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. . dam construction; . the estimated loss of KAS habitat (10.27% to 14,0%) contains an estimated 8.4% of the total Vasey's Paradise KAS population, which would be lost during 45,000 cfs BHBF(s) in 1998; and . the vegetation and the KAS population will re-colonize the scoured area in ~2 yr. Reclamation acknowledges that take of any amount of an endangered species is a matter of serious concern, and will work with the Service to mitigate impacts by: . translocation of KAS, as was done in 1996 . assisting the Service with KAS recovery activities The 1996 B.O, incidental take statement allowed for mitigation of take through relocation of KAS to a position within the habitat above the 45,000 cfs stage. Moving of snails may be the best long-term management strategy, as it is efficient, inexpensive, and continues to be the most obvious means of mitigating BHBF impacts. Despite concerns about detrimental effects on moved KAS resulting from disturbance due to handling and the potential for increased competition among the snails, the Kanab Ambersnaillnteragency Workgroup (1997a) reported few if any negative impacts of the 1996 BHBF related to translocation within the habitat. In the long-term, Reclamation favors focusing resources on improving understanding of the ecology of the species to help with recovery, establishment of additional populations, and refining overall ecosystem management strategies, In addition, Reclamation will monitor the population and its habitat both pre- and post- test flow, as required by the incidental take statements in the 1994, 1996 and 1997 biological opinions, to assist in defining the species' response to high flows. Reclamation believes the benefits of BHBF's to other Colorado River ecosystem resources outweighs the relatively minor impacts to KAS and its habitat resulting from planned high flows, HUMPBACK CHUB SPECIES ACCOUNT Distribution and Abundance The Grand Canyon supports the only successfully reproducing HBC population in the lower Colorado River basin (Kaeding and Zimmerman 1983, Valdez 1995, Valdez and RyeI1997). Valdez (1995) identified nine distinct aggregations in the mainstream Colorado River downstream from Glen Canyon Dam, including: 30-Mile, the Little Colorado River (LCR) confluence area, Lava/Chuar to Hance Rapids, Bright Angel Creek mouth, Shinumo Creek mouth, Stephens Aisle, Middle Granite Gorge, Havasu Creek mouth and Pumpkin Spring. 1998 GCD Beach/Habitat Building Flow 12 Biological Assessment