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Kanab Ambersnail By: Debra Bills, U.S. Fish and Wildlife Service Dennis Kubly, Arizona Game and Fish Department A smaIl, dully colored, inconspicuous terrestrial snail has joined the list of more prominent endangered fish and bird species receiving attention from scientists and resource managers considering future operations of Glen Canyon Dam. Little is known of the snail's biology or ecological require. ments, thus caution must be exercised when making operational decisions that could affect the species. Known best by its common name, the Kanab ambersnail has a mottled grayish- to yellowish- amber colored shell that reaches maximum lengths of approximately 3/4 inch. Specimens were first collected in 1909 from wetland habitat, among moss and orchids, near Kanab, Utah. Since its discovery, the species has been collected from ouly two addi- tionallocations, in Utah and Arizona. One of the Utah populations is believed extirpated, leaving only two occupied sites worldwide known to the scientific community: Three Lakes Canyon in southwestern Utah and Grand Canyon National Park, Arizona. The Grand Canyon population of Kanab amber- snails was discovered in 1991 by researchers surveying mollusks in conjunction with the Glen Canyon Environmental Studies. They found speci- mens in a 2-acre, spring-fed wetland on a talus slope abutting a Redwa11limestone cliff-face. The wetland is populated with semiaquatic plants (cardinal monkey flower, watercress, and maidenhair fern) and woody vegetation (poison ivy, redbud, and coyote willow). At present, no thorough surveys have been completed; and the percentage of the wetland actually occupied by Kanab ambersnail remains unknown. Although officially a terrestria1 animal, the Kanab ambersnail is really an amphibious creature always found in wet or moist environs. In the Grand Canyon, individuals have been found on wet, often dead or decaying stems of cardinal monkey flowers and less often, on watercress, but not directly on the substrates in which the plants grow. This occur. rence on plants growing in wet soils or bedrock is in keeping with the description of their original site of discovery and with the habitat affinities of the existing Utah population. There, the snails live in a marsh on cattails, another semiaquatic plant. The Arizona population of Kanab ambersnails occurs in a wilderness setting, unlike the Utah population which is threatened by development. Unfortunately, even in the relatively secure Arizona setting, threats do exist. One of the primary management objectives of agencies involved in management and conservation of the species is to control activities that can negatively affect the habitats and populations of the endangered snail. One concern is for the frequency, duration, timing, and magnitude of flood flows from Glen Canyon Dam. Because Kanab ambersnails occur down to the 20,000 cfs flow elevation in Grand Canyon, they will be affected by both regulated and unregulated floods. The biological opinion on the operation of Glen Canyon Dam issued by the U.S. FIsh and Wildlife Service (FWS) states that high flows in the Colorado River likely will not jeopardize the future existence of the species. High flows, including those proposed for the beach/habitat -building flows, likely will result in loss of some individuals. A second potential threat to the Arizona population arises from human visitation. The wetland receives recreational visitation from river runners in search of fresh, spring-fed drinking water; however, intrusion into Kanab ambersnail habitat generally is limited by poison ivy, a great deterrent for most people. The Arizona Game and Fish Department, National Park Service, FWS, and Reclamation are cooper- ating to minimize loss of Kanab ambersnails from dam operations or recreational activities. A recovery plan is being developed by the FWS to guide overall activities for the preservation and recovery of this species. 7