WSP03252

• File Number: 8220.101.09
• Description: Glen Canyon Dam/Lake Powell
• State: AZ
• Basin: Colorado Mainstem
• Date: 2/16/1996
• Title: Biological Opinion Summary
• Water Supply Pro - Doc Type: Biological Opinion

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b.In order to more accurately determine elevation of river stage at the range of now
that will be experienced during the test flow, and for use in developing a stage-
discharge relationship for future flow, the placement of a stage recorder, such as a
pressure transducer coupled to a recorder should be deployed, if possible, in the
mainstem at an appropriate site near the Kanab ambersnail population. The U.S.
Geologic Survey should be contacted regarding the possibility of changing the location
, of a stage recorder to be used in test flow studies to the Kanab ambersnail site.

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c. SALVAGE PROTOCOL. Kanab ambersnail specimens found dead, or taken as
part of research activities, shall be collected and held as specified in the AGPD
permit, with final deposition in a suitable museum collection such as at Northern
Arizona University.

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2. Relocate or collect approximately 90 percent of the Kanab ambers nail individuals
from the lower zone of inundation to higher stage levels within Vaseys Paradise as described
in the above 1.a. proposal. Control polygons must not receive moved snails.

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3. Determine the fate of the moved ambersnails, observe temperature, light level, and
local snail density; compare the survivorship of marked and moved versus resident Kanab
ambersnail; and facilitate the one time collection of 100 individuals to AGFD for future
studies.

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4. Determine the Kanab ambersnail population recovery and habitat recolonization for
one full year after the test flow and evaluate changes in the Kanab arnbersnail population, its
parasites, potential competitors, or predators, after the flood.

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5. The reasonable and prudent measures, with their implementing terms and conditions,
are designed to minimize incidental take that might otherwise result from the proposed
action. With implementation of these measures, the Service believes that no more than 17
percent of the total available primary habitat will be incidentally taken. If, during the course
of the action, this minimized level of incidental take is exceeded, such incidental take would
represent new information requiring review of the reasonable and prudent measures provided.
Reclamation must immediately provide an explanation of the causes of the taking and review
with the Service the need for possible modification of the reasonable and prudent measures.

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AMOUNTOF~NTOFTAKE

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Southwestern Willow Flycatcher

The Service anticipates incidental take of southwestern willow flycatcher will be difficult to
detect for the following reasons: Incidental take of actual species numbers may be difficult
to detect when the species is rare and wide-ranging and losses may be, maslced by seasonal
fluctuations in numbers or other causes. However. the following level of take of this species

Biological and Conference Opinions Glen Canyon BeachlHabltat-Bullding Flows 2116196

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