Yampa Canyon, Cataract Canyon). Supplemental stocking may be <br />necessary to achieve numerical criteria in other reaches (e.g., Westwater, Black Rocks).] <br /> <br />Acclimation of stocked fish in quiet water is preferred. Dispersal of stocking over larger area is <br />preferable to dumping large numbers in one small area. Backwater areas are not as readily <br />available in Colorado as they are in the Green River, Utah. <br /> <br />Uncertainties <br />All aspects of life history and habitat needs of bony taiL <br />Survival rates of stocked fish in the wild. <br />Variability in age of maturity for female fish in the wild as a function of growth. <br />Retention of age 3+ Colorado pikemiill10w in target reaches. <br />Acquisition of natural migratory and spawning behavior by hatchery-reared fish. <br /> <br />Recommendations <br />Monitor Colorado pikeminnow after release at a frequency adequate to detem1ine <br />survival, distribution, density and cause of mortality (e.g., predation, starvation). <br />PIT-tag all stocked fish. <br />Revise production and stocking based on monitoring estimates of survival. <br /> <br />Monitoring should be designed to also address unce11ainties. Time lines are critical to help direct <br />future production and stocking. If Colorado pikeminnow do not remain in the desired reach, <br />stocking should be reevaluated to determine if they are dispersing into already occupied habitats. <br /> <br />6 <br />