You may submit your comments and materials concerning this proposed rule by one of the methods listed in the ADDRESSES section.

We will post your entire commentincluding your personal identifying informationon http://www.regulations.gov. If you provide personal identifying information, in addition to the required items specified in the previous paragraphs, such as your street address, phone number, or email address, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so.

Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on http://www.regulations.gov, or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Idaho Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT).

We are holding a public hearing on the date listed in the DATES section at the address listed in the ADDRESSES section. We are holding this public hearing to provide interested parties an opportunity to present verbal testimony (formal, oral comments) or written comments regarding the proposed critical habitat designation and the associated Draft Economic Analysis. An informational session will precede the hearing from 4 p.m. to 6 p.m. During
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this session, Service biologists will be available to provide information and address questions on the proposed rule in advance of the formal hearing.

People needing reasonable accommodations in order to attend and participate in the public hearings should contact Jeff Foss, Idaho Fish and Wildlife Office, at 2083785243 as soon as possible (see FOR FURTHER INFORMATION CONTACT section). In order to allow sufficient time to process requests, please call no later than one week before the hearing date.

We are also holding public meetings on the dates listed in the DATES section at the addresses listed in the ADDRESSES section. During the public meetings, Service biologists will be available to provide information and address questions on the proposed rule. However, we will not accept verbal testimony at these public meetings.

Information regarding this notice is available in alternative formats upon request.

Background

It is our intent to discuss only those topics directly relevant to the designation of critical habitat in this proposed rule. For further information on the bull trout biology and habitat, population abundance and trend, distribution, demographic features, habitat use and conditions, threats, and conservation measures, please see the Bull Trout 5year Review Summary and Evaluation, completed April 25, 2008. This document is available on the Idaho Fish and Wildlife Office web site at http://ecos.fws.gov/docs/five_year_review/doc1907.pdf. Description, Distribution, Habitat and Recovery

Bull trout have more specific habitat requirements than most other salmonids (Rieman and McIntyre 1993, p. 4). Habitat components that particularly influence their distribution and abundance include water temperature, cover, channel form and stability, spawning and rearing substrate conditions, and migratory corridors (Fraley and Shepard 1989, p. 138; Goetz 1989, p. 19; Watson and Hillman 1997, p. 247). This proposed rule identifies those physical and biological features essential to bull trout conservation.

Bull trout are members of the char subgroup of the family Salmonidae and are native to waters of western North America. Bull trout range throughout the Columbia River and Snake River basins, extending east to headwater streams in Montana and Idaho, into Canada, and in the Klamath River basin of southcentral Oregon. The
distribution of populations, however, is scattered and patchy (Goetz 1989, p. 4; Ziller 1992, p. 6; Rieman and McIntyre 1993, p. 3; Light et al. 1996, p. 44; Quigley and Arbelbide 1997, p. 1176).

Bull trout exhibit a number of lifehistory strategies. Stream resident bull trout complete their entire life cycle in the tributary streams where they spawn and rear. Most bull trout are migratory, spawning in tributary streams where juvenile fish usually rear from one to four years before migrating to either a larger river (fluvial) or lake (adfluvial) where they spend their adult life, returning to the tributary stream to spawn (Fraley and Shepard 1989, p. 133). Resident and migratory forms may be found together, and either form can produce resident or migratory offspring (Rieman and McIntyre 1993, p. 2).

Bull trout, coastal cutthroat trout (Oncorhynchus clarki clarki), Pacific salmon (Oncorhynchus spp.), and some other species are commonly referred to as anadromous (fish that can migrate from saltwater to freshwater to reproduce). However, bull trout, coastal cutthroat trout, and some other species that enter the marine environment are more properly termed amphidromous. Unlike strictly anadromous species, such as Pacific salmon, amphidromous species often return seasonally to fresh water as subadults, sometimes for several years, before returning to spawn (Wilson 1997, p. 5). The amphidromous lifehistory form of bull trout is unique to the CoastalPuget Sound population (64 FR 58921; November 1, 1999). For additional information on the biology of this life form, see our June 25, 2004, proposed critical habitat designation for the Jarbidge River, CoastalPuget Sound, and Saint MaryBelly River populations of bull trout (69 FR 35767).

The decline of bull trout is primarily due to habitat degradation and fragmentation, blockage of migratory corridors, poor water quality, past fisheries management practices, impoundments, dams, water diversions, and the introduction of nonnative species (63 FR 31647; June 10, 1998; 64 FR 17112; April 8, 1999). Finalization of the 2002 draft recovery plan was held in abeyance pending completion of the 5 year review process, and was also affected by resource demands associated with the litigation discussed below. The bull trout 5year review (Service 2008, p. 45) recommended that the recovery units identified in the 2002 draft recovery plan be updated throughout their range based on assemblages of bull trout core areas (metapopulations or interacting breeding populations) that retain genetic and ecological integrity and are significant to the distribution of bull trout throughout the conterminous United States. After consulting with biologists from states, Federal agencies, and Native American tribes, and applying the best scientific information available, we identified six recovery units for bull trout in the conterminous United States. Please refer to the ``Critical Habitat'' section below for additional information on this topic.

Previous Federal Actions

On November 29, 2002, we proposed to designate critical habitat for the Klamath River and Columbia River bull trout populations (67 FR 71235). On October 6, 2004, we finalized the critical habitat designation for the Klamath River and Columbia River bull trout populations (69 FR 59995). On June 25, 2004, we proposed to designate critical habitat for the Jarbidge, CoastalPuget Sound, and Saint Mary Belly River bull trout populations (69 FR 35767). On September 26, 2005, we designated critical habitat for the Klamath River, Columbia River, Jarbidge River, CoastalPuget Sound, and Saint MaryBelly River populations of bull trout (70 FR 56212). Please refer to the above mentioned rules for a detailed summary of previous Federal actions completed prior to publication of this proposed rule.

On January 5, 2006, a complaint was filed in Federal district court by the Alliance for the Wild Rockies, Inc. and Friends of the Wild Swan, alleging the Service failed to designate adequate critical habitat, failed to rely on the best scientific and commercial data available, failed to consider the relevant factors that led to listing, and failed to properly assess the economic benefits and costs of critical habitat designation. Other allegations included an inadequate analysis and the unlawful use of exclusions. On March 23, 2009, the Service provided notice to the U.S. District Court for the District of Oregon that we would seek remand of the final critical habitat rule for bull trout based on the findings of an Investigative Report by the Department of the Interior Inspector General (USDI 2008, pp. 1038). On July 1, 2009, the court granted our request for a voluntary remand of the 2005 final rule and directed the Service to submit a new proposed rule to the Federal Register by December 31, 2009, and to submit a final decision on that proposed rule to the Federal Register by September 30, 2010 (Alliance for the Wild Rockies v. Allen, 2009 U.S. Dist. LEXIS 63122 (D. Or., July 1, 2009)). The court directed that the existing critical habitat rule shall remain in effect until completion of the remanded decision.
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Summary of Changes from Previously Designated Critical Habitat

Approximately 36,498 km (22,679 mi) of streams (which includes 1,585.7 km (985.3 mi) of marine shoreline area, and 215,870 ha (533,426 ac) of reservoirs or lakes) are being proposed as revised critical habitat in this rule. Areas that were proposed as critical habitat in the November 29, 2002, proposed designation for the Klamath River and Columbia River bull trout populations (67 FR 71235) and the June 25, 2004, proposed designation for the Jarbidge, CoastalPuget Sound, and Saint MaryBelly River bull trout populations (69 FR 35767) are identified in Table 1 below. Based on better occupancy data and refined information on the importance of certain habitats, we are proposing to designate 3 percent more critical habitat in streams (measured on a linear basis) and 10 percent less critical habitat in lakes and reservoirs (measured by area) than were proposed in the combined 2002 and 2004 proposed rules.
Table 1.Extent of Proposed Bull Trout Critical Habitat In The Combined 2002 and 2004 Proposed Rules (67 FR 71235; 69 FR 35767) Stream length Lakes, Reservoirs and Marshes Marine shoreline Bull Trout Population States km mi ha ac km mi Klamath DPS................................ 476 296 13,735 33,939 ........... ........... OR Columbia River DPS (CDPS).................. 14,416 8,958 83,219 205,639 ........... ........... ID CDPS....................................... 5,341 3,319 88,051 217,577 ........... ........... MT CDPS....................................... 5,460 3,391 18,077 44,670 ........... ........... OR CDPS....................................... 4,034 2,507 12,503 30,897 ........... ........... WA Jarbidge................................... 211 131 .............. .............. ........... ........... ID/NV CoastalPuget Sound........................ 3,685 2,290 21,262 52,540 1,585 985 WA St. MaryBelly............................. 142 88 2,548 6,295 ........... ........... MT

Total.................................. 33,765 20,980 239,395 591,577 1,585 985

This proposed rule differs from the September 26, 2005, final critical habitat designation for bull trout (70 FR 56212) in the following ways:

In the 2005 final rule, we designated approximately 6,161 km (3,828 mi) of streams and 57,9578 ha (143,218 ac) of lakes in Idaho, Montana, Oregon, and Washington; and 1,585 km (985 mi) of shoreline paralleling marine habitat in Washington as critical habitat (70 FR 56212). No critical habitat was designated in the Jarbidge River basin (70 FR 5624956251). In this rule, we are proposing to designate 36,498 km (22,679 mi) of streams (which includes 1,585.7 km (985.3 mi) of marine shoreline area in the Olympic Peninsula and Puget Sound), and 215,870 ha (533,426 ac) of lakes and reservoirs as critical habitat, which includes 266.9 km (165.9 mi) of streams in the Jarbidge River basin.

In the 2005 final rule, we did not designate any unoccupied critical habitat because the Secretary concluded that it was not possible to make a determination that such lands were essential to the conservation of the species (70 FR 56232). In this rule, we are proposing to designate 1,495 km (929 mi) of streams (four percent of the total) that are outside the geographical area occupied by the species at the time it was listed that have been determined to be essential for the conservation of the species.

In the 2005 rule, a variety of areas were exempted from critical habitat designation under section 4(a)(3) of the Act or excluded from designation as critical habitat under section 4(b)(2) of the Act (70 FR 56232). These areas included several DOD facilities; certain Tribal lands; Nisqually National Wildlife Refuge lands; lands subject to Habitat Conservation Plans (HCPs); lands subject to Federal or State management plans (including PACFISH, INFISH, Interior Columbia Basin Ecosystem Management Project, Northwest Forest Plan, Southwest Idaho Land and Resource Management Plan, Southeast Oregon Resource Management Plan, Federal Columbia River Power System, Snake River Basin Adjudication); waters impounded behind dams; and all lands that were proposed as critical habitat in the Jarbidge River in Nevada.

Federal agencies have an independent responsibility under section 7(a)(1) of the Act to use their programs in furtherance of the Act and to utilize their authorities to carry out programs for the conservation of endangered and threatened species. We consider the development and implementation of land management plans by Federal agencies to be consistent with this statutory obligation under section 7(a)(1) of the Act. For this reason, Federal land management plans, in and of themselves, are generally not an appropriate basis for excluding essential habitat, thus this rule does not propose to exclude any Federal lands under section 4(b)(2) of the Act. However, in some areas, Federal land management agencies actively manage for bull trout and its habitat and conduct specific conservation actions for the species. Therefore, in this proposed rule, we are asking for specific information regarding whether the effects of these actions are such that the benefits of excluding these particular areas from critical habitat outweigh the benefits of including these area as critical habitat under section 4(b)(2) of the Act (see ``Application of Section 4(b)(2) of the Act'' below).

In addition, we are exempting several DOD facilities under section 4(a)(3) of the Act based on existing Integrated Natural Resource Management Plans that provide a benefit to bull trout, and we are considering excluding certain nonFederal lands under section 4(b)(2) of the Act based on other conservation management considerations (see ``Exemptions under Section 4(a)(3) of the Act'' and ``Application of Section 4(b)(2) of the Act'' below). We are also proposing to designate 266.9 km (165.9 mi) of streams in the Jarbidge River basin.

Two economic analyses related to previous bull trout critical habitat proposed rules were prepared in 2004 and 2005, which followed a coextensive analytical approach, consistent with recent court rulings. Those analyses considered conservation and protection activities for bull trout, without distinguishing between impacts associated with listing the species and those associated with the designation of critical habitat. The economic analysis prepared for this proposed rule does not follow the coextensive analytical approach, and differentiates between
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baseline and incremental economic impacts. Under this approach, because of the conservation measures already in place for salmon, steelhead, the Klamath suckers, and other protected fish species, our analysis indicates that the incremental economic impact in areas occupied by bull trout will be small, and the most significant incremental effect will be in those areas not currently occupied (less than four percent of the areas being proposed as critical habitat). The majority of forecast incremental costs are associated with unoccupied critical habitat in the Upper Willamette River Basin and are associated with conservation efforts undertaken at flood control facilities. The discussion under ``Draft Economic Analysis'' below provides additional information in this regard.

The PCEs in this rule are similar to those described in the 2005 final designation (70 FR 56236); however, we are proposing an additional PCE related to the presence of nonnative fish that may prey on, compete with, or inbreed with, bull trout. In addition, we are considering reorganizing the PCEs, as noted above, into broad habitat attributes (water bodies and migratory corridors), and identify specific needs of bull trout within these broad categories. This reorganization would keep all of the PCEs presented in this proposal intact, but organizing them in such a way as to show the most important broad categories first, and then breaking them down into specific descriptions.

A small proportion of critical habitat designated in the 2005 final rule is not being proposed as critical habitat in this revision. These areas include streams and lakes determined either not to include bull trout or any of their PCEs, or not to be essential to their conservation. For example, Sycan Marsh in the Klamath River basin no longer holds enough water to support bull trout, so we propose the stream channels through the marsh as critical habitat, allowing connectivity among populations, instead of the entire marsh. The remainder of the areas designated in the 2005 final rule would remain designated as critical habitat if this proposed revision is finalized. A similarly small proportion of habitat proposed in this rule was not designated in the 2005 final rule. These areas include streams and lakes since determined to be occupied by bull trout, to provide one or more PCEs, or as essential to their conservation. For example, the mainstem Columbia River and the lower portions of connecting tributaries such as the John Day River have been found to be more important for FMO habitat for bull trout than was previously understood. All areas known to contain the most important bull trout habitat and PCEs, or that may be unoccupied but essential to their conservation, are proposed in this rule.

Copies of the previous proposed and final bull trout critical habitat rules and a map showing the relationship of the 2005 final rule and this proposed rule are available on the Idaho Fish and Wildlife Office web site at http://www.fws.gov/pacific/bulltrout. Critical Habitat

Background

Critical habitat is defined in section 3 of the Act as: (1) The specific areas within the geographical area occupied by the 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 the 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 pursuant to the Act are no longer necessary. Such methods and procedures include, but are not limited to, all activities associated with scientific resources 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 the landowner. Where a landowner seeks or 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 Federal action agency's and the applicant'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, habitat within the geographical area occupied by the species at the time it was listed must contain the physical and biological features that are 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 habitat areas that provide essential life cycle needs of the species (areas on which are found the physical and biological features (PBFs) laid out in the appropriate quantity and spatial arrangement for the conservation of the species), based on the best scientific data available. Under the regulation at 50 CFR 424.12(e), 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 and that designation limited to those areas occupied at the time of listing would be inadequate to ensure the conservation of the species. When the best available scientific data do not demonstrate that the conservation needs of the species require such additional areas, we will not designate critical habitat in areas outside the geographical area occupied by the species at the time of listing. An area currently occupied by the species but that was not occupied at the time of listing may, however, be essential to the conservation of the species and may be included in the critical habitat designation.

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. 106554; H.R. 5658)), and our associated Information Quality Guidelines, provide criteria,
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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 may include the recovery plan for the species, articles in peerreviewed 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.

Habitat is often dynamic, and species may move from one area to another over time. Furthermore, we recognize that critical habitat designated at a particular point in time may not include all of the habitat areas that we may later determine are necessary for the recovery of the species, based on scientific data not now available to the Service. For these reasons, a critical habitat designation does not signal that habitat outside the designated area is unimportant or may not be required for recovery of the species.

Areas that are important to the conservation of the species, but are outside the critical habitat designation, will continue to be subject to conservation actions Federal agencies implement under section 7(a)(1) of the Act. Areas that support populations 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 scientific information at the time of the agency action. Federally funded or permitted projects affecting listed species outside their designated critical habitat areas 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 (HCPs), or other species conservation planning efforts if new information available at the time of these planning efforts calls for a different outcome.

Relationship of Critical Habitat to Recovery Planning

In developing this proposed rule, we considered the conservation relationship between the proposed critical habitat designation and recovery planning. Although recovery plans formulate the recovery strategy for a species, they are not regulatory documents, and there are no specific protections, prohibitions, or requirements afforded a species based solely on a recovery plan. Furthermore, although critical habitat designation can contribute to the overall recovery strategy for a species, it does not, by itself, achieve recovery plan goals. The Act states in section 3(5)(C), ``except in those circumstances determined by the Secretary, critical habitat shall not include the entire geographical area which can be occupied by the threatened or endangered species.'' In most cases, it is not the intent of the Act to designate critical habitat for every population and every documented historical location of a species. Instead, the focus of critical habitat designation is on habitat that contains the physical and biological features essential to conservation of the species.

The 5year review (Service 2008, p. 45) recommended, in part, that we update recovery units from the 2002 draft recovery plan for bull trout throughout their range (Service 2002), based on assemblages of bull trout core areas (metapopulations or interacting breeding populations) that retain genetic and ecological integrity and are significant to the distribution of bull trout throughout the conterminous United States. To complete the recovery unit update, we consulted with biologists from States, Federal agencies, and Native American tribes, using the best scientific information available. Factors that were considered in determining the geographic arrangement of the updated recovery units included ensuring (1) resiliency by protecting large areas of highquality habitat; (2) redundancy by protecting multiple populations; and (3) representation by protecting diverse genetic and lifehistory aspects of bull trout populations distributed throughout the range of the listed entity (Tear et al. 2005, p. 841).

Bull trout are listed under the Act as ``Threatened'' throughout the coterminous United States primarily due to habitat threats. In 2008 the Service completed a 5year review of bull trout status and concluded in part that it should reevaluate the number of bull trout Distinct Population Segments (DPSs), and consider reclassifying bull trout into separate DPSs. The Service subsequently recommended not immediately pursuing reclassification due to time and cost constraints, but applied relevant factors in its 1996 DPS policy. As a result, six draft recovery units (RUs) were identified. Subsequent to identifying these six RUs, we evaluated each RU and determined that they were needed to ensure a resilient, redundant, and representative distribution of bull trout populations throughout the range of the listed entity. To accomplish these goals, we need to protect large areas of highquality habitat, protect multiple populations, and protect diverse genetic and lifehistory aspects.

The six draft recovery units identified for bull trout in the conterminous United States include: MidColumbia recovery unit; Saint Mary recovery unit; Columbia Headwaters recovery unit; Coastal recovery unit; Klamath recovery unit; and Upper Snake recovery unit (Figure 1). Conserving each RU is essential to conserving the listed entity as a whole. These six new biologically based recovery units will be proposed to replace the 27 recovery units previously identified in the bull trout draft recovery plan (Service 2002, Chapter 1, p. 3).
Figure 1. Map of bull trout draft recovery units
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Areas that support populations, but are outside the critical habitat designation, may continue to be subject to conservation actions we implement under section 7(a)(1) of the Act. 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 scientific information at the time of the agency action. Federally funded or permitted projects affecting listed species outside their designated critical habitat areas 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, HCPs, or other species conservation planning efforts if new information available to these planning efforts calls for a different outcome. Methods

As required by section 4(b)(2) of the Act, we use the best scientific data available in determining areas that contain the features that are essential to the conservation of bull trout. Data sources include research published in peerreviewed journals and previous Service documents on the species, including the final listing determination (FR 64 5890958933; November 1, 1999), the bull trout draft recovery plan (Service 2002), and the bull trout 5year review (Service 2008). Additionally, we utilized regional Geographic Information System (GIS) shape files for area calculations and mapping. Primary Constituent Elements

In accordance with section 3(5)(A)(i) of the Act and regulations at 50 CFR 424.12(b), in determining which areas occupied at the time of listing to propose as critical habitat, we consider the physical and biological features that are essential to the conservation of the species and that may require special management considerations or protection. These features are the PCEs 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, air, light, minerals, or other nutritional or physiological requirements;
(3) Cover or shelter;
(4) Sites for breeding, reproduction, or rearing (or development) of offspring; and
(5) Habitats that are protected from disturbance or are representative of the historic, geographical, and ecological distributions of a species.

As discussed in greater detail below, we derived nine specific PCEs required for bull trout from the biological needs of the species as described or referred to in the Background section of this proposed rule and the following information. The nine PCEs relate to (1) water quality; (2) migration corridors; (3) food availability; (4) instream habitat; (5) water temperature; (6) substrate characteristics; (7) stream flow; (8) water quantity; and (9) nonnative species. Space for Individual and Population Growth and for Normal Behavior

Streams and groundwater sources with high water quality and cold temperatures, complex habitat, and migratory corridors provide space for individual and population growth and for normal behavior for bull trout.

Bull trout exhibit a number of lifehistory strategies. Stream resident bull trout complete their entire life cycle in the tributary streams where they spawn and rear. Some bull trout are migratory, spawning in tributary streams where juvenile fish usually rear from one to four years before migrating to either a larger river (fluvial form) or lake (adfluvial form) where they spend their adult life, returning to the tributary stream to spawn (Fraley and Shepard 1989, p. 133). These migratory forms occur in areas where conditions allow for movement from upper watershed spawning streams to larger downstream waters that contain greater foraging opportunities (Dunham and Rieman 1999, p. 646). Resident and migratory forms may be found together, and either form can produce resident or migratory offspring (Rieman and McIntyre 1993, p. 2). Where ocean environments are accessible to bull trout they may also migrate to and from salt water (amphidromy).

The ability to migrate is important to the persistence of bull trout local populations (Rieman and McIntyre 1993, p. 2; Gilpin 1997, p. 4; Rieman and Clayton 1997, p 6; Rieman et al. 1997, p. 1121). Bull trout rely on migratory corridors to move from spawning and rearing habitats to foraging and overwintering habitats and back. Migratory bull trout become much larger than resident fish in the more productive waters of larger streams and lakes, leading to increased reproductive potential. Stream resident populations are associated with headwater streams in mountainous regions where cold water and velocity barriers are common. Typically, these streams are smaller and have higher gradients than those occupied by adfluvial and fluvial populations. In these headwater streams, resident bull trout are associated with deep pools and instream cover, and most streamresident populations are dwarfed (McPhail and Baxter 1996, p. 12). The use of migratory corridors by bull trout also results in increased dispersion, facilitating gene flow among local populations (interbreeding groups) when individuals from different local populations interbreed, stray, or return to nonnatal streams. Also, local populations that have been extirpated by catastrophic events may become reestablished because of movements by bull trout through migratory corridors (Rieman and McIntyre 1993, p. 7; MBTSG 1998, p. 45).

Lakes and reservoirs also figure prominently in meeting the life cycle requirements of bull trout. For adfluvial (migrating between lakes and rivers or streams) bull trout populations, lakes and reservoirs provide an important component of the core FMO habitat and are integral to maintaining the adfluvial lifehistory strategy that is commonly exhibited by bull trout. When juvenile bull trout emigrate downstream to a lake or reservoir from the spawning and rearing streams in its headwaters, they enter a more productive lentic (still or slow moving water) environment that allows them to achieve rapid growth and energy storage.

Some reservoirs may have adversely affected bull trout, while others have provided benefits. For example, the basin of Hungry Horse Reservoir has functioned adequately for 50 years as a surrogate home for stranded Flathead Lake bull trout trapped upstream of the dam when it was completed. While this is an artificial impoundment, the habitat the reservoir provides and the presence of an enhanced prey base of native minnows, suckers, and whitefish within the reservoir sustain a large adfluvial bull trout population. Additionally, while barriers to migration are often viewed as a negative consequence of dams, the connectivity barrier at Hungry Horse Dam has served an important, albeit unintended, function in restricting the proliferation of nonnative Salvelinus species (including brook trout (Salvelinus fontinalis) and lake trout (Salvelinus namaycush)) from downstream areas upstream above the dam.
Food, Water, Air, Light, Minerals, or Other Nutritional or

Physiological Requirements

Bull trout are opportunistic feeders that prey upon other organisms. Prey selection is primarily a function of size
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and lifehistory strategy. Resident and juvenile migratory bull trout prey on terrestrial and aquatic insects, macrozooplankton, and small fish (Donald and Alger 1993, p. 244; McPhail and Baxter 1996, p. 15). Adult migratory bull trout feed almost exclusively on other fish (Rieman and McIntyre 1993, p. 3). Habitats must provide the necessary aquatic and adjacent terrestrial conditions to harbor prey species in sufficient quantity and diversity to meet the physiological requirements necessary to maintain bull trout populations. An abundant food base, including a broad array of terrestrial organisms of riparian origin, aquatic macroinvertebrates, and forage fish, supports individual and population growth and allows for normal bull trout behavior.

Cover or Shelter

At all life stages, bull trout require complex forms of cover, including large woody debris, undercut banks, boulders, and pools (Fraley and Shepard 1989, pp. 137138; Watson and Hillman 1997, p. 249). Juveniles and adults frequently inhabit side channels, stream margins, and pools with suitable cover (Sexauer and James 1997, p. 368). McPhail and Baxter (1996, p. 11) reported that newly emerged fry are secretive and hide in gravel along stream edges and side channels. They also reported that juveniles are found mainly in pools but also in riffles and runs, maintain focal sites near the bottom, and are strongly associated with instream cover, particularly overhead cover such as woody debris or riparian vegetation. Bull trout have been observed overwintering in deep beaver ponds or pools containing large woody debris (Jakober 1995, p. 90). Adult bull trout migrating to spawning areas have been recorded as staying two to four weeks at the mouths of spawning tributaries in deeper holes or near logs or cover debris (Fraley and Shepard 1989, p. 137). Bull trout may also use lotic (swiftflowing water) and in some cases saltwater environments seasonally for reasons that include use as cover. Riparian vegetation; large wood; variable stream channel morphology including deep pools, sidechannels, undercut banks and substrates; and in some cases access to downstream environments provide cover and shelter, which support individual and population growth and allow for normal bull trout behavior.
Sites for Breeding, Reproduction, or Rearing (or Development) of Offspring

Bull trout have more specific habitat requirements than most other salmonids (Rieman and McIntyre 1993, p. 4). Habitat components that particularly influence their distribution and abundance include water temperature, cover, channel form and stability, spawning and rearing substrate conditions, and migratory corridors (Fraley and Shepard 1989, p. 138; Goetz 1989, p. 19; Watson and Hillman 1997, p. 247).

Watson and Hillman (1997, p. 248) concluded watersheds must have specific physical characteristics to provide the necessary habitat requirements for bull trout spawning and rearing, and that the characteristics are not necessarily ubiquitous throughout the watersheds in which bull trout occur. The preferred spawning habitat of bull trout consists of lowgradient stream reaches with loose, clean gravel (Fraley and Shepard 1989, p. 133). Bull trout typically spawn from August to November during periods of decreasing water temperatures (Swanberg 1997, p. 735). However, migratory forms are known to begin spawning migrations as early as April and to move upstream as much as 250 km (155 mi) to spawning areas (Fraley and Shepard 1989 p. 138; Swanberg 1997, p. 735).

Fraley and Shepard (1989, p. 137) reported that initiation of spawning by bull trout in the Flathead River system appeared to be related largely to water temperature, with spawning initiated when water temperatures dropped below 10 [deg]Celsius ([deg]C) (50 [deg]Fahrenheit ([deg]F)). Goetz (1989, pp. 2232) reported a temperature range from 4 to 10 [deg]C (39 to 50 [deg]F). Such areas often are associated with coldwater springs or groundwater upwelling (Rieman et al. 1997, p. 1121; Baxter et al. 1999, p. 137). Fraley and Shepard (1989, p. 137) also found that groundwater influence and proximity to cover are important factors influencing spawning site selection. They reported the combination of relatively specific requirements resulted in a restricted spawning distribution in relation to available stream habitat.

Depending on water temperature, egg incubation is normally 100 to 145 days (Pratt 1992, p. 5). Water temperatures of 1.2 to 5.4 [deg]C (34.2 to 41.7 [deg]F) have been reported for incubation, with an optimum (best embryo survivorship) temperature reported to be from 2 to 4 [deg]C (36 to 39 [deg]F) (Fraley and Shepard 1989, p. 138; McPhail and Baxter 1996, p. 10). Juveniles remain in the substrate after hatching, such that the time from egg deposition to emergence of fry can exceed 200 days. During the relatively long incubation period in the gravel, bull trout eggs are especially vulnerable to fine sediments and water quality degradation (Fraley and Shepard 1989, p. 141). Increases in fine sediment appear to reduce egg survival and emergence (Pratt 1992, p. 6). Juveniles are likely also affected. High juvenile densities have been reported in areas characterized by a diverse cobble substrate and a low percent of fine sediments (Shepard et al. 1984, p. 6). Habitats with cold water temperature, appropriatelysized stream substrate, and stream substrate with a low level of fine material (i.e., less than 12 percent of fine substrate less than 0.85 millimeter (mm) (0.03 inch (in.)) in diameter) are necessary factors for egg incubation and juvenile rearing that supports individual and population growth (WFPB 1997, pp. 98, F25).
Habitats Protected from Disturbance or Representative of the Historic, Geographical, and Ecological Distributions of the Species

There are some habitats throughout the range of the species that are well protected from disturbance and representative of ideal ecological conditions of the species. These areas mainly include wilderness, national parks, and other public lands specifically protected from most human disturbance (e.g., State parks), and often constitute bull trout ``strongholds'' with robust, welldistributed populations. Some populations outside of these areas may still be well protected for other reasons (e.g., conservation easements, Habitat Conservation Plans, Safe Harbor Agreements), but many other populations are threatened by human actions.

Water diversion and reservoir development can reduce stream flow, reduce the amount of water available in a stream channel, change water quality, and alter groundwater regimes. These changes may collectively impact habitat and passage for bull trout and can cause increases in water temperatures.

Impoundments may also increase nonnative species predation and competition, which can significantly affect bull trout populations. Some nonnative fish species that prey on bull trout include lake trout, walleye (Sander vitreum), northern pike (Esox lucius), smallmouth bass (Micropterus dolomieu), and brown trout (Salmo trutta). Brown trout or other introduced salmonids such as rainbow trout (Onchorynchus mykiss), as well as smallmouth bass, northern pike, walleye, and other species also compete with bull trout for limited resources. Brook trout commonly hybridize with bull trout (Ratliff and Howell 1992, p. 16; Leary et al. 1993, p. 857).

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The stability of stream channels and stream flows are important habitat characteristics for bull trout populations (Rieman and McIntyre 1993, p. 5). The side channels, stream margins, and pools with suitable cover for bull trout are sensitive to activities that directly or indirectly affect stream channel stability and alter natural flow patterns. For example, altered stream flow in the fall may disrupt bull trout during the spawning period, and channel instability may decrease survival of eggs and young juveniles in the gravel during winter through spring (Fraley and Shepard 1989, p. 141; Pratt 1992, p. 6; Pratt and Huston 1993, p. 70). Streams with a natural hydrograph (those with normal discharge variations over time as a response to seasonal precipitation); permanent water; and an absence of nonnative species are representative of the highest quality ecological habitat of the species. Streams with these characteristics provide space for individual and population growth.

We propose bull trout habitats of two primary use types: spawning and rearing (SR), and foraging, migration, and overwintering (FMO). All nine PCEs listed below may be found in, or be essential to, bull trout in each of these two habitat use types. This proposed rule identifies over 3,500 water body segments as either SR or FMO habitat. Due to a lack of sufficiently detailed data, we do not identify the specific PCEs present for each water body segment. Future consultations with the Service on specific agency actions will help identify those PCEs that are most important in a specific water body segment. Factors such as time of year, seasonal precipitation, drought conditions, and other phenomenon can influence the essential physical and biological features present at any particular location at any particular time across its range given the variability of habitats used by bull trout. In addition, attributes such as stream flow and substrate size and composition are influenced by stream order and gradient. Accordingly, establishing an upper and lower range of conditions for specific attributes in some cases may be impracticable.

Primary Constituent Elements for Bull Trout

Based on the above needs and our current knowledge of the life history, biology, and ecology of the species and the characteristics of the habitat necessary to sustain the essential lifehistory functions of the species, we have identified the following PCEs for bull trout critical habitat.
(1) Springs, seeps, groundwater sources, and subsurface water connectivity (hyporehic flows) to contribute to water quality and quantity and provide thermal refugia.
(2) Migratory habitats with minimal physical, biological, or water quality impediments between spawning, rearing, overwintering, and freshwater and marine foraging habitats, including but not limited to permanent, partial, intermittent, or seasonal barriers.
(3) An abundant food base, including terrestrial organisms of riparian origin, aquatic macroinvertebrates, and forage fish. (4) Complex river, stream, lake, reservoir, and marine shoreline aquatic environments and processes with features such as large wood, side channels, pools, undercut banks and substrates, to provide a variety of depths, gradients, velocities, and structure.
(5) Water temperatures ranging from 2 to 15 [deg]C (36 to 59 [deg]F), with adequate thermal refugia available for temperatures at the upper end of this range. Specific temperatures within this range will vary depending on bull trout lifehistory stage and form; geography; elevation; diurnal and seasonal variation; shade, such as that provided by riparian habitat; and local groundwater influence. (6) Substrates of sufficient amount, size, and composition to ensure success of egg and embryo overwinter survival, fry emergence, and youngoftheyear and juvenile survival. A minimal amount (e.g., less than 12 percent) of fine substrate less than 0.85 mm (0.03 in.) in diameter and minimal embeddedness of these fines in larger substrates are characteristic of these conditions.
(7) A natural hydrograph, including peak, high, low, and base flows within historic and seasonal ranges or, if flows are controlled, they minimize departures from a natural hydrograph.
(8) Sufficient water quality and quantity such that normal reproduction, growth, and survival are not inhibited.
(9) Few or no nonnative predatory (e.g., lake trout, walleye, northern pike, smallmouth bass; inbreeding (e.g., brook trout); or competitive (e.g., brown trout) species present.

Criteria Used To Identify Critical Habitat

As required by section 4(b) of the Act, we used the best scientific and commercial data available in determining areas that contain the physical and biological features essential to the conservation of bull trout that may require special management considerations or protection, and areas outside of the geographical area occupied at the time of listing that are essential for bull trout conservation (Service 2009; also see ``Previous Federal Actions'' section). The steps we followed in identifying critical habitat were:
(1) Our initial step in identifying critical habitat was to determine, in accordance with section 3(5)(A)(i) of the Act and regulations at 50 CFR 424.12, the physical and biological habitat features essential to the conservation of the species, as explained in the previous section. We reviewed the best available scientific data pertaining to the habitat requirements of this species, including consulting with biologists from partner agencies and entities including Federal, State, tribal, and private biologists; experts from other scientific disciplines such as hydrology and forestry; resource users; and other stakeholders with an interest in bull trout and the habitats they depend on for survival and recovery. We also reviewed available data concerning bull trout habitat use and preferences, habitat conditions, threats, limiting factors, population demographics, and known locations, distribution, and abundances of bull trout. (2) We then identified the geographical areas occupied by bull trout at the time of listing and areas not occupied that may be essential for the conservation of bull trout. We used data gathered during the bull trout recovery planning process and the bull trout draft recovery plan (Service 2002), and supplemented that data with recent data developed by State agencies, tribes, the U.S. Forest Service (USFS), and other entities. This data was used to update bull trout status and distribution data for purposes of the proposed critical habitat designation. For areas where we had data gaps, we solicited expert opinions from knowledgeable fisheries biologists in the local area. Material reviewed included data in reports submitted during section 7 consultations, reports from biologists holding section 10(a)(1)(A) recovery permits, research published in peerreviewed scientific journals, academic theses, State and Federal government agency reports, and regional GIS overlays.
(3) We identified specific areas within each of the six new draft recovery units described above that contain the physical and biological features essential to bull trout conservation, considering
distribution, abundance, trend, and connectivity needs. The objective was to ensure the areas proposed for designation as critical [[Page 2280]]
habitat would effectively serve the goals we believe are important for recovery: (a) conserve the opportunity for diverse lifehistory expression; (b) conserve the opportunity for genetic diversity; (c) ensure that bull trout are distributed across representative habitats; (d) ensure sufficient connectivity among populations; (e) ensure sufficient habitat to support population viability (e.g., abundance, trend indices); (f) address threats (see ``Special Management Considerations or Protection'' below), including climate change (see below); and (g) ensure sufficient redundancy in conserving population units. The above recovery goals take into account the threats and physical and biological needs of the species throughout its range, and focus on its rangewide recovery needs.

All critical habitat areas being proposed occur within the six new draft recovery units described above. Some areas contained the physical and biological features, but did not meet one or more of the above recovery goals because those features were not present in an appropriate quantity and spatial arrangement. Accordingly, we determined that such areas are not essential to bull trout
conservation. For example, some areas contained spawning habitat (PCEs 5 and 6), but are disconnected from other populations and not large enough to support viable bull trout populations. Other areas were not included in this proposal because of limited habitat, marginal habitat, low bull trout density, or only sporadic presence of bull trout recorded.

Predicted global climate change appears likely to pose additional threats to bull trout in many parts of their range in the coterminous United States; downscaled regional climate models for the Columbia River basin predict a general air temperature warming of 1.0 to 2.5 [deg]C (33.8 to 36.5 [deg]F) or more by 2050 (Reiman et al. 2007, p. 1,552). This predicted temperature trend will have important effects on the regional distribution and local extent of habitats available to salmonids (Rieman et al. 2007, p. 1,552). The optimal water temperatures for bull trout appear to be substantially lower than those for other salmonids (Rieman et al. 2007, p. 1,553). Coldwater fish do not physically adapt well to thermal increases (McCullough et al. 2009, pp. 96101). Instead, they are more likely to change their behavior, alter the timing of certain behaviors, experience increased physical and biochemical stress, and exhibit reduced growth and survival (McCullough et al. 2009, pp. 98100). Bull trout spawning and initial rearing areas are currently largely constrained by low fall and winter water temperatures, and existing thermally suitable habitat patches are often isolated from one another (Rieman et al. 2007, p. 1,553). With a warming climate, thermally suitable bull trout spawning and rearing areas are predicted to shrink during warm seasons, in some cases very dramatically, becoming even more isolated from one another under moderate climate change scenarios (Rieman et al. 2007, pp. 1,5581,562; Porter and Nelitz 2009, pp. 57).

Climate change will likely interact with other stressors, such as habitat loss and fragmentation (Rieman et al. 2007, pp. 1,5581,560; Porter and Nelitz 2009, p. 3); invasions of nonnative fish (Rahel et al. 2008, pp. 552553); diseases and parasites (McCullough et al 2009, p. 104); predators and competitors (McMahon et al. 2007, pp. 1,313 1,323; Rahel et al. 2008, pp. 552553); and flow alteration (McCullough et al. 2009, pp. 106108), to render some current spawning, rearing, and migratory habitats marginal or wholly unsuitable. For example, introduced congeneric populations of brook trout are widely distributed throughout the range of bull trout. McMahon et al. (2007, p. 1,320) demonstrated the presence of brook trout has a marked negative effect on bull trout, an effect that is magnified at higher water temperatures (1620 [deg]C (6068 [deg]F)). Changes and complex interactions are difficult to predict at a spatial scale relevant to bull trout conservation efforts, and key gaps exist in our understanding of whether bull trout (and other coldwater fishes) can behaviorally adapt to climate change.

We considered probable effects of climate change on bull trout by first qualitatively screening core areas to assess those which might be most vulnerable to climate change effects, and highlighting them in our 2008 update of status and threats data in the core area template documents (Service 2008, p. 15). For example, in many locations we prioritized cold water spring habitats for conservation because they may be among the most resistant habitats to climate change effects. In other locations we deemphasize

FOR FURTHER INFORMATION CONTACT

Jeff Foss, Field Supervisor, U.S. Fish and Wildlife Service, Idaho Fish and Wildlife Office, 1387 South Vinnell Way, Boise, ID 83702; telephone 2083785243; facsimile 208 3785262. If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 8008778339.