Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Marbled Murrelet, 53838-53951 [06-7437]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 71, Number 176 (Tuesday, September 12, 2006)]
[Proposed Rules]
[Pages 53838-53951]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-7437]



[[Page 53837]]

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Part III





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Designation of Critical 
Habitat for the Marbled Murrelet; Proposed Rule

Federal Register / Vol. 71, No. 176 / Tuesday, September 12, 2006 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AU91


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for the Marbled Murrelet

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
revise currently designated critical habitat for the marbled murrelet 
(Brachyramphus marmoratus marmoratus) in Washington, Oregon, and 
California, under the Endangered Species Act of 1973, as amended (Act). 
We originally designated critical habitat for the marbled murrelet in 
Washington, Oregon, and California on May 24, 1996 (61 FR 26256). Since 
that time, we completed a 5-year status review of the marbled murrelet 
(USFWS 2004). This proposed rule is in response to a settlement 
agreement reached on January 13, 2003.
    In our proposal to revise the current designation of critical 
habitat for the marbled murrelet, we are proposing 3,590,642 acres (ac) 
(1,453,000 hectares (ha)) as critical habitat. We are further 
considering excluding 3,368,950 ac (1,363,300 ha) of these lands under 
section 4(b)(2) of the Act from the final designation. This action, if 
adopted in its entirety, would result in a final revised designation of 
approximately 221,692 ac (89,700 ha) of land being designated as 
critical habitat for the marbled murrelet, a reduction of approximately 
3,666,108 ac (1,483,640 ha) from currently designated critical habitat.
    In this rule, we are further proposing to revise the entry in 50 
CFR 17.11 concerning the scientific name of the marbled murrelet from 
Brachyramphus marmoratus marmoratus to Brachyramphus marmoratus to 
reflect recent taxonomic information.

DATES: We will accept comments from all interested parties until 
November 13, 2006. We must receive requests for public hearings, in 
writing, at the address shown in the ADDRESSES section by October 27, 
2006.

ADDRESSES: If you wish to comment, you may submit your comments and 
materials concerning this proposal by any one of several methods:
    1. You may submit written comments and information to Ken Berg, 
Field Supervisor, U.S. Fish and Wildlife Service, Western Washington 
Fish and Wildlife Office, 510 Desmond Drive SE., Suite 101, Lacey, WA 
98503-1273.
    2. You may hand-deliver written comments to our Western Washington 
Fish and Wildlife Office, at the above address.
    3. You may send comments by electronic mail (e-mail) to 
MurreletCH@fws.gov. Please see the Public Comments Solicited section 
below for file format and other information about electronic filing.
    4. You may fax your comments to 360/753-9405.
    5. You may use the Federal Rulemaking Portal: https://
www.regulations.gov. Follow the instructions for submitting comments.
    Comments and materials received, as well as supporting 
documentation used in the preparation of this proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at the Western Washington Fish and Wildlife Office, at the 
address given above; the Oregon Fish and Wildlife Office, 2600 SE 98th 
Ave., Suite 100, Portland, OR 97266; or the Arcata Fish and Wildlife 
Office, 1655 Heindon Road, Arcata, CA 95521.

FOR FURTHER INFORMATION CONTACT: Ken Berg, Field Supervisor, Western 
Washington Fish and Wildlife Office (see ADDRESSES) (telephone 360-753-
9440); Kemper McMaster, Field Supervisor, Oregon Fish and Wildlife 
Office (see ADDRESSES) (telephone 503-231-6179); or Michael Long, Field 
Supervisor, Arcata Fish and Wildlife Office (see ADDRESSES) (telephone 
707-822-7201). Persons who use a telecommunications device for the deaf 
(TTD) may call the Federal Information Relay Service (FIRS) at 800-877-
8339, 24 hours a day, 7 days a week.

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, comments or 
suggestions from the public, other concerned governmental agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) The reasons any habitat should or should not be determined to 
be critical habitat as provided by section 4 of the Act, including 
whether it is prudent to revise currently designated critical habitat 
and whether the benefit of designation will outweigh any threats to the 
species due to designation;
    (2) Specific information on the amount and distribution of marbled 
murrelet habitat, and what areas that were occupied at the time of 
listing that contain the features that are essential for the 
conservation of the species should be included in our revised 
designation, and why and what areas that were not occupied at the time 
of listing are essential to the conservation of the species;
    (3) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed revised critical 
habitat;
    (4) Any foreseeable economic, national security, or other potential 
impacts resulting from the proposed revised designation, and in 
particular, any impacts on small entities;
    (5) Whether our approach to designating critical habitat could be 
improved or modified in any way to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concerns;
    (6) Specific information from the public on marbled murrelet and 
its habitat, and which habitat or habitat components (i.e., physical 
and biological features) are essential to the conservation of this 
species, and why; and
    (7) Specific information from the public regarding whether specific 
exclusions from this proposal may be appropriate for consideration.
    If you wish to comment, you may submit your comments and materials 
concerning this proposal by any one of several methods (see ADDRESSES 
section). Please submit e-mail comments to MurreletCH@fws.gov in ASCII 
file format. Please also include ``Attn: Marbled Murrelet'' in your e-
mail subject header and your name and return address in the body of 
your message. If you do not receive a confirmation from the system that 
we have received your e-mail message, contact us directly by calling 
our Western Washington Fish and Wildlife Office at phone number 360-
753-9440. Please note that the e-mail address MurreletCH@fws.gov will 
be closed at the end of the public comment period.
    Our practice is to make comments, including names and home 
addresses of respondents, available for public review during regular 
business hours. We will not consider anonymous comments, and we will 
make all comments available for public inspection in their entirety. 
Comments and materials received will be available for public 
inspection, by appointment, during normal business hours at the Western 
Washington Fish and Wildlife Office (see ADDRESSES).

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Role of Critical Habitat in Actual Practice of Administering and 
Implementing the Act

    Attention to and protection of habitat is paramount to successful 
conservation actions. The role that designation of critical habitat 
plays in protecting habitat of listed species, however, is often 
misunderstood. As discussed in more detail below in the discussion of 
exclusions under section 4(b)(2) of the Act, there are significant 
limitations on the regulatory effect of designation under section 
7(a)(2) of the Act. In brief, (1) designation provides additional 
protection to habitat only where there is a Federal nexus; (2) the 
protection is relevant only when, in the absence of designation, 
destruction or adverse modification of the critical habitat would in 
fact take place (in other words, other statutory or regulatory 
protections, policies, or other factors relevant to agency decision-
making would not prevent the destruction or adverse modification); and 
(3) designation of critical habitat triggers the prohibition of 
destruction or adverse modification of that habitat, but it does not 
require specific actions to restore or improve habitat.
    Currently, 475 species, or 36 percent of the 1,310 listed species 
in the United States under the jurisdiction of the Service, have 
designated critical habitat. We address the habitat needs of all 1,310 
listed species through conservation mechanisms such as listing, section 
7 consultations, the section 4 recovery planning process, the section 9 
protective prohibitions of unauthorized take, section 6 funding to the 
States, the section 10 incidental take permit process, and cooperative, 
nonregulatory efforts with private landowners. We believe that it is 
these measures that may make the difference between extinction and 
survival for many species.
    In considering exclusions of areas proposed as our revised 
designation of critical habitat, we evaluated the benefits of 
designation in light of Gifford Pinchot. In that case, the Ninth 
Circuit invalidated our regulation defining ``destruction or adverse 
modification of critical habitat.'' In response, on December 9, 2004, 
the Director issued guidance to be considered in making section 7 
adverse modification determinations. This proposal does not use the 
invalidated regulation in our consideration of the benefits of 
including areas in a final revised designation. We will carefully 
manage future consultations that analyze impacts to designated critical 
habitat, particularly those that appear to be resulting in an adverse 
modification determination. Such consultations will be reviewed by the 
Regional Office prior to finalizing to ensure that an adequate analysis 
has been conducted that is informed by the Director's guidance.
    On the other hand, to the extent that designation of critical 
habitat provides protection, that protection can come at significant 
social and economic cost. The administrative process of designation of 
critical habitat is expensive, time-consuming, and controversial. The 
current statutory framework of critical habitat, combined with past 
judicial interpretations of the statute, make critical habitat the 
subject of excessive litigation. As a result, critical habitat 
designations are driven by litigation and courts rather than biology, 
and made at a time and under a time frame that limits our ability to 
obtain and evaluate the scientific and other information required to 
make the designation most meaningful.
    In light of these circumstances, we believe that additional agency 
discretion would allow our focus to return to actions that provide the 
greatest benefit to the species most in need of protection.

Procedural and Resource Difficulties in Designating Critical Habitat

    We have been inundated with lawsuits for our failure to designate 
critical habitat, and we face a growing number of lawsuits challenging 
critical habitat determinations once they are made. These lawsuits have 
subjected us to an ever-increasing series of court orders and court-
approved settlement agreements, compliance with which now consumes 
nearly the entire listing program budget. This leaves us with little 
ability to prioritize its activities to direct scarce listing resources 
to the listing program actions with the most biologically urgent 
species conservation needs.
    The consequence of the critical habitat litigation activity is that 
limited listing funds are used to defend active lawsuits, to respond to 
Notices of Intent (NOIs) to sue relative to critical habitat, and to 
comply with the growing number of adverse court orders. As a result, 
listing petition responses, our own proposals to list critically 
imperiled species, and final listing determinations on existing 
proposals are all significantly delayed.
    The accelerated schedules of court-ordered designations have left 
us with limited ability to provide for public participation or to 
ensure a defect-free rulemaking process before making decisions on 
listing and critical habitat proposals, due to the risks associated 
with noncompliance with judicially imposed deadlines. This in turn 
fosters a second round of litigation in which those who fear adverse 
impacts from critical habitat designations challenge the designations. 
The cycle of litigation appears endless, and is very expensive, thus 
diverting resources from conservation actions that may provide 
relatively more benefit to imperiled species.
    The costs resulting from the designations result in legal expenses, 
and costs related to preparation and publication of the designation, 
analysis of the economic effects, requesting and responding to public 
comment, and in some cases compliance with the National Environmental 
Policy Act (NEPA; 42 U.S.C. 4321 et seq.). These costs, which are not 
required for many other conservation actions, reduce the funds 
available for direct and tangible conservation actions.

Background

    It is our intent to discuss only topics directly relevant to the 
revised designation of critical habitat in this proposed rule. For more 
information on the marbled murrelet, refer to the final rule for the 
designation of critical habitat published in the Federal Register on 
May 24, 1996 (61 FR 26256).

Previous Federal Actions

    For a description of Federal actions concerning marbled murrelet 
that occurred prior to our May 24, 1996, final rule for the designation 
of critical habitat for this species, please refer to that rule (61 FR 
26256). In that rule we designated 3,887,800 acres (1,573,340 ha) of 
critical habitat in 32 units.
    On January 22, 1997, we published a notice of availability of the 
Regulatory Flexibility Analysis examining the effects on small entities 
of the designation of critical habitat for the marbled murrelet (62 FR 
3241).
    On September 24, 1997, we completed the Recovery Plan for the 
marbled murrelet in Washington, Oregon, and California.
    On April 21, 2003, we published a notice of review initiating a 5-
year review of the marbled murrelet (68 FR 19569), and on July 25, 
2003, we published a second information request for the 5-year review 
(68 FR 44093). The 5-year review was completed on August 31, 2004. The 
evaluation report that preceded it was completed in March 2004, by 
McShane et al.
    On January 13, 2003, we reached a settlement agreement with the 
American Forest Resource Council and the Western Council of Industrial 
Workers to complete a rulemaking for critical

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habitat for the marbled murrelet that considers any new information. 
The settlement agreement includes the date of August 30, 2007, for 
submission to the Federal Register of any final regulation revising 
marbled murrelet critical habitat.

Taxonomy

    Two subspecies of the marbled murrelet were previously recognized--
North American murrelet (Brachyramphus marmoratus marmoratus) and 
Asiatic murrelet (B. marmoratus perdix). New information suggests that 
the Asiatic murrelet is a distinct species (Friesen et al. 1994, 1995). 
The American Ornithologists' Union, in its ``Forty-first Supplement to 
the Checklist of North American Birds,'' officially recognized the 
long-billed murrelet (B. perdix) and the marbled murrelet (B. 
marmoratus) as distinct species (American Ornithologists' Union 1997). 
Therefore, in this rule we are proposing to revise 50 CFR 17.11 to 
adopt the taxonomic clarification for the marbled murrelet to reflect 
the change from Brachyramphus marmoratus marmoratus to Brachyramphus 
marmoratus.

Ecological Considerations

    The marbled murrelet is a small seabird of the Alcidae family. The 
species' breeding range extends from Bristol Bay, Alaska, south to the 
Aleutian Archipelago, northeast to Cook Inlet, Kodiak Island, Kenai 
Peninsula and Prince William Sound, south along the coast through the 
Alexander Archipelago of Alaska, British Columbia, Washington, and 
Oregon to northern Monterey Bay in central California. Birds winter 
throughout the breeding range and also occur in small numbers off 
southern California.
    In the following discussion, we consider two components of marbled 
murrelet habitat that are biologically essential: (1) Marine foraging 
habitat, including prey spawning and concentration areas, and (2) 
terrestrial nesting habitat and associated forest stands. Forested 
areas with conditions that are capable of supporting nesting marbled 
murrelets are referred to as ``suitable nesting habitat.''

Marine Environment

    Marbled murrelets spend most of their lives in the marine 
environment where they consume a diversity of prey species including 
small fish and invertebrates. Marbled murrelets forage by pursuit 
diving in waters generally up to 98 feet (ft) (30 meters (m)) deep and 
up to 1.25 miles (mi) (2 kilometers (km)) off-shore (Strachan et al. 
1995, p. 247). Courtship behaviors have been observed at sea, although 
copulation occurs both at sea and at inland nest sites (Nelson 1997, p. 
13). Marbled murrelets also aggregate, loaf, preen, and exhibit wing-
stretching behaviors on the water. Marbled murrelets have been found 
occasionally on rivers and inland lakes (Carter and Sealy 1986, p. 
473).
    Areas that support populations of prey species are essential to 
maintaining successfully reproducing marbled murrelet populations 
(Burkett 1995, p. 244). However, there are no marine areas currently 
designated as critical habitat, and this proposal would not designate 
any critical habitat units in marine areas, because, while important to 
the life history of the birds, we are unable to define specific areas 
essential to the conservation of the species (see Areas Considered 
under Section 3(5)(A), Marine Areas for more detail).
    Use of marine habitat is constrained during the breeding season by 
the quality and quantity of forage resources available. During the 
breeding season, the distribution of marbled murrelets at sea along the 
Washington, Oregon, and California coasts has been correlated with 
specific marine habitat characteristics that concentrate prey, such as 
cape eddies, river mouths, upwellings, estuarine conditions, sandy 
substrates, and water temperature (Ainley et al. 1995, p. 365-367; 
Becker and Beissinger 2003, p. 252; Burger 2002a, pp. 727-728; Lougheed 
2000, p. 56-59, 75; Meyer et al. 2002, p. 95; Ostrand et al. 1998, p. 
292-295). Nesting marbled murrelets that are returning to their nest at 
least once per day must balance the energetic costs of foraging trips 
with the benefits for themselves and their young. This may result in 
marbled murrelets preferring to forage in marine areas in close 
proximity to their nesting habitat. However, if adequate or appropriate 
foraging resources (i.e., ``enough'' prey, and/or prey with the optimum 
nutritional value for themselves or their young) are unavailable in 
close proximity to their nesting areas, marbled murrelets may be forced 
to forage at greater distances or to abandon their nests (Huff et al. 
2006, p. 20).

Terrestrial Environment

    Throughout the forested portion of their range, marbled murrelet 
habitat use is positively associated with the presence and abundance of 
mature and old-growth forests, large core areas of old-growth, low 
amounts of edge and fragmentation, proximity to the marine environment, 
and increasing forest age and height (McShane et al. 2004, p. 4-39; 
Binford et al. 1975, pp. 315-316; Hamer and Nelson 1995b, pp. 72-75; 
Ralph et al. 1995b, p. 4). In all cases, marbled murrelets focus on the 
presence of platforms used for nesting. Platform presence is more 
important than the size of the nest tree, and tree size alone is not a 
good indicator of the abundance of platforms (Evans Mack 2003, p. 3).
    The presence of platforms is the most important characteristic of 
marbled murrelet nesting habitat (reviewed in Burger 2002b, pp. 40, 43; 
McShane et al. 2004, pp. 4-45--4-51, 4-53, 4-55, 4-56, 4-59; Nelson 
1997, p. 6; and Huff et al. 2006, pp. 12-13, 18). Individual tree 
attributes that provide platforms suitable for nesting include large or 
forked branches, deformities caused by broken tops or mistletoe 
infection, or other structures large enough to provide a platform for a 
nesting adult murrelet (Hamer and Nelson 1995b, p. 79). Platforms are 
defined as limbs greater or equal to 4 inches (in) diameter (10 
centimeters (cm)) and greater or equal to 33 ft (10 m) above ground 
(reviewed in Burger 2002b, pp. 41-42 and McShane et al. 2004, p. 4-31). 
Tree diameter and height have been positively correlated with platform 
size and the abundance of platforms, but the relationship may change 
depending on the variety of tree species and forest types marbled 
murrelets use for nesting (Huff et al. 2006, p. 12). Overall, nest 
trees in Washington, Oregon, and northern California have been greater 
than 19 in (48 cm) in diameter-at-breast-height and greater than 98 ft 
(30 m) tall (Hamer and Nelson 1995b, p. 81).
    Other important attributes of the platform are vertical and 
horizontal cover and substrate. Known nest sites have platforms that 
are generally protected by branches above (vertical cover) or to the 
side (horizontal cover) (Huff et al. 2006, p. 14). Marbled murrelets 
appear to select limbs and platforms that provide protection from 
predation (Luginbuhl et al 2001, p. 558; Marzluff et al. 2000, p. 1135; 
Raphael et al. 2002b, pp. 226, 228) and inclement weather (Huff et al. 
2006, p. 14). Substrate, such as moss, duff, or needles, on the nest 
limb is important for protecting the egg and preventing it from falling 
(Huff et al. 2006, p. 13).
    Marbled murrelets generally nest near the coast, but not usually 
directly adjacent to the ocean, where wind may affect nest availability 
and microclimate (Huff et al. 2006, pp. 17-18). It is likely that 
factors such as energetics, habitat availability, site fidelity, and 
predation influence where marbled murrelets choose to nest.
    At the landscape scale, marbled murrelets show fidelity to marine 
foraging areas and may return to specific

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watersheds for nesting (Nelson 1997, pp. 13, 16-17, 20; Cam et al. 
2003, p. 1123). For example, marbled murrelets have been observed to 
return to the same specific nest branches or sites (Hebert and 
Golightly 2006, p. 270). Repeated surveys in occupied or nesting stands 
have revealed site tenacity similar to that of other birds in the alcid 
family (Huff et al. 2006, p. 12) in that marbled murrelets have been 
observed in the same suitable habitat during the last 20 years in 
California and 15 years in Washington.
    Marbled murrelet dispersal mechanisms are not well understood, and 
social interactions may play an important role in determining nesting 
location. Because the presence of marbled murrelets in a forest stand 
may attract other pairs to currently unoccupied habitat within the 
vicinity. The potential use of these areas may depend on how close the 
new habitat is to occupied habitat, as well as distance to the marine 
environment, population size, and other factors (McShane et al. 2004, 
p. 4-78). Marbled murrelets in California and southern Oregon were less 
likely to occupy old-growth habitat if it was greater than 3 mi (5 km) 
from other nesting marbled murrelets (Meyer et al. 2002, p. 95).
    Raphael et al. (1995, p. 177) found marbled murrelets occupied 
sites with greater percentages of old-growth forest and large saw-
timber within 0.5 mi (0.8 km) of nest sites (501-acre (ac) (203-hectare 
(ha)) circles). Raphael et al. (1995, p. 189) suggested tentative 
guidelines based on this analysis that sites with 35 percent old-growth 
and large saw-timber in the landscape are more likely to be occupied.
    Detections of marbled murrelets at inland sites and densities 
offshore were found to be higher in or adjacent to areas with large 
patches of significant old-growth, and in areas of low fragmentation 
and isolation of old-growth patches (Raphael et al. 1995, pp. 188-189; 
2002a, p. 221; 2002b, p. 337; Burger 2002b, p. 54; Meyer and Miller 
2002, pp. 763-764; Meyer et al. 2002, pp. 109-112; Miller et al. 2002, 
p. 100). Overall, occupied landscapes tended to have large core areas 
of old-growth and low amounts of overall edge (Meyer and Miller 2002, 
pp. 763-764; Raphael et al. 2002b, p. 331). Marzluff and Restani (1999, 
pp. 8-9, 11-13) and Raphael et al. (2002b, p. 331) suggested that 
reduced amount of nesting habitat and increased isolation of nesting 
habitat would have long-term impacts on the number of nests and short-
term negative impacts on nest success, both of which affect population 
size.
    The conversion of large tracts of native forest to small, isolated 
forest patches with large edge areas can create changes in 
microclimate, vegetation species, and predator-prey dynamics. 
Unfragmented, older-aged forests have lower temperatures and solar 
radiation and higher humidity compared to clearcuts and other open 
areas (e.g., Chen et al. 1993, p. 219; 1995, p. 74). Edge habitat is 
also exposed to increased temperatures and light, high evaporative heat 
loss, increased wind, and decreased moisture. Fundamental changes in 
the microclimate of a stand have been recorded at least as far as 787 
ft (240 m) from the forest edge (Chen et al. 1995, p. 74). The changes 
in microclimate regimes with forest fragmentation can stress an old 
growth associate species, especially a seabird like the marbled 
murrelet (Meyer and Miller 2002, p. 764), and can affect the 
distribution of epiphytes that marbled murrelets use for nesting. 
Branch epiphytes or substrate have been identified as a key component 
of marbled murrelet nests (Nelson et al. 2003, p. 52; McShane et al. 
2004, pp. 4-48, 4-89, 4-104). While there are no data on the specific 
effects of microclimate changes on the availability of marbled murrelet 
nesting habitat at the scale of branches and trees, as discussed in the 
references above, the penetration of solar radiation, wind, and warm 
temperatures into the forest could change the distribution of epiphytes 
or blow moss off nesting platforms.
    Marbled murrelets have been known to locate their nests throughout 
forest stands and fragments, including along various types of natural 
and human-made edges (Hamer and Meekins 1999, p. 1; Manley 1999, p. 66; 
Bradley 2002, pp. 42, 44; Burger 2002b, p. 48; Nelson and Wilson 2002, 
p. 98). However, in California and southern Oregon, areas with abundant 
numbers of marbled murrelets were farther from roads, occurred more 
often in parks protected from logging, and were less likely to occupy 
old-growth habitat if it was isolated (greater than 3 mi (greater than 
5 km)) from other nesting marbled murrelets (Meyer et al. 2002, p. 102-
103). Marbled murrelets are no longer known to occur in areas without 
suitable forested habitat (sites with 35 percent old growth within 0.5 
mi (0.8 km) of nest sites), and they appear to abandon highly 
fragmented areas over time (areas highly fragmented before the late 
1980s generally did not support marbled murrelets by the early 1990s) 
(Meyer et al. 2002, p. 103).
    Fragmentation of older forests has resulted in increased 
populations of nest predators, and increased visibility and 
vulnerability of flying or nesting adults to potential predators. 
Marbled murrelets are highly vulnerable to nest site predation because 
their survival depends on their ability to remain hidden. Loss of eggs 
and chicks to avian predators has been determined to be the most 
significant cause of nest failure (McShane et al. 2004, p. 2-16). Rates 
of predation on marbled murrelet nests appear to be high, based on 
field observations, compared to most other seabirds and are due most 
often to predators, such as corvids, whose abundance has increased in 
western North America as a result of land use and urbanization (McShane 
et al. 2004, pp. 6-11). Nest predation is associated with forest edges; 
however, the intensity of predation varies with distance to edge, type 
of edge, structure of the adjacent forest, and proximity to human 
activity (Huff et al. 2006, p. 18).
    A large body of research implies that in fragmented landscapes, 
marbled murrelet nesting stands may be more productive if surrounded by 
simple-structured forests, and minimal human recreation and settlement. 
Marbled murrelet productivity is optimal in large, complex-structured 
forests far from human activity due to the reduced levels of predation 
present in such landscapes. Human activities can significantly 
compromise the effectiveness of the forested areas surrounding nests to 
protect the birds and/or eggs from predation (Marzluff et al. 1999, pp. 
3-4; 2000, pp. 1136-1138; Raphael et al. 2002a, p. 221; Marzluff and 
Restani 1999, pp. 7-9, 11; Ripple et al. 2003, p. 80; Huhta et al. 
1998, p. 464; DeSanto and Willson 2001, pp. 145-147).

Maintaining Habitat Distribution

    Maintaining and improving the current distribution of the marbled 
murrelet is important for maintaining genetic heterogeneity, and 
increasing the likelihood of future dispersal as populations recover, 
particularly in areas with low population numbers.
    In the geographic range in the United States where the species is 
listed, five areas exist in the at-sea distribution where marbled 
murrelet densities are low. The first occurs in the southern Straits of 
Georgia near and at the U.S. border. The second low density area occurs 
in southern Puget Sound in Washington. The third low density area 
occurs along the Washington coast beginning at Destruction Island and 
extending south past the Columbia River to Tillamook Head, Oregon. The 
fourth low density area is between Humboldt and San Mateo counties, 
California. The fifth low density area is

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from southern Santa Cruz County through Monterey County (McShane et al. 
2004, pp. 6-19--6-20). These low-density marine areas are likely 
correlated with terrestrial areas that once, but no longer, provided 
forested habitat. Where possible, it is important to protect and grow 
suitable marbled murrelet nesting habitat in these gap areas to reduce 
the impacts associated with fragmentation of the species' range.
    Suitable, unoccupied nesting habitat that is in close proximity to 
currently occupied nesting habitat is more likely to be used by 
dispersing birds. The species' tendency towards nest site fidelity, 
combined with the likelihood that occupation of new nesting habitat is 
more likely in areas already containing marbled murrelets, underscores 
the importance of maintaining a rangewide distribution of both 
currently used nesting sites and unoccupied, but suitable, nesting 
habitat.
    Marbled murrelets can be adversely affected by impacts to their 
nesting habitat, marine foraging habitat, and food supply, as well as 
by direct mortality from human activities such as oil spills and 
gillnet fisheries (refer to the October 1, 1992, final listing rule; 57 
FR 45328).
    We conclude that the maintenance of suitable nesting habitat in 
relatively large, contiguous blocks will be needed to recover the 
marbled murrelet. These blocks of nesting habitat should contain the 
structural features and spatial heterogeneity naturally found at the 
landscape level, the stand level, and the individual tree level in 
Pacific Northwest forest ecosystems in order to maintain species 
distribution and reduce primary threats of predation and fragmentation 
(see Special Management Considerations or Protections section) (Hansen 
and Urban 1992, p. 171-172; Raphael et al. 1995, p. 189; Meyer and 
Miller 2002, p. 763-764; Meyer et al. 2002, p. 95; Miller et al. 2002, 
p. 105-107).

Critical Habitat

    Critical habitat is defined in section 3 of the Act as--(i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in accordance with the Act, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) that may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by a species at the time it is listed, upon 
a determination that such areas are essential for the conservation of 
the species. Conservation, as defined under section 3 of the Act, means 
to use all methods and procedures necessary to bring any endangered 
species 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 destruction or adverse modification of 
critical habitat with regard to actions carried out, funded, or 
authorized by a Federal agency. Section 7 requires consultation on 
Federal actions that are likely to result in the destruction or adverse 
modification of 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 government or public access to private lands. Section 7 is a 
purely protective measure and does not require implementation of 
restoration, recovery, or enhancement measures.
    To be included in a critical habitat designation, the habitat 
within the area occupied by the species must first have features that 
are essential to the conservation of the species. Critical habitat 
designations identify, to the extent known using the best scientific 
data available, habitat areas that provide essential life cycle needs 
of the species (i.e., areas where the primary constituent elements are 
found, as defined at 50 CFR 424.12(b)).
    Habitat occupied at the time of listing may be included in critical 
habitat only if its essential features may require special management 
or protection. We do not include areas where existing management is 
sufficient to conserve the species. As discussed below, such areas may 
also be excluded from critical habitat under section 4(b)(2) of the 
Act. Accordingly, when the best available scientific data do not 
demonstrate that the conservation needs of the species require 
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 which was not 
known to be occupied at the time of listing will likely, but not 
always, be essential to the conservation of the species and, therefore, 
typically included in the critical habitat designation.
    Our Policy on Information Standards Under the Endangered Species 
Act, published in the Federal Register on July 1, 1994 (59 FR 34271), 
and Section 515 of the Treasury and General Government Appropriations 
Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658) and the 
associated Information Quality Guidelines issued by the Service, 
provide criteria, establish procedures, and provide guidance to ensure 
that decisions made by the Service represent the best scientific data 
available. They require Service biologists, to the extent consistent 
with the Act and the best scientific data available, to use primary and 
original sources of information as the basis for recommendations to 
designate critical habitat. When determining which areas to designate 
as critical habitat, a primary source of information is generally the 
listing package for the species. Additional information sources include 
the recovery plan for the species, articles in peer-reviewed journals, 
conservation plans developed by States and counties, scientific status 
surveys and studies, biological assessments, or other unpublished 
materials, and expert opinion or personal knowledge. All information is 
used in accordance with the provisions of Section 515 of the Treasury 
and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658) and the associated Information Quality Guidelines 
issued by the Service.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Habitat is often 
dynamic, and species may move from one area to another over time. 
Furthermore, we recognize that designation of critical habitat may not 
include all of the habitat areas that may eventually be determined to 
be necessary for the recovery of the species. For these reasons, 
critical habitat designations do not signal that habitat outside the 
designation is unimportant or may not be required for recovery.
    Areas that support populations, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions implemented under section 7(a)(1) of the Act and to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available information 
at the time of the action. Federally funded or permitted projects 
affecting listed species outside their designated critical habitat 
areas may still result in jeopardy findings in

[[Page 53843]]

some cases. Similarly, critical habitat designations made on the basis 
of the best available information at the time of designation will not 
control the direction and substance of future recovery plans, habitat 
conservation plans, or other species conservation planning efforts if 
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 the marbled 
murrelet. Such physical and biological features, as stated in 50 CFR 
424.12, include, but are not limited to, the following: (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, rearing of offspring; and (5) Habitats that are protected 
from disturbance or are representative of the historic geographical and 
ecological distributions of a species.
    We reviewed available information that pertains to the habitat 
requirements of the marbled murrelet and evaluated all known occurrence 
locations using data from numerous sources. This proposal was developed 
using various data layers. The data is mapped minimally at 1:100,000 
scale, and more refined in some cases depending on data. Data used in 
mapping varied by State, but generally included: Marbled murrelet 
occurrence information (e.g., terrestrial and marine from State 
agencies); marbled murrelet habitat (e.g., specific paper maps, 
reports, and modeling layers from the Regional Ecosystem Office termed 
Expert Judgment Habitat); Government Ownership (e.g., ownership from 
California Spatial Information Library, Major Public Lands 2003 from 
Washington Department of Natural Resources, refuge boundary, and U.S. 
Forest Service Administrative Boundaries); township, range, and 
section; contours (developed from USGS 30-meter Digital Elevation 
Model); orthophotos (e.g., National Agriculture Imagery Program from 
USDA, USGS Ortho photos, Terraserver); Digital Raster Graphics (USGS); 
and general boundaries (e.g., coastlines, counties, county parcel 
data). Mapping was completed using Universal Transverse Mercator System 
North American Datum 1983--Zone 10.
    We studied peer-reviewed and non-peer-reviewed articles and reports 
for this proposal, which included: The Service's Biological Report 
(Marshall 1988); the final listing rule published in the Federal 
Register on October 1, 1992 (57 FR 45328); the Status and Conservation 
of the Marbled Murrelet in North America (Carter and Morrison 1992); 
the Biology of the Marbled Murrelet: Inland and at Sea (Nelson and 
Sealy 1995); the Marbled Murrelet Recovery Plan (USDI 1997); the 
Ecology and Conservation of the Marbled Murrelet (Ralph et al. 1995a); 
Evaluation Report for the 5-Year Status Review of the Marbled Murrelet 
in Washington, Oregon, and California (McShane et al. 2004); and the 
Northwest Forest Plan--The first 10 years (1994-2003; Huff et al. 
2006).

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas to propose as revised 
critical habitat, we considered physical and biological features (also 
known as the primary constituent elements or PCEs) that are essential 
to the conservation of the species and within areas occupied by the 
species at the time of listing that may require special management 
considerations and protection. These include, but are not limited to 
space for individual and population growth and for normal behavior; 
food, water, air, light, minerals, or other nutritional or 
physiological requirements; cover or shelter; sites for breeding, 
reproduction, and rearing (or development) of offspring; and habitats 
that are protected from disturbance or are representative of the 
historic geographical and ecological distributions of a species.
    The specific PCEs required for the marbled murrelet are derived 
from the biological needs of the species as described in the Background 
section of this proposal. We determined that the physical and 
biological habitat features essential to the conservation of the 
marbled murrelet are associated with the terrestrial environment that 
supports nesting, roosting, and other normal behaviors. Marine areas, 
while important to marble murrelet survival, are not identifiable as 
specific areas essential to conservation of the species. Further, we 
find that the terrestrial features identified as being essential 
require special management considerations and protections.

Primary Constituent Elements for the Marbled Murrelet

    Under our regulations, we are required to identify the known 
physical and biological features essential to the conservation of the 
marbled murrelet. All areas proposed as revised critical habitat for 
marbled murrelet are within the geographic range occupied by the 
species at the time of listing, and contain sufficient PCEs to support 
at least one life history function. As indicated above, we have 
determined that habitat containing features essential to marbled 
murrelet only occurs in the terrestrial environment.
    Based on our current knowledge of the life history, biology, and 
ecology of the species and the requirements of the habitat to sustain 
the essential life history functions of the species, we have determined 
that the PCEs for the marbled murrelet are:
    (1) Forested stands containing large-sized trees, generally more 
than 32 inches (81 centimeters) in diameter with potential nesting 
platforms at sufficient height, generally greater than or equal to 33 
feet (10 meters) in height; and
    (2) The surrounding forested areas within 0.5 mi (0.8 km) of these 
stands with a canopy height of at least one-half the site-potential 
tree height.
    See previous discussion under Ecological Considerations, 
Terrestrial Environment for citations on these factors. These PCEs are 
more detailed than the PCEs established in the May 24, 1996, final 
critical habitat designation for marble murrelet (61 FR 26256). The 
following discussion provides the rationale and latest research on the 
PCEs, including the species' requirements for trees with large limbs, 
canopy cover, and surrounding forest.
    The site-potential tree height is the average maximum height for 
trees given the local growing conditions, and is based on species-
specific site index tables, such as those established by Franklin and 
Dyrness (1973). Canopy cover, which is important for nesting success, 
in the area of most marbled murrelet nests averages 84 percent (Hamer 
and Nelson 1995b, p. 72-79). Canopy cover generally increases with tree 
height, and we include tree height in the PCEs as a surrogate 
measurement for canopy cover.
    Within these forested stands, nest trees provide and support 
suitable nesting habitat for successful reproduction of the marbled 
murrelet. Individual tree attributes that provide these conditions 
include large size (generally more than 32 in (81 cm) diameter at 
breast height), large branches (greater than 4 in (10 cm)) or forked 
branches, deformities (e.g., broken tops), dwarf mistletoe infections, 
witches brooms, or other structures large enough to provide a platform 
for a nesting adult marbled murrelet. Because marbled murrelets do not 
build

[[Page 53844]]

nests, substrate on the tree limb (moss, needles, or duff) provides a 
nest cup and protects the egg from rolling off (Huff et al. 2006, p. 
12). Foliage cover above and around the nest provides protection from 
weather and visually screens the nest from detection by predators (Huff 
et al. 2006, p. 12). The platform needs to be at a sufficient height to 
allow jumpoff departures and stall landings, generally greater than or 
equal to 33 ft (10 m) in height (McShane et al. 2004, pp. 4-50 through 
4-58; Huff et al. 2006, p. 13).
    Marbled murrelets in southern Oregon and northern California were 
found to be most abundant in unfragmented old-growth forests located in 
a matrix of second-growth forest (Meyer et al. 2002, p. 95). Marbled 
murrelets in western Oregon nested in older-aged forests surrounded by 
younger forest; older forests surrounded by clearcuts were generally 
not used (Ripple et al. 2003, p. 84-87). In California, marbled 
murrelets have also been found in very small residual stands, and 
younger stands with residual trees (Hunter and Bond 2001, p. 996; Baker 
et al. in press, p. 3). The younger forests adjacent to older-aged 
forests may reduce the differences in microclimates associated with 
forested and unforested areas (Chen et al. 1992, pp. 391-392; Chen et 
al. 1993, p. 219; Chen et al. 1995, p. 84), reduce potential for 
windthrow during storms by buffering effects of wind on older forests 
(Chen et al. 1992, p. 394), and provide a landscape that has a higher 
probability of occupancy by marbled murrelets (Raphael et al. 1995, pp. 
188-189).
    The most important factors in the risk of predation on marbled 
murrelet nests appear to be the landscape context or composition and 
its effect on the type and abundance of predators (McShane et al. 2004, 
p. 4-96). While the relationship between forest fragmentation, edge 
effects, and marbled murrelet nest success is not completely clear, it 
is apparent that the abundance of some predators is affected by human-
caused factors (McShane et al 2004, p. 6-11; U.S. Fish and Wildlife 
Service 2004, p. 10-11), and the risk of predation, particularly by 
corvids, may be higher in proximity to human activities (Raphael et al. 
2002a, p. 221). Lowering the risk of predation requires maintaining 
complex-structured forest in areas that are isolated from human 
development (McShane et al. 2004, p. 4-96). Simple-structured stands 
adjacent to nesting areas may provide some ability to decrease 
predation at marbled murrelet nests by helping to maintain interior 
conditions and reduce edge effects (Raphael et al. 2002a, pp. 231-232; 
Ripple et al. 2003, p. 80).
    Therefore, on a landscape basis, forests with a canopy height of at 
least one-half the site-potential tree height around potential nest 
trees are essential to the conservation of the marbled murrelet because 
they reduce the effects of microclimate, windthrow, and predation. Nest 
trees may be scattered or clumped throughout the area. Potential 
nesting areas may contain less than one suitable nesting tree per acre 
(0.5 hectare).

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(1)(A) of the Act, we used the best 
scientific data available to determine whether areas contain the 
features that are essential to the conservation of the marbled 
murrelet.
    Several qualitative criteria were considered in the selection of 
specific areas for inclusion in revised critical habitat. These 
criteria are similar to criteria used in the development of Federal 
management proposals, such as the Scientific Panel information 
originally used in development of the Northwest Forest Plan (USDA and 
USDI 1994b) and the Recovery Plan for the Marbled Murrelet (USDI 1997). 
The following is a description of the five criteria considered.
    (1) The presence of primary constituent elements (PCEs).
    As listed above, we determined that the PCEs for marbled murrelet 
are:
    Forested stands containing large-sized trees, generally more than 
32 inches (81 centimeters) in diameter with potential nesting platforms 
at sufficient height, generally greater than or equal to 33 feet (10 
meters) in height. Research has shown that the most important component 
of marbled murrelet nesting habitat is the presence of appropriate 
platforms (Huff et al. 2006, p. 12). The abundance of nest substrate 
(e.g., moss, detritus, etc.), foliage cover above and around the nest, 
tree size, limb height, and location of the nest tree with respect to 
gaps within a stand of trees also are factors in determining the 
suitability of nesting habitat (Huff et al. 2006, p. 12). All but the 
last of these are characteristics of individual nest trees. Tree 
diameter and height have been directly correlated with platform size 
and the abundance of platforms (bigger trees provide more and larger 
platforms), but the relationship is not exact given the variety of tree 
species and forest types marbled murrelets use for nesting (Huff et al. 
2006, p. 12).
    Forested areas within 0.5 mi (0.8 km) of forested stands containing 
trees with potential nesting platforms. In addition to the presence of 
nest platforms, the condition of the surrounding forest plays an 
important role in suitable habitat and successful nesting (Huff et al. 
2006, p. 15). Suitable habitat includes forest structure of sufficient 
height and depth to provide vertical and horizontal cover to the nest 
and nest tree. These forests contribute to nesting success by 
protecting the nest from weather, supporting adequate microclimate 
conditions, and minimizing predation (Luginbuhl et al. 2001, p. 570; 
Marzluff et al. 2000, p. 1137; Raphael et al. 2002b, p. 339; Meyer et 
al. 2004, p. 207; Huff et al. 2006, p. 14).
    Individual tree characteristics cannot be mapped through general 
stand data or remote sensing, and require on-the-ground examination of 
individual trees. In some cases, the average tree diameter in a stand 
can be used as a surrogate measure, but this measure alone will not 
enable identification of each tree capable of supporting nesting. Even 
individual low-elevation aerial photos may not allow identification of 
scattered nest trees containing potential nest structure, such as 
mistletoe infection or the presence of moss and detritus. Because 
marbled murrelets can make use of individual trees, available maps 
often miss this type of suitable nesting habitat, even when a mapped 
surrogate such as tree diameter is used. Suitable habitat maps 
generally do not include the intermediate age forests (surrounding 
forest PCE) that provide cover for residual nest trees. Existing 
mapping and remote sensing may include information on the size of major 
stand components. Areas mapped or identified in databases as containing 
large trees generally provide suitable nesting habitat. However, areas 
missing these mapped components may also provide habitat where residual 
nest trees remain.
    We used all available information to map areas that were likely to 
contain the primary constituent elements. These included site-specific 
knowledge, GIS data, remote sensing data, habitat maps from many 
sources (e.g., suitable habitat data layers generated by the Northwest 
Forest Plan (NWFP) Effectiveness Monitoring team, site specific data 
from land managers and landowners), aerial photos, the current marbled 
murrelet critical habitat designation based on forest stand maps, and 
history leading to specific stand conditions.
    (2) Within the inland range of the marbled murrelet.
    Marbled murrelet nesting habitat is defined by forest stands that 
are within the distance marbled murrelets are

[[Page 53845]]

known to travel inland from marine foraging areas and contain the 
appropriate forest structure to produce and buffer potential nest 
trees. Birds must make this flight at least once a day during the 
nesting period. Inland distances traveled during the breeding season 
differ with habitat availability, energetics, predation pressure, and a 
variety of other factors (McShane et al. 2004, p. 2-5; Huff et al. 
2006, p. 10). While some birds have been detected up to 70 mi (112 km) 
inland, most birds nest within 55 mi (88 km) of marine habitat in 
Washington, within 35 mi (56 km) in Oregon and northern California, and 
within 10 to 15 mi (16 to 24 km) in central California. To address this 
range of use, we propose to revise designated critical habitat to 
within 55 mi (88 km) of the marine environment in Washington, within 35 
mi (56 km) in northern and central Oregon (consistent with Forest 
Ecosystem Management Assessment Team Zone 1 within the NWFP), within 
the modified survey zone in southern Oregon and northern California, 
and within the inland extent of redwood forests in the remainder of the 
range in California.
    (3) Large, contiguous blocks of nesting habitat.
    The maintenance and development of large blocks of nesting habitat 
and contiguous forest cover is important to the stability and long-term 
recovery of marbled murrelets (USDI 1997, pp. 139-140). Several studies 
and reviews have emphasized the positive association of marbled 
murrelets with large core areas of late-seral forest, low amount of 
edge, and lower fragmentation levels (McShane et al. 2005, pp. 4-39, 4-
42-43). Detections of marbled murrelets at inland sites and densities 
offshore were found to be higher in or adjacent to areas with large 
patches of significant old-growth, and in areas of low fragmentation 
and isolation of old-growth patches (all citations from McShane et al. 
2004, pp. 6-11).
    Large blocks of forest help maintain interior conditions that may 
support moss or other nest substrate development and reduce the 
potential for predation. Fragmentation of the remaining older forests 
has resulted in increased populations of nest predators, and increased 
visibility and vulnerability of flying or nesting adults to potential 
predators. Increased predator populations, in turn, may lead to 
increased rates of predation on young in nests and possibly on adults. 
Rates of predation on marbled murrelet nests appear to be high, based 
on field observations, compared to most other seabirds and are due most 
often to predators, such as corvids, whose abundance has increased in 
western North America as a result of forest fragmentation, increased 
agriculture, and urbanization (McShane et al. 2004, p. 6-11).
    There is no established minimum or optimal size defining large 
blocks for marbled murrelet nesting habitat. Based on the 0.5 mi (0.80 
km) data from Raphael et al. 1995 (see Ecological Considerations) in 
areas where the suitable habitat remains in larger blocks, we generally 
sought areas of at least 500 ac (200 ha) where possible. In areas where 
habitat is already limited and fragmented to the point where 500 ac 
(200 ha) blocks are not available, we selected smaller, more isolated 
patches of habitat to maintain the distribution of the species. Under 
these circumstances, small habitat patches are extremely important for 
the conservation of the species because they represent the only option 
for maintaining the nest trees and forest buffers that are essential in 
supporting existing marbled murrelet populations and slowing population 
declines in these areas. Given the extended time required to develop 
habitat (decades to centuries depending on the starting condition and 
tree species involved), maintaining current populations is an important 
element in the recovery of marbled murrelets (USDI 1997, pp. 138-140). 
Marzluff and Restani (1999, pp. 8-9, 11-13) and Raphael et al. (2002b, 
pp. 337-339) suggested that a reduced amount of nesting habitat and 
increased isolation of nesting habitat would have long-term impacts on 
the number of nests and short-term impacts on nest success, both of 
which affect population size. In these situations, we are proposing to 
designate small areas of critical habitat to maintain the distribution 
of current populations and PCEs.
    (4) Sites occupied by marbled murrelets.
    For the purposes of this revised designation, occupied sites are 
defined as locations where marbled murrelet presence has been 
documented via a variety of survey techniques or processes. Suitable 
marbled murrelet habitat, in Late-Successional Reserves (LSRs) in 
National Forests in Oregon and Washington and in areas covered by 
Bureau of Land Management (BLM) Western Oregon Land Use Plans, is 
managed by the Forest Service and the BLM as occupied and therefore we 
have included the LSRs as occupied habitat.
    Surveys not conducted in adherence to the strict protocol may miss 
occupied sites due to the cryptic nature of marbled murrelets and their 
nests. For example, a single visit to a location where marbled 
murrelets are present has only a 55 percent chance of detecting marbled 
murrelets (Evans Mack et al. 2003, p. 39). Surveys prior to the listing 
of the marbled murrelet were few and not conducted to a standardized 
survey protocol. Marbled murrelet nesting habitat is generally in 
older, more complex stands including older trees for nesting platforms, 
and this habitat is slow to recover or to develop. It is highly 
unlikely that any new significant marbled murrelet nesting habitat has 
developed since this seabird was listed in 1992. In addition, based on 
the site tenacity of marbled murrelets (see Ecological Considerations), 
sites that have been found to be occupied since listing are considered 
likely to have been occupied at the time of listing.
    Marbled murrelets tend to use large watercourses to access inland 
habitat (Nelson 1997, p. 11; Manley 1999, p. 54; Burger 2002b, p. 27). 
They cross ridges to enter neighboring watersheds. The likelihood of 
use would apply to the entire watershed in which marbled murrelets are 
known to occur, and probably to neighboring watersheds as well.
    (5) Maintenance of rangewide distribution.
    The current distribution of the species is important for 
maintaining genetic heterogeneity. Increasing the likelihood of future 
colonization is equally important as populations recover, particularly 
in areas with low population numbers. Appropriately distributed nesting 
habitat reduces the probability that a natural or human-caused 
catastrophe would threaten the survival or recovery of the species in 
the three States. Catastrophes that could significantly impact a large 
portion of the nesting population include wildfires and windstorms. Oil 
spills could have a significant impact on marbled murrelet foraging. 
Accordingly, essential habitat was identified throughout the range of 
the species in Washington, Oregon, and California.

Special Management Considerations or Protections

    When designating critical habitat, we assess whether areas that 
contain the primary constituent elements may require special management 
considerations or protections.
    Marbled murrelets can be adversely affected by impacts to their 
nesting habitat, marine foraging habitat, and food supply, as well as 
by direct mortality from human activities such as oil spills and 
gillnet fisheries. These impacts, and the resulting decline from 
historic population levels, formed the

[[Page 53846]]

basis for the listing of the species as threatened in 1992 (57 FR 
45328).
    In evaluating marine areas for potential critical habitat 
designation, we reviewed whether these areas important to the 
conservation of marbled murrelets require special management 
consideration or protection at this time beyond that provided by the 
existing Federal laws and regulations. While the marine habitat is 
important to the survival of marbled murrelets, the primary concern 
with respect to marbled murrelet populations is loss of nesting 
habitat.
    In 1996, when we designated critical habitat (61 FR 26256), we 
concluded that activities or events that adversely affect marbled 
murrelets in the marine environment seem to be more associated with the 
mortality of individual birds than the long-term destruction or adverse 
modification of habitat. We concluded that gillnet fisheries, for 
example, result in incidental capture of marbled murrelets, but do not 
significantly adversely affect the prey base. Marbled murrelets appear 
to forage opportunistically on available fish, and are likely able to 
respond to minor changes in fish abundance and location.
    We also concluded that the principal adverse impacts of oil and 
other pollutant spills are to individual birds, not their prey base. 
Our assessment of these events typically relies on bird mortality 
rather than habitat issues that include prey availability. We indicated 
we would continue to monitor marine threats and may propose marine 
critical habitat in the future if warranted.
    In this critical habitat revision, we reassessed the importance of 
marine habitats to marbled murrelets and reaffirm their importance to 
marbled murrelet conservation. Our consultation experience since 1996 
reinforces our previous finding that existing Federal laws and 
regulations adequately protect marine habitats. For example, section 7 
consultations over the last several years on projects authorized, 
funded, or carried out by Federal agencies in Puget Sound most often 
conclude as informal consultations because elements of the marine 
habitat that are important to marbled murrelet prey species production, 
such as eelgrass beds and forage fish spawning beaches, are adequately 
protected by the Clean Water Act section 404 permit requirements or 
State of Washington Hydraulic Permit Application requirements and 
restrictions. Our Marbled Murrelet 5-Year Review (U.S. Fish and 
Wildlife Service 2004, p. 11) documented that gill-netting regulations 
have reduced this threat to marbled murrelets in the marine environment 
in northern California and Washington.
    Current and historic loss of marbled murrelet nesting habitat is 
generally attributed to timber harvest and land conversion practices, 
although, in some areas, catastrophic disturbances such as forest fires 
have caused losses (Ripple 1994, p. 45). Reduction of the remaining 
older forest has not been evenly distributed in western Washington, 
Oregon, and California. Timber harvest has been concentrated at lower 
elevations and in the Coast Ranges (Thomas et al. 1990, p. 13), 
generally overlapping the range of the marbled murrelet.
    Some of the forests that were affected by past natural 
disturbances, such as forest fires and windthrow, currently provide 
suitable nesting habitat for marbled murrelets because they retain 
scattered individual or clumps of large trees that provide structure 
for nesting. This is particularly true in coastal Oregon where 
extensive fires occurred historically. Marbled murrelet nests have been 
found in remnant old-growth trees in mature forests in Oregon. Forests 
providing suitable nesting habitat and nest trees generally require 200 
to 250 years to develop characteristics that supply adequate nest 
platforms for marbled murrelets.
    In the marbled murrelet 5-year r