Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca9-14-16375/USCOURTS-ca9-14-16375-0/pdf.json

Nature of Suit Code: 893
Nature of Suit: Environmental Matters
Cause of Action: 

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FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

NATURAL RESOURCES DEFENSE

COUNCIL, INC.; HUMANE

SOCIETY OF THE UNITED STATES;

CETACEAN SOCIETY

INTERNATIONAL; OCEAN

FUTURES SOCIETY; JEANMICHEL COUSTEAU; MICHAEL

STOCKER,

Plaintiffs-Appellants,

v.

PENNY PRITZKER, Secretary,

U.S. Department of Commerce;

NATIONAL MARINE FISHERIES

SERVICE; EILEEN SOBECK,

Assistant Administrator for

Fisheries; KATHRYN D.

SULLIVAN, Administrator of the

National Oceanic and

Atmospheric Administration;

RAY MABUS, Secretary of the

Navy; JONATHAN GREENERT,

Admiral, Chief of Naval

Operations,

Defendants-Appellees.

No. 14-16375

D.C. No.

3:12-cv-05380-EDL

OPINION

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2 NRDC V. PRITZKER

Appeal from the United States District Court

for the Northern District of California

Elizabeth D. Laporte, Magistrate Judge, Presiding

Argued and Submitted March 17, 2016

San Francisco, California

Filed July 15, 2016

Before: John T. Noonan, Ronald M. Gould,

and Michelle T. Friedland, Circuit Judges.

Opinion by Judge Gould

SUMMARY*

Environmental Law

The panel reversed the district court’s grant of summary

judgment to federal defendants in a case relating to the proper

scope under the Marine Mammal Protection Act (“MMPA”)

of mitigation measures required to protect marine mammals

when the responsible federal agency, the National Marine

Fisheries Service, sought to approve incidental “take” relating

to military readiness activities, namely, the Navy’s peacetime

use of Surveillance Towed Array Sensor System Low

Frequency Active sonar.

* This summary constitutes no part of the opinion of the court. It has

been prepared by court staff for the convenience of the reader.

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NRDC V. PRITZKER 3

The Fisheries Service most recently authorized incidental

take of marine mammals from Low Frequency Active sonar

use for five years beginning in 2012 in a Final Rule.

The panel held that the 2012 Final Rule did not establish

means of “effecting the least practicable adverse impact on”

marine mammal species, stock and habitat, as was

specifically required by the MMPA. The panel further held

that the Fisheries Service impermissibly conflated the “least

practicable adverse impact” standard with the “negligible

impact” finding; and concluded that to authorize incidental

take, the Fisheries Service must achieve the “least practicable

adverse impact” standard in addition to finding a negligible

impact.

The panel held that the Fisheries Service did not give

adequate protection to areas of the world’s oceans flagged by

its own experts as biologically important, based on the

present lack of data sufficient to meet the Fisheries Service’s

designation criteria. The panel remanded for further

proceedings.

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COUNSEL

Michael E. Wall (argued), Natural Resources Defense

Council, San Francisco, California; Joel R. Reynolds and

Giulia C.S. Good Stefani, Natural Resources Defense

Council, Santa Monica, California; Sara C. Tallman, Natural

Resources Defense Council, Chicago, Illinois; Barbara J.

Chisholm, Altshuler Berzon LLP, San Francisco, California;

for Plaintiffs-Appellants.

Emily Polachek (argued), Kevin W. McArdle, Ty Bair, J.

David Gunter II, and Andrew C. Mergen, Trial Attorneys;

John C. Cruden, Assistant Attorney General; Environment

and Natural Resources Division, Department of Justice,

Washington, D.C.; for Defendants-Appellees.

OPINION

GOULD, Circuit Judge:

This appeal presents a challenging question relating to the

proper scope under the Marine Mammal Protection Act

(MMPA) of mitigation measures required to protect marine

mammals when the responsible federal agency, the National

Marine Fisheries Service (NMFS), seeks to approve

incidental “take” relating to military readiness activities. The

appeal concerns the Navy’s peacetime use of Surveillance

Towed Array Sensor System Low Frequency Active sonar

(SURTASS LFA or “LFA sonar”).1 Congress has required

1 The limitations of government activity under the MMPA that we

review here do not apply in the context of a war in which the Navy must

locate enemy submarines at the risk of civilian casualties or maritime

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NRDC V. PRITZKER 5

that NMFS set limitations on activities that may cause

“take”—i.e. harm to marine mammals— such as military

readiness activities, to reduce their impacts to the least

practicable level.2 The question here is whether NMFS

property destruction if it fails. A maxim made famous by Marcus Tullius

Cicero is that in times of war, the laws fall silent (in Latin “silent enim

leges inter arma”). Cicero inTwenty-Eight Volumes, Volume XIV 16–17

(N.H. Watts trans., Harvard University Press 1972). Here, as in prior

disputes on the Navy’s LFA sonar use, the parties’ disagreement concerns

peacetime use of LFA sonar. See Nat. Res. Def. Council v. Evans, 279 F.

Supp. 2d 1129, 1138 (N.D. Cal. 2003) (“It is true that only peacetime use

of this new sonar system is at issue; the Navy is free to use the system

without restriction in time of war or heightened threat.”). Moreover, in

2003 Congress added a general national defense exception to the MMPA,

under which “[t]he Secretary of Defense, after conferring with the

Secretary of Commerce, the Secretary of the Interior, or both, as

appropriate, may exempt any action or category of actions undertaken by

the Department of Defense or its components from compliance with any

requirement of this chapter, if the Secretary determines that it is necessary

for national defense.” 16 U.S.C. § 1371(f)(1). The exemption cannot last

longer than two years, and the Secretary must report it to the Committees

on Armed Services in both the House of Representatives and the Senate. 

16 U.S.C. §§ 1371(f)(2)(B) & (f)(4). We are confident that the mitigation

measures the MMPA requires do not infringe on the Navy’s capacity to

defend the United States during wartime or heightened threats to national

security.

2

It has recently been reported that increased numbers of Russian attack

submarines are being deployed to patrol the coastlines of Scandinavia,

Scotland, the Mediterranean Sea and the North Atlantic in what military

officials describe as a significantly increased presence aimed at contesting

American and NATO undersea dominance. Eric Schmitt, Russia Bolsters

its Submarine Fleet, and Tensions with U.S. Rise, N.Y. Times (April 20,

2016), http://www.nytimes.com/2016/04/21/world/europe/russia-bolsterssubmarine-fleet-and-tensions-with-us-rise.html. This development

underscores the importance of effective military readiness training so that

if LFA sonar is needed in a war, the Navy will be prepared to use it

effectively. The importance of military readiness activities should not be

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correctly authorized the incidental take of marine mammals

in connection with the Navy’s use of LFA sonar for training,

testing, and routine operations. NMFS determined that the

incidental take of a specified number of marine mammals by

use of LFA sonar would have a negligible impact on the

marine mammal species, and Plaintiffs do not appeal that

determination. Plaintiffs appeal only the district court’s

conclusion that NMFS’s mitigation measures satisfied the

MMPA’s least practicable adverse impact standard.3

The district court granted summary judgment to

Defendants on the issue of MMPA compliance. It held that

“[e]ven if the impact on the population is negligible under

16 U.S.C. §1371(a)(5)(A)(i)(I), the agency could still impose

mitigation that would further reduce the impact on the

population to the least practicable [level] under

16 U.S.C.§ 1371(a)(5)(A)(i)(II)(aa).” The district court

further held that “[t]he requirement to adopt measures to

ensure the ‘least practicable adverse impact’ on marine

mammals is ‘a stringent standard,’” and that though the

agency has discretion to choose among possible mitigation

measures, it cannot exercise that discretion to vitiate that

stringent standard. We agree with those principles. But,

because we disagree with the district court’s methodology

and with its conclusion that the least practicable adverse

impact standard was satisfied, we reverse.

denied or minimized. But the need for them makes it all the more

important that NMFS craft mitigation measures that comply with the

statutory commands.

 

3

 Plaintiffs initially brought claims under not only the MMPA, but also

the Endangered Species Act (ESA) and the National EnvironmentalPolicy

Act (NEPA). But rulings on the ESA and NEPA claims were not

appealed, so our sole concern is the application of the MMPA.

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NRDC V. PRITZKER 7

I

The Navy’s plans for use of LFA sonar, as approved by

NMFS, have gone through several iterations, resulting in

increased protection for marine mammals. We have every

reason to believe that the Navy has been deliberate and

thoughtful in its plans to follow NMFS guidelines and limit

unnecessary harassment and harm to marine mammals. But

the question is whether NMFS has satisfied the Congressional

mandate that mitigation measures ensure the “least

practicable adverse impact” on marine mammals.

The MMPA was enacted in response to Congressional

concern that marine mammal species and population stocks

were in danger of extinction or depletion due to human

activity. 16 U.S.C. § 1361(1). The MMPA aims to balance

marine mammal protection with other strong but opposing

interests, such as national security. To prevent marine

mammal species and population stocks from diminishing

“beyond the point at which they cease to be a significant

functioning element in the ecosystem,” the MMPA broadly

prohibits “take” of marine mammals. 16 U.S.C. §§ 1361(2),

1371. “Take” means to harass, hunt, capture, or kill any

marine mammal. 16 U.S.C. § 1362(13).

There are exceptions to the MMPA take prohibition. The

MMPA allows NMFS to authorize take of “small numbers”

of marine mammals, incidental to a specified activity, for up

to five years.416 U.S.C. § 1371(a)(5)(A)(i). NMFS may

4 The MMPA delegated authority for oceanic marine mammals to the

Secretary of the department in which the National Oceanic and

Atmospheric Administration (NOAA) operates. 16 U.S.C. § 1362(12). 

NOAA is part of the U.S. Department of Commerce. NMFS, a division

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authorize such incidental take if the take meets two

requirements. First, NMFS must find that the total authorized

take during the five-year period “will have a negligible

impact on such species or stock[.]” 16 U.S.C.

§ 1371(a)(5)(A)(i)(I). Second, NMFS must prescribe

regulations setting forth “permissible methods of taking

pursuant to such activity, and other means of effecting the

least practicable adverse impact on such species or stock and

its habitat, paying particular attention to rookeries, mating

grounds, and areas of similar significance[.]” 16 U.S.C.

§ 1371(a)(5)(A)(i)(II)(aa). The “least practicable adverse

impact” standard applies both to “permissible methods of

taking pursuant to” the activity causing incidental take and to

“other means” of reducing incidental take. See Evans, 279 F.

Supp. 2d at 1142 (NMFS’s rulemaking must, among other

things, “prescribe methods and means of effecting the ‘least

practicable adverse impact’ on species and stock and their

habitat” (quoting 16 U.S.C. § 1371(a)(5)(A))).

In connection with peacetime activities such as use of

LFA sonar for training, testing, and routine operations,

Congress struck a balance to permit incidental take of marine

mammals caused by deployment of LFA sonar or other

techniques that might incidentally harm whales and other

marine mammals, so long as the incidental take from the

activity has a negligible impact on the species or stock

involved, and so long as mitigation measures were fashioned

to limit harm to the marine mammals to the “least practicable

of NOAA, is responsible for species of the order Cetacea, whales and

dolphins, and the order Pinnipedia, seals and sea lions, except for

walruses. The U.S. Department of the Interior is responsible for all other

marine mammals including manatees, polar bears, sea otters, and

walruses. Id.

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NRDC V. PRITZKER 9

adverse impact.” As the agency with delegated authority to

implement the MMPA, NMFS is bound by these

congressional mandates.

II

Whales, dolphins, walruses, and other marine mammals

rely on perceptions of underwater sound for vital biological

functions such as catching prey, navigating, and

communicating. The United States Navy operates LFA sonar

vessels around the world for another vital purpose: to protect

the nation from increasingly quiet foreign submarines. The

Navy has determined that LFA sonar is the most effective

way to detect potentially hostile submarines.5 LFA sonar

uses a set of transmitting projectors that are suspended by a

cable from an ocean surveillance ship. The projectors

produce low-frequency sound pulses at an intensity of

approximately 215 decibels (dB), in sequences that last 60

seconds on average. LFA sonar can detect enemy ships day

and night in varied weather conditions over hundreds of

miles.

LFA sonar, while beneficial to national defense, can harm

many marine mammal species, particularly “low-frequency

hearing specialists” such as baleen whales, but also sperm

5 LFA sonar can detect submarines over much larger distances than midfrequency active sonar, which the Navy has used since World War II,

because lower frequencies suffer less attenuation in seawater. Kristina

Alexander, Whales and Sonar: Environmental Exemptions for the Navy’s

Mid-Frequency Active Sonar Training, Congressional Research Service,

February 18, 2009, available at https://www.fas.org/sgp/crs/

weapons/RL34403.pdf. In contrast, passive sonar systems merely use

hydrophones to detect, amplify, and identify sounds from other sources. 

Id.

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whales and pinnipeds such as seals and walruses. LFA sonar

disrupts the hearing of these animals and can cause physical

injury at sound levels greater than 180 dB. Effects from

exposures below 180 dB can cause short-term disruption or

abandonment of natural behavior patterns. These behavioral

disruptions can cause affected marine mammals to stop

communicating with each other, to flee or avoid an ensonified

area, to cease foraging for food, to separate from their calves,

and to interrupt mating. LFA sonar can also cause heightened

stress responses from marine mammals. Such behavioral

disruptions can force marine mammals to make trade-offs

like delaying migration, delaying reproduction, reducing

growth, or migrating with reduced energy reserves.

The MMPA classifies such forms of harassment in two

categories: “Level A” harassment and “Level B” harassment. 

With respect to “military readiness activit[ies],”6such as the

Navy’s use of LFA sonar, the MMPA defines Level A

6 The MMPA uses the definition of “military readiness activity” in Pub.

L. 107-314 § 315(f)(1). See 16 U.S.C. § 1371(a)(5)(A)(ii). The term

“includes (A) all training and operations of the Armed Forces that relate

to combat; and (B) the adequate and realistic testing of military

equipment, vehicles, weapons, and sensors for proper operation and

suitability for combat use.” Pub. L. 107-314 § 315(f)(1). Military

readiness activities are also the subject of 2003 amendments to the

MMPA, which specify that NMFS “shall include consideration of

personnel safety, practicability of implementation, and impact on the

effectiveness of the military readiness activity” in making a “least

practicable adverse impact” determination. National Defense

Authorization Act for Fiscal Year 2004, H.R. Cong. Rep. 108-354,

reprinted in 2003 U.S.C.C.A.N. 1407 (Nov. 7, 2003); see 16 U.S.C.

§ 1371(a)(5)(A)(ii). These changes define considerations relevant to

determining the practicability of mitigation measures, but they do not

eliminate the requirement that the “adverse impact on such species or

stock” must be mitigated to the greatest extent practicable.

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NRDC V. PRITZKER 11

harassment as “any act that injures or has the significant

potential to injure amarine mammal or marine mammal stock

in the wild.” 16 U.S.C. § 1362(18)(B), (C). Level A

harassment happens when marine mammals are exposed to

sound pulses of 180 dB or greater. Level B harassment, less

severe, includes “any act that disturbs or is likely to disturb a

marine mammal or marine mammal stock in the wild by

causing disruption of natural behavioral patterns, including,

but not limited to, migration, surfacing, nursing, breeding,

feeding, or sheltering, to a point where such behavioral

patterns are abandoned or significantly altered.” 16 U.S.C.

§ 1362(18)(B), (D). Level B harassment is caused by sound

levels below 180 dB. Sound intensities of 165 dB subject

marine mammals to a 50% risk of Level B harassment. And

sound intensities as low as 120 dB can still cause “increasing

probabilityof avoidance and other behavioral effects.” Stated

another way, Level A harassment involves activities that

directly injure or are likely to injure marine mammals. By

contrast, Level B harassment involves activities that interfere

with normal behavioral patterns of the marine mammals, with

the risk of indirect harm that creates.

NMFS most recently authorized incidental take of marine

mammals from LFA sonar use for five years beginning in

2012. See Taking and Importing Marine Mammals: Taking

Marine Mammals Incidental to U.S. Navy Operations of

Surveillance Towed Array Sensor System Low Frequency

Active Sonar, 77 Fed. Reg. 50290 (Aug. 20, 2012) (2012

“Final Rule”). This authorization, and the accompanying

mitigation measures, apply to the Navy’s routine training and

testing and use of LFA sonar during military operations in

areas of the Pacific, Atlantic, and Indian Oceans and the

Mediterranean Sea between 2012–2017. 77 Fed. Reg. at

50291. They do not constrict the Navy’s operations during a

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war or active military engagement. The 2012 Final Rule

provides guidelines for incidental take regulations for LFA

sonar use on a maximum of four Navy vessels in 70–75% of

the world’s oceans, covering the Pacific, Atlantic, and Indian

Oceans, and the Mediterranean Sea. Id. at 50303. Each LFA

sonar vessel may perform up to 240 days per year of active

sonar operations. Id. at 50292. The 2012 Final Rule allows

the Navy to incidentally take, through Level A harassment,

up to six baleen whales, 25 toothed whales, and 25 pinnipeds

annually. Id. at 50313, 50317. The Navy may also take,

through Level B harassment, up to 12% of the entire stock of

every affected marine mammal species every year. Id. at

50316–17.

The 2012 Final Rule contains three mitigation measures

intended to minimize the impact of this incidental take on

marine mammal species, stock, and habitat. First, there is a

requirement that the Navy shut down or delay LFA sonar use

if it detects a marine mammal near a sonar vessel. This

requirement instructs the Navy to use a combination of

human lookouts and a dedicated marine mammal detection

system (called the “High Frequency Marine Mammal

Monitoring” system) to detect nearby marine mammals. If a

marine mammal is detected within two kilometers of an LFA

sonar vessel, the Navy must delay or suspend sonar

transmissions. The intensity of an LFA sonar pulse drops

from 215 dB at the source to 175 dB at two kilometers.7

Consequently, NMFS expects this two-kilometer shutdown

zone to almost completely prevent Level A harassment,

7 Decibels measure sound intensity on a logarithmic scale. For example,

a sound measuring 180 dB is approximately ten times more intense than

a 170 dB sound. Nat. Res. Def. Council v. Evans, 232 F. Supp. 2d 1003,

1014 (N.D. Cal. 2002).

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NRDC V. PRITZKER 13

including physical injury, which occurs only at intensities of

180 dB or greater.

Second, the Final Rule prohibits the Navy from creating

LFA sonar pulses of 180 dB or greater within a “coastal

exclusion zone” extending 22 km, or about 12 nautical miles

(nm), of any coastline. Continental shelf waters are

recognized as biologicallyimportant to marine mammals, and

the district court previously ordered NMFS to protect these

waters even in areas without site-specific data. Evans, 279 F.

Supp. 2d at 1164.

Third, the Final Rule prohibits the Navy from creating

LFA sonar pulses of 180 dB or greater within a kilometer of

several designated “offshore biologically important areas”

(OBIAs). OBIAs are marine protected areas providing

marine mammals with relatively low-noise environments, as

LFA sonar pulses moving in from the periphery of an OBIA

gradually dissipate.

III

The key provisions of the Administrative Procedure Act

(APA) require the court to hold unlawful and set aside a final

order of an agency if the order is “arbitrary, capricious, an

abuse of discretion, or otherwise not in accordance with law.” 

See 5 U.S.C. § 706(2)(A). The Supreme Court has made

clear that the federal courts should give deference to federal

agency decisions in several ways. Motor Vehicle Mfrs. Ass’n

of U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29,

43 (1983). First, we generally only set aside a final agency

action if the agency decision is “arbitrary and capricious,” or

“not in accordance with law.” The general rule elaborating

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the meaning of “arbitrary and capricious” was stated in State

Farm as follows:

Normally, an agency rule would be arbitrary

and capricious if the agency has relied on

factors which Congress has not intended it to

consider, entirely failed to consider an

important aspect of the problem, offered an

explanation for its decision that runs counter

to the evidence before the agency, or is so

implausible that it could not be ascribed to a

difference in view or the product of agency

expertise.

463 U.S. at 43.

Further, if the agency itself did not provide reasons to

satisfy the above standard, we will not use our own line of

reasoning to bolster the agency decision on grounds that it did

not include in its reasoning. See, e.g., SEC v. Chenery Corp.,

332 U.S. 194, 196 (1947).8

8 This case comes before us on summary judgment, not a decision at

trial. We review a district court’s grant of summary judgment de novo. 

Szajer v. City of Los Angeles, 632 F.3d 607, 610 (9th Cir. 2011). We view

in the light most favorable to Plaintiffs evidence of harm to marine

mammals caused by LFA sonar and evidence of whether required

mitigation measures achieve the “least practicable adverse effect” on the

marine mammals, and we must determine “whether there are any genuine

issues of material fact and whether the district court correctly applied the

relevant substantive law.” Id. (quoting Universal Health Servs., Inc. v.

Thompson, 363 F.3d 1013, 1019 (9th Cir. 2004)).

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NRDC V. PRITZKER 15

IV

The conflict in this case is about whether the mitigation

measures set forth in NMFS’s 2012 Final Rule achieve the

required “least practicable adverse impact” on marine

mammal species, stock, and habitat. 16 U.S.C.

§ 1371(a)(5)(A)(i)(II)(aa). In Evans, 279 F. Supp. 2d at 1159,

which applied the “least practicable adverse impact” standard

on summary judgment to LFA sonar operations authorized by

NMFS’s 2002 Final Rule, the district court held: “In

requiring the agency to adopt measures to ensure the ‘least

practicable adverse impact’ on marine mammals, Congress

imposed a stringent standard. Although the agency has some

discretion to choose among possible mitigation measures, it

cannot exercise that discretion to vitiate this stringent

standard.” We agree with this formulation.

Defendants on appeal advance several arguments for why

NMFS was not required to comply with this stringent

standard in authorizing the Final Rule. First, they contend

that once NMFS makes a negligible impact finding, it “must

allow the activity,” and the “only question at that point is

what mitigation measures will be required for the proposed

activity to go forward.” We disagree. To ascertain the

meaning of the “least practicable adverse impact” standard,

we look to the statutory text, and we must “presume that [the]

legislature says in a statute what it means and means in a

statute what it says there.” BedRoc Ltd., LLC v. United

States, 541 U.S. 176, 183 (2004) (alteration in original)

(quotingConn. Nat’l Bank v. Germain, 503 U.S. 249, 253–54

(1992)). It is clear from the statute’s text—which sets forth

a two-part requirement for authorization of incidental take,

see 16 U.S.C. § 1371(a)(5)(A)(i)—that mitigation sufficient

to achieve the “least practicable adverse impact” is not a mere

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16 NRDC V. PRITZKER

secondary issue, but rather an independent, threshold

statutory requirement. As with a “negligible impact” finding,

it is central to whether NMFS can authorize incidental take in

the first place. Congress’s mandate that NMFS must find

negligible impact “and” set forth regulations to minimize

adverse impact in order to authorize incidental take makes the

independent nature of these requirements clear. 16 U.S.C.

§ 1371(a)(5)(A)(i)(I) (emphasis added). Defendants’ contrary

reading of the statute is “at odds with one of the most basic

interpretive canons, that ‘[a] statute should be construed so

that effect is given to all its provisions, so that no part will be

inoperative or superfluous, void or insignificant[.]’” Corley

v. United States, 556 U.S. 303, 314 (2009) (alteration in

original) (quoting Hibbs v. Winn, 542 U.S. 88, 101 (2004)).

Defendants next contend that the mitigation requirement

is superfluous; in their words, the agency “cannot mitigate

adverse population-level impacts to any degree less than

zero.” This argument is based on a misreading of the

agency’s own implementing regulations. These regulations

define “negligible impact” as “an impact resulting from the

specified activity that cannot be reasonably expected to, and

is not reasonably likely to, adversely affect the species or

stock through effects on annual rates of recruitment or

survival.” 50 C.F.R. § 216.103. The inquiry as to “negligible

impact” is thus focused on population-level effects—i.e. on

“annual rates of recruitment or survival.” Defendants seek to

import that population-level focus to the “least practicable

adverse impact” standard, but the regulations do not even

define that standard, let alone limit its focus to populationlevel effects. Instead, the MMPA itself simply requires

NMFS to prescribe regulations setting forth “means of

effecting the least practicable adverse impact on such species

or stock and its habitat,” both of which could be adversely

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NRDC V. PRITZKER 17

affected by activities that do not necessarily affect annual

rates of recruitment or survival. 16 U.S.C.

§ 1371(a)(5)(A)(i)(II)(aa). The statute is properly read to

mean that even if population levels are not threatened

significantly, still the agencymust adopt mitigation measures

aimed at protecting marine mammals to the greatest extent

practicable in light of military readiness needs.

We conclude that NMFS is required to prescribe

regulations to achieve the “least practicable adverse impact”

before it can authorize incidental take. While NMFS’s

finding that LFA sonar operations will have a “negligible

impact” on marine mammal populations is a required element

for approval of incidental take, it is not a substitute for an

analysis of whether the proposed mitigation measures in the

2012 Final Rule reduce the impact of incidental take on

marine mammals to the lowest level practicable. Compliance

with the “negligible impact” requirement does not mean there

was compliance with the “least practicable adverse impact”

standard during rulemaking. Moreover, NMFS did not in

agency proceedings contend that its finding of negligible

impact on populations meant it satisfied the “least practicable

adverse impact” standard for mitigation. NMFS makes that

argument only in its briefing on appeal, “underscor[ing] the

absence of an adequate explanation in the administrative

record itself.” Humane Soc. of U.S. v. Locke, 626 F.3d 1040,

1050 (9th Cir. 2010); see also Chenery, 332 U.S. at 196; State

Farm, 463 U.S. at 50 (explaining that “post hoc

rationalizations for agency action” are no substitute for “the

basis articulated by the agency itself”).

Having determined that NMFS was required to

promulgate regulations to effect the “least practicable adverse

impact,” we turn to examining what that standard requires

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and whether the 2012 Final Rule complied with it. In seeking

the meaning of “least practicable adverse impact,” we

naturally start with the language of the statute. United States

v. Am. Trucking Ass’ns, 310 U.S. 534, 543 (1940) (“There is,

of course, no more persuasive evidence of the purpose of a

statute than the words by which the legislature undertook to

give expression to its wishes.”). “Practicable” normally

means that something is capable of being done, or practical

and effective. Practicable, OED Online,

http://www.oed.com/view/Entry/149217; Practicable,

Merriam-Webster, http://www.merriam-webster.com/

dictionary/practicable. In context, a mitigation measure that

is practicable in reducing the impact of military readiness

activities on marine mammals must be both effective in

reducing impact, but also not so restrictive of military activity

as to unduly interfere with the government’s legitimate needs

for military readiness activities.9

NMFS in its Final Rule did not appear to disagree with

this formulation of the “least practicable adverse impact”

standard. In discussing its evaluation of the standard, it

stated:

We have reviewed the Navy’s proposed

SURTASS LFA sonar activities and the

proposed mitigation measures in the Navy’s

application to determine whether the resulting

activities and mitigation measures would

9 The need to focus on what is practicable can be illustrated with a

simple example. Ruling out 99% of the world’s oceans from LFA sonar

use would obviously provide more protection to marine mammals. But it

would not be practicable because it would so restrict military options for

readiness training, that it would render such training ineffective.

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effect the least practicable adverse impact on

marine mammals which includes a careful

balancing of the likely degree to which the

measure is expected to minimize adverse

impacts to marine mammals with the likely

effect of that measure on personnel safety,

practicality of implementation, and impact of

the effectiveness of the military readiness

activity (i.e., minimizing adverse impacts to

the lowest level practicable with mitigation

measures).

77 Fed. Reg. at 50294.

This formulation makes sense so far as it is stated

literally, but the problem arises that the Final Rule does not

meaningfully discuss how the mitigation measures meet that

“stringent standard.” Evans, 279 F. Supp. 2d at 1159. See

77 Fed. Reg. at 50295, 50303. Similarly, the Final Rule

states that “[o]ur responsibility under 16 U.S.C.

1371(a)(5)(A) and our implementing regulations is to

prescribe the means of effecting the least practicable adverse

impact, which involves consideration of impacts on military

readiness training and operations,” but nowhere in

rulemaking is that consideration provided. Merely reciting

the statutory language is not enough to satisfy the statute’s

explicit requirement.10 An agency acts contrary to the law

when it gives mere lip service or verbal commendation of a

standard but then fails to abide the standard in its reasoning

10 Defendants’ brief contends that NMFS did perform the required

analysis, but the segment of the Final Rule they cite discusses only the

“negligible impact” standard.

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and decision. See Conner v. Burford, 848 F.2d 1441, 1453

(9th Cir. 1988).

NMFS was required to analyze whether its proposed

mitigation measures reduce the effects of LFA sonar to the

“least practicable adverse impact.” 16 U.S.C.

§ 1371(a)(5)(A)(i)(I)–(II). The agency failed to do so. The

Final Rule gave only cursory attention to the requirement that

the impact to marine mammals caused by the Navy’s military

readiness activities be reduced to the least level practicable. 

Then, the agency in its briefing to us conflated the least

practicable adverse impact standard with the separate

obligation that the Final Rule have a negligible impact on

marine mammal species and stock. NMFS should have

considered whether additional mitigation measures were

necessary to achieve the least practicable adverse impact on

marine mammals, and also whether these mitigationmeasures

would be practicable in light of the Navy’s need for effective

military readiness training.

V

Reviewing the evidence before the agency, we conclude

that the “least practicable adverse impact” standard for

mitigation measures was not satisfied. The facts before

NMFS do not support its unexplained conclusion that the

Final Rule’s mitigation measures achieve the “least

practicable adverse impact” on marine mammal species,

stock, and habitat. 16 U.S.C. § 1371(a)(5)(A)(i)(II)(aa).

We consider the practical impacts of mitigation measures

adopted by NMFS and the likely practical impact of

mitigation measures that were not adopted. Plaintiffs, while

acknowledging that the three chosen mitigation measures

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reduce incidental take to some extent, contend that the

measures are not sufficient to effect the least practicable

adverse impact on marine mammal species, stock, and

habitat, as the MMPA requires. Plaintiffs do not challenge

the shutdown protocol and the coastal exclusion zone, two of

the three mitigation measures discussed in Part II above. 

They do, however, contend that these measures taken as a

whole are inadequate to make up for deficiencies in the third

mitigation measure, the designation of OBIAs.

The parties’ dispute over OBIA designation dates to the

beginning of the Navy’s LFA sonar program. In the two

previous iterations of LFA sonar rulemaking, many of the

same Plaintiffs in this case challenged NMFS’s OBIA

designations as underinclusive. Plaintiffs first challenged the

2002 Final Rule’s designation of only three OBIAs. Evans,

279 F. Supp. 2d at 1162. The district court concluded that

NMFS acted arbitrarily and capriciously in refusing to

designate more OBIAs despite knowing of potentially

sensitive areas, and that NMFS improperly shifted the burden

to members of the public to prove that more OBIAs were

necessary. Id. at 1163. Five years later, the 2007 Final Rule

prescribed 10 OBIAs, which Plaintiffs again challenged, and

which the district court again concluded were inadequate to

meet the MMPA’s least practicable adverse impact standard. 

Nat. Res. Def. Council v. Gutierrez, No. C-07-04771 EDL,

2008 WL 360852 at *10 (N.D. Cal. Feb. 6, 2008).

For its 2012 rulemaking, the most recent in the series,

NMFS flagged 73 candidate OBIAs by consulting prior

designated OBIAs, the World Database on Protected Areas,

the First and Second Editions of Marine Protected Areas for

Whales, Dolphins, and Porpoises by Dr. Erich Hoyt, and

senior NMFS scientists identified as “subject matter experts.” 

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77 Fed. Reg. at 50300. Four subject matter experts, all senior

NMFS scientists, raised concerns about OBIA selection to

NMFS’s Office of Protected Resources in a 2010 White

Paper titled Identifying Areas of Biological Importance to

Cetaceans in Data-Poor Regions. The White Paper authors

were concerned that identifying OBIAs based only on known

data would be difficult because in many instances, “relevant

cetacean data are lacking for the appropriate region or spatial

scale.” The White Paper recommended against equating

data-poor regions with “zero population density” or “no

biological importance.” Stated another way, the White Paper

cautioned that NMFS should not assume that no or minimal

data meant there were no or minimal cetacean populations in

those areas.

The subject matter experts concluded that “proven

ecological principles” suggest a precautionary approach that

protects three types of areas as OBIAs: (1) continental shelf

waters and waters within 100 km of the continental slope;

(2) 100 km around all islands and seamounts that rise within

500 meters of the ocean surface; and (3) regions of high

primary productivity, known to correspond to higher sperm

whale presence, as explained in a 2009 monograph that the

White Paper cites. Michael A. Huston & Steve Wolverton,

The Global Distribution of Net Primary Production:

Resolving the Paradox, 79 Ecological Monographs 343

(2009). Separate from the White Paper, but consistent with

itsrecommendations, the Marine MammalCommission urged

that it was “not possible” to “ensure adequate protection of

marine mammals” “if candidate areas are rejected simply

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because of insufficient information.”11 Again, no data does

not mean no cetaceans.

None of the subject matter experts who wrote the White

Paper was involved in drafting the Final Rule. The White

Paper appears to have played no role in the drafting of the

Final Rule until less than two months before the Final Rule

was finalized, when one of the rule drafters told the Navy that

she had “unearthed” the subject matter experts’ “guidelines

for selecting OBIAs in data-poor areas.” Even still, NMFS

only responded to the White Paper in the Final Rule

preamble’s response-to-comments section, which referred to

the White Paper’s authors as “several other commenters”

rather than as NMFS subject matter experts specifically

convened to provide their expertise to the selection process. 

77 Fed. Reg. at 50303.

NMFS’s chosen OBIA designation criteria differ

significantly from the White Paper’s recommendations. The

agency employed a multiple-step designation process that

required for designation presence of one or more of the

following attributes: high densities of animals, known

breeding/calving grounds, foraging grounds,migration routes,

or small distinct populations with limited distributions. 

NMFS evaluated these criteria based on what it termed the

“best available information.” This designation method

11 The Marine Mammal Commission is “a federal entity possessing

expertise on issues relating to the protection of marine mammals.” 

Humane Soc., 626 F.3d at 1051. The Commission is required under the

MMPA to, among other things, produce reports and recommendations on

the condition of marine mammals and the status of policies arranging for

their protection and to consult with NMFS. 16 U.S.C. § 1402.

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resulted in NMFS cutting nearly 70% of the candidate

OBIAs. 77 Fed. Reg. at 50299–300.

NMFS’s stated reason for cutting so many potential

OBIAs was that there were insufficient data proving at least

one of the chosen criteria above, even though such data do

not exist for most of the world’s oceans. NMFS also cut

some areas that its subject matter experts had nominated for

protection based on their judgment, regional expertise, or

non-peer-reviewed literature, stating that those areas

“require[d] more justification.” As the district court observed

in its review of the 2007 Final Rule’s OBIA selection, the

current list of OBIAs once again shows what the Marine

Mammal Commission deemed a “bias toward U.S. waters.” 

Only one OBIA was designated in each of the Caribbean Sea,

Mediterranean Sea, Antarctic Convergence Zone, Southeast

Atlantic, northwest Pacific, and southeast Pacific, and no area

was designated on the Pacific Coast of South America. By

contrast, NMFS designated four OBIAs each in the northwest

Atlantic and the Northeast Pacific.

Plaintiffs contend that the resulting list of 22 OBIAs was

an arbitrary and capricious policy choice. Defendants

respond that NMFS considered the White Paper’s

recommendations for data-poor regions but properly chose a

different approach, to which this court must defer. First,

Defendants contend that NMFS was under no obligation to

follow the White Paper’s guidelines, because the White Paper

itself acknowledged the existence of a policy choice between

a “precautionary” approach that “minimize[s] the chances of

overlooking biologically important areas,” or a “pure”

approach that “minimize[s] the chances of nominating sites

that are of marginal biological importance and, therefore

risk[s] overlooking biologicallyimportant areas.” Defendants

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contend that NMFS’s resulting policy choice is entitled to

deference, in essence that NMFS’s explaining its decision not

to adopt the White Paper’s recommendations is all that the

APA requires.

The district court agreed with Defendants. First, the

district court found that the White Paper acknowledged that

the “precautionary” approach that it advanced “risked

designating OBIAs in areas of ‘marginal biological

importance’ that did not meet NMFS’s criteria.” The district

court concluded that because the White Paper refrained from

choosing between the “precautionary” and “pure”

approaches, it was inappropriate for the district court to

substitute its judgment for that of the agency. The district

court was satisfied that “NMFS chose the pure approach and

explained its decision in the record, including reference to the

White Paper and reasons for choosing a different approach.” 

Second, the district court found it probative that the White

Paper did not recommend specific OBIAs, but only provided

guidelines for inferring biological significance.

Although review under the APA is deferential, here we

evaluate the agency’s choices in the context not just of the

APA, but also of the MMPA’s least practicable adverse

impact requirement, which sets a “stringent standard.” 

Evans, 279 F. Supp. 2d at 1159. We conclude that NMFS

erred because the measures adopted do not result in the “least

practicable adverse impact” on marine mammal species,

stock, and habitat.

OBIAs are a central component of the Final Rule’s

mitigation measures. The White Paper recommended a

“precautionary” approach toward OBIA designation. The

subject matter experts made clear that given the state of the

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science, particularly the many data-poor areas of the world’s

oceans, NMFS faced a choice whether to protect areas likely

to have biological importance based on “proven ecological

principles,” or instead to “minimize the chances of

nominating sites that are of marginal biological importance

and, therefore, risk overlookingbiologicallyimportant areas.” 

These competing options would either risk overprotection, or

risk underprotection. NMFS chose the latter option without

evaluating whether its choice satisfied the least practicable

adverse impact standard. It should have considered whether

the precautionary approach would give more protection to

marine mammals, and then whether that protection would

impede military training to a degree making that mitigation

not practicable.

For areas of potentially high biological importance,

NMFS’s protocol made non-designation the default, and

required specific data to overturn that conclusion. This

default is directly adverse to the subject matter experts’

recommended principle that shelf and slope areas should be

protected absent “specific data to the contrary.” NMFS

identified no science to support its conclusion that protecting

data-poor areas of potential importance as OBIAs would not

reduce adverse impacts on marine mammal species and

habitat. In fact, Defendants themselves, as well as the district

court, seem to agree with Plaintiffs that the Final Rule chose

to forego some protections that would have further reduced

the impact on marine mammals. For example, Defendants

accept that there may be alternative OBIA criteria or

mitigation measures that NMFS could have reasonably

selected, but argue that the agency’s choice should still be

given deference. Yet the MMPA requires the “least

practicable adverse impact,” and the agency has offered no

explanation why it meets that standard—in fact, as explained

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above, it instead argues that it does not have to meet that

standard.

Nor did NMFS consider more protected areas only to

conclude that more protection was not practicable. Although

Defendants argue that national security would be threatened

without the long-range detection capacity that LFA sonar

provides, NMFS’s decision to cut the list of potential OBIAs

did not rely on practical considerations that particular

additional OBIAs would impede military readiness training,

aside from one decision regarding the Southern California

Bight, which Plaintiffs did not challenge. Otherwise, military

practicability played no role in NMFS’s decision; in fact,

NMFS deemed it “immaterial.” Similarly, although counsel

for Defendants claimed at oral argument that the Final Rule

intended to balance the equities between military readiness

and conservation, we hold that such balancing must be made

explicit in rulemaking.

12

We owe “[o]ur highest deference” to the agency’s

“technical analyses and judgments within its area of

expertise.” League of Wilderness Defs. Blue Mountains

Biodiversity Proj. v. Allen, 615 F.3d 1122, 1131 (9th Cir.

2010). But we do not “rubber-stamp . . . administrative

decisions that [we] deem inconsistent with a statutory

mandate or that frustrate the congressional policy underlying

a statute.” Ocean Advocates v. U.S. Army Corps of

12 In rulemaking, it is not enough to assert without meaningful

discussion that more protective mitigation measures are impracticable. 

See Conservation Council for Haw. v. Nat’l Marine Fisheries Serv., 97 F.

Supp. 3d 1210, 1230 (D. Haw. 2015) (ruling that to meet the least

practicable adverse impact standard, “something more than a refusal to

consider mitigation measures and an unexplained assertion that further

mitigation is not practical is needed”).

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Engineers, 402 F.3d 846, 859 (9th Cir. 2005) (alterations in

original) (citation omitted). The agency decision here

conflicts with the statutory mandate requiring mitigation at

levels that yield the least practicable adverse impact. An

agency conclusion that is in “direct conflict with the

conclusion of its own experts,”—here, the agency’s drastic

reduction of OBIAs by eliminating candidate OBIAs in datapoor waters against the recommendations of its subject matter

experts—is arbitrary and capricious. W. Watersheds Proj. v.

Kraayenbrink, 632 F.3d 472, 492 (9th Cir. 2011).

Defendants also urge us to defer to the agency’s chosen

OBIA selection criteria, which differed from the White

Paper’s, on the ground that we should not second-guess an

agency’s reasonable treatment of scientific data. Defendants

rely on this court’s decision in San Luis & Delta-Mendota

Water Authority v. Jewell, 747 F.3d 581 (9th Cir. 2014), in

which we stated that we will “reject an agency’s choice of a

scientific model ‘only when the model bears no rational

relationship to the characteristics of the data to which it is

applied.’” Id. at 621 (first quoting Nat’l Wildlife Fed’n v.

EPA, 286 F.3d 554, 565 (D.C. Cir. 2002); then quoting

Appalachian Power Co. v. EPA, 135 F.3d 791, 802 (D.C. Cir.

1998)). In San Luis, experts differed on which of two

methods was best suited to assess the effect of certain water

projects on the endangered delta smelt. Id. The U.S. Fish

and Wildlife Service (FWS) chose the more conservative

method, and the court found that the choice was supported by

the record and within FWS’s discretion. Id. at 610. But here,

NMFS did not choose between competing methods designed

to answer the same question; it made a policy choice not to

protect areas—composing most of the world’s oceans—for

which little scientific data exist.

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This policy choice is underprotective compared to the

alternative proposed by the agency’s subject matter experts. 

Although NMFS considered the White Paper’s discussion of

data-poor regions, the record does not show that NMFS

critiqued the White Paper’s scientific analysis or concluded

that its proposed guidelines were unsound.13 NMFS instead

offered two reasons for refusing to designate additional

OBIAs based on the White Paper’s principles.

First, NMFS said that areas identified using the White

Paper’s ecological principles did “not meet the criteria we

established” for designating such areas. 77 Fed. Reg. at

50303–04. But this distinction is tautological. The White

Paper’s criteria were different than those NMFS ultimately

chose, but the difference itself does not explain why NMFS’s

criteria were equally or more capable of meeting the statutory

standard, particularly in areas where site-specific data do not

exist.

Defendants contend that NMFS need not consider

mitigation measures that are not supported by the best

available information because federalregulations provide that

the Final Rule and its mitigation measures are to be based on

the “best available information.” 50 C.F.R. § 216.105(c). 

Moreover, Defendants contend, “[t]he determination of what

constitutes the ‘best scientific data available’ belongs to the

agency’s ‘special expertise.’” San Luis, 747 F.3d at 602 (first

quoting 50 C.F.R. § 402.14(g)(8); then quoting Balt. Gas &

Elec. Co. v. Nat. Res. Def. Council, 462 U.S. 87, 103 (1983)). 

Defendants make a case that NMFS used the best available

science in deciding if a potential OBIA met its screening

 

13 NMFS said the White Paper was not “unearthed” until July 9, 2012,

less than two months before NMFS published its Final Rule on August 20.

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criteria. But the screening criteria themselves required a

definitive showing of biological significance even though

NMFS’s own experts concluded that “[t]he task of identifying

OBIAs for cetaceans is particularly difficult for regions in

which data on cetacean distribution or population density are

limited or lacking entirely, which includes the majority of the

world’s oceans.”

This selection of screening criteria, in our view, was a

policy choice, not a scientific determination. We review it

according to the standard voiced by the Supreme Court in

State Farm, and hold that NMFS “failed to consider an

important aspect of the problem,” namely the underprotection

that accompanies making conclusive data an indispensable

component of OBIA designation. 463 U.S. at 43. This

systematic underprotection of marine mammals cannot be

consistent with the requirement that mitigation measures

result in the “least practicable adverse impact” on marine

mammals.

Second, in response to the White Paper’s conclusion that

it is “not acceptable to proceed in the decision making

process as if the ‘no data’ scenario were equivalent to . . . ‘no

biological importance,’” NMFS reasoned that OBIAs are but

one component of a “suite” of mitigation measures. 77 Fed.

Reg. at 50304. However, the other two mitigation measures,

the shutdown zone and coastal exclusion zone, apply

regardless of whether an area is considered potentially

biologically important or not. Relative to these mitigation

measures, the only heightened protection possible under the

agency’s plan is designation as an OBIA. Defendants

repeatedly emphasize that NMFS’s decision not to designate

an area as an OBIA did not mean that the agency assumed the

area was biologically unimportant. But this is exactly how

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NMFS treated data-poor areas when it categorically barred

their designation as OBIAs.

Furthermore, theMMPA’s mitigation requirement applies

to marine mammal “species or stock and its habitat,” and

NMFS must “pay[] particular attention to rookeries, mating

grounds, and areas of similar significance[.]” 16 U.S.C.

§ 1371(a)(5)(A)(i)(II)(aa) (emphasis added). This statutory

guidance means that protecting marine mammal habitat from

the effects of LFA sonar is of paramount importance under

the MMPA. Defendants’ reference to their “suite” of

mitigation measures does not repair the underinclusive OBIA

designation protocol, particularlyin light of the subject matter

experts’ conclusion that “the other forms of mitigation [are]

considerably less effective than specifying OBIAs.” The

result is that a meaningful proportion of the world’s marine

mammal habitat is underprotected.

Relying on the other two mitigation measures—shutdown

upon detection of a marine mammal and a coastal exclusion

zone—in all areas of the ocean not designated as OBIAs

ignores that OBIAs are one of only two mitigation measures

capable of measurably reducing Level B harassment. The

shutdown zone around LFA sonar vessels is not large enough

to protect marine mammals from Level Beffects between 165

and 175 dB. As a result, unless an area is designated as an

OBIA or lies within 22 km of the coast, there is minimal

mitigation of Level B harassment. Although Defendants

emphasize that OBIAs are not the core component of the

Final Rule’s “suite” of mitigation measures, the record does

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not show that the other mitigation measures achieve the least

practicable adverse impact.14

14 To illustrate the underprotection given by NMFS’s designation

criteria, we note elimination in the 2012 Final Rule of two OBIAs that the

district court in Gutierrez faulted NMFS for refusing to include in the

2007 Final Rule: the Papahanaumokuakea Marine National Monument

(formerly named the Northwestern Hawaiian Islands Marine National

Monument) and the Galapagos Islands off the coast of Ecuador. 

Gutierrez, 2008 WL 360852 at *24. The district court here did not

analyze the exclusion of Papahanaumokuakea, other than repeating

Defendants’ determination that “[m]arine animals present in the

operational [national monument] area are more than adequately protected

by the Navy’s three-part mitigation monitoring (visual, passive acoustic,

and active acoustic), delay/shutdown protocols for LFAtransmissions, and

geographic restrictions,” and that the monument “is the habitat for the

endangered Hawaiian monk seal, which is not [a low-frequency] hearing

specialist. For this reason, the area did not qualify as an [OBIA].” But the

government’s management plan for Papahanaumokuakea says that “[t]he

waters of the Monument are also home to more than 20 cetacean species,

six of them federally recognized as endangered under the ESA . . . and

“depleted” under the Marine Mammal Protection Act . . . but

comparativelylittle is known about the distributions and ecologies ofthese

whales and dolphins . . . . Recent research . . . reveals that the Monument

also hosts many more humpback whales than originally thought.” 

Papahanaumokuakea Marine National Monument Management Plan,

December 2008, http://sanctuaries.noaa.gov/management/mpr/mprpapahanaumokuakeamp-2008.pdf. For Papahanaumokuakea, NMFS

faced the familiar choice of how to handle uncertainty, and chose

underprotection without adequately explaining the decision, or how the

least practicable adverse impact standard for mitigation was met.

The treatment of the Galapagos Islands is also illustrative. Like the

2012 Final Rule, the previous 2007 Final Rule did not designate this area

as an OBIA. The district court in Gutierrez noted with disapproval that

according to the government’s own website, the Galapagos Islands consist

of “‘highly productive coastal waters’that create ‘important feeding zones

for marine mammals . . . . Dolphins, orcas, and blue and humpback

whales are some of the 24 species of cetacean known to visit this refuge

for feeding and mating.’” Gutierrez, 2008 WL 360852 at *7. The district

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VI

Defendants contend, and the district court was persuaded,

that NMFS’s plans to engage in “adaptive management” will

in time allow the Final Rule to achieve the least practicable

adverse impact standard. For example, the Final Rule allows

NMFS and the Navy to specify additional OBIAs or other

forms of mitigation in annual letters of authorization (LOAs),

based on new information. Responding to the problem of

data-poor oceanic regions, the Final Rule notes: 

“Recognizing that many areas throughout the world’s oceans

currently have few data to support an OBIA designation at

this time, we and the Navy will continue to conduct literature

reviews under the adaptive management provision of this

regulation.” 77 Fed. Reg. at 50303. Moreover, “information

regarding data poor areas is likely to evolve over the five year

course of the final rule and beyond, and NMFS will consider

new information to continue identifying OBIAs for [LFA

sonar] operations.” Id. at 50304. Similarly, although the

Final Rule did not designate any OBIAs for sperm whales, it

promised to consider designating such OBIAs “through the

adaptive management process.” Id. at 50309.

court concluded that “the limited and skewed selection of OBIAs

demonstrates the arbitrariness of the decision not to designate more

OBIAs, including outside the United States.” Id. In this round of

litigation, the district court reversed course and cited with approval

NMFS’s stated reason for excluding the Galapagos Islands: “Even though

blue whales are reported to be present, there is no scientific evidence that

these whales occur in these waters in densities higher than any other

similar location. Therefore, this area was not recommended as an

[OBIA].” The district court concluded without analysis that “[o]n balance,

Defendants did not act arbitrarily or capriciously.” We disagree and hold

that Defendants arbitrarily gave insignificant weight to the district court’s

prior ruling.

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Despite these nods to the future, the Final Rule does not

require that any specific mitigation measure be taken as a

result of adaptive management activities. The mere

possibility of changing the rules to accommodate new

information does not satisfy the MMPA’s strict requirements

for mitigating the effects of incidental take. The district court

observed that “the duty to adopt in advance measures to

ensure the least practicable adverse impact cannot be met

simply by deferring to potential unknown future measures.” 

See also Greater Yellowstone Coal., Inc. v. Servheen,

665 F.3d 1015, 1029 (9th Cir. 2011) (“Just as it is not enough

simply to invoke ‘scientific uncertainty’ to justify an agency

action, it is not enough to invoke ‘adaptive management’ as

an answer to scientific uncertainty.”). We agree with these

principles and conclude that “adaptive management” is not an

answer to the failure to adopt mitigation measures effecting

the least practicable adverse impact on those marine mammal

species, stocks, and habitats.

VII

The 2012 Final Rule does not establish means of

“effecting the least practicable adverse impact on” marine

mammal species, stock, and habitat, as is specificallyrequired

by the MMPA. NMFS impermissibly conflated the “least

practicable adverse impact” standard with the required

“negligible impact” finding. The statute’s text makes clear

that to authorize incidental take, NMFS must achieve the

“least practicable adverse impact” standard in addition to

finding a negligible impact. NMFS also did not give

adequate protection to areas of the world’s oceans flagged by

its own experts as biologically important, based on the

present lack of data sufficient to meet NMFS’s designation

criteria, even though NMFS’s own experts acknowledged that

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NRDC V. PRITZKER 35

“[f]or much of the world’s oceans, data on cetacean

distribution or density do not exist.”

The district court’s grant of summary judgment to

Defendants is REVERSED and the matter is REMANDED

to the district court for further proceedings.

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