Listing Endangered and Threatened Species and Designating Critical Habitat: 12-Month Finding on Petition to List Puget Sound Steelhead as an Endangered or Threatened Species under the Endangered Species Act, 15666-15680 [06-2972]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 71, Number 60 (Wednesday, March 29, 2006)]
[Proposed Rules]
[Pages 15666-15680]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-2972]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 223

[Docket No. 060313064-6064-01; I.D.031006D]
RIN 0648-AU43


Listing Endangered and Threatened Species and Designating 
Critical Habitat: 12-Month Finding on Petition to List Puget Sound 
Steelhead as an Endangered or Threatened Species under the Endangered 
Species Act

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Proposed rule; petition finding.

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SUMMARY: We (NMFS) have completed an updated Endangered Species Act 
(ESA) status review of steelhead (Oncorhynchus mykiss) populations in 
the Puget Sound area (Washington). We initiated this review in response 
to a petition received from Mr. Sam Wright on September 13, 2004, to 
list Puget Sound steelhead as a threatened or endangered species. We 
have determined that naturally spawned winter- and summer-run steelhead 
populations and two hatchery steelhead stocks, below natural and 
manmade impassable barriers, in the river basins of the Strait of Juan 
de Fuca, Puget Sound, and Hood Canal (Washington) constitute a Distinct 
Population Segment (DPS) and hence a ``species'' for listing 
consideration under the ESA. After reviewing the best available 
scientific and commercial information, evaluating threats facing the 
species, and taking into account those efforts being made to protect 
the species, we conclude that the Puget Sound steelhead DPS is likely 
to become an endangered species within the foreseeable future 
throughout all or a significant portion of its range. Therefore, we are 
proposing that the Puget Sound steelhead DPS be listed under the ESA as 
a threatened species. We will announce the timing and location of a 
public hearing to be held in the Puget Sound area, and propose 4(d) 
protective regulations and critical habitat for the Puget Sound 
steelhead DPS in subsequent Federal Register notices. We are soliciting 
public comment on this proposed listing determination, as well as any 
other information relevant to the designation of critical habitat and 
the promulgation of 4(d) protective regulations for the Puget Sound 
steelhead DPS.

DATES: Information and comments on the proposed action must be received 
by June 27, 2006.

ADDRESSES: You may submit comments and information by any of the 
following methods. Please identify submittals as pertaining to the 
``Puget Sound Steelhead Proposed Listing''
     E-mail: PS.Steelhead.nwr@noaa.gov. Include ``Puget Sound 
Steelhead Proposed Listing'' in the subject line of the message.
     Internet: Comments may also be submitted electronically 
through the Federal e-Rulemaking portal at: https://www.regulations.gov.
     Mail: Submit written comments and information to Chief, 
NMFS, Protected Resources Division, 1201 NE Lloyd Boulevard, Suite 
1100, Portland, OR 97232.
     Hand Delivery/Courier: NMFS, Protected Resources 1201 NE 
Lloyd Boulevard, Suite 1100, Portland, OR 97232.
     Fax: 503-230-5441

FOR FURTHER INFORMATION CONTACT: For further information regarding this 
notice contact Dr. Scott Rumsey, NMFS, Northwest Region, (503) 872-
2791, or Marta Nammack, NMFS, Office of Protected Resources, (301) 713-
1401.

SUPPLEMENTARY INFORMATION:

Background

    On September 13, 2004, we received a petition from Mr. Sam Wright 
of Olympia, Washington, to list Puget Sound steelhead as an endangered 
or threatened species under the ESA, and to designate critical habitat. 
On April 5, 2005, we issued our finding that the petition presents 
substantial information indicating that the petitioned action may be 
warranted (70 FR 17223), and we announced that we would initiate an 
updated review of the species' status. This Federal Register notice 
summarizes the information gathered and the analyses conducted as part 
of this review, and announces our finding regarding the ESA listing 
status of steelhead in Puget Sound.
    For a more detailed summary of the specific information presented 
in the petition, the reader is referred to the Federal Register notice 
which describes our analysis of the petition (70 FR 17223; April 5, 
2005). Most significantly, the petitioner provided 10 years of new 
harvest, spawning escapement, and total-run-size data for nine natural-
origin Puget Sound steelhead stocks. The petitioner concluded that the 
new information describes significant short- and long-term declining 
trends in nearly all river systems where data are available, despite 
significant reductions by the State of Washington in recreational and 
tribal harvest rates on wild steelhead. The petitioner argued that the 
populations of Puget Sound steelhead are at such low levels of 
abundance that risks posed by catastrophic events, environmental and 
demographic variability, and depensation confer a high level of 
extinction risk for the foreseeable future. The petitioner also 
underscored concerns regarding the widespread propagation of 
domesticated and non-indigenous stocks of hatchery steelhead, a lack of 
adequate monitoring of steelhead stocks, and habitat loss and 
degradation in the Puget Sound area.

Policies for Delineating Species under the ESA

    Section 3 of the ESA defines ``species'' as including ``any 
subspecies of fish or wildlife or plants, and any distinct population 
segment of any species of vertebrate fish or wildlife which interbreeds 
when mature.'' The term ``distinct population segment'' is not 
recognized in the scientific literature. In 1991 we issued a policy for 
delineating distinct population segments (DPSs) of Pacific salmon (56 
FR 58612; November 20, 1991). Under this policy a group of Pacific 
salmonid populations is considered an

[[Page 15667]]

``evolutionarily significant unit'' (ESU) if it is substantially 
reproductively isolated from other conspecific populations, and it 
represents an important component in the evolutionary legacy of the 
biological species. Further, an ESU is considered to be a ``DPS'' (and 
thus a ``species'') under the ESA. On February 7, 1996, we and FWS 
adopted a joint policy for recognizing DPSs under the ESA (DPS Policy; 
61 FR 4722). The DPS Policy adopts criteria similar to, but somewhat 
different from, those in the ESU Policy for determining when a group of 
vertebrates constitutes a DPS: the group must be discrete from other 
populations; and it must be significant to its taxon. A group of 
organisms is discrete if it is ``markedly separated from other 
populations of the same taxon as a consequence of physical, 
physiological, ecological, and behavioral factors.'' Significance is 
measured with respect to the taxon (species or subspecies). Although 
the ESU Policy did not by its terms apply to steelhead, the DPS Policy 
states that NMFS will continue to implement the ESU Policy with respect 
to ``Pacific salmonids'' (which include O. mykiss). FWS, however, does 
not use our ESU policy in any of its ESA listing decisions. In a 
previous instance of shared jurisdiction over a species (Atlantic 
salmon), we and FWS used the DPS policy in our determination to list 
the Gulf of Maine DPS of Atlantic salmon as endangered (65 FR 69459; 
November 17, 2000).
    In the recently published findings of our updated status review of 
listed West Coast steelhead ESUs (71 FR 834; January 5, 2006), we 
departed from our previous practice of applying the ESU policy to 
delineate species of O. mykiss, and instead applied the joint DPS 
policy. Given our shared jurisdiction with FWS over O. mykiss, and 
consistent with our approach for Atlantic salmon, we believe that 
application of the joint DPS policy is logical, reasonable, and 
appropriate for delineating species of O. mykiss under our 
jurisdiction. In applying the joint DPS policy, we concluded that the 
resident and anadromous life forms of identified population groups of 
O. mykiss are ``discrete,'' and we delineated 10 steelhead-only DPSs of 
O. mykiss. In this notice we similarly apply the joint DPS policy in 
defining the group of steelhead populations in the Puget Sound area 
that qualifies for listing consideration under the ESA. The reader is 
referred to previously published Federal Register notices for further 
discussion of the delineation of O. mykiss DPSs under the joint DPS 
policy (70 FR 67131, November 4, 2005; 71 FR 834, January 5, 2006).

Listing Determinations under the ESA

    The ESA defines an endangered species as one that is in danger of 
extinction throughout all or a significant portion of its range, and a 
threatened species as one that is likely to become endangered in the 
foreseeable future throughout all or a significant portion of its range 
(sections 3(6) and 3(20), respectively). The statute requires us to 
determine whether any species is endangered or threatened because of 
any of the following five factors: (1) the present or threatened 
destruction, modification or curtailment of its habitat or range; (2) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (3) disease or predation; (4) the inadequacy of 
existing regulatory mechanisms; or (5) other natural or manmade factors 
affecting its continued existence (section 4(a)(1)(A) (E)). We are to 
make this determination based solely on the best available scientific 
information after conducting a review of the status of the species and 
taking into account any efforts being made by states or foreign 
governments to protect the species. The focus of our evaluation of the 
ESA section 4(a)(1) factors is to evaluate whether and to what extent a 
given factor represents a threat to the future survival of the species. 
The focus of our consideration of protective efforts is to evaluate 
whether and to what extent they address the identified threats and so 
ameliorate a species' risk of extinction. The steps we follow in 
implementing this statutory scheme are to: (1) delineate the species 
under consideration; (2) review the status of the species; (3) consider 
the ESA section 4(a)(1) factors to identify threats facing the species; 
(4) assess whether certain protective efforts mitigate these threats; 
and (5) predict the species' future persistence.
    As noted above, as part of our listing determinations we must 
consider efforts being made to protect a species, and whether these 
efforts ameliorate the threats facing the species and reduce risks to 
its survival. Some protective efforts may be fully implemented, and 
empirical information may be available demonstrating their level of 
effectiveness in conserving the species. Other protective efforts are 
new, not yet implemented, or have not demonstrated effectiveness. We 
evaluate such unproven efforts using the criteria outlined in the 
Policy for Evaluating Conservation Efforts (``PECE''; 68 FR 15100; 
March 28, 2003) to determine their certainties of implementation and 
effectiveness.

Life History of West Coast Steelhead

    Steelhead is the name commonly applied to the anadromous form of 
the biological species O. mykiss. The present distribution of steelhead 
extends from Kamchatka in Asia, east to Alaska, and extending south 
along the Pacific coast to the U.S. Mexico border (Busby et al., 1996; 
67 FR 21586, May 1, 2002). O. mykiss exhibit perhaps the most complex 
suite of life-history traits of any species of Pacific salmonid. O. 
mykiss can be anadromous (``steelhead''), or freshwater residents 
(``rainbow or redband trout''), and under some circumstances yield 
offspring of the opposite life-history form. Those that are anadromous 
can spend up to 7 years in freshwater prior to smoltification (the 
physiological and behavioral changes required for the transition to 
salt water), and then spend up to 3 years in salt water prior to first 
spawning. O. mykiss are also iteroparous (meaning individuals may spawn 
more than once), whereas the Pacific salmon species are principally 
semelparous (meaning individuals generally spawn once and die). Within 
the range of West Coast steelhead, spawning migrations occur throughout 
the year, with seasonal peaks of activity. In a given river basin there 
may be one or more peaks in migration activity; since these ``runs'' 
are usually named for the season in which the peak occurs, some rivers 
may have runs known as winter, spring, summer, or fall steelhead.
    Steelhead can be divided into two basic reproductive ecotypes, 
based on the state of sexual maturity at the time of river entry and 
duration of spawning migration (Burgner et al., 1992). The summer or 
``stream-maturing'' type enters fresh water in a sexually immature 
condition between May and October, and requires several months to 
mature and spawn. The winter or ``ocean-maturing'' type enters fresh 
water between November and April with well-developed gonads and spawns 
shortly thereafter. In basins with both summer and winter steelhead 
runs, the summer run generally occurs where habitat is not fully 
utilized by the winter run, or where an ephemeral hydrologic barrier 
separates them, such as a seasonal velocity barrier at a waterfall. 
Summer steelhead usually spawn farther upstream than winter steelhead 
(Withler, 1966; Roelofs, 1983; Behnke, 1992).

Previous ESA Status Review

    In 1996, we conducted a comprehensive status review of coastal and 
inland steelhead stocks in

[[Page 15668]]

California, Oregon, Washington, and Idaho (Busby et al., 1996). We 
convened a Biological Review Team (BRT) (an expert panel of scientists 
from NMFS' Northwest and Southwest Fisheries Science Centers, FWS, the 
U.S. Geological Survey, and the U.S. Forest Service) to: (1) identify 
ESUs of West Coast steelhead; and (2) evaluate the risk of extinction 
for the identified ESUs. As part of this review we identified a Puget 
Sound ESU of coastal steelhead occupying river basins of the Strait of 
Juan de Fuca, Puget Sound, and Hood Canal (Washington), as far west as 
the Elwha River, and as far north as the Nooksack River and Dakota 
Creek (inclusive), and the United States/Canada border. The Puget Sound 
ESU is primarily composed of winter steelhead stocks, but also includes 
several small stocks of summer steelhead occupying limited habitat. The 
BRT also included the resident life-history form in the Puget Sound 
ESU. Genetic studies generally show that, in the same geographic area, 
the resident and anadromous life forms of O. mykiss are more similar to 
each other than either is to the same form from a different geographic 
area. In particular, the BRT cited a scientific study indicating that 
rainbow trout and steelhead are not reproductively isolated in two 
river basins within the Puget Sound ESU (Leider et al., 1995).
    In the 1996 status review the BRT concluded that the Puget Sound 
steelhead ESU was not in danger of extinction or likely to become 
endangered in the foreseeable future throughout all or a significant 
portion of its range. However, the BRT did express concern that 17 of 
21 stocks in the ESU for which there were adequate data exhibited 
overall declining trends. Positive trends in abundance for the two 
largest steelhead runs in the ESU (the Skagit and Snohomish Rivers) 
mitigated the immediacy of extinction risk, although there was 
significant concern regarding the sustainability of other steelhead 
runs in the ESU (most notably the Deer Creek summer and Lake Washington 
winter steelhead populations, and populations in the Hood Canal area). 
Given the lack of strong trends in abundance for the major populations 
and the apparent limited contribution of hatchery fish to natural 
production, the BRT concluded that most winter steelhead stocks in the 
Puget Sound ESU appeared to be naturally self-sustaining.
    The BRT noted concern about the potential threat to the genetic 
integrity of Puget Sound steelhead posed by past and present hatchery 
practices in the Puget Sound area. Hatchery production in this ESU is 
widespread, and it is managed to support harvest. Most of the hatchery 
fish propagated in the Puget Sound region are winter-run steelhead 
derived from a single stock (the Chambers Creek hatchery stock) that is 
indigenous to the ESU but generally is not native to the local river 
basins where it is propagated. The summer steelhead hatchery programs 
in the Puget Sound area are derived from an out-of-ESU stock (the 
Skamania summer steelhead stock from the Columbia River). The Skamania 
hatchery stock has generally been introduced in river systems where 
summer steelhead did not naturally exist, although it has been 
introduced in some Puget Sound river basins having native summer 
steelhead populations (e.g., the Stillaguamish and Snohomish Rivers). 
The Washington Department of Fish and Wildlife (WDFW) employs a 
hatchery management strategy of promoting isolation between hatchery 
and natural stocks by releasing smolts early and selecting for early 
spawn timing in winter steelhead hatchery programs. This separation in 
run timing is intended to: allow for high rates of selective harvest on 
returning hatchery fish, while limiting harvest mortality on wild 
stocks; and minimize competition (as smolts and adults) and 
opportunities for interbreeding between naturally spawning hatchery 
fish and wild fish. However, the BRT noted that separation of run 
timing is seldom complete. High harvest rates targeting early-returning 
hatchery fish have likely resulted in high mortality levels for early-
run natural fish and reduced the natural diversity in spawn timing. 
Naturally spawning hatchery fish comprise a substantial proportion of 
the spawning escapement in many of the rivers in the ESU, possibly 
competing with, and posing genetic risks to, the local steelhead 
populations. Additionally, the BRT discussed evidence for hatchery 
introgression in some natural Puget Sound winter steelhead populations 
(Phelps et al., 1994).
    Informed by the BRT's findings (Busby et al., 1996), we concluded 
that the Puget Sound steelhead ESU did not warrant listing under the 
ESA (61 FR 41541; August 9, 1996), but expressed concern regarding the 
sustainability of summer steelhead populations and potentially adverse 
impacts from hatchery practices in Puget Sound.

Updated Status Review of Puget Sound Steelhead

    To ensure that our review was based on the best available and most 
recent scientific information, we solicited information during a 60-day 
public comment period regarding the ESU structure and extinction risk 
of, and efforts being made to protect, the species (70 FR 17223; April 
5, 2005). In July 2005 we convened a BRT to review the available 
information regarding the ESU structure and extinction risk of O. 
mykiss in the Puget Sound area. Specifically, the BRT addressed: (1) 
whether the geographic boundaries of the previously identified Puget 
Sound ESU warrant redelineation or refinement; (2) the relationship to 
the defined ESU of hatchery programs propagating O. mykiss within the 
Puget Sound area; (3) the relationship to the defined ESU of resident 
rainbow trout above and below impassable barriers; and (4) the level of 
extinction risk of the ESU throughout all or a significant portion of 
its range, including the consideration of the contribution of within-
ESU hatchery programs and resident populations to the viability of the 
ESU. The data reviewed, analyses conducted, and findings by the BRT are 
summarized in a July 26, 2005, memorandum ``Status Review Update for 
Puget Sound Steelhead'' (NMFS, 2005).
    On June 28, 2005, NMFS finalized a new policy for the consideration 
of hatchery-origin fish in ESA listing determinations (``Hatchery 
Listing Policy;'' 70 FR 37204). Under the Hatchery Listing Policy, 
hatchery stocks are considered part of an ESU if they exhibit a level 
of genetic divergence relative to the local natural population(s) that 
is no more than what occurs within the ESU (70 FR at 37215; June 28, 
2005). We recognize that there are a number of ways to compute and 
compare genetic divergence and that it is not possible to sample all 
fish within the ESU to precisely determine the range of genetic 
diversity within an ESU. In evaluating hatchery stocks associated with 
Puget Sound steelhead, the BRT included as part of the ESU those 
hatchery stocks that are no more than moderately diverged from local, 
native populations in the watershed(s) in which they are released. This 
approach is consistent with our recent status review updates for 27 
West Coast ESUs (see 71 FR 835, January 5, 2006; 70 FR 37160, June 28, 
2005; NMFS, 2003; NMFS, 2004). In factoring artificial propagation into 
the extinction risk assessment for the ESU, the BRT evaluated potential 
risks to the naturally-spawned components of the ESU posed by Puget 
Sound area hatchery programs determined not to be part of the ESU; as 
well as the specific benefits and risks for each of the hatchery 
programs included in the ESU.

[[Page 15669]]

    As noted above, we have adopted the approach of applying the joint 
DPS policy in delineating species of West Coast O. mykiss for listing 
consideration under the ESA (see 71 FR, 834; January 5, 2006). Although 
the BRT applied the ESU policy in delineating the species of Puget 
Sound steelhead for ESA listing consideration, their findings directly 
inform the delineation of the geographic boundaries for an O. mykiss 
DPS (summarized below).

Review of ``Species'' Delineation

    The BRT concluded that the best available scientific information 
did not warrant a reconsideration of the previously described 
geographic boundaries for the Puget Sound O. mykiss ESU (Busby et al., 
1996). The BRT's findings delineating a Puget Sound ESU of O. mykiss 
directly inform our species delineation under the joint DPS policy. 
Based on established phylogenetic groupings, available population 
genetic data, differences in migration and spawn timing, patterns in 
the duration of freshwater and marine residence, and the geographic 
separation of populations, the BRT concluded that steelhead in Puget 
Sound are substantially reproductively isolated from other such 
groupings of West Coast O. mykiss (Busby et al., 1996). These 
observations regarding reproductive isolation similarly satisfy the 
discreteness criterion under the joint DPS policy, as Puget Sound 
steelhead are markedly separated from other such population groups of 
O. mykiss as a consequence of physical, physiological, ecological or 
behavioral factors.
    The BRT also concluded that the Puget Sound steelhead represent an 
important component in the evolutionary legacy of the O. mykiss species 
based on its unique life-history, genetic, and ecological 
characteristics, as well as the unique glacial and fjord-like 
characteristics of the ecoregion it occupies (Busby et al., 1996). 
These traits that establish the evolutionary importance of the Puget 
Sound steelhead ESU also satisfy the ``significance'' criterion of the 
DPS Policy. The proposed Puget Sound steelhead DPS, if lost, would 
represent: the loss of unusual or unique habitats and ecosystems 
occupied by the species; a significant gap in the species' range; and a 
significant loss to the ecological, life-history, and genetic diversity 
of the taxon.
    Based on the BRT's findings summarized above, and our 
considerations under the joint DPS policy, we conclude that Puget Sound 
steelhead warrant delineation as a DPS. Consistent with previous 
findings under the ESU policy, the geographic boundaries of the Puget 
Sound steelhead DPS continue to include winter- and summer-run 
steelhead runs in the river basins of the Strait of Juan de Fuca, Puget 
Sound, and Hood Canal, Washington, bounded to the west by the Elwha 
River (inclusive) and to the north by the Nooksack River and Dakota 
Creek (inclusive).

DPS Membership of Resident O. mykiss

    The BRT concluded that where resident and anadromous O. mykiss co-
occur there is likely to be interbreeding between the two life-history 
forms. Applying the ESU policy, the BRT concluded that resident and 
anadromous O. mykiss below long-standing impassable barriers are not 
substantially reproductively isolated, and warrant consideration as 
part of the same Puget Sound O. mykiss ESU. This conclusion was based 
on empirical studies showing that resident and anadromous O. mykiss are 
typically very similar genetically when they co-occur with no physical 
barriers to migration or interbreeding (Chilcote, 1976; Currens et al., 
1987; Leider et al., 1995; Busby et al., 1996; Pearsons et al., 1998). 
It is also well established that resident forms of O. mykiss can 
occasionally produce anadromous migrants, and vice versa (Shapovalov 
and Taft, 1954; Burgner et al., 1992; Mullan et al., 1992; Zimmerman 
and Reeves, 2000; Kostow, 2003; Ardren, 2003; Blouin, 2003; Pearsons et 
al., 2003; Marshal and Foley, 2004; Narum et al., 2004; Seamons et al., 
2004). Additionally, there was information specific to the Puget Sound 
area describing the interbreeding of the two life-history forms, as 
well as the production of outmigrating smolts by resident O. mykiss 
(Marshall et al., 2004; McMillan, 2005).
    The discreteness criterion of the DPS Policy, however, does not 
rely on reproductive isolation but on the marked separation of 
population groups as a consequence of biological factors. Despite the 
apparent reproductive exchange between resident and anadromous O. 
mykiss, the two life forms remain markedly separated physically, 
physiologically, ecologically, and behaviorally. Steelhead differ from 
resident rainbow trout physically in adult size and fecundity, 
physiologically by undergoing smoltification, ecologically in their 
preferred prey and principal predators, and behaviorally in their 
migratory strategy. We recognize that there may be some overlap between 
co-occurring steelhead and rainbow trout in physical, ecological, 
behavioral and physiological traits; however, this apparent overlap 
does not prevent the two life forms from satisfying the discreteness 
criterion under the DPS policy. While O. mykiss display a continuum of 
life-history and morphological traits, at the end of that continuum, 
steelhead are markedly separate in their extreme marine migration 
(leading to, or resulting from, marked separation in physical, 
physiological, and ecological factors). As we stated in adopting the 
DPS policy, ``the standard adopted [for discreteness] does not require 
absolute separation of a DPS from other members of its species, because 
this can rarely be demonstrated in nature for any population of 
organisms. . . . [T]he standard adopted allows for some limited 
interchange among population segments considered to be discrete, so 
that loss of an interstitial population could well have consequences 
for gene flow and demographic stability of a species as a whole'' (61 
FR 4722; February 7, 1996). Given the marked separation between the 
anadromous and resident life-history forms in physical, physiological, 
ecological, and behavioral factors, we conclude that the anadromous 
steelhead populations are discrete from the resident rainbow trout 
populations within the DPS under consideration (see previous 
determination of West Coast steelhead DPSs for further elaboration of 
the discreteness between the anadromous and resident life-history 
forms, 71 FR, 834; January 5, 2006).

DPS Membership of Hatchery-origin Steelhead

    Prior to the meeting of the BRT, a Steelhead Hatchery Assessment 
Group (SHAG) convened to review the relationships of hatchery steelhead 
stocks to natural populations of Puget Sound steelhead. The SHAG 
reviewed the stock histories for 25 hatchery programs, and identified 
those stocks that are no more than moderately diverged from local, 
native populations in the watershed(s) in which they are released. The 
SHAG based these assessments on the available information describing 
the hatchery stock life-history characteristics, genetics, stock 
transfers, and hatchery practices. (For a more detailed treatment of 
the information reviewed by SHAG, the reader is referred to Appendix C 
of the BRT's report, NMFS, 2005).
    Informed by the SHAG review, the BRT identified two hatchery stocks 
that are part of the Puget Sound steelhead DPS: the Green River natural 
and Hamma Hamma winter-run steelhead stocks. Although the SHAG 
identified

[[Page 15670]]

the Lake Washington winter-run steelhead stock as having been closely 
related to the local natural population, the BRT concluded that the 
stock no longer exists since the program has not been in operation 
since 1993, and therefore the stock is not included as part of the 
Puget Sound steelhead DPS.
    The remaining 23 hatchery stocks reviewed, the Chambers Creek 
winter-run and Skamania summer-run steelhead hatchery stocks and their 
derivatives, were determined to be more than moderately diverged from 
the local native populations and are not included in the DPS. The 
Chambers Creek hatchery stock has been altered from the original donor 
natural stock over time through purposeful selection for early run 
timing and maturation, resulting in an advancement of the natural spawn 
timing from April to December-January. The Chambers Creek hatchery 
stock has been transferred from its native watershed and propagated 
widely throughout the Puget Sound and the Pacific Northwest. Many of 
the 16 hatchery stocks derived from the Chambers Creek stock and 
propagated in other Puget Sound watersheds have subsequently 
incorporated local native winter-run steelhead into their respective 
broodstocks. Genetic analyses by Phelps et al. (1997) indicate that 
there is a high degree of similarity among these hatchery populations 
and the founding Chambers Creek stock, and little detectible genetic 
introgression in the local natural populations from the many years of 
Chambers Creek hatchery winter-run steelhead introductions. This result 
suggests a large degree of reproductive divergence from the local 
natural populations in the DPS from the Chambers Creek stock and its 
derivatives. The Skamania Hatchery summer-run steelhead stock was 
founded from outside the range of the Puget Sound DPS, with fish 
collected in the Washougal and Klickitat Rivers in the Columbia River 
Basin. The Skamania Hatchery, and the four other Puget Sound summer-run 
hatchery programs derived from it, are genetically distinct from the 
Puget Sound steelhead populations, possessing 58 chromosomes in 
contrast to the 60 chromosomes commonly found in Puget Sound steelhead 
(Busby et al., 1996; Phelps et al., 1997).

Determination of ``Species''

    Based on the foregoing information, we conclude that the Puget 
Sound steelhead DPS constitutes a ``species'' under the ESA and 
includes: all naturally spawned winter-run and summer-run steelhead 
populations, below natural and man-made impassable barriers, in streams 
in the river basins of the Strait of Juan de Fuca, Puget Sound, and 
Hood Canal, Washington, bounded to the west by the Elwha River 
(inclusive) and to the north by the Nooksack River and Dakota Creek 
(inclusive), as well as the Green River natural and Hamma Hamma winter-
run hatchery steelhead stocks.

Assessment of Extinction Risk

    The BRT assessed the risk of extinction for Puget Sound steelhead 
at two levels first, at the individual population level, then at the 
overall ESU level. Individual populations were assessed according to 
the four ``Viable Salmonid Populations'' criteria (VSP; McElhany et 
al., 2000): abundance, productivity, spatial structure (including 
connectivity), and diversity. These four parameters are universal 
indicators of species' viability, and individually and collectively 
function as reasonable predictors of extinction risk. The collective 
viability of individual populations was then evaluated in the context 
of the entire ESU by the inclusion of larger-scale considerations such 
as the total number of viable populations, the geographic distribution 
and connectivity of populations, and the vulnerability of populations 
or certain genetic and life-history attributes to regional catastrophic 
events. The BRT included in its assessment of population- and ESU-level 
viability an evaluation of the likely contributions of resident and 
hatchery-origin fish included in the ESU. The BRT's assessment of ESU-
level extinction risk was expressed in terms that correspond to the 
statutory definitions of endangered and threatened species in the ESA: 
in danger of extinction throughout all or a significant portion of its 
range; likely to become endangered within the foreseeable future 
throughout all or a significant portion of its range; or neither. The 
BRT's ESU-level extinction risk assessment reflects the BRT's 
professional scientific judgment, guided by the analysis of the VSP 
factors, as well as by expectations about the likely interactions among 
the individual VSP factors. The BRT's assessment, however, did not 
include an evaluation of efforts being made to protect the species, as 
required under section 4(b)(1)(A) of the ESA. Therefore, the BRT's 
findings should not be interpreted as recommendations regarding ESA 
listing.

Consideration of Resident O. mykiss

    The BRT fully considered the best available scientific and 
commercial information on resident populations in assessing the 
extinction risk of the Puget Sound O. mykiss ESU. However, little or no 
data are available on the abundance, productivity, spatial structure, 
or diversity of the component resident populations, nor on their 
contribution to the viability of the entire ESU. As a result, the 
majority of the information available with which to assess the level of 
extinction risk for this ESU pertained to the anadromous component. In 
general, the BRT considered the resident component of O. mykiss 
populations in the Puget Sound ESU to be relatively minor based on 
field surveys of juvenile fish in freshwater. The majority of the BRT 
felt that resident O. mykiss below barriers to migration may reduce 
risks to ESU abundance by providing short-term buffers against 
demographic stochasticity in many of the ESU's populations, although 
there was insufficient information to characterize the effectiveness of 
such buffers. The BRT concluded that resident populations in the Puget 
Sound ESU are unlikely to significantly reduce the risk of extinction 
of anadromous populations over the long term. This conclusion is also 
supported by recent reports by the Independent Science Advisory Board 
(ISAB) and NMFS' Recovery Science Review Panel (RSRP) which recently 
concluded that anadromous O. mykiss contribute ``substantially and 
irreplaceably to any measure of O. mykiss productivity and viability'' 
(RSRP, 2004), and that the ``the presence of both resident and 
anadromous life-history forms is critical for conserving the diversity 
of steelhead/rainbow trout populations and, therefore, the overall 
viability of ESUs'' (ISAB, 2005-2). The RSRP and ISAB underscored that 
``resident populations by themselves should not be relied upon to 
maintain long-term viability of an [O. mykiss] ESU'' (RSRP, 2004), and 
that the ``likelihood of long-term persistence would be substantially 
compromised by the loss of anadromy in O. mykiss ESUs'' (ISAB, 2005-2). 
Based on the minor contribution of resident O. mykiss to the viability 
of the Puget Sound O. mykiss ESU, we conclude that the BRT's extinction 
risk assessment directly informs our evaluation of extinction risk for 
the Puget Sound steelhead-only DPS under consideration.

Consideration of Hatchery-Origin Steelhead

    The BRT explicitly considered both the potential positive and 
negative effects of hatchery production on the viability of the Puget 
Sound O. mykiss ESU. The BRT felt that the two within-ESU hatchery 
programs (the Hamma Hamma River and Green River natural

[[Page 15671]]

winter-run steelhead hatchery programs), have the potential to benefit 
natural steelhead populations in their respective rivers, but that both 
programs are relatively recent and have not collected sufficient data 
to demonstrate any contributions with any certainty. The BRT did note 
that the Hamma Hamma program does appear to have successfully increased 
the number of natural spawners in the population (although the relative 
increase in natural spawners is large, the absolute increase in natural 
spawners is modest), but the success of the program cannot be fully 
evaluated until the naturally produced offspring of the hatchery-origin 
fish return and reproduce.
    Given the widespread and high levels of production of hatchery fish 
not included in the Puget Sound ESU, the BRT concluded that the overall 
negative effect of artificial propagation in the Puget Sound area 
likely outweighs any potential positive effects. Informed by the above 
considerations regarding hatchery-origin steelhead, the BRT's analysis 
of ESU viability (summarized below) focused on the available 
information concerning the status of naturally spawning steelhead 
populations in the ESU. As previously noted, we conclude that the BRT's 
extinction risk assessment directly informs our evaluation of 
extinction risk for the Puget Sound steelhead-only DPS under 
consideration.

Summary of Puget Sound Steelhead Viability Analysis

    Abundance - Steelhead in the Puget Sound DPS are most abundant in 
northern Puget Sound, with winter-run steelhead in the Skagit and 
Snohomish rivers supporting the two largest populations. The Skagit and 
Snohomish river winter-run populations have been approximately three to 
five times larger than the other populations in the DPS, with average 
annual spawning of approximately 5,000 and 3,000 total adult spawners, 
respectively. Populations in Hood Canal and along the Strait of Juan de 
Fuca are generally small, averaging fewer than 100 spawners annually. 
The geometric means of most populations have declined in the last 5 
years, and are below the long-term means. However, winter-run 
populations in the Samish River (northern Puget Sound) and the Hamma 
Hamma River (Hood Canal) appear to be growing rapidly with recent 
increases in the abundance of natural spawners. The recent abundance in 
the Hamma Hamma River likely reflects supplementation from the (within-
DPS) Hamma Hamma hatchery program. The recent abundance estimates in 
the Samish River may include an uncertain number of hatchery fish 
originating from the (out-of-DPS) Whatcom Creek hatchery, and their 
naturally spawned progeny. WDFW reports that from 1992 to 2002 there 
has been a general downgrade in the abundance of Puget Sound steelhead 
populations, with declines in the proportion of ``healthy'' 
populations, and an increase in the proportion of ``depressed'' and 
``unknown status'' populations (SaSI, 1992, 2002). No abundance data 
series exists for most of the 16 summer-run steelhead populations in 
the DPS, although all appear to be small, averaging fewer than 200 
spawners annually. The BRT expressed concern that populations at such 
low levels of abundance may be near or below a ``quasi-extinction'' 
threshold, below which population dynamics become inherently 
unpredictable. The BRT concluded that the risk to the viability of 
Puget Sound steelhead due to declining abundance is high.
    ESU Productivity - Nearly all steelhead populations in the DPS 
exhibited diminished productivity as indicated by below-replacement 
population growth rates, and declining short- and long-term trends in 
natural escapement and total run size. Declining productivity was 
particularly evident in southern Puget Sound steelhead populations, but 
was also exhibited by some populations in northern Puget Sound, Hood 
Canal, and the Strait of Juan de Fuca. At the time of the 1996 status 
review (Busby et al., 1996), the Skagit and Snohomish river populations 
appeared to be relative strongholds of productivity, demonstrating 
strongly positive and statistically significant population trends and 
growth rates. The recent trends, however, in escapement, total run 
size, recruitment, and population growth rate for these two populations 
are downward or below replacement, although not all analyses were 
statistically significant. Positive population trends were observed in 
the Samish and Hamma Hamma river winter-run populations (as noted 
above, the increasing trend for the Hamma Hamma River population likely 
reflects a recently established supplementation hatchery program, 
rather than an increase in naturally produced steelhead). Relevant 
productivity data are unavailable for all but one of the summer-run 
populations in the DPS. The Tolt River summer-run population, for which 
data are available, is showing evidence for increasing productivity. 
The BRT expressed concern that the observed population declines in the 
DPS have occurred despite widespread reductions by WDFW in the direct 
harvest of natural steelhead since the 1990s. The BRT also expressed 
concern that WDFW uses a March 15 date to delineate between naturally 
spawning hatchery-origin fish and native winter-run fish. The BRT felt 
that such an approach could bias productivity estimates as it does not 
provide a consistently accurate estimate of the proportion of hatchery-
origin fish or their contribution to natural production. Information 
was not available to evaluate trends in marine survival for any of the 
populations in the DPS. The BRT concluded that the risk to the 
viability of Puget Sound steelhead due to declining productivity is 
high.
    Spatial Structure/Connectivity - The BRT noted that the 
distribution of steelhead has been affected by a number of dams in 
several Puget Sound river basins that block accessibility to habitat 
and connectivity among populations. Additionally, the BRT noted that 
urban development has degraded or eliminated wetland and riparian 
habitats, resulting in changes to river hydrology and the loss of side-
channel areas, thereby reducing the spawning and rearing distribution 
of Puget Sound steelhead populations. Declines in natural abundance 
observed in nearly all of the DPS's populations, coupled with large 
numbers of man-made impassable barriers, have sharply reduced 
opportunities for migration and connectivity among steelhead 
populations in different watersheds. The BRT expressed concern 
regarding the sharp reduction in natural escapement for the centrally 
located Lake Washington watershed, and noted that the observation of 
weakening abundance trends for populations in neighboring river basins 
may reflect degraded connectivity among populations. The BRT concluded 
that the viability of Puget Sound steelhead is at moderate risk due to 
the reduced spatial complexity of, and connectivity among, populations.
    Diversity - The BRT noted concern regarding the apparent reduction 
of the summer-run steelhead populations in Puget Sound. Summer-run 
populations are concentrated in northern Puget Sound, with only two 
other populations distributed throughout the rest of the DPS. One of 
these latter summer-run populations (the Elwha River summer-run 
population) is thought to have been extirpated in the early1900s and 
replaced by out-of-DPS Skamania stock summer-run hatchery steelhead. 
Several BRT members noted that anecdotal historical accounts discuss 
significant early runs of wild steelhead, but

[[Page 15672]]

expressed concern that these early wild spawners have apparently 
disappeared from several river systems. Despite evidence of increasing 
productivity in the largest summer-run population in the ESU (the Tolt 
River population), it exhibits a negative trend in total run size and a 
flat trend in escapement. The other summer-run populations appear to be 
at very low levels of abundance. Additionally, the substantial 
production of out-of-DPS Skamania stock summer-run hatchery fish in 
watersheds with native summer-run populations (e.g., in the 
Stillaguamish River and South Fork Skykomish populations) poses genetic 
risks to the summer-run component of the DPS. The BRT expressed concern 
that the Chambers Creek and Skamania stock hatchery programs and their 
derivatives may have adverse effects on the DPS's diversity through 
genetic introgression and outbreeding depression. Some members of the 
BRT felt that adverse impacts from these out-of-DPS hatchery programs 
may be contributing to the declines in natural steelhead productivity, 
but acknowledged that the magnitude of any such impact could not be 
ascertained. Although these hatchery programs have selected for 
differences in average spawning time, any interbreeding between native 
and hatchery fish that may occur will likely have adverse consequences 
for the reproductive fitness of the local natural populations. The BRT 
noted that even very low levels of hatchery introgression can have a 
significant impact on genetic diversity after several generations. The 
BRT recognized the substantial reductions in the harvest of wild 
steelhead that were implemented in the mid 1990s, but noted that the 
previous harvest management may have removed a substantial proportion 
of the native summer-run and early winter-run steelhead spawn timing 
from many of the populations in the DPS. Present-day high harvest rates 
for marked hatchery-origin fish, although preventing out-of-DPS 
hatchery fish from spawning naturally, may continue to reduce the 
diversity of natural spawn timing through the incidental mortality of 
early-returning natural steelhead. The BRT concluded that the viability 
of Puget Sound steelhead is at moderate risk due to the reduced life-
history diversity of populations and the potential threats posed by 
artificial propagation and harvest in the Puget Sound.
    Overall DPS Viability - Informed by the assessment of demographic 
risks for each of the four VSP criteria (summarized above), an 
overwhelming majority of the BRT concluded that Puget Sound steelhead 
are likely to become endangered within the foreseeable future 
throughout all or a significant portion of their range. The BRT's 
conclusion fully considered the best available information concerning 
the contribution of resident and hatchery-origin O. mykiss to the 
overall viability of the steelhead in the Puget Sound DPS. As noted 
above, the BRT's assessment did not include an evaluation of efforts 
being made to protect the species and therefore does not represent a 
recommendation for ESA listing status. The following sections summarize 
the likely factors for the decline of Puget Sound steelhead, as well as 
the protective efforts being made to protect steelhead and other 
salmonids in the Puget Sound area.

Summary of Factors Affecting the Species

    Section 4(a)(1) of the ESA and NMFS' implementing regulations (50 
CFR part 424) state that the Secretary of Commerce (Secretary) must 
determine, through the regulatory process, if a species is endangered 
or threatened because of any one or a combination of the following 
factors: (1) the present or threatened destruction, modification, or 
curtailment of its habitat or range; (2) overutilization for 
commercial, recreational, scientific, or educational purposes; (3) 
disease or predation; (4) inadequacy of existing regulatory mechanisms; 
or (5) other natural or human-made factors affecting its continued 
existence. We have previously detailed the impacts of various factors 
contributing to the decline of West Coast steelhead in our previous 
listing determinations (e.g., 62 FR 43937, August 18, 1997; 57 FR 
14517, March 25, 1999) and supporting documentation (e.g.; NMFS, 1997, 
``Factors Contributing to the Decline of Chinook Salmon An Addendum to 
the 1996 West Coast Steelhead Factors for Decline Report;'' NMFS, 1996, 
``Factors for Decline A Supplement to the Notice of Determination for 
West Coast Steelhead Under the Endangered Species Act''). These Federal 
Register notices and technical reports conclude that all of the factors 
identified in section 4(a)(1) of the ESA have played a role in the 
decline of West Coast steelhead stocks. The following discussion 
briefly summarizes findings regarding the principal factors for decline 
in general terms, and notes factors of specific relevance to the Puget 
Sound DPS. The reader is referred to the above Federal Register 
notices, technical reports, and the BRT's findings (NMFS, 2005) for a 
more detailed treatment of the relevant factors for decline for this 
ESU.

1. The Present or Threatened Destruction, Modification, or Curtailment 
of its Habitat or Range

    West Coast steelhead have experienced declines in abundance over 
the past several decades as a result of loss, damage, or change to 
their natural environment. Water diversions for agriculture, flood 
control, domestic, and hydropower purposes have greatly reduced or 
eliminated historically accessible habitat and degraded remaining 
habitat. Forestry, agriculture, mining, and urbanization have degraded, 
simplified, and fragmented habitat. The destruction or modification of 
estuarine areas has resulted in the loss of important rearing and 
migration habitats. Losses of habitat complexity and habitat 
fragmentation have also contributed to observed declines. Sedimentation 
and degraded water quality from extensive and intensive land use 
activities (e.g., timber harvests, road building, livestock grazing, 
and urbanization) are recognized as primary causes of habitat 
degradation throughout the range of West Coast steelhead.
    Habitat utilization by steelhead in the Puget Sound area has been 
dramatically affected by large dams and other man-made barriers in a 
number of river basins: the Nooksack, Skagit, White, Nisqually, 
Skokomish, and Elwha river basins. Several of these dams have 
eliminated access to historical habitats, while others are located 
above historically impassable natural barriers. In addition to limiting 
habitat accessibility, dams (whether located above or below 
historically impassable barriers) affect habitat quality through 
changes in river hydrology, altered temperature profile, reduced 
downstream gravel recruitment, and the reduced recruitment of large 
woody debris. In some rivers, such as the Elwha River, increased water 
temperatures have decreased disease resistance in salmonids.
    Many upper tributaries in the Puget Sound region have been affected 
by poor forestry practices, while many of the lower reaches of rivers 
and their tributaries have been altered by agriculture and urban 
development. Urbanization has caused direct loss of riparian vegetation 
and soils, significantly altered hydrologic and erosional rates and 
processes (e.g., by creating impermeable surfaces such as roads, 
buildings, parking lots, sidewalks etc.), and polluted waterways with 
stormwater and point-source discharges. The loss of wetland and 
riparian habitat

[[Page 15673]]

has dramatically changed the hydrology of many streams, with increases 
in flood frequency and peak flow during storm events and decreases in 
groundwater driven summer flows (Moscrip and Montgomery, 1997; Booth et 
al., 2002; May et al., 2003). Flood events result in gravel scour, bank 
erosion, and sediment deposition. Land development for agricultural 
purposes has also altered the historical land cover, and as much of 
this development has occurred in river floodplains, there has been a 
direct impact on river flow levels and morphology. River braiding and 
sinuosity have been reduced through the construction of dikes, 
hardening of banks with riprap, and channelization of the mainstem. 
Constriction of river flows, particularly during high flow events, 
increases the likelihood of gravel scour and the dislocation of rearing 
juveniles. The loss of side-channel habitats has also reduced important 
areas for spawning, juvenile rearing, and overwintering habitats. 
Estuarine areas have been dredged and filled, resulting in the loss of 
important juvenile rearing areas. In addition to being a factor that 
contributed to the present decline of Puget Sound steelhead 
populations, the continued destruction and modification of steelhead 
habitat is the principal factor limiting the viability of the Puget 
Sound steelhead DPS into the foreseeable future.

2. Overutilization for Commercial, Recreational, Scientific or 
Educational Purposes

    Steelhead runs have supported, and continue to support, important 
tribal and recreational fisheries throughout their range, contributing 
millions of dollars to numerous local economies, as well as providing 
important cultural and subsistence needs for Native Americans. 
Overfishing in the early days of European settlement led to the 
depletion of many stocks of salmonids, prior to extensive modifications 
and degradation of natural habitats. However, following the degradation 
of many west coast aquatic and riparian ecosystems, exploitation rates 
were higher than many populations could sustain. Therefore, harvest may 
have contributed to the further decline of some populations.
    Extensive artificial propagation has historically supported high 
levels of steelhead harvest in the Puget Sound area. The majority of 
harvest occurred in recreational fisheries, but tribal fisheries 
directed at steelhead are also important. Prior to the promulgation of 
regulations by WDFW in the mid 1990s protecting all wild steelhead from 
recreational fishery harvest, Puget Sound steelhead fisheries likely 
contributed to the present decline in abundance of natural steelhead 
populations. It is also likely that harvest directed at early returning 
hatchery-origin fish adversely affected natural population life-history 
diversity through the selective removal of commingled native summer-run 
and early-winter run steelhead adults. Present-day fisheries are 
implemented to harvest marked hatchery-origin fish only, and are 
managed in time to target early run hatchery-origin fish and minimize 
the incidental harvest of early-returning natural steelhead. Existing 
steelhead recreational fisheries in Puget Sound, while appropriately 
minimizing potential adverse impacts on natural steelhead populations, 
may still result in a continued mortality of early-returning natural 
steelhead through poaching and hook-and-release mortalities. Although 
overutilization for recreational purposes was a factor that contributed 
to the present decline of Puget Sound steelhead populations, we do not 
believe that overutilization is a factor limiting the viability of the 
Puget Sound steelhead DPS into the foreseeable future.

3. Disease or Predation

    Introductions of non-native species (e.g., largemouth bass) and 
habitat modifications that benefit the survival or feeding 
effectiveness of native or introduced predators have resulted in 
increased predation risks to natural steelhead populations in many 
Pacific Northwest rivers and lakes. Predation by marine mammals 
(principally harbor seals and sea lions) is also of concern in areas 
where steelhead populations are already diminished due to other 
factors, or where man-made structures concentrate fish and make them 
susceptible to predation by marine mammals (e.g., the Ballard Locks at 
Lake Washington). Although fishes form the principal food sources of 
many marine mammals, salmonids appear to be a minor component of their 
overall diet, given the seasonal availability of anadromous fishes 
(Scheffer and Sperry, 1931; Jameson and Kenyon, 1977; Graybill, 1981; 
Brown and Mate, 1983; Roffe and Mate, 1984; Hanson, 1993). However, 
predation by marine mammals may significantly decrease salmonid 
abundance in some local populations when other prey species are absent 
and where physical and behavioral conditions lead to the concentration 
of salmonid adults and juveniles (Cooper and Johnson, 1992). Predation 
by seabirds can also substantially reduce the abundance of juvenile 
salmon and steelhead populations in some locations. Although predation 
may be a concern for some local populations at low abundance, we do not 
believe that it is a factor limiting the viability of the Puget Sound 
steelhead DPS into the foreseeable future.
    Fish disease and epizootics can also be a limiting factor to adult 
and juvenile steelhead survival. Salmonids are exposed to numerous 
naturally occurring bacterial, protozoan, viral, and parasitic 
organisms in spawning and rearing areas, hatcheries, migratory routes, 
and the marine environment. Included are fish pathogens causing 
diseases such as bacterial kidney disease, ceratomyxosis, columnaris, 
furunculosis, infectious hematopoietic necrosis, enteric redmouth 
disease, black spot disease, erythrocytic inclusion body syndrome, and 
whirling disease, among others, that are known to affect West Coast 
salmonids (Rucker et al., 1953; Wood, 1979; Leek, 1987; Foott et al., 
1994; Gould and Wedemeyer, undated). In general, very little current or 
historical information exists to quantify changes in infection levels 
and mortality rates attributable to these diseases. However, studies 
have shown that naturally spawned fish tend to be less susceptible to 
pathogens than hatchery-reared fish (Buchanon et al., 1983; Sanders et 
al., 1992). Hatchery-origin fish may have an increased risk of carrying 
fish disease pathogens because of relatively high rearing densities 
that increase stress levels and can lead to a greater manifestation and 
transmission of diseases within the hatchery population. Under natural, 
low density conditions, most pathogens do not lead to a disease 
outbreak in wild populations. When disease outbreaks do occur, they are 
often triggered by stressful hatchery rearing conditions, or by an 
adverse change in the natural environment. Consequently, it is possible 
that the release of hatchery fish may lead to the infection and 
increased mortality of natural-origin populations, particularly if 
habitat conditions such as low water flows and high temperatures 
exacerbate the susceptibility of natural- and hatchery-origin 
populations to infectious diseases. Although hatchery populations may 
be considered to be reservoirs for disease pathogens because of their 
elevated rearing densities and increased stress levels, there is little 
evidence to suggest that diseases are routinely transmitted from 
hatchery-orign to natural-origin fish (Steward and Bjornn, 1990). We do 
not believe that disease is a factor limiting the viability of the 
Puget Sound steelhead DPS into the foreseeable future.

[[Page 15674]]

4. The Inadequacy of Existing Regulatory Mechanisms

    A variety of Federal, state, tribal, and local laws, regulations, 
treaties and measures affect the abundance and survival of West Coast 
steelhead, and the quality of their habitat. We reviewed existing 
regulatory mechanisms as part of our recent updated listing 
determinations for West Coast salmon and steelhead (69 FR 33102, June 
14, 2004; 70 FR 834, January 5, 2006). We noted several Federal, state, 
and local regulatory programs that have been successfully implemented 
to substantially reduce historical risks to West Coast steelhead DPSs 
(for example, the elimination of hatchery rainbow trout stocking in 
anadromous waters, and the conversion of many in-river recreational 
fisheries to mark-selective fisheries or catch-and-release only). The 
reader is referred to the previous proposed rule (69 FR 33102; June 14, 
2004) for a regional and state-by-state summary of these regulatory 
mechanisms, including those in the Puget Sound area. In particular, 
changes in regulations governing steelhead fisheries have significantly 
reduced the risks for many West Coast steelhead DPSs, including the 
Puget Sound DPS under consideration. Hatchery managers have implemented 
measures to reduce the potential negative interactions between 
hatchery-origin and natural-origin steelhead in the Puget Sound area. 
However, it is unclear whether some of these measures have been 
effective in minimizing the adverse consequences of artificial 
propagation on natural populations (e.g., the selection for early run 
timing in the Chambers Creek steelhead hatchery stock has reduced the 
frequency of interactions between hatchery-origin and natural fish, but 
it may have increased the severity of any interactions that do occur). 
The Hatchery Science Review Group (HSRG) recently detailed 
recommendations intended to further minimize the potentially harmful 
effects of artificial propagation on natural populations of Puget Sound 
salmonids (HSRG, 2004). At present, however, the regulatory and funding 
mechanisms are not in place to fully implement the HSRG's 
recommendations (HSRG, 2005; also see further discussion in the 
``Efforts Being Made to Protect West Coast Salmon and Steelhead `` 
section, below). In addition, although there have been efforts to 
improve habitat conditions across the range of the Puget Sound 
steelhead DPS, land-use regulations across its range do not adequately 
address continued threats from habitat degradation and modification. We 
conclude that the inadequacy of existing regulatory mechanisms (e.g., 
governing potentially harmful hatchery practices and certain land-use 
activities) is a factor limiting the viability of the Puget Sound 
steelhead DPS into the foreseeable future.

5. Other Natural or Manmade Factors Affecting Its Continued Existence

    Variability in ocean and freshwater conditions can have profound 
impacts on the productivity of salmon and steelhead populations. 
Natural climatic conditions have at different times exacerbated or 
mitigated the problems associated with degraded and altered riverine 
and estuarine habitats. In the last decade, evidence has shown: (1) 
recurring, decadal-scale patterns of ocean-atmosphere climate 
variability in the North Pacific Ocean (Zang et al., 1997; Mantua et 
al., 1997); and (2) correlations between these oceanic productivity 
``regimes'' and salmon population abundance in the Pacific Northwest 
and Alaska (Hare et al., 1999; Mueter et al., 2002). One indicator of 
the ocean-atmosphere variation for the North Pacific is the Pacific 
Decadal Oscillation index (PDO). Negative PDO values are associated 
with relatively cool ocean temperatures (and generally high salmon 
productivity) off the Pacific Northwest, and positive values are 
associated with warmer, less productive conditions. These favorable 
ocean conditions may also be correlated with favorable conditions for 
salmonid survival in the freshwater environment (e.g., above-average 
rainfalls resulting in improved flow regimes for smolt outmigration). 
Increases in many salmon populations in recent years may be largely a 
result of more favorable ocean conditions. PDO values were mostly 
positive during the two decades preceding 1998, and this regime was 
generally characterized by less productive ocean conditions and 
declining salmonid abundances. Between July 1998 and July 2002, the PDO 
exhibited mostly negative values, associated with higher ocean 
productivity and increasing returns for many West Coast salmonid 
populations. From August 2002 to present, the PDO has exhibited mostly 
positive values. It is not clear what impact, if any, these most recent 
conditions will have on West Coast salmonid populations in general, and 
the Puget Sound steelhead DPS in particular. Ocean-climate change and 
variability is a factor contributing considerable uncertainty to the 
viability of the Puget Sound steelhead DPS into the foreseeable future.
    Extensive hatchery programs have been implemented throughout the 
range of West Coast steelhead. While these programs may have succeeded 
in providing fishing opportunities and increasing the total number of 
naturally spawning fish, the programs have also likely increased risks 
to natural populations as a result of food resource competition, 
increased predation, reduced genetic diversity and reproductive fitness 
through interbreeding, and masking of trends in natural populations 
through the straying of hatchery-origin fish onto spawning grounds. 
More recently, hatchery programs using local native salmon populations 
as broodstock have been initiated that are specifically designed to 
conserve depressed Pacific salmonid populations. State natural resource 
agencies have adopted or are developing policies designed to ensure 
that the use of artificial propagation is conducted in a manner 
consistent with the conservation and recovery of natural, indigenous 
populations. The role of artificial propagation in the conservation and 
recovery of salmonid populations con