8197

• UCREFRP Catalog Number: 8197
• Author: Martinez, P. J.
• Title: Development and Application of Procedures for Stocking Nonnative Fish Speacies in the Upper Colorado River Basin.
• USFW Year: 1997.
• USFW - Doc Type: Grand Junction, CO.
• Copyright Material: NO

13378 Federal Register / Vol. 59. No. 54 / Monday, March 21. 1994 / Rules and R atiew '
indirectly eoatn"buting to recovery of a
species.
Areas outside of critical habitat are
still subject to section 7 consultation on
whether or not an action is likely to
jeopardize the continued existence of a
species, and section 9 "take"
prohibitions for an action that may
affect Colorado River endangered fishes
or their habitat The Service anticipates
that the importance of areas outside of
critical habitat to the conservation of the
Colorado Biveimdangere fishes will
be addressed through section 7. section
9, and section 10 permit processes. the
recovery planning process, and other
appropriate State and Federal laws.
Primary Constituent FAemr#s
In determining which areas to
designate as critical habitat for a
species, the Service considers those
physical and biological aw butes that
are essential to species conservation
(i.e.. constituent elaments). Such
physical and$iolggical features are
stated in So CSR 424_12 and inclade.
but are not limited to, the following
items: (1) Spacelorindividual and
population growth.and for no=al
behavior, -
(2) Food, ova a.sir, Mehl minerals„ or
other nutritional or physiological
3) Cover 43r shelter;
(4) Sites fnrbreedinZ. reproduction.
rearing of ofg: germination, or
seed dispersat and generally;
(5) Habitats that are protected from
disturbance or are representative of the
historical geographical and ecological
distributionsof a species.
In addidon.-the Act stipulates that the
areas containing these elements may
regime specisimanagement
considerations arprotection.
Detailed descriptions and the
biological basis for the constituent
elements were presented in the Draft
Biological Support Document f Maddux
et al. 1993). In considering the
biological basis for determining critical
habitat, the Service focused on the
primary physical and biological
elements essential to the conservation of
the species. The primary constituent
elements are interrelated in the life
history of these species. This
relationship was a prime consideration
in the designation of critical habitat.
The Service is required to list the
known primary constituent elements
together with a description of any
critical habitat that is designated.
The primary constituent elements
determineduecessary for survival and
recovery of the font Colorado River
endangered fishes include, but are not
limited to:
Water
This includes a quantity of luster of
sufficient quality G-e-. temperature.
dissolved oxygen, lark of contaminants.
nutrients, tushidity, etc.) that is
delivered to a specific location in
accordance with a hydrologic regime
that is required for the particular life
stage for each species.
Physical Habitat
This includes areas of the Colorado
River system that are inhabited or
potentially habitable by fish for use in
spawning, nursery, feeding, and searing.
or corridors between these areas. In
addition to river channels, these areas
also include bottom lands, side
channels, secondary channels, oxbows,
backwaters, and other areas in the 100-
year flood plain, which when inundated
provide spawning, nursery, feeding and
rearing habitats, or access to these
habitats. .
Biological Environment
Food supply, predation, and
competition are important elements of
the biological environment and are
considered components of this
constituent element. Food supply is a
fimction of nutrient supply.
productivity, and aver to each
life stage of the species. Predation and
competition, although ca Adered
normal compooents of this
environment, are out ofbalance due to
introduced nonnative fish species in
many areas.
Additioncl Selection Criteria fvrthe
Razorback Sucker
Because a recovery plan for the
razorback sucker has not been
completed, additional selection criteria
were developed to assist the Service in
making a determination of areas to
propose as critical habitat. Previous
Service findings, published and
unpublished literature sources, and
discussions with individual members of
the Colorado River Fishes Recovery
Team were utilized to develop the
constituent elements and additional
selection criteria.
Adult razorback suckers have
displayed a degree of versatility in their
ability to survive and spawn in different
habitats. However, razorback sucker
populations continue to decline and are
considered below the survival level.
Tins, as versatile as the adult tife stage
of razorback sucker appears to be in
selecting spawning habitat there has
been little or no recruitment of young to
the adult population. Therefore, special
consideration was given to habitats
required for reproduction and
recruitment.
The following selection
considerations were used by the Service
to help determine areas necessary for
survival and recoveryof the razorback
sucker.
1. Presence of known or suspected
wild spawning populations, although
recruitment may be limited or
nonexistent.
2. Areas where juvenile razorback
suckers have been collected or which
could provide suitable nursery habitat
(backwaters, flooded bottom lands. or
coves).
3. Areas presently occupied or that
were historically occupied that are
considered necessary for recovery and
that have the potential for
reestablishment of ravorback suckers.
4. Areas and water required to
maintain rangewide fish distribution
and diversity under a variety of
physical, chemical, and biological
conditions.
5. !Teas that need special
management or protection to insure
razorback survival sada at These
areas once met the habatat of the
razorback sucker and may be
reoovetable with additional prutedkm
and management
The primary constituent elements
were identified throughout The
historical range of the Colorado ltiver
endangered fishes. In addition, the five
selection considerations described
above also were used to evaluate
potential razorback sucker critical.
habitat ereas.The taicnl habitat
designationswere based on the primary
constituent elements, published and
unpolished sources of information,
Service reports and other findings,
recovery plans tfor Colorado squawfish.
humpback chub, and bonytaii rhub), the
additional selection considerations, and
the Service's preliminary recovery goals
for the razorback sucker.
? djrrsmxetuts to Bogies
The 190-year flood plain is generally
included as part of the critical habitat
designation: however, only those
portions of the flood plain that contain
the constituent elements are considered
part of critical habitat Specific areas in
the flood plain must be evaluated on a
case-by-case basis to determine if the
areas constitute critical habitat. The
Service stresses that, although critical
habitat may only be seasonally occupied
by the fish. such habitat remains
important for their conservation.
Protection of such seasonally occupied
habitats contributes to the conservation
of the species.
As a result of obtaining additional
biological information and review of
comments received during the public

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