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Arizona Game and Fish Department Draft EA: Kanab Ambersnail June 1998 Page 13 the eggs and thus were not absolutely sure of their fate, but the transfer did not appear to be successful (pers, comm, C. Nelson), One KAS investigator observed that the eggs began to darken within an hour of being collected (pers, comm, V, Meretsky), She believes this was an indication of unsuitable conditions, and that successful transfer of egg masses will require a much better understanding of their environmental tolerances coupled with better environmental controls during the transfer, In the same effort, NAU researchers moved 248 immature KAS (<4,5 mm in size), Mos!' of these individuals survived, and as of June 1998 they have produced >900 progeny after three generations, None of the transported immature KASs have shown any evidence of Leucochloridium infestation, D, PROPOSED ALTERNATIVES Alternative 1 (preferred), Establish a new population of Kanab ambersnail in Grand Canyon National Park. NPS/AGFD propose to establish a wild population ofKASs in Grand Canyon National Park, by simultaneously relocating KASs from VP to three proposed sites with suitable habitat Using three sites concurrently will increase the probability of successful establishment of one population, A long- term refugium population ofKASs will also be started at The Phoenix Zoo (TPZ), Wild stock of KASs will be taken from VP to maintain genetic integrity and simplify logistic and monitoring activities, Based on discussions with p, Keirn (geneticist at NAU) and a review of scientific literature (see Chapter 3), a genetically-stable population of mollusks would require a minimum of 50-100 reproductive individuals contributing successive progeny, An annual immigration of 1-5 individuals (also reproductively contributing) to this population are required for genetic variability, Specifics on collection and transportation protocol and planned monitoring will be provided in a NPS/ AGFD Biological Evaluation to the USFWS, Early life stage KASs (<5 mm immatures and/or egg masses) will be translocated in August 1998, Any KASs exhibiting visible sporocysts of Leucochloridium will not be translocated, Each site should have approximately 100 KASs in residence prior to the end of October. These residents should be acclimated to the new site, and have grown sufficiently (5-10 mm in size) to enable them to survive winter hibernation, With a predicted overwinter mortality of 50%, half this population may survive to contribute reproductively to successive generations, Additional translocations of KASs in 1999 will help augument new site populations and maintain genetic intergrity, AGFD monitoring trips in spring, early summer, and late summer 1999 will ascertain secondary population establishment success and conduct population estimates and habitat mapping Establishment of a new population will satisfy the 1996 and 1997 Biological Opinion requirements for Glen Canyon Dam operations concerning KASs, Likewise, establishment of additional KAS populations will progress the KAS Recovery Plan objectives, Ten new populations are required for KASs to be downlisted to threatened status,