WSP07923

• File Number: 8220.101.10.E
• Description: Glen Canyon Dam/Lake Powell
• State: AZ
• Basin: Colorado Mainstem
• Date: 4/1/1998
• Author: Sorensen/et al. - Ar
• Title: Monitoring and Habitat Surveys of the Endangered Kanab Ambersnail in Grand Canyon and Northern Arizona
• Water Supply Pro - Doc Type: Report/Study

Arizona Game and Fish Department
NGTR 125: Kanab Ambersnail Report

Apri11998
Pa2e 9

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infested KAS is difficult to measure. This parasite has only been detected in KAS at VP, and not
in the other three Oxyloma popuIations in the region, or other succineid species in Grand Canyon
and vicinity.

HABITAT SURVEYS
Between 1991 and 1995, 81 springs and seeps in Grand Canyon were examined for mollusks
(Stevens et al. 1997b). No additional populations of KASs were found. Site visits were primarily
reconnaissance efforts to document presence or absence of mollusks, and did not provide detailed
habitat information. Sorensen and Kubly (1997) conducted habitat surveys on 59 springs, seeps,
and streamside habitats (including VP and 3L) in the Grand Canyon region between June 1996 and
June 1997. An additional 17 sites were studied between July and October 1997.

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The single-specie3 correIal:ion model provided a simple evaluation of KAS habitat suitability based
on various site attributes. Some localities have many quality attributes, but a single unfavorable
condition may disqualify it from a higher ranking. Potential KAS establishment sites will have to
undergo review of the interagency Kanab Ambersnail Working Group (KA WG), agencies involved
directly with species and habitat conservation, peer groups, and the public.

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Potential wild establishment sites require jurisdictional or land management authority that provides
for species and habitat conservation. Grand Canyon National Park provides the best protection for
sensitive wetland habitats from multiple-use practices (i.e., livestock grazing, commercial
development, mining, unrestricted recreation access). Management stipulations for most federal
lands require the protection of endangered species. State and tribal lands have various land-use
mandates, offering less protection to species of concern and sensitive habitats. Jurisdictional
protection of KASs and their habitat on slate and tribal lands will require case-by-case evaluation.
Private landowners may not be willing to protect wetlands or endangered species on their
property. For this reason, private land is the least preferable choice for KAS reintroduction sites.
However, private landowners that are inle1Q1ed in participating in long-term conservation will be
rated more favorably in this category.

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REcOMMENDATIONS

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MONITORING
As a participant of the interagency KA WG and field studies, AGFD supports the continued
monitoring of the VP popuIati.on to provide information on KAS demographics, habitat recovery,
and the role of predators, competitors, and parasites (KA WG 1997). Continued studies at VP
provide us with an increased understanding of KAS life history, interactions with other fauna,
habitat use, and response to natural and recreational disturbances--information needed for
satisfying USFWS Biological Opinion requirements and successful recovery efforts.