FOR PUBLICATION
UNITED STATES COURT OF APPEALS
FOR THE NINTH CIRCUIT
HUMANE SOCIETY OF THE UNITED
STATES; WILD FISH CONSERVANCY;
BETHANIE O’DRISCOLL; ANDREA
KOZIL,
Plaintiffs-Appellants,
v. No. 08-36038
GARY LOCKE, Secretary of
Commerce; JAMES W BALSIGER;
D.C. No.
3:08-cv-00357-MO
JAMES LECKY, OPINION
Defendants-Appellees,
WASHINGTON STATE DEPARTMENT OF
FISH AND WILDLIFE; STATE OF OREGON
DEPARTMENT OF FISH AND WILDLIFE,
Defendant-intervenors-Appellees.
Appeal from the United States District Court
for the District of Oregon
Michael W. Mosman, District Judge, Presiding
Argued and Submitted
November 6, 2009—Portland, Oregon
Filed November 23, 2010
Before: Raymond C. Fisher and Richard A. Paez,
Circuit Judges, and Jeremy D. Fogel, District Judge.*
Opinion by Judge Fisher
*The Honorable Jeremy D. Fogel, United States District Judge for the
Northern District of California, sitting by designation.
18675
HUMANE SOCIETY v. LOCKE 18679
COUNSEL
Rebecca G. Judd, Sarah Uhlemann (argued) and Jonathan R.
Lovvorn, The Humane Society of the United States, Washing-
ton, D.C.; Gary K. Kahn and Peggy Hennessy, Reeves, Kahn
& Hennessy, Portland, Oregon, for the plaintiffs-appellants.
John C. Cruden, James A. Maysonett and Mark R. Haag
(argued), United States Department of Justice, Washington,
D.C.; Mark A. Hodor, National Oceanic & Atmospheric
Administration, Silver Spring, Maryland; Lori L. Caramanian,
United States Department of Justice, Denver, Colorado; Coby
Howell, Office of the U.S. Attorney, Portland, Oregon, for
appellees Gary Locke, James W Balsiger and James Lecky.
Robert M. McKenna, Attorney General, Neil L. Wise, Assis-
tant Attorney General, and Michael B. Ferguson, Assistant
Attorney General, Olympia, Washington, for defendant-
intervenor-appellee Washington State Department of Fish and
Wildlife.
18680 HUMANE SOCIETY v. LOCKE
John R. Kroger, Attorney General, Jerome Lidz, Solicitor
General, and Cecil A. Reniche-Smith (argued), Assistant
Attorney General, Salem, Oregon, for defendant-intervenor-
appellee State of Oregon Department of Fish and Wildlife.
OPINION
FISHER, Circuit Judge:
In March 2008, the National Marine Fisheries Service
(NMFS) authorized the states of Oregon, Washington and
Idaho to kill up to 85 California sea lions annually at Bonne-
ville Dam. NMFS made the decision under section 120 of the
Marine Mammal Protection Act (MMPA), which allows “the
intentional lethal taking of individually identifiable pinnipeds
which are having a significant negative impact on the decline
or recovery of salmonid fishery stocks” that have been listed
as threatened or endangered under the Endangered Species
Act (ESA). 16 U.S.C. § 1389(b)(1). We must decide whether
the agency’s action was “arbitrary” or “capricious” within the
meaning of the Administrative Procedure Act (APA), as well
as whether the agency violated the National Environmental
Policy Act (NEPA) by failing to prepare an environmental
impact statement.
BACKGROUND
I. Factual Background
Like seals and walruses, California sea lions are pinnipeds
— marine mammals having fin-like flippers for locomotion.
The Bonneville Dam is on the Columbia River, which serves
as a migration path for a number of ESA-listed salmonid pop-
ulations, including five salmon and steelhead populations at
issue here: the Upper Columbia River Spring run of Chinook
salmon, the Snake River Spring/Summer run of Chinook
salmon, the Snake River Basin population group of steelhead,
the Middle Columbia River population group of steelhead and
HUMANE SOCIETY v. LOCKE 18681
the Lower Columbia River population group of steelhead.
Each of these populations is listed as threatened or endan-
gered under the ESA. See Final Listing Determinations for 10
Distinct Population Segments of West Coast Steelhead, 71
Fed. Reg. 834, 859-60 (Jan. 5, 2006); Final Listing Determi-
nations for 16 ESUs of West Coast Salmon, and Final 4(d)
Protective Regulations for Threatened Salmonid ESUs, 70
Fed. Reg. 37,160, 37,193 (June 28, 2005).
Before 2001, few California sea lions were observed feed-
ing in the area of the dam. In recent years, however, sea lion
predation has become more prevalent. Since 2002, the U.S.
Army Corps of Engineers has observed sea lion predation of
salmonids in the area below the dam each year from January
to May, when sea lions are present. The Corps has observed,
among other things, the number of pinnipeds present, the
number of salmonids consumed and the proportion of all sal-
monids passing the dam that are taken by pinnipeds foraging
in the area:
U.S. Dep’t of Commerce, Nat’l Oceanic & Atmospheric
Admin., Nat’l Marine Fisheries Serv., Decision Memorandum
1
The last two rows in the table report data for all pinnipeds, not just Cal-
ifornia sea lions. As a practical matter, however, the numbers approximate
predation by California sea lions because they are responsible for 99 per-
cent of salmonid mortality caused by all pinnipeds collectively.
18682 HUMANE SOCIETY v. LOCKE
Authorizing the States of Oregon, Washington and Idaho to
Lethally Remove California Sea Lions at Bonneville Dam
under Section 120 of the Marine Mammal Protection Act
(Mar. 12, 2008). Under the Corps’ estimates, California sea
lions kill between 0.4 and 4.2 percent of migrating salmonid
each year, although the Corps considers these to be minimum
estimates because not all predation events are observed.2
NMFS has concluded that the actual number of salmonids
consumed by California sea lions “is certainly larger than the
numbers actually observed, since not all sea lions are
observed nor are all predation events.” Pinniped Removal
Authority, 73 Fed Reg. 15,483, 15,485 (Mar. 24, 2008).
Accordingly, NMFS calculated the potential consumption of
salmonids based on the average number of California sea
lions actually observed (86) and their bioenergetic needs. See
id. Applying this formula, NMFS estimated that 86 California
sea lions at the dam can consume up to 17,458 salmonids
annually, of which up to 6,003 salmonids would be listed
spring Chinook and up to 611 would be listed steelhead. See
id. “Using the observed minimum rate of predation averaged
over 2005-2007, and the estimated maximum potential preda-
tion rate, yields predation rates ranging from 3.6 percent to
12.6 percent for listed spring Chinook and 3.6 percent to 22.1
percent for listed steelhead.” Id.
Sea lions are only one source of salmonid mortality on the
Columbia River. Fisheries and federal power system dams are
also major contributors to mortality among listed salmonids.
Consistent with the ESA, NMFS manages these other sources
of mortality through a variety of recovery plans. Under these
plans, commercial, recreational and tribal fisheries are autho-
2
Although the total number of individual California sea lions observed
during the year declined after 2004, the overall level of predation has
increased because sea lions are staying at the dam for longer periods of
time. The average number of days individual sea lions were present
increased from 7.6 days in 2004 to 20.3 days in 2007.
HUMANE SOCIETY v. LOCKE 18683
rized to take between 5.5 and 17 percent of listed salmonids,
depending on the size of the run in any particular year. The
dam system takes a comparable number of salmonids. Over
the past several years, NMFS, the Corps and other federal
agencies have issued a series of environmental and biological
assessments concluding that those fishery- and dam-related
takes have minimal adverse impacts on the viability of listed
salmonid populations in the Columbia River. Plaintiffs con-
tend that those assessments are incompatible with NMFS’s
conclusion here, that California sea lion predation causing
lesser mortality among the listed salmonid populations is hav-
ing a significant negative impact on the populations’ decline
or recovery.
In November 2006, the states of Washington, Oregon and
Idaho applied to NMFS for authorization to lethally remove
California sea lions from the Bonneville Dam area under sec-
tion 120 of the MMPA, which “authorize[s] the intentional
lethal taking of individually identifiable pinnipeds which are
having a significant negative impact on the decline or recov-
ery of salmonid fishery stocks which . . . have been listed as
threatened . . . or endangered species under the [ESA].” 16
U.S.C. § 1389(b)(1). In accordance with the MMPA, NMFS
appointed an 18-member task force to evaluate the applica-
tion. See id. § 1389(c)(1). In November 2007, the task force
delivered its formal recommendations to NMFS. Seventeen
members concluded that California sea lions at Bonneville
Dam were having a “significant negative impact on the
decline or recovery of salmonid fishery stocks” within the
meaning of the MMPA and recommended approving the
states’ application. The Humane Society, a plaintiff in this
action, was the sole member of the task force to dissent from
that recommendation.
Once the task force completed its work, NMFS addressed
the merits of the application. First, to comply with NEPA,
NMFS prepared an environmental assessment. See Nat’l
Marine Fisheries Serv., Nw. Region, Final Environmental
18684 HUMANE SOCIETY v. LOCKE
Assessment (Mar. 12, 2008). The final environmental assess-
ment resulted in a finding of no significant impact under
NEPA, concluding that approval of the states’ application
would not significantly affect the quality of the human envi-
ronment. See 42 U.S.C. § 4332(2)(C). Accordingly, the
agency determined that preparation of an environmental
impact statement was not required.
Second, NMFS issued a decision partially approving the
states’ MMPA application. See Pinniped Removal Authority,
73 Fed. Reg. 15,483. NMFS adopted a two-part test for deter-
mining whether “individually identifiable pinnipeds” were
having a “significant negative impact on the decline or recov-
ery” of at-risk salmonids. Id. at 15,484. NMFS would first
determine “whether pinnipeds collectively are having a signif-
icant negative impact on listed salmonids” and then determine
“which pinnipeds are significant contributors to that impact
and therefore may be authorized for removal.” Id.
NMFS found that both parts of the test were satisfied. First,
NMFS found that California sea lions collectively were hav-
ing a significant negative impact on the decline or recovery of
the listed salmonid populations, based on three factors: (1)
“[t]he predation is measurable, growing, and could continue
to increase if not addressed”; (2) “[t]he level of adult sal-
monid mortality is sufficiently large to have a measurable
effect on the numbers of listed adult salmonids contributing
to the productivity of the affected [populations]”; and (3)
“[t]he mortality rate for listed salmonids is comparable to
mortality rates from other sources that have led to corrective
action under the ESA.” Id. at 15,485.
Second, NMFS identified the individual sea lions that were
significant contributors to the impact — the animals that
could be lethally removed. The significant contributors were
those California sea lions that both have identifiable physical
characteristics, such as natural features or brands, and can be
classified as predatory. See id. at 15,486. To be deemed pred-
HUMANE SOCIETY v. LOCKE 18685
atory, sea lions must meet three criteria: (1) they have been
observed eating salmonids in the observation area below Bon-
neville Dam between January 1 and May 31 of any year, (2)
they have been observed in the observation area on a total of
any five days between January 1 and May 31 of any year and
(3) they have been sighted in the observation area after having
been subjected to active nonlethal deterrence. See id.
NMFS authorized the states to kill California sea lions
meeting these criteria for an initial period of five years, with
the possibility of a renewal for an additional five years. See
id. at 15,487-88. NMFS limited the number of sea lions that
could be killed, however, to the lesser of either 85 sea lions
per year or, and particularly relevant to our analysis, “the
number required to reduce the observed predation rate to 1
percent of the salmonid run at Bonneville Dam.” Id. at
15,486. The 1 percent predation target, the agency said, “is
not equivalent to a finding that a one percent predation rate
represents a quantitative level of salmonid predation that is
‘significant’ under section 120, and that less than one percent
would no longer be significant.” Id. “Rather, it is an indepen-
dent limit on the numbers of sea lions that can be lethally
removed to address the predation problem and is intended to
balance the policy value of protecting all pinnipeds, as
expressed in the MMPA, against the policy value of recover-
ing threatened and endangered species, as expressed in the
ESA.” Id.
II. Procedural Background
On March 24, 2008, the same day NMFS published notice
of its action in the Federal Register, Humane Society of the
United States, Wild Fish Conservancy and two individuals
(collectively, “plaintiffs”) filed this action for declaratory and
injunctive relief against the Secretary of Commerce and two
NMFS officials (collectively, “defendants”), alleging that
NMFS’s decision violates section 120 of the MMPA, as well
as NEPA. The Washington State Department of Fish and
18686 HUMANE SOCIETY v. LOCKE
Wildlife and the State of Oregon Department of Fish and
Wildlife intervened as defendants.
Plaintiffs in due course filed a motion for summary judg-
ment. Defendants filed cross-motions for summary judgment,
as well as a motion to strike the environmental assessments
and biological assessment relating to the fisheries and dams
to the extent they were not already part of the administrative
record. The district court denied plaintiffs’ motion for sum-
mary judgment, granted defendants’ cross-motions for sum-
mary judgment and granted in part defendants’ motion to
strike. The court entered judgment, and plaintiffs timely
appealed. In February 2009, a motions panel of this court
denied plaintiffs’ motion for a stay of NMFS’s decision pend-
ing appeal. See Humane Soc’y v. Gutierrez, 558 F.3d 896 (9th
Cir. 2009) (order). We now proceed to the merits of plaintiffs’
claims.
STANDARDS OF REVIEW
We review de novo a district court’s grant or denial of sum-
mary judgment. LaVine v. Blaine Sch. Dist., 257 F.3d 981,
987 (9th Cir. 2001). Section 120 of the MMPA does not con-
tain a separate provision for judicial review. Accordingly, our
review of NMFS’s actions under the MMPA is governed by
the judicial review provisions of the APA, 5 U.S.C. §§ 701-
06. See City of Sausalito v. O’Neill, 386 F.3d 1186, 1205 (9th
Cir. 2004); see also Ctr. for Biological Diversity v. Kemp-
thorne, 588 F.3d 701, 707 (9th Cir. 2009). The APA also gov-
erns our review of an agency’s compliance with NEPA, see
Ocean Advocates v. U.S. Army Corps of Eng’rs, 402 F.3d
846, 858 (9th Cir. 2005), including an agency’s decision,
based on an environmental assessment, not to prepare an envi-
ronmental impact statement, High Sierra Hikers Ass’n v.
Blackwell, 390 F.3d 630, 640 (9th Cir. 2004). Under the APA,
agency decisions may be set aside if “arbitrary, capricious, an
abuse of discretion, or otherwise not in accordance with law.”
5 U.S.C. § 706(2)(A). We discuss the APA standard in greater
HUMANE SOCIETY v. LOCKE 18687
detail below. A district court’s decision to exclude extra-
record evidence when reviewing an agency’s decision is
reviewed for an abuse of discretion. See Partridge v. Reich,
141 F.3d 920, 923 (9th Cir. 1998); Great Basin Mine Watch
v. Hankins, 456 F.3d 955, 975 (9th Cir. 2006) (NEPA).
DISCUSSION
I. Marine Mammal Protection Act Claim
A. Administrative Procedure Act
Plaintiffs contend that NMFS’s application of the MMPA
is “arbitrary, capricious, an abuse of discretion, or otherwise
not in accordance with law.” 5 U.S.C. § 706(2)(A). We agree
with their contention, at least to the extent that we conclude
that NMFS has not satisfactorily explained the basis of its
decision.
[1] Under the APA, “the agency must examine the relevant
data and articulate a satisfactory explanation for its action
including a ‘rational connection between the facts found and
the choice made.’ ” Motor Vehicle Mfrs. Ass’n of U.S., Inc. v.
State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983) (quot-
ing Burlington Truck Lines v. United States, 371 U.S. 156,
168 (1962)). “The reviewing court should not attempt itself to
make up for [an agency’s] deficiencies: ‘We may not supply
a reasoned basis for the agency’s action that the agency itself
has not given.’ ” Id. (quoting SEC v. Chenery Corp., 332 U.S.
194, 196 (1947)).
Here, we hold that NMFS has not offered a satisfactory
explanation for its action. First, the agency has not adequately
explained its finding that sea lions are having a “significant
negative impact” on the decline or recovery of listed salmonid
populations given earlier factual findings by NMFS that fish-
eries that cause similar or greater mortality among these pop-
ulations are not having significant negative impacts. Second,
18688 HUMANE SOCIETY v. LOCKE
the agency has not adequately explained why a California sea
lion predation rate of 1 percent would have a significant nega-
tive impact on the decline or recovery of these salmonid pop-
ulations. These procedural errors require us to direct the
district court to vacate NMFS’s decision and remand to the
agency to reconsider the action or provide a fuller explana-
tion.
1.
In four environmental assessments prepared between 2003
and 2007, NMFS concluded that fishery takes comparable to
(or greater than) takes by California sea lions would not have
a significant adverse effect on the survival or recovery of
many of the same listed salmonid populations involved here.
In 2003, NMFS prepared, under NEPA, an environmental
assessment of a fisheries plan submitted by Oregon and
Washington for the Lower Columbia River and concluded
that the plan, which would result in the taking of up to 4 per-
cent of steelhead in one area, would “adversely affect[ ]”
ESA-listed salmon and steelhead in the Lower Columbia pop-
ulations but “will not appreciably reduce the likelihood of
survival and recovery of Lower Columbia River steelhead,
chinook salmon, and chum salmon in the wild” (emphasis
added). In April 2005, NMFS prepared a NEPA environmen-
tal assessment with respect to a comprehensive plan for the
management of fisheries in the Columbia River. The plan,
based on an agreement between NMFS, the states of Oregon
and Washington and several Indian tribes, allows fisheries to
take between 5.5 and 17 percent of listed Columbia River sal-
monids annually, depending on the size of the run. NMFS
found that implementation of the decision would be expected
to result in “minimal adverse effects on Listed Salmonid [pop-
ulations] in the Columbia River Basin,” and that
“[c]umulative impacts from NMFS’s Proposed Action would
be minor if at all measurable” (emphasis added). In January
2007, NMFS conducted a NEPA environmental assessment
addressing a fisheries plan submitted by Oregon and Wash-
HUMANE SOCIETY v. LOCKE 18689
ington for the Middle Columbia River. The agency found that
the plan, which would result in the taking of up to “10 percent
of the annual abundance of natural-origin adult and juvenile
steelhead” (emphasis added), would not appreciably reduce
the likelihood of survival and recovery of salmon and steel-
head listed under the ESA. Finally, in March 2007, NMFS
conducted a NEPA environmental assessment of a plan to
provide limited ocean fishing of Klamath River fall Chinook
salmon. NMFS found that the plan, which permitted fishing
of 10 percent of Klamath River fall Chinook salmon, would
not “jeopardize the long-term productivity” of the Klamath
River fall Chinook population and would result in “no signifi-
cant adverse effects to the environment.”
[2] NMFS has not adequately explained its finding that sea
lion predation is having a significant negative impact on sal-
monid decline or recovery in light of its positive environmen-
tal assessments of harvest plans having greater mortality
impacts. The absence of an explanation is particularly con-
cerning with respect to the 2005 fishery environmental assess-
ment. In that assessment, NMFS found that a plan providing
for fisheries to take between 5.5 and 17 percent of listed sal-
monids annually, depending on run size, would be expected
to result in “minimal adverse effects on Listed Salmonid
[populations] in the Columbia River Basin,” and that the
“[c]umulative impacts from NMFS’s Proposed Action would
be minor if at all measurable.” Those findings are in apparent
conflict with NMFS’s finding in this case that sea lions
responsible for less or comparable salmonid mortality have a
“significant negative impact” on the decline or recovery of
these same populations, yet the agency has not offered a ratio-
nale to explain the disparate findings. Cf. FCC v. Fox Televi-
sion Stations, Inc., 129 S. Ct. 1800, 1811 (2009) (explaining
that an agency must offer “a reasoned explanation” when its
current course “rests upon factual findings that contradict
those which underlay” a previous course). Without an ade-
quate explanation, we are precluded from undertaking mean-
ingful judicial review. Divergent factual findings with respect
18690 HUMANE SOCIETY v. LOCKE
to seemingly comparable causes of salmonid mortality raise
questions as to whether the agency is fulfilling its statutory
mandates impartially and competently. A satisfactory expla-
nation is therefore required.
We cannot gloss over the absence of a cogent explanation
by the agency by relying on the post hoc rationalizations
offered by defendants in their appellate briefs. Defendants’
briefs offer several explanations designed to reconcile
NMFS’s findings: that “[t]he facile percentage-based compar-
isons that [plaintiffs’ brief] offers oversimplify and, in several
instances, mischaracterize the complex facts addressed in
those [earlier] analyses”; that the 2005 fishery take environ-
mental assessment is not comparable to the MMPA determi-
nation here because the former “cover[s] all fishing on over
280 miles of the Columbia River, Snake, and Clearwater riv-
ers” whereas “the decision at issue here involves mortality
from a single source at a single location”; that the fishery
plans reviewed under the 2003 Lower Columbia River envi-
ronmental assessment “completely prohibited the retention of
any unmarked wild steelhead,” limiting mortality to “inciden-
tal injuries associated with catch and release of listed steel-
head”; that the fishery plans under review in the 2007 Middle
Columbia River fishery environmental assessment “com-
pletely prohibit[ed] the retention of wild listed salmonids”;
and that, “unlike fishing, NMFS lacks the ability to regulate
sea lion predation from year to year so as to reduce the effects
in years when salmon and steelhead runs are low.” These dis-
tinctions might be valid, but with one exception they are
raised for the first time in defendants’ briefs and were not
mentioned by NMFS in the decision under review.3 They are
3
The only one of these rationales mentioned in NMFS’s decision is that
fishery takes can be reduced to adjust for a smaller run size, whereas sea
lion predation cannot be. See Pinniped Removal Authority, 73 Fed. Reg.
at 15,485 (“In contrast to a managed harvest regime, which can reduce
mortality in response to decreased run sizes, pinniped predation has the
potential to increase even when run sizes are depressed, magnifying the
HUMANE SOCIETY v. LOCKE 18691
therefore not part of our review. See Nw. Envtl. Def. Ctr. v.
Bonneville Power Admin., 477 F.3d 668, 688 (9th Cir. 2007)
(“[W]e ‘may not accept appellate counsel’s post hoc rational-
izations for agency action.’ ” (quoting Burlington Truck
Lines, 371 U.S. at 168)). Defendants’ post hoc explanations
serve only to underscore the absence of an adequate explana-
tion in the administrative record itself.
[3] Defendants also object to the very premise that an
agency is obligated to address apparent inconsistencies such
as those at issue here. They point out that the previous envi-
ronmental assessments addressed the impact of fisheries
under NEPA, whereas the present action assessed the impact
of pinnipeds under the MMPA. They contend that the MMPA
action here cannot reasonably be construed as a “swerve”
from “prior precedent.” We agree with defendants’ argument
up to a point: NMFS’s MMPA action here is not a swerve
from prior precedent, as the courts have applied that principle
in administrative law cases.4 But an agency’s duty to explain
impact.”). We agree with defendants that this distinction could help recon-
cile the apparent inconsistency between the finding that sea lion predation
has a significant negative impact on the decline or recovery of listed sal-
monid populations and the finding that comparable fishery activities do
not. NMFS’s decision, however, did not adequately develop this possible
rationale, so we cannot say that it resolves the apparent inconsistency. Fur-
thermore, even at 5.5 percent, fishery takes appear to be roughly compara-
ble to sea lion predation rates.
4
We therefore reject plaintiffs’ argument that the agency’s decision in
this case constitutes an unexplained “swerve” from “prior precedent.”
Plaintiffs are correct that an agency has a duty to explain a departure from
precedent. See Atchison, Topeka & Santa Fe Ry. Co. v. Wichita Bd. of
Trade, 412 U.S. 800, 808 (1973) (plurality opinion) (describing an “agen-
cy’s duty to explain its departure from prior norms” and holding that when
an agency departs from prior norms, its reasons “must be clearly set forth
so that the reviewing court may understand the basis of the agency’s
action and so may judge the consistency of that action with the agency’s
mandate”). This principle indisputably applies when an agency rescinds an
existing rule, see, e.g., State Farm, 463 U.S. at 41-42 (holding that “an
18692 HUMANE SOCIETY v. LOCKE
cogently the bases of its decisions is not limited to circum-
stances in which the agency departs directly from an earlier
path. An agency “must examine the relevant data and articu-
late a satisfactory explanation for its action including a ‘ratio-
nal connection between the facts found and the choice
made.’ ” State Farm, 463 U.S. at 43 (emphasis added) (quot-
ing Burlington Truck Lines, 371 U.S. at 168). In the circum-
stances of this case, NMFS’s factual findings in the earlier
environmental assessments appear to be “relevant data,” such
that it was incumbent on the agency to offer a “satisfactory
explanation” for its decision in light of the earlier findings.5
agency changing its course by rescinding a rule is obligated to supply a
reasoned analysis”), applies a legal standard inconsistently, see, e.g., W.
States Petroleum Ass’n v. EPA, 87 F.3d 280, 285 (9th Cir. 1996), or
departs from longstanding practice “without supplying a reasoned analysis
for its change of course,” Nw. Envtl. Def. Ctr., 477 F.3d at 690. In addi-
tion, at least one district court in this circuit has applied this principle to
an agency’s unexplained departure from an earlier factual finding. See
Defenders of Wildlife v. Hall, 565 F. Supp. 2d 1160, 1170 (D. Mont. 2008)
(holding that the agency acted arbitrarily when it failed to explain its
departure from an earlier determination that genetic exchange between
wolves located in three distinct recovery areas would be a precondition to
delisting the northern Rocky Mountain gray wolf under the ESA). But
plaintiffs’ attempt to apply this principle here extends it too far. The fac-
tual findings contained in NMFS’s earlier environmental assessments,
which the agency completed under NEPA rather than the MMPA, and
which analyzed the effects of fishery activities rather than sea lion preda-
tion, do not constitute “precedents” within the meaning of the Atchison
line of authority. Hall is distinguishable. There, the U.S. Fish and Wildlife
Service’s factual determination that genetic exchange was unnecessary for
the health of the wolf population directly contradicted its earlier determi-
nation that such exchange was required. Here, by contrast, NMFS’s fac-
tual findings are at most potentially inconsistent, not directly
contradictory. NMFS’s action therefore cannot be faulted on plaintiffs’
theory that the agency has “swerved from prior precedent” without expla-
nation.
5
Plaintiffs also fault NMFS for failing to address an August 2007 bio-
logical assessment (BA) of the effects of the Federal Columbia River
Power System (FCRPS) on salmonid species listed under the ESA. The
HUMANE SOCIETY v. LOCKE 18693
[4] NMFS cannot avoid its duty to confront these inconsis-
tencies by blinding itself to them. We do not suggest that an
agency has a duty to identify and address any potential ten-
sion between current and earlier factual determinations in
marginally related administrative actions. But in this case the
agency’s seemingly inconsistent approach to, on the one hand,
fishery and hydropower activities, which are deemed not to be
significant obstacles to the recovery of listed salmonid popu-
lations, and, on the other hand, sea lion predation, which is
deemed to be a significant barrier to salmonid recovery, has
occupied the center of this controversy from the start. The
issue surfaced prominently in the task force proceedings, see
generally Minority Report, Final Report and Recommenda-
tions of the Marine Mammal Protection Act, Section 120
Pinniped-Fishery Interaction Task Force: Columbia River
(Nov. 5, 2007), and has been raised repeatedly and forcefully
by the Marine Mammal Commission, which is a federal entity
possessing expertise on issues relating to the protection of
FCRPS kills approximately 7.7 percent of listed juvenile salmonids, 9.9
percent of adult listed spring-run Chinook salmon and 16.8 percent of
listed adult Snake River steelhead, but the BA concluded “that the net
effects of the proposed actions, including the existence and operations of
the dams with the proposed mitigation, meet or exceed the objectives of
doing no harm and contributing to recovery with respect to the [listed sal-
monid populations] affected by the operation of the FCRPS” (emphasis
added). Plaintiffs argue with some force that the factual findings in the
2007 dam take BA are at odds with the finding of significant negative
impact in this case. The dam take BA, however, was compiled by the U.S.
Army Corps of Engineers, the Bonneville Power Administration and the
Bureau of Reclamation within the U.S. Department of Interior, not NMFS.
The unexplained inconsistencies between NMFS’s finding in this case and
the findings in the dam take BA thus do not raise the same level of con-
cern as apparent inconsistencies among NMFS’s own environmental
assessments. We do not, however, suggest that NMFS is necessarily free
to ignore the dam take BA: to comply with the APA and provide a basis
for meaningful judicial review, an agency must examine the “relevant
data” and articulate a rational connection between the facts found and the
choice made. State Farm, 463 U.S. at 43. The dam take BA may fall
within the category of relevant data.
18694 HUMANE SOCIETY v. LOCKE
marine mammals, see 16 U.S.C. § 1402, throughout the
administrative decisional process, see, e.g., Letter from Timo-
thy J. Ragen, Executive Director, Marine Mammal Commis-
sion, to Donna Darm, Assistant Regional Administrator,
Protected Resources Division, NMFS, at 3 (Apr. 2, 2007)
(“[T]o put the estimated level of pinniped predation on listed
stocks in context, it should be compared to other sources of
mortality, including the various forms of human-related
take.”); Letter from Timothy J. Ragen to D. Robert Lohn,
Regional Administrator, Northwest Region, NMFS, at 1
(Nov. 23, 2007) (recommending that NMFS “compare the
estimated level of removals of ESA-listed salmonids by pinni-
peds with authorized levels of incidental and directed take
from other sources and explain why some sources are consid-
ered significant while others are not”); id. at 3 (same); id. at
5 (noting that “the comparison of pinniped predation with
authorized levels of takes from other sources is an area largely
glossed over by the Task Force,” and recommending that
NMFS “provide[ ] clear explanations to support any determi-
nations that some are significant while others are not”); id. at
6 (noting that “this issue is at the heart of the controversy over
pinniped predation” and advising NMFS to “provide a ratio-
nale to support its decisions on how to reduce a significant
take level when multiple risk factors are involved”); cf. H.R.
Rep. No. 103-439, at 47 (1994) (House Committee Report on
the Marine Mammal Protection Act Amendments of 1994,
Pub. L. No. 103-238, which added section 120 to the MMPA)
(“[T]he Committee recognizes that a variety of factors may be
contributing to the declines of these stocks, and intends that
the current levels of protection afforded to seals and sea lions
under the Act should not be lifted without first giving careful
consideration to other reasons for the decline, and to all other
available alternatives for mitigation.”). Under these circum-
stances, NMFS was required to provide some explanation for
the apparent inconsistencies.
HUMANE SOCIETY v. LOCKE 18695
2.
[5] We also conclude that further explanation is required
for NMFS’s conclusion that California sea lion predation
greater than 1 percent would have a significant negative
impact on the decline or recovery or the listed salmonid popula-
tions.6
[6] NMFS said only that the 1 percent target “is intended
to balance the policy value of protecting all pinnipeds, as
expressed in the MMPA, against the policy value of recover-
ing threatened and endangered species, as expressed in the
ESA.” Pinniped Removal Authority, 73 Fed. Reg. at 15,486.
This may be a worthy public policy goal, but the agency’s
explanation does not help us to understand why this level of
predation amounts to a “significant negative impact” or how
this level of removal is related to the decline or recovery of
listed salmonids. Without that explanation, we cannot ascer-
tain whether NMFS has complied with its statutory mandate
under the MMPA.
In this respect we once again echo the concerns of the
Marine Mammal Commission, which repeatedly emphasized
to NMFS the need to “identify the level at which predation of
salmonids by pinnipeds no longer would be considered signif-
icant,” because “the taking authority should lapse once preda-
tion is reduced to a level where it no longer is having a
significant impact.” Letter from Timothy J. Ragen to D. Rob-
ert Lohn, Regional Administrator, Northwest Region, NMFS,
at 1, 6 (Nov. 23, 2007); see also Letter from Timothy J.
Ragen, Executive Director, Marine Mammal Commission, to
6
This finding is implicit in NMFS’s decision to authorize lethal removal
up to the point at which a 1 percent predation level is achieved. The
MMPA authorizes the lethal removal only of “individually identifiable
pinnipeds which are having a significant negative impact on the decline
or recovery of salmonid fishery stocks.” 16 U.S.C. § 1389(b)(1). Thus, by
authorizing lethal removal up to the 1 percent level, NMFS has impliedly
found that this level of predation would have the requisite adverse impact.
18696 HUMANE SOCIETY v. LOCKE
Donna Darm, Assistant Regional Administrator, Protected
Resources Division, NMFS, at 2 (Apr. 2, 2007) (imploring the
task force to “take a hard look at the justification for the num-
ber of any lethal removals that it recommends be autho-
rized”); Letter from Timothy J. Ragen, Executive Director,
Marine Mammal Commission, to D. Robert Lohn, Regional
Administrator, Northwest Region, NMFS, at 1 (Nov. 23,
2007) (recommending that NMFS “identify the level at which
predation of salmonids by pinnipeds no longer would be con-
sidered significant and adopt that level as the goal of any
authorized removal program”); id. at 6 (urging NMFS to
determine “the level at which the impact would cease to be
significant,” at which point the taking authority would
“lapse”); id. (criticizing the task force for adopting a 1 percent
predation target without engaging “in any quantitative analy-
ses to support” it); id. at 10 (indicating that some members of
the task force “appeared to be driven more by the pragmatic
goal of designing the authorization they thought most likely
to resolve the pinniped-fishery conflict than by whether that
authorization would satisfy the requirements of section 120”
of the MMPA); Letter from Timothy J. Ragen, Executive
Director, Marine Mammal Commission, to Garth Griffin,
NMFS, at 3 (Feb. 19, 2008) (stating that “a justification
should be provided for establishing [the 1 percent] level of
predation as . . . a threshold” at which predation “would no
longer be considered significant”); Letter from Timothy J.
Ragen, Executive Director, Marine Mammal Commission, to
Robert Lohn, Regional Administrator, Northwest Regional
Office, NMFS, at 2 (Feb. 25, 2008) (“There are two issues
about which the Service should be particularly clear in its
rationale. The first is the basis for determining the extent to
which predation must be reduced to promote conservation and
recovery of the salmonid stocks. . . . The second is the manner
and rationale by which the Service is, in effect, allocating
allowable salmonid mortality among different sources of mor-
tality.”). The finding that predation at the 1 percent level is
significant is not adequately explained.
HUMANE SOCIETY v. LOCKE 18697
[7] For each of the foregoing reasons, we hold that
NMFS’s explanation is incomplete and inadequate to permit
meaningful judicial review. On the current record, NMFS has
not explained its significance determination in light of seem-
ingly inconsistent factual determinations in earlier environ-
mental assessments of fishery impacts. Nor has the agency
properly explained the basis of its determination that Califor-
nia sea lion predation of salmonids is significant at the 1 per-
cent level. The agency’s action is therefore “arbitrary,
capricious, an abuse of discretion, or otherwise not in accor-
dance with law.” 5 U.S.C. § 706(2)(A). Accordingly, we
direct the district court to vacate NMFS’s decision approving
the states’ MMPA application and remand to NMFS to afford
the agency the opportunity either to articulate a reasoned
explanation for its action or to adopt a different action with
a reasoned explanation that supports it. See Local Joint Exec.
Bd. v. NLRB, 309 F.3d 578, 585 (9th Cir. 2002).7
In so holding, we do not impose an undue burden on NMFS
on remand. The APA requires only a “cogent explanation.”
Nw. Envtl. Def. Ctr., 477 F.3d at 691. We recognize the chal-
lenges NMFS faces in addressing salmonid conservation and
recovery in the Columbia River, the efforts it has taken to
address multiple sources of mortality and the practical diffi-
culties presented by uncertainties and changing conditions on
7
In rare circumstances, when we deem it advisable that the agency
action remain in force until the action can be reconsidered or replaced, we
will remand without vacating the agency’s action. See Heartland Reg’l
Med. Ctr. v. Sebelius, 566 F.3d 193, 198 (D.C. Cir. 2009) (explaining that
special circumstances may justify remand without vacatur “[w]hen an
agency may be able readily to cure a defect in its explanation of a deci-
sion”); Idaho Farm Bureau Fed’n v. Babbitt, 58 F.3d 1392, 1405-06 (9th
Cir. 1995) (holding that the court may remand without vacatur “when
equity demands”). In this case, the government has not specifically
requested that we remand without vacatur, and it is not otherwise apparent
that the circumstances call for doing so. Accordingly, the appropriate rem-
edy here is to direct the district court to vacate NMFS’s action and remand
to the agency.
18698 HUMANE SOCIETY v. LOCKE
the ground. We also recognize that sea lion predation is a seri-
ous and potentially significant problem in this location, and
that Congress, in enacting section 120 of the MMPA, has
authorized NMFS to give priority to ESA-listed salmonid
populations over MMPA-protected pinnipeds under specific
circumstances. As judges, our limited role is to ensure that
NMFS has properly determined that those specific circum-
stances exist. To do so, we require an explanation from the
agency that enables meaningful judicial review. We conclude
that a remand is necessary in this case to permit us to fulfill
our function.
B. Chevron Analysis
We are not persuaded by plaintiffs’ argument that NMFS’s
interpretation of the MMPA is impermissible or unreasonable
under the Chevron framework. See Chevron, U.S.A., Inc. v.
Natural Res. Def. Council, Inc., 467 U.S. 837 (1984).8 Chev-
ron establishes a two-step framework for reviewing agency
interpretations of statutes they administer. Under the first step,
we determine “whether Congress has directly spoken to the
precise question at issue. If the intent of Congress is clear,”
then we “must give effect to the unambiguously expressed
intent of Congress.” Id. at 842-43. Under step two, “if the
statute is silent or ambiguous with respect to the specific
issue, the question for the court is whether the agency’s
8
As a threshold matter, all parties agree that Chevron deference applies
to NMFS’s interpretation of the MMPA in this case. We therefore assume
without deciding that Chevron deference applies. We observe, however,
that in some circumstances we have suggested that agencies’ one-time
statutory interpretations, if lacking in precedential force with respect to
future agency actions, may not warrant this deference. See High Sierra
Hikers, 390 F.3d at 648 (holding that the U.S. Forest Service’s interpreta-
tion of the Wilderness Act was not entitled to Chevron deference because
the agency “was not acting with the force of law” when it was “granting
permits,” an action that would not have “precedential value for subsequent
parties”). Given the parties’ agreement that Chevron governs, we have no
occasion to decide whether High Sierra Hikers would preclude Chevron
deference here.
HUMANE SOCIETY v. LOCKE 18699
answer is based on a permissible construction of the statute.”
Id. at 843. “If a statute is ambiguous, and if the implementing
agency’s construction is reasonable, Chevron requires a fed-
eral court to accept the agency’s construction of the statute,
even if the agency’s reading differs from what the court
believes is the best statutory interpretation.” Nat’l Cable &
Telecomm. Ass’n v. Brand X Internet Servs., 545 U.S. 967,
980 (2005).
[8] Here, plaintiffs challenge NMFS’s interpretation of the
MMPA’s requirement that “individually identifiable pinni-
peds” are having a significant negative impact on the decline
or recovery of listed salmonid populations. Following the sug-
gestion of the Marine Mammal Commission, NMFS adopted
a two-part interpretation for this requirement, in which it
would first determine whether California sea lions collectively
were having a significant negative impact on listed salmonids
and would next determine which sea lions were significant
contributors to that impact and therefore eligible for lethal
removal. Plaintiffs contend that the agency’s interpretation is
contrary to the plain language and the legislative history of
the statute, which, they argue, require a finding that an indi-
vidual pinniped is having a significant negative impact on
fishery stocks, not whether sea lions in the aggregate are hav-
ing the requisite impact. The legislative history lends some
support to plaintiffs’ position, see S. Rep. No. 103-220, at 524
(1994) (“The Secretary would be authorized to allow the
lethal removal of a nuisance pinniped if it is identified as
habitually exhibiting dangerous or damaging behavior that
cannot be deterred by other means.” (emphasis added)), but
the language and purpose of the statute as a whole do not pre-
clude the agency’s two-part interpretation. See 16 U.S.C.
§ 1389(b)(1) (authorizing “the intentional lethal taking of
individually identifiable pinnipeds which are having a signifi-
cant negative impact” (emphasis added)), (b)(2) (requiring
applicants to specify “a means of identifying the individual
pinniped or pinnipeds” sought to be removed (emphasis
added)), (d)(3) (requiring the agency to consider “the extent
18700 HUMANE SOCIETY v. LOCKE
to which such pinnipeds are causing undue injury or impact
to, or imbalance with, other species in the ecosystem, includ-
ing fish populations” (emphasis added)). We therefore cannot
say that the agency’s interpretation is an unreasonable one.
Plaintiffs also challenge NMFS’s interpretation of the
phrase “significant negative impact,” arguing that the three
factors relied on by the agency to make a finding of signifi-
cance amount to an impermissible interpretation. Because we
conclude that NMFS’s action is inadequately explained and
must be remanded under the APA for reasons we have
explained above, we need not resolve this question here. See
Shay v. FEC, 414 F.3d 76, 97 (D.C. Cir. 2005) (“[W]e need
not decide whether these . . . rules represent altogether imper-
missible interpretations . . . — the Chevron step two inquiry
— because in any event the [agency] has given no rational
justification for them, as required by the APA’s arbitrary and
capricious standard.”) (citation omitted).
II. National Environmental Policy Act Claim
We next address plaintiffs’ argument that NMFS violated
NEPA by failing to prepare an environmental impact state-
ment (EIS). Under NEPA, a federal agency must prepare an
EIS for any “major Federal actions significantly affecting the
quality of the human environment.” 42 U.S.C. § 4332(2)(C).
An agency may first prepare an environmental assessment
(EA) to determine whether the effects of a proposed action are
significant. If the EA establishes that the action may have sig-
nificant environmental impacts, the agency must prepare an
EIS. If the agency makes a finding on the basis of an EA that
the action will have no significant impact (FONSI), no EIS is
required. See 40 C.F.R. § 1501.4. Plaintiffs contend an EIS
was required in this case on two bases, which we discuss in
turn.
A. Beneficial Impact
Plaintiffs first argue that NMFS’s finding of significance
under the MMPA in essence compels a finding of significance
HUMANE SOCIETY v. LOCKE 18701
under NEPA. According to plaintiffs, NMFS’s determination
under the MMPA that sea lions are having a “significant neg-
ative impact on the decline or recovery” of listed salmonid
populations necessarily implies that the environmental bene-
fits of authorizing the lethal removal of sea lions will have a
significant positive impact on these salmonid populations.
They contend that this significant beneficial environmental
impact triggers the duty to prepare an EIS under NEPA.
[9] As a threshold matter, plaintiffs’ argument appears to
raise an issue of first impression in this circuit: whether
NEPA requires an agency to prepare an EIS when an action
has a significant beneficial impact but no significant adverse
impact on the environment.9 This is a question we need not
9
We reject defendants’ argument that our decision in Bering Strait Citi-
zens for Responsible Resource Development v. U.S. Army Corps of Engi-
neers, 524 F.3d 938, 956 (9th Cir. 2008), addressed that issue. Bering
Strait involved a permit issued by the Corps for a major gold-mining proj-
ect near Nome, Alaska. We observed that the project would “favorably
affect[ ] parts of the Nome area that suffered environmental damage from
previously unconstrained resource development” and held that “the Corps
was not required to prepare an EIS” because the project had “no signifi-
cant detrimental effect on the environment in and near Nome.” Id. at 957.
The plaintiffs in Bering Strait did not contend that an EIS was required
based on beneficial environmental effects, so we did not squarely address
whether significant beneficial effects alone would trigger an EIS. Bering
Strait therefore left this issue unresolved.
Other circuits are divided on this question. Compare Sierra Club v.
Froehlke, 816 F.2d 205, 211 n.3 (5th Cir. 1987) (“[Because] NEPA is con-
cerned with accurate and informed decisionmaking as a general matter[,
a]n environmental report that erroneously depicts positive environmental
consequences poses as significant an obstacle to informed decisionmaking
as one that inadequately assesses adverse circumstances.”), Natural Res.
Def. Council, Inc. v. Herrington, 768 F.2d 1355, 1431 (D.C. Cir. 1985)
(stating in dictum that “both beneficial and adverse effects on the environ-
ment can be significant within the meaning of NEPA, and thus require an
EIS”), Nat’l Wildlife Fed’n v. Marsh, 721 F.2d 767, 783 (11th Cir. 1983)
(holding that post-EIS changes required a supplemental EIS where a “Mit-
igation Plan involves a number of proposed project changes that are likely
to have a significant, though beneficial, impact on the environment”), and
18702 HUMANE SOCIETY v. LOCKE
resolve, however, because even if solely beneficial impacts
trigger an EIS, the record does not demonstrate a significant
beneficial impact on the human environment in this instance.
First, just because NMFS has concluded that sea lions are
having a significant negative impact on listed salmonid popu-
lations does not mean that the agency has also determined that
the removal action authorized here will have a significant pos-
itive impact on these same populations. Second, even if
NMFS concluded that its action would have a “significant”
positive impact on the fish populations involved, that would
not necessarily translate into a finding of a significant effect
on the quality of the human environment, as required by
NEPA: although both statutes speak of significance, the legal
standards under the MMPA and NEPA are distinct.10
B. Adverse Impacts
In the alternative, plaintiffs contend that NMFS should
have prepared an EIS based on significant adverse impacts.
Envtl. Def. Fund v. Marsh, 651 F.2d 983, 993 (5th Cir. 1981) (“[E]ven if
the Corps was correct in deciding that the new land use will be beneficial
in impact, a beneficial impact must nevertheless be discussed in an EIS,
so long as it is significant. NEPA is concerned with all significant environ-
mental effects, not merely adverse ones.”), with Friends of Fiery Gizzard
v. Farmers Home Admin., 61 F.3d 501, 504-05 (6th Cir. 1995) (conclud-
ing that only adverse impacts trigger the obligation to prepare an EIS).
Although we do not reach the question, plaintiffs’ view is consistent with
the weight of circuit authority and has the virtue of reflecting the plain lan-
guage of the statute.
10
We do not intend to suggest that the legal standards under the two
statutes are unrelated. A significant impact on listed salmonids, as defined
by the MMPA, certainly could constitute a significant effect on the human
environment under NEPA. See 40 C.F.R. § 1508.27(b)(9) (providing that
one factor an agency should consider in making the determination of
whether to prepare an EIS under NEPA is “[t]he degree to which the
action may adversely affect an endangered or threatened species”). We
hold only that a finding of significance under the MMPA does not ipso
facto mandate a finding of significance under NEPA.
HUMANE SOCIETY v. LOCKE 18703
They rely on three theories of adverse impact, none of which
is persuasive.
[10] First, plaintiffs contend that an EIS was required
based on the controversial and uncertain nature of the action.
See 40 C.F.R. § 1508.27(b)(4) (in deciding whether an action
has a significant impact, the agency should consider “[t]he
degree to which the effects on the quality of the human envi-
ronment are likely to be highly controversial”); id.
§ 1508.27(b)(5) (the agency also should consider “[t]he
degree to which the possible effects on the human environ-
ment are highly uncertain or involve unique or unknown
risks”). As plaintiffs correctly point out, the lethal removal of
sea lions at Bonneville Dam has been the subject of some
controversy. Most significantly, the Marine Mammal Com-
mission criticized aspects of NMFS’s decisionmaking.
NMFS, however, acted reasonably in concluding that the
Commission’s concerns did not make the agency’s action
highly controversial within the meaning of the NEPA regula-
tions. “The term ‘controversial’ refers ‘to cases where a sub-
stantial dispute exists as to the size, nature, or effect of the
major federal action rather than to the existence of opposition
to a use.’ ” Found. for N. Am. Wild Sheep v. U.S. Dep’t of
Agric., 681 F.2d 1172, 1182 (9th Cir. 1982). “A substantial
dispute exists when evidence . . . casts serious doubt upon the
reasonableness of an agency’s conclusions.” Nat’l Parks &
Conservation Ass’n v. Babbitt, 241 F.3d 722, 736 (9th Cir.
2001) (emphasis added). Here, the Commission criticized
some aspects of NMFS’s draft EA, but it did not disagree with
the EA’s primary conclusions that an EIS was not required,
that sea lions are having a significant impact under section
120 and that some sort of lethal removal is reasonable.
[11] Second, plaintiffs contend an EIS was required based
on the action’s potentially deadly consequences for Steller sea
lions that frequent the Bonneville Dam area. Plaintiffs con-
tend that Steller sea lions, which, unlike California sea lions,
are listed as threatened under the ESA, could be killed mis-
18704 HUMANE SOCIETY v. LOCKE
takenly because NMFS’s decision authorizes shooting sea
lions that are in the water, where Steller sea lions can be hard
to distinguish from California sea lions. See 40 C.F.R.
§ 1508.27(b)(9) (in deciding the question of significance
under NEPA, an agency should consider “[t]he degree to
which the action may adversely affect an endangered or
threatened species”). Plaintiffs’ argument is unpersuasive
because NMFS adopted a series of safeguards to ensure that
only targeted sea lions would be killed, and concluded that,
“[b]ecause of these requirements, it is highly unlikely that a
marksman would shoot any sea lion other than one on the list
of predatory sea lions.” The record does not demonstrate that
this conclusion is in error.
[12] Third, plaintiffs contend an EIS was required based
on the impacts to local wildlife viewing opportunities if sea
lions are removed from the Bonneville Dam area. Plaintiffs
correctly observe that the lethal removal program will reduce
or eliminate sea lion viewing opportunities in the vicinity of
the dam. But their argument is unpersuasive, in part because
the NEPA regulations do not treat wildlife viewing opportuni-
ties as a major factor in deciding whether an EIS is required.
See 40 C.F.R. § 1508.27(b)(8). Nor does the record contain
substantial evidence showing that the dam is a popular site for
sea lion viewing. We therefore reject this argument.
III. Defendants’ Motion to Strike
[13] Plaintiffs also contend that the district court abused its
discretion by granting defendants’ motion to strike NMFS’s
previous, fishery-related environmental assessments to the
extent they were not included in the administrative record. As
a general matter, judicial review of agency decisions is lim-
ited to the record considered by the agency in making its deci-
sion. See, e.g., Camp v. Pitts, 411 U.S. 138, 142 (1973). A
court may consider extra-record documents, however, “if nec-
essary to determine ‘whether the agency has considered all
relevant factors and has explained its decision.’ ” Sw. Ctr. for
HUMANE SOCIETY v. LOCKE 18705
Biological Diversity v. U.S. Forest Serv., 100 F.3d 1443, 1450
(9th Cir. 1996) (quoting Inland Empire Pub. Lands Council
v. Glickman, 88 F.3d 697, 703 (9th Cir. 1996)). As we have
discussed, NMFS should have explained the apparent factual
inconsistency between its significance finding here and its
previous fishery assessments. Thus, supplementing the admin-
istrative record to include those earlier assessments is “neces-
sary to determine ‘whether the agency has considered all
relevant factors and has explained its decision.’ ” Id. We
therefore vacate the order granting defendants’ motion to
strike.
IV. NMFS’s Use of Bioenergetic Modeling
[14] Finally, plaintiffs challenge NMFS’s use of bioener-
getic modeling to supplement the Corps’ observation-based
estimates of sea lion predation. Plaintiffs have not demon-
strated that NMFS’s estimates are arbitrary or capricious
under the APA. We therefore uphold the agency’s use of
bioenergetic modeling.
As we have explained, the Corps observed pinniped preda-
tion at the Bonneville Dam between 2002 and 2007 and pro-
duced predation estimates based on those actual observations.
NMFS determined that the Corps’ observation-based method
underestimated the number of fish killed by sea lions at the
dam and therefore supplemented the Corps’ figures with esti-
mates produced through a bioenergetic consumption model.11
Although plaintiffs raise a number of objections to NMFS’s
reliance on the bioenergetic estimates to augment the Corps’
predation rates, their arguments are unpersuasive.
11
NMFS inaccurately characterizes the predation numbers produced by
the Corps as predation “actually observed.” Although the Corps’ numbers
are based on actual observations, they in fact are estimates that reflect not
only observed kills but also kills estimated to have occurred during breaks
in observation. The Corps’ numbers are therefore estimates, though they
are based on actual observations rather than bioenergetic consumption cal-
culations.
18706 HUMANE SOCIETY v. LOCKE
First, there is no meaningful dispute that the Corps’
observation-based estimates lead to some undercounting.
Thus, NMFS’s conclusion that “[t]he actual number of sal-
monids consumed is certainly larger than the numbers”
reported by the Corps is not unreasonable. The Marine Mam-
mal Commission agreed with the agency’s conclusion that the
Corps understated predation, concurring in NMFS’s conclu-
sion “that the number of pinnipeds present at the dam likely
is greater than the number observed.” NMFS’s decision to
look beyond the Corps’ observation-based estimates was
therefore reasonable. See Lands Council v. McNair, 537 F.3d
981, 993-94 (9th Cir. 2008) (en banc) (“[A]s non-scientists,
we decline to impose bright-line rules on the [agency] regard-
ing particular means that it must take in every case to show
us that it has met the [statutory] requirements. Rather, we hold
that the [agency] must support its conclusions that a project
meets the requirements of the [statute] . . . with studies that
the agency, in its expertise, deems reliable.”), abrogated in
part on other grounds by Winter v. Natural Res. Def. Council,
Inc., 129 S. Ct. 365 (2008).
[15] Second, plaintiffs have not demonstrated that the
bioenergetic models used by the agency produced unreliable
estimates. Plaintiffs rely on a letter in which the Marine Mam-
mal Commission questioned some of the agency’s early esti-
mates based on bioenergetic modeling. Plaintiffs have not
shown, however, that the Commission criticized the agency’s
final bioenergetic calculations. Nor have they shown that the
Commission asserted that modeling was an improper method
of helping to estimate actual sea lion predation. Plaintiffs also
rely on a declaration submitted by their expert, Dr. Andrew
Trites, that challenges some of the assumptions of NMFS’s
bioenergetic consumption model. Dr. Trites’ submission,
however, demonstrates only that several of the agency’s fac-
tual assumptions are subject to some dispute, not that the
agency’s assumptions were arbitrary or capricious. See Marsh
v. Oregon Natural Res. Council, 490 U.S. 360, 378 (1989)
(“When specialists express conflicting views, an agency must
HUMANE SOCIETY v. LOCKE 18707
have discretion to rely on the reasonable opinions of its own
qualified experts even if, as an original matter, a court might
find contrary views more persuasive.”); see also Baltimore
Gas & Elec. Co. v. Natural Res. Def. Council, 462 U.S. 87,
103 (1983) (when an agency is “making predictions, within its
area of special expertise . . . , as opposed to simple findings
of fact, a reviewing court must generally be at its most defer-
ential”).
Furthermore, in measuring sea lion predation, NMFS relied
primarily on the Corps’ estimates and only secondarily on the
bioenergetic consumption estimates. See Pinniped Removal
Authority, 73 Fed. Reg. at 15,485, 15,486. NMFS used the
bioenergetic data to supplement rather than supplant the
Corps’ estimates.
Finally, we observe that the bioenergetic consumption esti-
mates do not appear to have been material to NMFS’s deci-
sion. NMFS determined that sea lion predation was
“significant” under the MMPA even at the mortality levels
supplied by the Corps. See id. at 15,485. The agency’s deci-
sion thus would have been the same even if the Corps’ esti-
mates were not supplemented by the bioenergetic
consumption estimates.
CONCLUSION
We affirm summary judgment in favor of defendants on
plaintiffs’ NEPA claim. We reverse summary judgment on
plaintiffs’ MMPA claim and remand to the district court with
instructions to vacate the decision of NMFS and remand to
NMFS. We vacate the district court’s order granting defen-
dants’ motion to strike. Each party shall bear its own costs on
appeal.
AFFIRMED IN PART, REVERSED IN PART,
REMANDED.