Endangered and Threatened Wildlife and Plants; Critical Habitat Revised Designation for the Kootenai River Population of the White Sturgeon (Acipenser transmontanus, 39506-39523 [E8-15134]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 73, Number 132 (Wednesday, July 9, 2008)]
[Rules and Regulations]
[Pages 39506-39523]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-15134]



[[Page 39505]]

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Part III





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Critical Habitat Revised 
Designation for the Kootenai River Population of the White Sturgeon 
(Acipenser transmontanus); Final Rule

Federal Register / Vol. 73, No. 132 / Wednesday, July 9, 2008 / Rules 
and Regulations

[[Page 39506]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R1-ES-2008-0072] [92210-1117-0000-FY08-B4]
RIN 1018-AU47


Endangered and Threatened Wildlife and Plants; Critical Habitat 
Revised Designation for the Kootenai River Population of the White 
Sturgeon (Acipenser transmontanus)

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are revising 
the designation of critical habitat for the Kootenai River population 
of the white sturgeon (Acipenser transmontanus) (Kootenai sturgeon) 
under the Endangered Species Act of 1973, as amended (Act). In total, 
18.3 river miles (RM) (29.5 river kilometers (RKM)) of the Kootenai 
River are designated as critical habitat within Boundary County, Idaho.

DATES: This rule becomes effective August 8, 2008.

ADDRESSES: This final rule is available on the Internet at https://
www.regulations.gov and https://www.fws.gov/easternwashington. 
Supporting documentation we used in preparing this final rule will be 
available for public inspection, by appointment, during normal business 
hours, at the U.S. Fish and Wildlife Service, Upper Columbia Fish and 
Wildlife Office, 11103 E. Montgomery Drive, Spokane, WA 99206; 
telephone 509-891-6839; facsimile 509-891-6748.

FOR FURTHER INFORMATION CONTACT: Susan Martin, Field Supervisor, Upper 
Columbia Fish and Wildlife Office (see ADDRESSES). If you use a 
telecommunications device for the deaf (TDD), call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

Home Range

    The Kootenai sturgeon, listed as endangered in 1994 (September 6, 
1994; 59 FR 45989), is restricted to approximately 168 RM (270 RKM) of 
the Kootenai River in Idaho, Montana, and British Columbia, Canada. One 
of 18 land-locked populations of white sturgeon known to occur in 
western North America, the range of the Kootenai sturgeon extends from 
Kootenai Falls, Montana, located 31 RM (50 RKM) below Libby Dam, 
Montana, downstream through Kootenay Lake to Corra Linn Dam at the 
outflow from Kootenay Lake in British Columbia. The downstream waters 
of Kootenay Lake drain into the Columbia River system. For the purposes 
of this rule, this portion of the Kootenai River is divided into three 
geomorphic reaches: (1) The canyon reach, which extends from Kootenai 
Falls at RM 193.9 (RKM 312.0) in Montana to RM 159.7 (RKM 257.0) below 
the confluence with the Moyie River in Idaho; (2) the braided reach, 
which begins at the end of the canyon reach and extends downstream to 
RM 152.6 (RKM 246.0) at Bonners Ferry; and (3) the meander reach, which 
extends from the end of the braided reach at RM 152.6 (RKM 246.0) 
downstream to the confluence with Kootenay Lake in British Columbia at 
RM 74.6 (RKM 120.0). This reach includes an area described as the 
``transition zone'' between RM 142.7 (RKM 245.9) and RM 151.8 (RKM 
244.5) that joins the braided and meander reaches.
    Critical habitat is currently designated in the braided reach from 
RM 159.7 (RKM 257.0), below the confluence with the Moyie River, 
downstream to RM 152.7 (RKM 245.9) at Bonners Ferry, and continues 
downstream into the meander reach to RM 141.4 (RKM 228), for a total of 
18.3 RM (29.5 RKM) (71 FR 6383).
    The canyon reach is characterized by rocky substrates and a 
relatively high water surface gradient. Downstream the valley broadens, 
and the river forms the low-gradient ``braided reach'' as it courses 
through multiple shallow channels over gravel and cobbles (Barton et 
al. 2005, p. 19; Berenbrock 2005a, p. 7). The meander reach is 
characterized by primarily sandy substrate, a low water-surface 
gradient, a series of deep holes, and low water velocities under 
present river operations. A deep hole (39 to 49 feet (ft) (12 to 19 
meters (m)) deep) exists near Ambush Rock at approximately 151.7 RM 
(RKM 244.2) (Berenbrock 2005b, pp. 7-8) and is frequented by sturgeon 
in spawning condition. Both adult and juvenile sturgeon forage in and 
migrate freely throughout the lower Kootenai River, but apparently no 
longer commonly occur upstream of Bonners Ferry, Idaho (Partridge 1983, 
pp. 1, 23, 25; Apperson and Anders 1990, pp. 19, 22, 23, 25; Apperson 
and Anders 1991, pp. 36-37, 39-44, 48-49), although there are no 
apparent physical barriers to sturgeon migration within these three 
geomorphic reaches of the Kootenai River. However, during recovery team 
discussions, shallow waters in the braided reach that have occurred 
since construction of Libby Dam have been suggested as a possible 
behavioral barrier to migration into the upstream canyon reach, where 
suitable spawning and incubation habitats appear to exist.

Population Status and Life History

    Although information is not available specifically for Kootenai 
sturgeon, white sturgeon in general are very long-lived, with females 
living from 34 to 70 years; some individuals may approach or exceed 100 
years of age (NatureServe 2008; PSMFC 2008). It is believed that 
Kootenai sturgeon do not reach sexual maturity until 28 and 30 years, 
respectively, for males and females (Paragamian et al. 2005, p. 525). 
Thereafter, females spawn at 4-to 6-year intervals.
    The number of Kootenai sturgeon has decreased from approximately 
7,000 individuals in the 1970s to fewer than an estimated 500 adults by 
2005, with fewer than 30 females projected to be spawning annually 
after the year 2015 (Paragamian et al. 2005, p. 526). Decreases in the 
abundance of Kootenai sturgeon were first noted beginning in the mid-
1960s. These decreases were attributed primarily to the effects of 
diking and pollutants (Partridge 1983, p. 42). Almost no recruitment of 
juveniles has been detected since 1974, soon after Libby Dam began 
operating (Partridge 1983, p. 28; Apperson and Anders 1991, p. 45; 
Paragamian et al. 2005, p. 524). The current rate of population decline 
is estimated to be 9 percent per year, based on annual mortality rates 
in the absence of significant recruitment (Paragamian et al. 2005, p. 
528). The final listing rule for the Kootenai sturgeon cites the 
hydropower and flood control operations of Libby Dam, a U.S. Army Corps 
of Engineers (Corps) facility upstream in Montana, as the primary 
threat to the Kootenai sturgeon because these operations adversely 
affect spawning and incubation habitat (September 6, 1994; 59 FR 
45989).
    Many Kootenai sturgeon spend part of their lives in Kootenay Lake 
in British Columbia and migrate upstream to spawn in the Kootenai 
River. The sturgeon have been described as having a unique two-step 
pre-spawning migration process, migrating first from the lower river 
and Kootenay Lake during autumn to staging reaches in the Kootenai 
River, then migrating in spring to the spawning reach near Bonners 
Ferry, Idaho (Paragamian et al. 2001, p. 22; Paragamian et al. 2002, p. 
608). Successful reproduction is dependent upon Kootenai sturgeon 
spawning at

[[Page 39507]]

sites where the eggs can settle in an area that supports their 
viability, and where the free embryos that emerge from the eggs have 
appropriate habitat for development and protection from predators 
(mobile or free embryos are embryos that have hatched and still have 
the yolk sac attached; larvae refers to young fish that have absorbed 
the yolk sac and are actively feeding). For the Kootenai sturgeon, 
these needs appear to be met by rocky substrates for spawning and 
attachment of eggs, and meeting in-water minimum flow, depth, and 
temperature requirements on at least an intermittent basis during the 
spawning period from May through the end of June.
    Although rocky substrates do not seem to be a cue for spawning site 
selection, they appear to be essential to the viability of eggs and the 
survival of free embryos. White sturgeon are broadcast spawners and 
release demersal eggs (eggs that quickly sink to the bottom) that are 
initially adhesive upon exposure to water (Paragamian et al. 2001, pp. 
24, 27, and references therein; Anders et al. 2002, p. 73). Rocky 
substrates provide fixed surfaces for the attachment of the adhesive 
eggs during incubation and also provide shelter for the ``hiding 
phase,'' the period following hatching in which free embryos seek cover 
from predators in the inter-gravel spaces (Brannon et al. 1985, p. 58; 
Parsley et al. 2002, pp. 58-59). Although we have little information 
specific to spawning substrates for Kootenai sturgeon, in other areas 
where white sturgeon are reliably reproducing and recruiting, the river 
bed at spawning sites typically consists of several miles of gravel, 
cobble, and boulder substrates that provide shelter and cover during 
this free embryo hiding phase. Successful spawning and incubation 
sites, such as the tailraces at Bonneville and Ice Harbor Dams on the 
Columbia River, have at least 5 RM (8 RKM) of suitable rocky substrate 
before transitioning into sandy substrate (Parsley et al. 1993, Table 
2, p. 220 and p. 224).
    White sturgeon spawn in fast-flowing water, and water velocity 
appears to act as a cue for spawning. In the reach of the lower 
Columbia River immediately below Bonneville Dam, water velocity at 
spawning sites ranged from 2.6 to 9.2 ft per second (ft/s) (0.8 to 2.8 
m per second (m/s)) (Parsley et al. 1993, Table 2, p. 220). Parsley and 
Beckman (1994, Figure 2, p. 815) suggest that optimal spawning 
conditions may occur when the mean water column velocity is 4.9 ft/s 
(1.8 m/s) or greater. In the Sacramento River, observed white sturgeon 
spawning sites had water velocities exceeding 3.3 ft/s (1.0 m/s) 
(Schaffter 1997, pp. 1, 113). White sturgeon spawning in fast-flowing 
water greater than or equal to 3.3 ft/s (1.0 m/s) may experience 
reduced predation on eggs by limiting access of some predators to 
spawning and incubation areas (Brannon et al. 1985, p. 13; Miller and 
Beckman 1996, pp. 338-339; Anders et al. 2002, p. 73 and Table 1, p. 
75; Parsley et al. 2002, p. 60). Fast-flowing waters also serve to 
maintain the exposed rocky substrate essential for successful egg 
incubation and the free embryo hiding phase of the Kootenai sturgeon's 
reproduction cycle.
    Water depth also appears to be an important factor in spawning site 
selection for the Kootenai sturgeon. In the Columbia River, sturgeon 
eggs collected on mats ranged in depth from 13 to 89 ft (4 to 27 m), 
with median spawning depths of 19.7 to 36.1 ft (6 m to 11 m) (Parsley 
et al. 1993, Table 2, p. 220). In the Kootenai River, the mean depth of 
radio-tagged white sturgeon during the spawning period was 21.3 ft (6.5 
m) (Paragamian and Duehr 2005, p. 265). The mean water depth of the 
river during the spawning period was 30.8  15.1 ft (9.4 
 4.6 m) (Paragamian and Duehr 2005, p. 263). In a study 
based on sturgeon egg collections in the Kootenai River, Paragamian et 
al. 2001 (Table 2, p. 26) report average river depths at egg sites 
ranging from 27.9 to 42.7 ft (8.5 to 13.3 m), and eggs were found at 
depths ranging from 16.4 to 59 ft (5 to 18 m). Egg collection sites are 
likely more shallow than actual spawning sites, because high water 
velocity and turbulence in spawning areas may transport eggs to more 
shallow water (Parsley 2005, p. 1; Parsley 2006a, p. 1; Parsley 2006b, 
p. 1); thus, the depth at which spawning occurs is most likely greater 
than the depth at which eggs are found.
    Although data collected on white sturgeon spawning in other areas 
may be considered as additional support for identifying the water 
depths associated with Kootenai sturgeon for spawning, we consider data 
specific to the environmental conditions in the Kootenai River to 
represent the best available scientific information for the Kootenai 
sturgeon. Our synthesis of the best available data specific to the 
Kootenai sturgeon, as described, indicates that a minimum water depth 
of 23 ft (7 m) is requisite for successful spawning at a level 
sufficient to achieve recovery.
    Kootenai sturgeon spawn within a fairly narrow range of water 
temperatures, from 47.3 to 53.6 degrees Fahrenheit ([deg]F) (8.5 to 12 
degrees Celsius ([deg]C)) (Paragamian et al. 2002, p. 27). Paragamian 
and Wakkinen (2002, p. 547) identify temperatures between 49.1 and 
49.9[deg]F (9.5 and 9.9[deg]C), or roughly 50[deg]F (10[deg]C), as 
those at which spawning has the highest probability of occurring in the 
Kootenai River. Sudden drops of water temperature greater than 
3.6[deg]F (2.0[deg]C) cause males to become reproductively inactive, 
thereby negatively affecting egg fertilization (Lewandowski 2004, p. 
6).
    Successful spawning of Kootenai sturgeon thus appears to require 
several synchronous environmental factors during the spawning period: 
the presence of sufficient rocky substrates to provide shelter for egg 
attachment and for normal free embryo behavior, and fast-flowing (in 
excess of 3.3 ft/s (1.0 m/s), deep (equal to or greater than 23 ft (7.0 
m)) water at a relatively stable temperature of approximately 50 [deg]F 
(10 [deg]C).
    Although Kootenai sturgeon continue to spawn annually in the 
Kootenai River, this spawning has not resulted in significant levels of 
recruitment for over 30 years. A Kootenai sturgeon female is capable of 
releasing at least 100,000 eggs per spawning year, and field monitoring 
has shown most eggs are being fertilized (Paragamian et al. 2001, p. 
26). However, based on data from 1992 through 2001, it is estimated 
that on average, a total of only about 10 juvenile sturgeon currently 
may be naturally produced in the Kootenai River annually (Paragamian et 
al. 2005, p. 524). The last significant sturgeon recruitment in the 
Kootenai River occurred in 1974, the last season prior to Libby Dam 
becoming fully operational in 1975 (Partridge 1983, p. 28). This 
recruitment failure is attributed largely to the spawning of Kootenai 
sturgeon over unsuitable sandy substrates (Paragamian et al. 2001, p. 
29).
    Since the construction of Libby Dam, most Kootenai sturgeon spawn 
over sandy substrates in the meander reach below Bonners Ferry. The 
meander reach has a low stream gradient, and substrates are composed 
primarily of sand and other fine materials overlying lacustrine clay 
(Barton 2003, p. 45; Barton et al. 2004, pp. 1, 18-21). Many of the 
eggs that are located in this reach are found drifting along the river 
bottom, covered with fine sand particles in sites without rocky 
substrate (Paragamian et al. 2001, p. 26), and where mean water column 
velocities seldom exceeded 3.3 ft/s (1.0 m/s) (Paragamian et al. 2001, 
Table 2, p. 26; Barton et al. 2005, Table 3). The sandy substrate in 
the current spawning sites in the Kootenai River differs from the rocky 
substrate that occurs in successful

[[Page 39508]]

white sturgeon spawning sites elsewhere in the Columbia River Basin 
(Paragamian et al. 2001, pp. 28-29; Parsley et al. 1993, Table 2, p. 
220 and Figure 6, p. 222; Parsley and Beckman 1994, pp. 812-827; Kock 
et al. 2006, pp. 134-135, 139 and references therein).
    Laboratory experiments suggest that high embryo or larval mortality 
results from smothering by fine-sediment substrates, such as the sand 
that dominates the Kootenai River at the present spawning sites (Kock 
et al. 2006, pp. 134-141). Larval white sturgeon kept in an aquarium 
were observed to burrow into fine sediments with lethal results 
(Brannon 2002, as cited in Anders et al. 2002, p. 76). Due to the 
predominately sandy substrate in the meander reach and its 
unsuitability for egg attachment, incubation, and larval survival, it 
is unlikely that this area was the historical spawning site for 
Kootenai sturgeon. However, white sturgeon hatchery releases of age 2-
plus years in this area have shown high survival (Ireland et al. 2002, 
p. 647), indicating that the meander reach can successfully support age 
2-plus year-old juvenile sturgeon.
    The altered hydrograph of the Kootenai River below Libby Dam has 
resulted in decreased water velocities and depths, with negative 
effects on Kootenai sturgeon reproduction. In the current sturgeon 
spawning sites in the meander reach, the Kootenai River is 
characterized by mean water column velocities less than 3.3 ft/s (1.0 
m/s), as well as shifting sand substrates (Barton et al. 2004, pp. 18-
21; Anders et al. 2002, Table 1, p. 75). Low water velocity is believed 
to be a factor facilitating predation of sturgeon eggs and free embryos 
in the Columbia River (Golder Associates 2005, pp. 1-2, 29-30; Miller 
and Beckman 1996, pp. 338-339). Free embryos emerging in low water 
velocities (0.8 in/s (2.0 cm/s)), such as those that presently dominate 
in the meander reach, remained mobile in the water column 2 days longer 
than did those emerging in higher water velocity (3.1 in/s (7.9 cm/s)) 
(Brannon et al. 1985, pp. 14, 16). This delay in initiating the free 
embryo hiding phase may increase the risk of mortality of embryos 
emerging in these waters (Brannon et al. 1985, pp. 13-15).
    Since Libby Dam became operational, the peak flow events in the 
Kootenai River at Bonners Ferry during the sturgeon spawning and 
incubation period have been significantly reduced (Partridge 1983, p. 
3; Corps 2005, p. 9). Mean spring flows that reached 80,000 cubic feet 
per second (cfs) (2,265.3 cubic meters per second (cms)) prior to the 
construction of the dam were reduced to flows of less than 10,000 cfs 
(283.2 cms) through the early 1990s (Berenbrock 2005a, p. 2). The 
median river stage at Bonners Ferry during peak flow events in the 
Kootenai River during the sturgeon spawning and incubation period has 
been reduced by 14 ft (4.27 m) (U.S. Army Corps of Engineers 2004, 
Figure 2-5, p. 10). This is a substantial change, since the braided 
reach beginning at Bonners Ferry is now usually less than 7 ft (2.2 m) 
deep (Berenbrock 2005, p. 7). There is recent evidence that portions of 
the Kootenai River channel within the braided reach have become wider, 
shallower, and more unstable since Libby Dam became operational (Barton 
2005a, p. 3, and unpublished data). Peak flows of 40,000 cfs (1,200 
cms) that typically occurred during the spawning and incubation period 
in the Kootenai River over an average of 30 days prior to dam 
construction have not been reached for a period of more than 2 days 
since the dam was completed, with only two exceptions (Hoffman 2005a, 
p. 8).
    In summary, natural spawning in the Kootenai River has not resulted 
in sufficient levels of recruitment into the aging population of the 
Kootenai sturgeon to reverse the strong negative population trend that 
has been observed over the last 30 years. This recruitment failure 
appears to be related to changes in riverbed substrate and reduced 
river flows, reduced water velocities, lowered water depths, and 
downstream movement of the velocity transition points with reduced 
flows since Libby Dam became operational. While water depth appears to 
be a significant factor, it is unclear how other altered parameters may 
be involved in causing the sturgeon to spawn primarily at sites below 
Bonners Ferry in the meander reach. These sites have unsuitable sandy 
riverbed substrates, insufficient rocky substrate (Barton 2003, pp. 1-
48; Barton 2004, pp. 18-21; Anders et al. 2002, pp. 73, 76), and water 
velocities insufficient to provide protection from predation for eggs 
and free embryos and to assure normal dispersal behavior among free 
embryos (Parsley et al. 1993, pp. 220-222, 224-225; Miller and Beckman 
1996, pp. 338-339). The braided reach provides suitable rocky 
substrates, but a large portion of the braided reach has become wider 
and shallower due to loss of energy from reduced flows, reduced 
backwater effects, and bed load accumulation (the accumulation of large 
stream particles, such as gravel and cobble carried along the bottom of 
the stream) (Barton et al. 2004, p. 17; Hoffman 2005, p. 9; Barton 
2005a and unpublished data). The increase in bed load is a result of 
the broadening of the braids and water velocity reductions.
    Further details on the ecology and life history requirements of the 
Kootenai sturgeon can be found in our final listing rule (September 6, 
1994; 59 FR 45989), the recovery plan for the Kootenai sturgeon (U.S. 
Fish and Wildlife Service 1999), our previous final rule designating 
critical habitat for the Kootenai sturgeon (September 6, 2001; 66 FR 
46548), and our interim rule designating critical habitat for the 
Kootenai sturgeon (February 8, 2006; 71 FR 6383).

Previous Federal Actions

    A description of Federal actions concerning the Kootenai sturgeon 
that occurred prior to our September 6, 2001, final rule designating 
critical habitat can be found in that final rule (September 6, 2001; 66 
FR 46548). That final rule designated 11.2 RM (18 RKM) of the Kootenai 
River in the meander reach as critical habitat, from RM 141.4 (RKM 228) 
to RM 152.6 (RKM 246).
    On February 21, 2003, the Center for Biological Diversity filed a 
complaint against the Corps and the Service (CV 03-29-M-DWM) in Federal 
Court in the District of Montana, stating, among other issues, that 
designated critical habitat for the Kootenai sturgeon was inadequate, 
as it failed to include areas of rocky substrate.
    On May 25, 2005, the District Court of Montana ruled in favor of 
the plaintiffs, and remanded the critical habitat designation to the 
Service for reconsideration with a due date of December 1, 2005. We 
filed a motion to alter or amend the judgment, and the Court extended 
the deadline for releasing a revised critical habitat designation to 
February 1, 2006. In the interim, the Court ruled that the 2001 
designation of critical habitat remained in effect. In response to the 
District Court ruling and to meet the Court's deadline, we published an 
interim rule designating an additional reach of the Kootenai River, the 
braided reach, as critical habitat for the Kootenai River sturgeon on 
February 8, 2006 (71 FR 6383), resulting in a total of 18.3 RM (29.5 
RKM) designated; we also completed a Draft Economic Analysis of 
Critical Habitat Designation for the Kootenai River White Sturgeon 
(Northwest Economic Associates 2006) and the Final Economic Analysis of 
Critical Habitat Designation for the Kootenai River White Sturgeon 
(ENTRIX, Inc. 2008; ENTRIX was formerly Northwest Economic Associates). 
Although the interim rule designating critical habitat for the Kootenai 
sturgeon constituted a final

[[Page 39509]]

rule with regulatory effect, it also opened a comment period on the 
substance of the rule. This revised final rule considers and 
incorporates, where appropriate, the comments received on the interim 
rule.
    We solicited comments from species experts and the public on the 
interim rule and the draft economic analysis. A summary of these 
comments and our responses follow.

Summary of Comments and Recommendations

    We requested comments from the public on the interim rule's 
designation of critical habitat for the Kootenai sturgeon and the 
associated draft economic analysis during a comment period that opened 
concurrent with the publication of the interim rule on February 8, 2006 
(71 FR 6383), and closed on April 10, 2006. In addition, we held an 
information meeting and public hearing in Bonners Ferry, Idaho, on 
March 16, 2006. We contacted appropriate Federal, State, and local 
agencies and Tribes; scientific organizations; and other interested 
parties and invited them to comment on the interim rule and draft 
economic analysis during this open comment period.
    We received six comments during the comment period and public 
hearing, all from organizations or individuals. We did not receive any 
comments from State or Federal agencies or Tribes. In addition, in 
accordance with our peer review policy published on July 1, 1994 (59 FR 
34270), we solicited expert opinions from five knowledgeable 
individuals with scientific expertise that included familiarity with 
the Kootenai sturgeon, the geographic region where the species occurs, 
and conservation biology principles. All five of the individuals we 
contacted responded.
    We reviewed all comments received from the public and the peer 
reviewers for substantive issues and new information regarding the 
designation of critical habitat for the Kootenai sturgeon. All 
substantive information provided from the public and the peer reviewers 
has been either incorporated directly into this final rule or addressed 
in the following summary.

Peer Reviewer Comments

    1. Comment: Both the braided channel and the canyon reach are 
essential to the conservation of the Kootenai sturgeon. Without these 
areas, it is difficult to understand how natural recruitment of the 
magnitude and frequency required to recover the sturgeon can occur.
    Our Response: We have included the braided channel in this revised 
final critical habitat designation because it is essential to 
successful spawning and egg attachment and incubation, which are 
currently the life stages we believe are limiting natural recruitment 
of Kootenai sturgeon. There is limited information on whether, or how, 
Kootenai sturgeon use the canyon reach. Information available at this 
time indicates the canyon reach has the elements necessary to support 
Kootenai sturgeon spawning, but the fish do not currently appear to use 
the area for this purpose. We are willing to consider any additional 
information demonstrating that the canyon reach is essential to the 
conservation of the Kootenai sturgeon.
    2. Comment: The background information regarding the need for a 
sustained increase in river discharge from Libby Dam to restore natural 
spawning habitat conditions is compelling.
    Our Response: We identified the primary constituent elements (PCEs) 
of Kootenai sturgeon critical habitat based on the best available 
scientific information, including a flow regime during the spawning 
season that approximates natural variable conditions.
    3. Comment: The rule indicates that Kootenai sturgeon spawning and 
the initial three weeks of life are the most important stage to 
protect, but does not elaborate on why this period was selected. The 
commenter offered that while critical data are lacking, their 
experience and that of many other sturgeon researchers suggest that 
year-class strength and recruitment is established by the end of the 
larval life interval, which for white sturgeon occurs at about day 55-
65, not day 21.
    Our Response: In designating critical habitat, we consider those 
physical and biological features that are essential to the conservation 
of the species, and within areas occupied by the species at the time of 
listing, that may require special management considerations or 
protections. Current data indicate that the population bottleneck that 
is limiting Kootenai sturgeon recovery is at the egg attachment and 
incubation life phase (Paragamian et al. 2001, pp. 22-33; Paragamian et 
al. 2002, pp. 608, 615); thus we have concentrated on this stage as the 
most important life phase to protect. We are not aware of data 
indicating that the larval period between day 21 and day 65 is 
currently limiting Kootenai sturgeon recovery and is in need of special 
management. We are willing to consider additional information in this 
regard.
    4. Comment: The background information states that fertilized eggs 
will be deposited just downstream of the spawning site; yet, no data 
are given to support this conclusion. The information on spawning of 
adults in deep pools with high water velocities suggest most eggs will 
not be at the spawning site and that eggs could be distributed 
downstream for several kilometers, as happens during white sturgeon 
spawning in the Columbia River.
    Our Response: We agree with the peer reviewer that fertilized eggs 
can drift downstream and may not remain immediately below the spawning 
site. In the interim rule published in the Federal Register on February 
8, 2006 (71 FR 6383), we state, ``The linear downstream extent of rocky 
substrate from spawning sites is also important because eggs and free 
embryos are dispersed downstream by the current.''
    5. Comment: The rule shows designated critical habitat ending at RM 
141.4, which does not include all of the pre-spawning staging reach of 
adults (RM 125-152). Furthermore, no estimate of the length of river 
reach needed downstream of existing spawning areas for rearing of egg-
larvae-juvenile life intervals is provided. Given recently documented 
dispersal behavior of Kootenai sturgeon during early life intervals, 
there is not one discrete rearing reach but, instead, a long reach 
downstream from egg deposition used for rearing of free embryos and 
larvae. Dispersal likely places early juveniles many miles (kilometers) 
downstream from the spawning site.
    Our Response: We agree with the peer reviewer that areas downstream 
from the critical habitat designation are important for the pre-
spawning staging of adult Kootenai sturgeon and rearing of free 
embryos, larvae, and juveniles. However, the best available scientific 
information indicates that spawning and egg attachment and incubation 
are the limiting life stages of Kootenai sturgeon population growth 
(Paragamian et al. 2001, pp. 22-33; Paragamian et al. 2002, pp. 608, 
615). Therefore, this final rule focuses solely on these life stages 
and the physical and biological features essential to support these 
life stages that may require special management.
    6. Comment: Research data specific to the Kootenai River supports 
increasing the primary constituent element for water depth to a minimum 
of 23 ft.
    Our Response: We concur. The preponderance of applicable scientific 
information from the Kootenai River and elsewhere in the range of white 
sturgeon where reproduction is successfully occurring suggests a mean

[[Page 39510]]

water depth of at least 23 ft (7 m) is necessary for a level of 
spawning that could potentially lead to recovery (Parsley et al. 1993, 
Table 2, p. 220; Parsley 1995, p. 1; Parsley and Kappenman 2000, Table 
1, p. 199; Paragamian et al. 2001, pp. 28, 30; Golder and Associates 
2005, Table 4.1, p. 59 and Table 4.4, p. 62; Barton et al. 2005 p. 37; 
Paragamian and Duehr 2005, Figure 2, pp. 264-265; Parsley 2006a, p. 1; 
Parsley 2006b, p. 1). Based on public comments and other information 
received, a second round of peer review comments was sought 
specifically on the primary constituent elements for water depth and 
changes in water temperature associated with spawning behavior. We 
received five responses, all of which addressed a spawning site depth 
criterion of at least 23 ft (7 m). These reviewers acknowledged that 
this criterion is well supported by data on sites within the range of 
white sturgeon where reproduction is occurring. Based on the 
reconsideration of the data, along with public and peer review 
comments, we have changed the primary constituent element for water 
depth from a minimum of 16 ft (5 m) (February 8, 2006; 71 FR 6383) to 
23 ft (7 m) in this final rule.
    7. Comment: Regarding the depth Primary Constituent Element (PCE), 
there are examples of white sturgeon in other river systems utilizing 
shallow water habitat. For example, sturgeon were observed rolling in a 
shallow side channel and embryos and larvae were then collected in that 
side channel of the Fraser River, British Columbia, Canada (see Perrin 
et al. 1999).
    Our Response: The lower Fraser River is an area where white 
sturgeon continue to reproduce regularly. Perrin et al. (1999, p. iv) 
noted that waters of the mainstem Fraser River in the vicinity of the 
Minto channel are approximately 33 ft (10 m) deep, and that they had no 
actual sturgeon spawning observations in their study. Two eggs were 
collected at one location in the adjacent Minto channel at a depth of 
9.8 ft (3 m), and where water velocity was 4.3 ft/s (1.3 m/s). Based on 
observations by Parsley (2005, p. 1; 2006a, p. 1; 2006b, p. 1), when 
water velocity is high, some sturgeon eggs may be redistributed to 
shallower sites prior to attachment on substrate. A single female may 
release more than 100,000 eggs in a spawning event. Therefore, we 
believe that the presence of only two eggs found at a depth of 9.8 ft 
(3 m) in the Minto channel of the Fraser River may be anomalous and not 
useful in defining minimum spawning habitat water depth. Furthermore, 
the comment is based primarily on the capture sites of 20 free embryos; 
free embryos are mobile upon hatching (Perrin et al. 1999, p. iii), and 
are therefore an unreliable indicator of actual sturgeon spawning 
sites.
    8. Comment: The derivation of the 5-mile linear extent of the PCE 
involving rocky substrate is not cited.
    Our Response: We have identified 5 miles (8 kilometers) as a 
minimum length of continuous rocky substrate based on observations of 
minimum habitat conditions at similar sites below Bonneville and Ice 
Harbor Dams where white sturgeon are known to reproduce annually. 
Although the authors do not explicitly state the linear extent of the 
rocky substrate utilized in these areas, this information is derived 
from the observations of spawning locations, water velocity, and 
substrate use provided in Parsley et al. 1993.

Comments from the Public

    1. Comment: The February 8, 2006, critical habitat interim rule (71 
FR 6383) was legally deficient because it failed to alert the public 
that a significant practical effect or goal of the critical habitat 
designation is increasing the level of Kootenay Lake in British 
Columbia.
    Our Response: The February 8, 2006, interim critical habitat rule 
included a section on special management considerations documenting 
that ``threats to the braided reach include shallow water depths'' (71 
FR 6388). The public was advised that appropriate special management 
would include measures to provide for water depths during the sturgeon 
spawning season that would provide for the conservation needs of the 
species. The operation of Kootenay Lake is outside the control of 
Federal agencies and the Service; nothing in the critical habitat 
designation has the legal effect of requiring Canadian authorities to 
raise the level of the lake.
    2. Comment: The Service should have prepared an environmental 
document under the National Environmental Policy Act (NEPA) analyzing 
the effect of the critical habitat designation. The court opinion that 
held that NEPA is not applicable to critical habitat designations is 
limited to its facts and should not apply to the Kootenai sturgeon 
critical habitat.
    Our Response: The Ninth Circuit, in Douglas County v. Babbitt, 48 
F.3d 1495 (9th Cir. 1995) (Douglas County), held that NEPA is 
inapplicable to critical habitat designations. We contend that the 
court's opinion in Douglas County contained no intention to limit the 
holding to that specific situation. The opinion speaks in broad terms 
that apply to any critical habitat designation, explaining that 
requiring a NEPA analysis would be inconsistent with, or redundant to, 
Act requirements for designating critical habitat. The court explained:
    ``The purpose of the ESA [Act] is to prevent extinction of species, 
and Congress has allowed the Secretary to consider economic 
consequences of actions that further that purpose. But Congress has not 
given the Secretary the discretion to consider environmental factors, 
other than those related directly to the preservation of the species. 
The Secretary cannot engage in the very broad analysis NEPA requires 
when designating a critical habitat under the ESA [Act]'' (48 F.3d at 
1507).
    The court concluded that ``the legislative histories of NEPA and 
the ESA (Act) likewise indicate that Congress did not intend that the 
Secretary file an Environmental Impact Statement (EIS) before 
designating a critical habitat'' (48 F.3d at 1507).
    3. Comment: The draft economic analysis is defective because it 
does not factor in the increased level of Kootenay Lake that may be 
necessary to achieve desired river depths for sturgeon, and the impacts 
of higher lake levels are likely to have enormous economic 
consequences. No information regarding any costs above the amount that 
might be expected as a result of higher Kootenay Lake levels was 
provided.
    Our Response: The level of Kootenay Lake is controlled by Canadian 
authorities; critical habitat designation has no legal effect on the 
actions of a foreign government. The draft economic analysis included 
an estimate of the cost of crop damage that might be expected as a 
result of flows required for Kootenai sturgeon recovery.
    4. Comment: The critical habitat designation would result in higher 
water tables and an increased risk of flooding, which would be a 
compensable taking of private property under the Fifth Amendment. In 
addition, a potential ``relative benefits'' defense by the Service, 
where the landowner incurs both harm and benefits that must be weighed 
against each other, would not apply because no relative benefits would 
be imparted by critical habitat designation.
    Our Response: Designation of critical habitat imposes no direct 
regulatory burden on private parties; it requires Federal agencies to 
insure that actions that they authorize, fund, or carry out, do not 
adversely modify designated habitat (16 U.S.C. 1536(a)(2)). A private 
party with a Federal grant or permit that constitutes a ``nexus'' for 
purposes of the Act's section 7 might bear an

[[Page 39511]]

indirect regulatory burden as a result of a critical habitat 
designation. Courts assess takings claims based on the degree of 
impairment of the property interest, the owner's reasonable 
expectations, and the importance of the government interest being 
advanced. In light of these factors, we believe that no compensable 
taking will occur as a result of designation of critical habitat.
    5. Comment: The Service violated the Act by promulgating the 
interim rule without the requisite 90-day notice as is indicated under 
section 4(b)(5) of the Act.
    Our Response: We were under a court order to issue a critical 
habitat rule for Kootenai sturgeon by a specific date, and the schedule 
imposed by the court made it impracticable to issue a proposed rule 
prior to a final rule. We acknowledge that section 4(b)(5) of the Act 
requires a 90-day advance notice before the effective date of a final 
rule. However, we believe that we remedied the situation as well as 
possible by seeking both public and peer review comments on the interim 
rule and reconsidering it in light of those comments, as we are doing 
here. In the declaration that accompanied our motion to amend the 
court's May 25, 2005, judgment, we explained that the timeline given by 
the court to issue a new final rule was insufficient to complete a 
legally proper and well-justified revision of critical habitat.
    Under these circumstances, we have determined under 5 U.S.C. 
553(b)(3)(B) that we had good cause to issue the interim rule without 
prior opportunity for public comment because prior notice and public 
procedure would have been impracticable. From the time required to 
research the interim rule, we did not have sufficient time to issue a 
proposed rule, open a reasonable comment period, and subsequently issue 
a final rule prior to the court-imposed deadline. Therefore, without 
issuance of an interim rule, we would have been in violation of the 
court order. Thus, in effect, the interim rule served as the proposed 
rule for this revised final rule, and the Service treated the interim 
rule as the proposed rule for the purpose of complying with ESA Sec.  
4(b)(5).
    6. Comment: The Service has failed to acknowledge the need for 
special management to address PCEs that may not be fully available at 
all times or places within designated critical habitat.
    Our Response: This final rule designates critical habitat within 
the braided and meander reaches of the Kootenai River that will require 
special management to restore functional water depth, flow timing, and 
water temperature. At this time, these PCEs are intermittently present 
within these reaches of the Kootenai River.
    7. Comment: The Service used flawed reasoning in stating that Libby 
Dam is part of the environmental baseline, and thus that its continued 
operation will not result in adverse modification of critical habitat. 
The commenter further stated that the operations of Libby Dam are 
widely acknowledged as being the primary reason the sturgeon is headed 
toward extinction, and the reason why the sturgeon fails to spawn in 
the braided reach.
    Our Response: The Service's use of the term ``environmental 
baseline'' is restricted to the section 7 compliance process under the 
Act. In that context, the future effects of Libby Dam operations on the 
Kootenai sturgeon and its critical habitat are not part of the 
environmental baseline. The Service defines the term ``environmental 
baseline'' as ``* * * the past and present impacts of all Federal, 
State, or private actions and other human activities in the action 
area, the anticipated impacts of all proposed Federal projects in the 
action area that have already undergone formal or early section 7 
consultation, and the impact of State or private actions which are 
contemporaneous with the consultation in process.'' On that basis, the 
effects of Libby Dam construction and past operations on the Kootenai 
sturgeon and its critical habitat are part of the environmental 
baseline.
    At the time the sturgeon was listed and critical habitat was 
designated, all future operations of Libby Dam were subject to the 
jeopardy and adverse modification of critical habitat standards under 
section 7(a)(2) of the Act. Because the action of constructing the dam 
was completed in 1973, the continued presence of the dam is not an 
action subject to the requirements of section 7 of the Act. However, 
the effects of future operations on listed species and critical habitat 
are subject to the requirements of section 7 of the Act. Subsequently, 
we completed formal consultations with the Corps, Bureau of Reclamation 
(BOR), and the Bonneville Power Administration (BPA) on the effects of 
Libby Dam operations on the sturgeon in 1995, 2000, and 2006; our 2006 
Biological Opinion (BO) on the effects of Libby Dam operations on the 
Kootenai sturgeon also addressed the effects of dam operations on 
designated critical habitat (USFWS 2006b). The latter two consultations 
resulted in BOs in which we concluded that future operations of Libby 
Dam, as proposed by the Federal action agencies, were likely to 
jeopardize the continued existence of the sturgeon and adversely modify 
its critical habitat.
    In accordance with our regulations, we included a Reasonable and 
Prudent Alternative (RPA) to the proposed operation of Libby Dam that 
would avoid jeopardy and adverse modification in our 2006 BO. The 
Corps, as operator of Libby Dam, and BPA, as marketer of the hydropower 
generated at Libby Dam, are currently implementing the RPA.
    8. Comment: The current designation of critical habitat, which 
includes only the river to the high water mark, improperly excludes 
side channel habitats.
    Our Response: The braided reach of the Kootenai River designated as 
critical habitat includes several side channels that, because of their 
structure and condition, function as both foraging and spawning habitat 
for the Kootenai sturgeon. These areas have not been excluded from the 
designation.
    9. Comment: If in the future it is found that designation of this 
critical habitat is not necessary, what process is there for removing 
it from critical habitat?
    Our Response: Section 4(a)(3)(A) of the Act and implementing 
regulations at 50 CFR 424.12 require that ``critical habitat shall be 
specified to the maximum extent prudent and determinable.'' Critical 
habitat is considered not prudent when the identification of critical 
habitat can be expected to increase the degree of threat from taking or 
other human activity, or if the designation of critical habitat would 
not be beneficial to the species. In the absence of a ``not prudent'' 
finding, the Act requires that we designate critical habitat for listed 
species. The Act does provide that critical habitat designations may be 
revised, as appropriate. Any revisions would occur through the 
rulemaking process.
    10. Comment: Hopefully, this designation will not affect the 
private gravel operations that take place upstream of the designated 
area.
    Our Response: The effect of a critical habitat designation is that 
activities authorized, funded, or carried out by a Federal agency 
require consultation under section 7 of the Act to ensure that they are 
not likely to destroy or adversely modify critical habitat. For 
example, activities on private or State lands requiring a permit from a 
Federal agency, such as a permit from the Corps under section 404 of 
the Clean Water Act, a section 10(a)(1)(B) permit from us, or some 
other Federal action, including funding (for example, Federal Highway 
Administration or Federal Emergency Management Agency funding), would 
be subject to the

[[Page 39512]]

section 7 consultation process. Activities on State, Tribal, local, or 
private lands that are not carried out, funded, or authorized by a 
Federal agency are not subject to any regulatory requirements as a 
result of critical habitat designation. The designation of critical 
habitat does not affect land ownership or establish a refuge, 
wilderness, reserve, preserve, or other conservation area, and the 
designation of critical habitat does not allow government or public 
access to private lands.

Summary of Changes from the Interim Rule

    In developing this revised final critical habitat rule for the 
Kootenai sturgeon, we reviewed peer review and public comments received 
on the interim rule and draft economic analysis published in the 
Federal Register on February 8, 2006 (71 FR 6383), as well as a second 
round of peer review comments received specifically on the PCEs. Based 
on comments received, including peer review comments, this final rule 
modifies the interim rule in the following ways:
    (1) We have made the PCEs more explicit to more clearly communicate 
the best available scientific information regarding the conservation 
needs of the species.
    (2) We have modified the depth PCE (PCE 1) from a minimum of 16 ft 
(5 m) to a minimum of 23 ft (7 m) to more accurately reflect the best 
available science, indicating that mean water depth of at least 23 ft 
(7 m) is necessary for spawning site selection by white sturgeon in the 
Kootenai River (for example, Paragamian et al. 2001, Table 2, p. 27, p. 
29, and Figure 4, p. 29; Paragamian and Duehr 2005, p. 263, 265; 
Parsley 2006a, p. 1; Parsley 2006b, p. 1).
    (3) In the interim rule, we stated that we added 6.9 RM (11.1 RKM) 
to the critical habitat designation, but later stated that this 
additional reach extends from ``RM 159.7 (RKM 257) to RM 152.6 (RKM 
245.9),'' which is actually 7.1 RM. The area designated as critical 
habitat in the interim rule remains unchanged in this revised final 
rule. This final rule simply corrects the RM totals to indicate that we 
added 7.1 RM to our 2001 designation of 11.2 RM, for a total of 18.3 
RM.
    (4) We have combined the two former units, the braided reach and 
the meander reach, into a single designation because the two units are 
contiguous, and clarified the location of the river reaches within the 
designation:
    (i) The braided reach begins at RM 159.7 (RKM 257.0), below the 
confluence with the Moyie River, and extends downstream within the 
Kootenai River to RM 152.6 (RKM 246.0) below Bonners Ferry.
    (ii) The meander reach begins at RM 152.6 (RKM 246.0) below Bonners 
Ferry, and extends downstream to RM 141.4 (RKM 228.0) below Shorty's 
Island.
    (iii) This designation includes the 0.9 mi (1.5 km) ``transition 
zone,'' described in the February 2006 interim rule (71 FR 6383) that 
joins the meander and braided reaches at Bonners Ferry.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by a 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features (a) essential to the 
conservation of the species and (b) which may require special 
management considerations or protection; and
    (2) Specific areas outside the geographical area occupied by a 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Conservation, as defined under section 3 of the Act, means the use 
of all methods and procedures that are necessary to bring an endangered 
or threatened species to the point at which the measures provided under 
the Act are no longer necessary. Such methods and procedures include, 
but are not limited to, all activities associated with scientific 
resource management, such as research, census, law enforcement, habitat 
acquisition and maintenance, propagation, live trapping, and 
transplantation, and (in the extraordinary case where population 
pressures within a given ecosystem cannot be otherwise relieved), may 
include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against Federal agencies carrying out, funding, 
or authorizing the destruction or adverse modification of critical 
habitat. Section 7(a)(2) of the Act requires consultation on Federal 
actions that may affect critical habitat. The designation of critical 
habitat does not affect land ownership or establish a refuge, 
wilderness, reserve, preserve, or other conservation area. Such 
designation does not allow the government or public to access private 
lands. Such designation does not require implementation of restoration, 
recovery, or enhancement measures by private landowners. Where a 
landowner requests Federal agency funding or authorization for an 
action that may affect a listed species or critical habitat, the 
consultation requirements of section 7(a)(2) would apply, but even in 
the event of a destruction or adverse modification finding, the 
landowner's obligation is not to restore or recover the species, but to 
implement reasonable and prudent alternatives to avoid destruction or 
adverse modification of critical habitat.
    For inclusion in a critical habitat designation, the habitat within 
the geographical area occupied by the species at the time of listing 
must contain the physical and biological features essential to the 
conservation of the species, and be included only if those features may 
require special management considerations or protection. Critical 
habitat designations identify, to the extent known using the best 
scientific data available, habitat areas that provide essential life 
cycle needs of the species. Under the Act, we can designate critical 
habitat in areas outside the geographical area occupied by the species 
at the time it is listed only when we determine that those areas are 
essential for the conservation of the species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, our Policy on Information Standards Under the Endangered 
Species Act (published in the Federal Register on July 1, 1994 (59 FR 
34271)), the Information Quality Act (section 515 of the Treasury and 
General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658)), and our associated Information Quality Guidelines 
provide criteria, establish procedures, and provide guidance to ensure 
that our decisions are based on the best scientific data available. 
They require our biologists, to the extent consistent with the Act and 
with the use of the best scientific data available, to use primary and 
original sources of information as the basis for recommendations to 
designate critical habitat.
    When we are determining which areas should be proposed as critical 
habitat, our primary source of information is generally the information 
developed during the listing process for the species. Additional 
information sources include the recovery plan for the species, if 
available; articles in peer-reviewed journals; conservation plans 
developed by States and counties; scientific status surveys and 
studies; biological assessments; or other unpublished materials and 
expert opinion or personal knowledge.

[[Page 39513]]

    Habitat is often dynamic, and species may move from one area to 
another over time. Furthermore, we recognize that designation of 
critical habitat may not include all of the habitat areas that we may 
eventually determine to be necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated area is unimportant or may not promote 
the recovery of the species.
    Areas that support populations, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions. They are also subject to the regulatory protections afforded 
by the section 7(a)(2) jeopardy standard, as determined on the basis of 
the best available information at the time of the action. Federally 
funded or permitted projects affecting listed species outside their 
designated critical habitat areas may require consultation under 
section 7 of the Act and may still result in jeopardy findings in some 
cases. Similarly, critical habitat designations made on the basis of 
the best available information at the time of designation will not 
control the direction and substance of future recovery plans, habitat 
conservation plans, or other species conservation planning efforts if 
information available at the time of these planning efforts calls for a 
different outcome.

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and the 
regulations at 50 CFR 424.12, in determining which areas occupied at 
the time of listing to propose as critical habitat within areas 
occupied by the species at the time of listing, we consider the 
physical and biological features that are essential to the conservation 
of the species to be the primary constituent elements laid out in the 
appropriate quantity and spatial arrangement for conservation of the 
species. These include, but are not limited to:
    (1) Space for individual and population growth and for normal 
behavior;
    (2) Food, water, or other nutritional or physiological 
requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, rearing of offspring, 
germination, or seed dispersal;
    (5) Habitats that are protected from disturbance or are 
representative of the historical geographical and ecological 
distributions of a species.
    As required by 50 CFR 424.12(b)(5), we are to list the known PCEs 
with our description of critical habitat. The PCEs provided by the 
physical and biological features upon which the designation is based 
may include, but are not limited to, the following: roost sites, 
nesting grounds, spawning sites, feeding sites, seasonal wetland or 
dryland, water quality or quantity, host species or plant pollinator, 
geological formation, vegetation type, tide, and specific soil types.

Primary Constituent Elements for the Kootenai Sturgeon

    We identified the PCEs for Kootenai sturgeon critical habitat based 
on our knowledge of the life history, biology, and ecology of the 
species, and the physical and biological features of the habitat 
necessary to sustain its essential life history functions, as described 
in the Background section of this rule. We are changing the PCEs from 
those identified in our critical habitat interim rule (February 8, 
2006; 71 FR 6383) to better fit our current understanding of the 
features needed to support the sturgeon's life history functions, and 
to reflect the information received from peer review and public 
comment.
    This designation focuses solely on spawning and rearing habitats, 
the factors that we understand to be currently limiting to sturgeon 
conservation (Paragamian et al. 2001, pp. 22-33; Paragamian et al. 
2002, pp. 608, 615). All of the following PCEs must be present during 
the spawning and incubation period for successful spawning, incubation, 
and embryo survival to occur. However, although the PCEs to support 
successful spawning must occur simultaneously in time and space, it is 
not necessary for them to be present through the entire spawning 
period, nor must they be present throughout the entire designated area. 
The PCEs are:
    (1) A flow regime, during the spawning season of May through June, 
that approximates natural variable conditions and is capable of 
producing depths of 23 ft (7 m) or greater when natural conditions (for 
example, weather patterns, water year) allow. The depths must occur at 
multiple sites throughout, but not uniformly within, the Kootenai River 
designated critical habitat.
    (2) A flow regime, during the spawning season of May through June, 
that approximates natural variable conditions and is capable of 
producing mean water column velocities of 3.3 ft/s (1.0 m/s) or greater 
when natural conditions (for example, weather patterns, water year) 
allow. The velocities must occur at multiple sites throughout, but not 
uniformly within, the Kootenai River designated critical habitat.
    (3) During the spawning season of May through June, water 
temperatures between 47.3 and 53.6 [deg]F (8.5 and 12 [deg]C), with no 
more than a 3.6 [deg]F (2.1 [deg]C) fluctuation in temperature within a 
24-hour period, as measured at Bonners Ferry.
    (4) Submerged rocky substrates in approximately 5 continuous river 
miles (8 river kilometers) to provide for natural free embryo 
redistribution behavior and downstream movement.
    (5) A flow regime that limits sediment deposition and maintains 
appropriate rocky substrate and inter-gravel spaces for sturgeon egg 
adhesion, incubation, escape cover, and free embryo development. Note: 
the flow regime described above under PCEs 1 and 2 should be sufficient 
to achieve these conditions.
    This critical habitat designation is focused on Kootenai sturgeon 
spawning habitats and egg attachment and egg incubation habitats, as 
these areas are currently the limiting habitat components essential to 
Kootenai sturgeon conservation (Paragamian et al. 2001, pp. 22-33; 
Paragamian et al. 2002, pp. 608, 615). Maintaining the PCEs in this 
designated area is consistent with our recovery objective to re-
establish successful natural recruitment of Kootenai sturgeon (U.S. 
Fish and Wildlife Service 1999, p. iv). However, the presence of PCE 
components related to flow, temperature, and depth are dependent in 
large part on the amount and timing of precipitation in any given year. 
These parameters vary during and between years, and at times some or 
all of the parameters are not present in the area designated as 
critical habitat. Within the critical habitat reaches, the specific 
conditions are variable due to a number of factors such as snowmelt, 
runoff, and precipitation. This designation recognizes the natural 
variability of these factors, and does not require that the PCEs be 
available year-round, or even every year during the spawning period. At 
present, the PCEs are achieved only infrequently, such as in 2006 
during the ``stacked flow'' operations when the Kootenai River reached 
river stage 1,763.61 MSL (feet above mean sea level; 537.5 m) at 
Bonners Ferry (Corps 2007, p. 6), resulting in the first documented 
movement of tagged female Kootenai sturgeon into the braided reach 
above Bonners Ferry (Kootenai Sturgeon Recovery Team 2006, pp. 1-2). 
The designation means that sufficient PCE components to support 
successful spawning must be present and protected during the spawning 
season of May through June at multiple sites throughout, but not 
uniformly within,

[[Page 39514]]

the Kootenai River designated critical habitat in all years when 
natural conditions (for example, weather patterns, water year) make it 
possible.

Special Management Considerations or Protections

    When designating critical habitat, we assess whether the areas 
occupied by the species at the time of listing contain the physical and 
biological features essential to the conservation of the species, and 
whether these features may require special management consideration or 
protections. In this case, the threats to the physical and biological 
features in the area designated as critical habitat that may require 
special management considerations or protections include shallow water 
depths (loss of deeper water habitat), low water velocities, and sudden 
drops in water temperature that adversely affect Kootenai sturgeon 
breeding behavior.
    Both of the designated reaches provide the physical and biological 
features that are essential to the Kootenai sturgeon for spawning, egg 
attachment, incubation, and juvenile rearing, and both require special 
management to ensure that the appropriate water depths, velocities, and 
temperature are achieved during the spawning period in all years when 
natural conditions allow.
    Libby Dam is operated by the Corps to meet a variety of needs, 
including power production, flood control, recreation, and special 
operations for the recovery of species listed under the Act, including 
Kootenai sturgeon, bull trout, and salmon in the lower Columbia River. 
The Corps currently operates the dam so as not to exceed 1,764 MSL at 
Bonners Ferry, Idaho (the flood stage designated by the National 
Weather Service for the purposes of flood protection). However, flood 
stage can be exceeded due to unexpected increased inflow to Libby Dam 
or due to tributary flows downstream of Libby Dam (U.S. Fish and 
Wildlife Service 2006b, p. 5). The Corps has noted that it considers 
1,764 MSL to be the ``current target river stage for Libby Dam 
operations'' (Corps 2007, p.1).
    The Corps conducted a stacked flow operation in spring 2006 to test 
different flow strategies for meeting the habitat attributes identified 
for the Kootenai sturgeon in the Service's 2006 BO on the effects of 
Libby Dam operations on the Kootenai sturgeon and its critical habitat 
(U.S. Fish and Wildlife Service 2006b). The stacked flow operation was 
developed to utilize Libby outflows at full powerhouse capacity (25,000 
cfs) and temperature control at the dam (to the extent possible) such 
that releases were timed to ``stack'' on local tributary inflows to 
provide velocities, depth, and temperature conditions specified in the 
BO. The operation, initiated in May 2006, controlled releases from the 
dam as much as possible to provide the appropriate temperature for 
sturgeon migration and spawning (Corps 2006, p. 5). This stacked flow 
operation demonstrated that the Corps was able to achieve depth in the 
middle of the channel, continuously exceeding 23 ft (7m) as far 
upstream as RM 153.1, with some areas exceeding 39 ft (12 m) between RM 
152 and 157, at flows below flood stage (Corps 2007, p. 6).
    We recognize that, due to existing morphologic constraints and 
limitations at Libby Dam, the depth PCE described in this rule (23 ft; 
7 m) is currently not achievable on an annual basis in the braided 
reach. Since the construction of Libby Dam and the subsequent altered 
hydrograph, the braided reach has become shallower and wider (Barton 
2005a, unpublished data), thus limiting the ability to achieve the 
depth PCE in the braided reach in most years. To address this issue, 
the Kootenai Tribe of Idaho, in cooperation with regional partners and