Court Opinion

ID: 6118228
Source: CourtListenerOpinion
Date Created: 2022-02-03 20:00:35.625173+00
Date Added: 2024-06-11T08:22:27.256427
License: Public Domain

PUBLISHED

                       UNITED STATES COURT OF APPEALS
                           FOR THE FOURTH CIRCUIT

                                      No. 20-2159

APPALACHIAN VOICES; WILD VIRGINIA; WEST VIRGINIA RIVERS
COALITION; PRESERVE GILES COUNTY; PRESERVE BENT MOUNTAIN, a
chapter of Blue Ridge Environmental Defense League; WEST VIRGINIA
HIGHLANDS       CONSERVANCY;       INDIAN    CREEK    WATERSHED
ASSOCIATION; SIERRA CLUB; DEFENDERS OF WILDLIFE; CHESAPEAKE
CLIMATE ACTION NETWORK; CENTER FOR BIOLOGICAL DIVERSITY,

      Petitioners,

v.

UNITED STATES DEPARTMENT OF THE INTERIOR; DEB HAALAND, in her
official capacity as Secretary of the U.S. Department of the Interior; UNITED
STATES FISH AND WILDLIFE SERVICE, an agency of the U.S. Department of
the Interior; AURELIA SKIPWITH, in her official capacity as Director of the U.S.
Fish and Wildlife Service; CINDY SCHULZ, in her official capacity as Field
Supervisor, Virginia Ecological Services, Responsible Official,

      Respondents,

MOUNTAIN VALLEY PIPELINE, LLC,

      Intervenor.

On Petition for Review of the United States Fish and Wildlife Service’s Biological Opinion
and Incidental Take Statement. (CP16-10-000)

Argued: October 29, 2021                                      Decided: February 3, 2022

Before GREGORY, Chief Judge, and WYNN and THACKER, Circuit Judges.
Vacated and remanded by published opinion. Judge Wynn wrote the opinion, in which
Chief Judge Gregory and Judge Thacker joined.

ARGUED: Elizabeth Fay Benson, SIERRA CLUB, Oakland, California, for Petitioners.
Kevin William McArdle, UNITED STATES DEPARTMENT OF JUSTICE, Washington,
D.C., for Respondents. George Peter Sibley, III, HUNTON ANDREWS KURTH, LLP,
Richmond, Virginia, for Intervenor. ON BRIEF: Nathan Matthews, SIERRA CLUB,
Oakland, California; Benjamin A. Luckett, Derek O. Teaney, APPALACHIAN
MOUNTAIN ADVOCATES, Lewisburg, West Virginia, for Petitioners. Jean E.
Williams, Acting Assistant Attorney General, Environment and Natural Resources
Division, UNITED STATES DEPARTMENT OF JUSTICE, Washington, D.C.; S.
Amanda Bossie, UNITED STATES DEPARTMENT OF THE INTERIOR, Washington,
D.C., for Respondents. J. Pierce Lamberson, HUNTON ANDREWS KURTH LLP,
Richmond, Virginia; Sandra A. Snodgrass, HOLLAND & HART LLP, Denver, Colorado;
W. Parker Moore, Katrina M. Krebs, BEVERIDGE & DIAMOND, PC, Washington, D.C.,
for Intervenor.

                                       2
WYNN, Circuit Judge:

       Petitioners, a collection of environmental nonprofit organizations, challenge the

Fish and Wildlife Service’s 2020 Biological Opinion and Incidental Take Statement for the

Mountain Valley Pipeline. They allege, among other things, that the agency failed to

adequately consider the project’s environmental context while analyzing impacts to two

species of endangered fish, the Roanoke logperch and the candy darter. We agree, and

therefore vacate the 2020 Opinion and Incidental Take Statement and remand for further

proceedings.

                                              I.

       Before we can analyze the merits of this case, we must lay out some background

details. We begin by briefly describing the relevant legal framework. Then, we turn to the

facts and procedural history of this case. Finally, we describe the biological context for the

two endangered species at issue.

                                             A.

       The Endangered Species Act of 1973 (“Endangered Species Act” or “the Act”)

represents “the most comprehensive legislation for the preservation of endangered species

ever enacted by any nation.” Tenn. Valley Auth. v. Hill, 437 U.S. 153, 180 (1978); Jacob

Malcom & Andrew Carter, Better Representation Is Needed in U.S. Endangered Species

Act Implementation, 2 Frontiers in Conservation Sci., April 20, 2021, at 1, https://doi.org/

10.3389/fcosc.2021.650543 (“The U.S. Endangered Species Act . . . is often considered

the strongest conservation law in the world for imperiled wildlife.”) (saved as ECF opinion

attachment). “The plain intent of Congress in enacting this statute was to halt and reverse

                                              3
the trend toward species extinction, whatever the cost.” Tenn. Valley Auth., 437 U.S. at

184. To that end, the Endangered Species Act requires federal agencies “to afford first

priority to the declared national policy of saving endangered [or threatened] species”—

even when this goal conflicts with agencies’ “primary missions.” Id. at 185. The Act also

prohibits “[v]irtually all dealings with [listed] species” by any individual or entity “except

in extremely narrow circumstances.” Id. at 180.

       These “broad[ly] sweep[ing]” policies are codified in Sections 7 and 9 of the

Endangered Species Act. Id. at 188. Section 7 requires federal agencies to ensure that “any

action authorized, funded, or carried out by [the] agency . . . is not likely to jeopardize the

continued existence of any [listed] species.” 16 U.S.C. § 1536(a)(2). To “jeopardize the

continued existence” means “to engage in an action that reasonably would be expected,

directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery

of a listed species in the wild by reducing the reproduction, numbers, or distribution of that

species.” 50 C.F.R. § 402.02.

       This substantive duty to avoid jeopardy is policed by a procedural consultation

requirement. 16 U.S.C. § 1536(a)(2). Whenever an agency action “may affect listed

species,” the agency must formally consult with the Fish and Wildlife Service. 50 C.F.R.

§ 402.14(a). During consultation, the Fish and Wildlife Service must formulate a

“biological opinion” on whether that action, in light of the relevant environmental context,

“is likely to jeopardize the continued existence of [those] species.” Id. § 402.14(g). In

making this determination, the Fish and Wildlife Service must “use the best scientific and

commercial data available.” 16 U.S.C. § 1536(a)(2); 50 C.F.R. § 402.14(g)(8).

                                              4
       Section 9 of the Endangered Species Act broadly prohibits the “take” of any listed

species. 16 U.S.C. § 1538(a)(1)(B). To “take” means to “harass, harm, . . . wound, [or]

kill, . . . or to attempt to engage in any such conduct.” Id. § 1532(19). If the Fish and

Wildlife Service determines that an agency action is not likely to jeopardize a listed species

but is “reasonably certain” to lead to incidental “take” of that species, it must provide the

action agency with an incidental take statement. 50 C.F.R. § 402.14(g)(7), (i). This

statement shall specify the “amount or extent” of incidental take, “reasonable and prudent”

mitigation measures, and “terms and conditions” to implement those measures. Id.

§ 402.14(i)(1). Any incidental take consistent with these limits is not prohibited by

Section 9. Id. § 402.14(i)(5). But whenever these limits are exceeded the action agency

must “reinitiate consultation immediately.” Id. § 402.14(i)(4).

                                             B.

       The Mountain Valley Pipeline (the “Pipeline” or the “Project”) is a 42-inch

diameter, 304-mile proposed natural gas pipeline stretching from West Virginia to

Virginia. The proposed route crosses seventeen counties and more than 1,100 streams, and

will disturb 6,951 acres of land, including 4,168 acres of soils that have the potential for

severe water erosion. Nearly one-quarter of the proposed Pipeline will traverse slopes

greater than 30%. 1 When fully complete, the Pipeline will deliver up to two billion cubic

feet of natural gas per day to markets in the mid-Atlantic and Southeast.

       1
        For comparison, black diamond ski slopes—among the steepest and most difficult
runs on any mountain—typically “have a gradient of 40% or higher.” SKI Profiles, Ski
Slope Levels: What Are They and What Skill Do I Need? (Nov. 12, 2019),

                                              5
       The Federal Energy Regulatory Commission (“FERC”) authorized construction of

the Project on October 13, 2017. Mountain Valley Pipeline, LLC, 161 FERC ¶ 61,043

(2017) (order issuing certificates). Because the Project could impact listed species, FERC

consulted with the Fish and Wildlife Service, as required by Section 7 of the Endangered

Species Act. About a month later, the Fish and Wildlife Service submitted its original

Biological Opinion and Incidental Take Statement to FERC. This opinion concluded the

Project was not likely to jeopardize any of the listed species it examined, including the

Roanoke logperch and the Indiana bat.

       On July 27, 2018, this Court found the U.S. Forest Service violated the National

Environmental Policy Act (“NEPA”) when it adopted FERC’s Environmental Impact

Statement for the Project. Sierra Club, Inc. v. U.S. Forest Serv., 897 F.3d 582, 596 (4th

Cir.), reh’g granted in part on other grounds, 739 F. App’x 185 (4th Cir. 2018). In relevant

part, we held that the Forest Service arbitrarily adopted FERC’s flawed sedimentation

analysis when assessing impacts to the Jefferson National Forest. Id. A few months later,

U.S. Geological Survey scientist Dr. Paul Angermeier sent comments to the Fish and

Wildlife Service, pointing out that the same arbitrary assumptions undergirded its 2017

Biological Opinion’s assessment of the Project’s impacts on the logperch. He also

identified several other “unjustified” analytical choices that caused the Fish and Wildlife

Service to “significantly underestimate potential impacts” of the Project on the logperch.

https://skiprofiles.com/ski-slope-levels-what-skill-do-i-need/ (saved as ECF opinion
attachment).

                                             6
J.A. 1358–66. 2 Around the same time, the Fish and Wildlife Service published a final rule

listing the candy darter as endangered. Endangered and Threatened Wildlife and Plants;

Endangered Species Status for the Candy Darter, 83 Fed. Reg. 58,747 (Nov. 21, 2018)

(codified at 50 C.F.R. pt. 17).

       On August 12, 2019, several of the Petitioners filed a petition for review with this

Court and separately requested that the Fish and Wildlife Service stay its 2017 Biological

Opinion. The agency denied the stay request because Mountain Valley Pipeline, LLC

(“Mountain Valley”) had already voluntarily suspended certain activities. On August 21,

these groups requested a judicial stay pending review of their petition. Shortly after, this

Court issued an order staying the 2017 Biological Opinion.

       During this same time period, FERC reinitiated consultation for the Project with the

Fish and Wildlife Service. On September 4, 2020, the Fish and Wildlife Service issued a

new Biological Opinion (“BiOp” or “2020 BiOp”) and Incidental Take Statement. The Fish

and Wildlife Service determined that the Project was likely to adversely affect five listed

species: a shrub called the Virginia spiraea, the Roanoke logperch, the candy darter, the

Indiana bat, and the northern long-eared bat. However, the agency ultimately found that

the Project was unlikely to jeopardize any of these five species.

       On October 27, 2020, Petitioners filed a petition for review. A few days later we

granted Mountain Valley’s motion to intervene.

       2
        Citations to the “J.A.” refer to the Joint Appendix filed by the parties in this appeal.
Citations to the “S.J.A.” refer to the Sealed Joint Appendix.

                                               7
                                              C.

       Petitioners’ current petition for review concerns three endangered species: the

Roanoke logperch, candy darter, and Indiana bat. 3 We need only describe the factual

context for the first two. 4

       3
         Throughout this opinion, we refer to the Roanoke logperch as the “logperch” and
the candy darter as the “darter.” This is for ease of reference only, and is not meant to imply
that the logperch is not a species of darter (it is), or that we are talking about any other
species sharing the logperch or darter names.
       4
         Because the Fish and Wildlife Service’s deficient analysis of the logperch and
darter requires us to vacate and remand, we find it unnecessary to address Petitioners’
claims concerning the arbitrary nature of the Incidental Take Statement for the Indiana bat.
See Or. Nat. Res. Council v. Allen, 476 F.3d 1031, 1041 (9th Cir. 2007) (holding that when
the “underlying BiOp has been [vacated], the Incidental Take Statement lacks a rational
basis”); see also id. at 1036–37 (“Without understanding the scope and purpose of the
action itself—information contained in the BiOp—there is no way to know whether the
take being authorized is properly ‘incidental.’”).

        However, on remand, we recommend that the Fish and Wildlife Service further
explain why it anticipates no effects to the bat from clearing more than 1,000 acres of
suitable but unoccupied summer habitat. In 2017, the agency found that the “majority of
effects to [the bat]” from the nearby Atlantic Coast Pipeline “will occur” from tree clearing
of this same habitat type—even though no bats were identified in summer surveys of these
areas. J.A. 1512 (emphasis added). These effects were anticipated because bats, including
pregnant females, may use these areas “as a travel corridor between hibernacula and roost
trees” in non-summer months. J.A. 1512.

        In contrast, for the 2020 BiOp the Fish and Wildlife Service found that clearing
suitable but unoccupied summer habitat would have no adverse effects on the bat because
2015–16 summer survey results “indicate that [Indiana bats] are not present.” J.A. 82. But
summer surveys would necessarily fail to account for bats traveling through these areas
during non-summer months. The Fish and Wildlife Service appreciated this fact in 2017;
it anticipated impacts to the bat from clearing suitable unoccupied summer habitat even
though no bats were found there during the summer. On remand, the agency must explain
why it has now come to a different conclusion based on similarly negative summer-only
survey results.

                                              8
                                            1.

        The Roanoke logperch is an endangered freshwater fish endemic to Virginia and

North Carolina. The logperch inhabits medium to large warmwater streams and requires

“[m]icrohabitats with loosely embedded substrate free of silt.” J.A. 45. They reach sexual

maturity after two to three years but can live up to 6.5 years. Logperch are benthic (bottom-

dwelling) sight feeders that “flip rocks with their snout to expose invertebrates and ingest

the exposed prey.” J.A. 46. Increased sedimentation can wipe out many of the invertebrates

that logperch feed on and interfere with their ability to see prey. Sedimentation can also

interfere with egg and larval development and cause the production of fewer and smaller

eggs.

       We also encourage the agency to further clarify—in the BiOp—why its 2015–16
Indiana bat surveys are still valid. It is unclear from the record whether surveys from this
time period are valid for a minimum of two, three, or five years. Compare J.A. 82 (2020
BiOp noting that “[s]ince 2018” the agency “has accepted negative surveys rangewide for
a minimum of 5 years . . . [while] prior to that it was a minimum of 2 years”), with J.A.
1282 (letter from Fish and Wildlife Service Deputy Assistant Regional Director noting that
a bat survey completed using pre-2018 guidelines “remains valid for 3 years”). Though
these minimum time frames will undoubtedly be exceeded on remand, “[t]here is no
automatic expiration of survey results . . . as these are minimum[]” time frames. J.A. 82
(emphasis added). And it probably still makes sense to rely on these older surveys as the
last—and therefore best—snapshot of bat activity in the area pre-Project. After all, most of
the suitable unoccupied summer habitat has already been cleared. But if that is so, the
agency must make it explicit.

                                             9
Figure 1: Adult male Roanoke logperch. J.A. 1613.

       The Roanoke logperch is only found in four river systems within Virginia and North

Carolina: the Nottoway, Pigg, Roanoke, and Smith Rivers. These four river systems are

home to seven distinct populations. The Project will impact two of these populations

located in the Pigg and Roanoke Rivers. Because these two watersheds “cover a large

geographic extent, contain an estimated large population, and run a lower risk of being

susceptible to extirpation,” they are expected to “underpin the recovery of the species.”

J.A. 73. The Roanoke River population in particular “harbors the majority of the species’

extant genetic diversity” and therefore “should receive the highest priority for protection.”

J.A. 1238. In total, the Project will impact 6.7 kilometers of habitat in the Pigg River

system, resulting in take of 6.7% of the Pigg River population. The Project will also impact

17.6 kilometers of habitat in the Roanoke watershed, resulting in take of 14.9% of the total

estimated Roanoke River population.

                                             10
                                             2.

       The candy darter is an endangered freshwater fish endemic to Virginia and West

Virginia. It is a “habitat specialist” that is “typically found in high- to moderate-gradient,

cool- or cold-water stream ecosystems.” J.A. 50. This species has a “relatively short life

cycle, reaching sexual maturity by age 2 and often dying during their third year.” J.A. 50.

The candy darter is “generally intolerant of excessive stream sedimentation”; indeed,

“[e]xcessive sedimentation was likely a primary cause of the [darter’s] historical decline.”

J.A. 50, 53. The darter is not as mobile as its logperch cousin, meaning it “will likely not

avoid areas of heavy sediment deposition by moving to other areas of suitable habitat

within the system.” J.A. 111.

Figure 2: Adult male candy darter. J.A. 1416.

       Eighteen fragmented populations of candy darter remain. Many of these populations

are threatened by excessive sedimentation and hybridization with the closely related

variegate darter. Due largely to the increasing threat of hybridization, a 2018 Species Status

Assessment Report predicted the species’ “most likely future scenario” is near-total

                                             11
extirpation across its current range, which “significantly increases the candy darter’s risk

of extinction over the next 25 years.” J.A. 1408, 1462. Importantly, the two populations

that will be impacted by the Pipeline—the Gauley River and Stony Creek populations—

have yet to experience significant hybridization. Because they are “among the most

genetically pure populations” remaining, they are “essential to the recovery of the species.”

J.A. 75 (emphasis added). In total, the Pipeline is projected to impact 2 of the 44 kilometers

of proposed critical habitat in the Upper Gauley River and 1 of the 31 kilometers of

proposed critical habitat in Stony Creek. 5

                                              II.

       This Court has original and exclusive jurisdiction to review the BiOp under the

Natural Gas Act. See 15 U.S.C. § 717r(d)(1). “Because the Endangered Species Act does

not specify a standard of review, we apply the general standard of review of agency action

established by” the Administrative Procedure Act. Sierra Club v. U.S. Dep’t of the Interior,

899 F.3d 260, 270 (4th Cir. 2018) (citation and internal quotation marks omitted).

       Under the Administrative Procedure Act, we must “hold unlawful and set aside

agency action, findings, and conclusions found to be . . . arbitrary, capricious, an abuse of

discretion, or otherwise not in accordance with law.” 5 U.S.C. § 706(2)(A). Agency action

is arbitrary and capricious “if the agency has relied on factors which Congress has not

       5
         The Fish and Wildlife Service did not calculate a numeric incidental take estimate
for the darter because “data is either unavailable (Gauley River) or lacks the precision
needed to generate meaningful take estimates (Stony Creek), and such data cannot be
readily obtained.” J.A. 172.

                                              12
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.” Motor Vehicle Mfrs. Ass’n of U.S. v. State Farm Mut. Auto. Ins. Co.,

463 U.S. 29, 43 (1983).

       “Review under this standard is highly deferential, with a presumption in favor of

finding the agency action valid.” Ohio Valley Env’t Coal. v. Aracoma Coal Co., 556 F.3d

177, 192 (4th Cir. 2009). “Nevertheless, we must conduct a ‘searching and careful’ review

to determine whether the agency’s decision ‘was based on a consideration of the relevant

factors and whether there has been a clear error of judgment.’” Sierra Club, 899 F.3d at

270 (quoting Marsh v. Or. Nat. Res. Council, 490 U.S. 360, 378 (1989)). In determining

whether such an error was made, the “reviewing court may look only to [the agency’s]

contemporaneous justifications” for its actions. Dow AgroSciences LLC v. Nat’l Marine

Fisheries Serv., 707 F.3d 462, 467 (4th Cir. 2013). Because “an agency’s action must be

upheld, if at all, on the basis articulated by the agency itself,” “courts may not accept

appellate counsel’s post hoc rationalizations for agency action.” State Farm, 463 U.S. at

50.

       Petitioners advance numerous challenges to the 2020 BiOp. We start by assessing

Petitioners’ claim that the Fish and Wildlife Service did not adequately analyze the

environmental context for the Roanoke logperch and candy darter. Because we agree with

Petitioners’ argument, we conclude we must vacate and remand on that basis. Next, we

                                            13
address additional minor challenges further attacking the agency’s analysis and Incidental

Take Statement. We conclude these additional challenges are meritless.

                                             A.

       When it comes to protecting listed species, environmental context is critical. See

Pac. Coast Fed’n of Fishermen’s Ass’ns v. U.S. Bureau of Reclamation, 426 F.3d 1082,

1093 (9th Cir. 2005) (holding a proper jeopardy analysis requires investigating whether

“jeopardy might result from the agency’s proposed actions in the present and future human

and natural contexts”). If the Fish and Wildlife Service conducted its “jeopardy analysis in

a vacuum,” focusing only on the individual agency action at issue, then “a listed species

could be gradually destroyed, so long as each step on the path to destruction [wa]s

sufficiently modest.” Nat’l Wildlife Fed’n v. Nat’l Marine Fisheries Serv., 524 F.3d 917,

929–30 (9th Cir. 2008). But this “slow slide into oblivion is one of the very ills the

[Endangered Species Act] seeks to prevent.” Id. at 930.

       The Act guards against this danger by requiring the Fish and Wildlife Service to

formulate its biological opinion in three primary steps.

       First, the Fish and Wildlife Service must “[r]eview all relevant information provided

by the [action] agency or otherwise available.” 50 C.F.R. § 402.14(g)(1) (emphases

added). This requirement meshes with, and is partially derived from, the Act’s mandate to

“use the best scientific and commercial data available.” 16 U.S.C. § 1536(a)(2). These are

not passive directives; rather, the Fish and Wildlife Service “must seek out and consider

all existing scientific data relevant to the decision it is tasked with making.” Defs. of

Wildlife v. U.S. Dep’t of the Interior, 931 F.3d 339, 346 (4th Cir. 2019).

                                             14
       Second, the Fish and Wildlife Service must “[e]valuate” four different categories of

information: (1) the “current status” of the listed species; (2) the “environmental baseline”;

(3) the “cumulative effects” of non-federal action; and (4) the “effects of the [agency]

action.” 50 C.F.R. § 402.14(g)(2), (3). This case primarily concerns the middle two

categories: the “environmental baseline” and “cumulative effects.”

       The “environmental baseline” is defined by the Fish and Wildlife Service’s

regulations as “the condition of the listed species or its designated critical habitat in the

action area, without the consequences to the listed species or designated critical habitat

caused by the proposed action.” 6 50 C.F.R. § 402.02. This includes “the past and present

impacts of all Federal, State, or private actions and other human activities in the action

area” as well as the “anticipated impacts” of contemporaneous actions. Id. (emphasis

added). This definition is further fleshed out in the Fish and Wildlife Service’s Consultation

Handbook, which describes the “environmental baseline [a]s a ‘snapshot’ of a species’

health at a specified point in time.” U.S. Fish & Wildlife Serv. & Nat’l Marine Fisheries

Serv., Endangered Species Consultation Handbook 4-22 (1998) [hereinafter “Consultation

Handbook”]. 7 This “snapshot” folds in the “effects of past and ongoing human and natural

       6
         The action area is the area “to be affected directly or indirectly by the Federal
action.” 50 C.F.R. § 402.02.
       7
        This document provides internal guidance for the Fish and Wildlife Service during
consultation. Notice of Availability of Final Endangered Species Consultation Handbook
for Procedures for Conducting Consultation and Conference Activities Under Section 7 of
the Endangered Species Act, 64 Fed. Reg. 31,285 (June 10, 1999). Though it is over twenty
years old, the definition of environmental baseline has changed only slightly since, and the
Fish and Wildlife Service still considers the Consultation Handbook relevant.

                                             15
factors leading to the current status of the species,” as well as an analysis of the local

ecosystem and the species’ habitat in the action area. Id.

       “[C]umulative effects” are defined by the Fish and Wildlife Service’s regulations as

“those effects of future State or private activities, not involving Federal activities, that are

reasonably certain to occur within the action area.” 50 C.F.R. § 402.02. “‘[R]easonably

certain to occur’ does not require a guarantee the action will occur,” but wholly

“[s]peculative non-Federal actions that may never be implemented are not factored into the

‘cumulative effects’ analysis.” Consultation Handbook at 4-30 (emphasis added). This

definition is “narrower” than that found in since-repealed implementing regulations for

NEPA, although there was certainly overlap between the two. 8 Id. at 4-31 (suggesting the

Fish and Wildlife Service “can review the broader NEPA discussion of cumulative effects”

in any NEPA analyses conducted for a project and then “apply the [Endangered Species]

Act’s narrower cumulative effects definition” to those analyses).

       Though climate change could be considered a cumulative effect, see Turtle Island

Restoration Network v. U.S. Dep’t of Com., 878 F.3d 725, 736 (9th Cir. 2017), it does not

fit neatly into just this category. We take no position on whether climate change is best

addressed as a baseline factor, cumulative effect, some mixture of the two, or something

else entirely. See Wild Fish Conservancy v. Irving, 221 F. Supp. 3d 1224, 1234 (E.D. Wash.

       8
        This regulation was still in effect when FERC prepared its original Environmental
Impact Statement for the Project. The regulation defined cumulative impacts as “impacts
on the environment which result from incremental impact of the [proposed] action when
added to other past, present, and reasonably foreseeable future actions.” J.A. 1566 (quoting
40 C.F.R. § 1508.7 (1978)).

                                              16
2016) (“It is, of course, not the Court’s place to tell the agency how to . . . consider climate

change in its analysis, it simply must consider it.”); J.A. 49 (Fish and Wildlife Service

mentioning climate change as part of its environmental baseline analysis for the logperch);

Response Br. at 21 (Fish and Wildlife Service referring to climate change as a “current and

future baseline” factor). It is clear, however, that climate change typically must form part

of the analysis in some way. S. Yuba River Citizens League v. Nat’l Marine Fisheries Serv.,

723 F. Supp. 2d 1247, 1274 (E.D. Cal. 2010) (reviewing cases finding that the “failure to

discuss the impacts of climate change rendered BiOps arbitrary and capricious”).

       Third, and finally, the Fish and Wildlife Service must “[a]dd the effects of the action

and cumulative effects to the environmental baseline and[,] in light of the status of the

species and critical habitat, formulate [its] opinion as to whether the action is likely to

jeopardize the continued existence of [the] listed species.” 50 C.F.R. § 402.14(g)(4)

(emphases added). In effect, the Fish and Wildlife Service must make its jeopardy

determination while viewing the action “against the aggregate effects of everything that

has led to the species’ current status and, for non-Federal activities, those things

[reasonably certain] to affect the species in the future.” Consultation Handbook at 4-35.

       Petitioners here allege issues with the second and third steps. We consider them

each in turn.

                                              1.

       Petitioners first argue—at the second primary step of the Fish and Wildlife Service’s

biological-opinion process—that the agency failed to adequately evaluate the

“environmental baseline” and “cumulative effects” for two listed species: the Roanoke

                                              17
logperch and the candy darter. They also allege that the agency neglected to fully consider

the impacts of climate change. We agree on all counts.

                                               i.

       We turn first to the Fish and Wildlife Service’s evaluation of the environmental

baseline. As noted above, the agency must evaluate the environmental baseline within “the

action area.” 50 C.F.R. § 402.02 (emphasis added). The action area is the area “to be

affected directly or indirectly by the Federal action.” Id. In this case, the action area

includes the Pipeline construction right-of-way and waterbodies that may be impacted by

the Project. We conclude that while the BiOp ably describes the range-wide conditions of

the Roanoke logperch and the candy darter, it fails to adequately evaluate the

environmental baseline for these species within the action area itself.

       To begin, the BiOp’s evaluation of the environmental baseline for the logperch is

sparse and scattered. 9 It starts by discussing the species’ range-wide status and population-

level threats, though the latter information is fifteen years old. See J.A. 45–48 (referencing

a 2007 Fish and Wildlife Service study). It also mentions watershed-level characteristics

of the Roanoke and Pigg Rivers. The BiOp then narrows its focus, describing basic habitat

       9
         Only some of what follows is actually within the “Environmental Baseline” section
of the BiOp. But this is a distinction without a difference; the question is whether this factor
was evaluated by the Fish and Wildlife Service, not what section of the BiOp it is in. Cf.
Oceana, Inc. v. Pritzker, 125 F. Supp. 3d 232, 242 (D.D.C. 2015) (concluding that the
agency properly analyzed cumulative impacts by relying on population trends and
trajectories set forth in the “Status of the Species” and “Environmental Baseline” sections
of the biological opinion); 5 U.S.C. § 706 (requiring courts to “review the whole record”
when assessing agency actions).

                                              18
conditions for some, but not all, of the Project’s crossings. 10 Compare, e.g., J.A. 72 (noting

the Harpen Creek crossing “was classified as low gradient with shallow riffles that exhibit

heavy embeddedness and siltation”), with J.A. 71–72 (neglecting to describe the in-stream

habitat for the North Fork Roanoke River 1 crossing). It also mentions that the logperch’s

“decline in the action area is primarily the result of destruction and modification of habitat

and fragmentation of the species range.” J.A. 72 (emphases added). It then zooms back out

to note that, generally speaking, the “[p]rimary causes of [logperch] habitat degradation

include chemical spills, non-point runoff, channelization, impoundments, impediments,

and siltation.” J.A. 72–73.

       This is an inadequate evaluation. In effect, the Fish and Wildlife Service is

attempting to pass off its summary of range-wide conditions and threats as an action-area

analysis. But vaguely referring to the “destruction and modification of habitat” within the

action area, without explaining the specific causes or extent of this local degradation, leaves

us guessing at what the baseline condition for the logperch might actually be.

       In fact, other portions of the record suggest that a host of unaddressed stressors

might already be impacting logperch in the action area. For example, the Fish and Wildlife

Service acknowledges that “there are numerous state and private activities currently

       10
           Though we applaud the Fish and Wildlife Service for describing the habitat
conditions for at least a few of the crossings, these crossings are not the only part of the
action area. The action area also includes stream segments upstream and downstream of
the crossing, as well as “stream[s] expected to experience a measurable increase in
[P]roject-related sediment” and “the mixing zone in a stream segment where sediment from
tributaries (crossed or receiving sediment from the [P]roject) is delivered to streams of
interest.” J.A. 40.

                                              19
occurring within the action area.” J.A. 141 (emphasis added). However, it never tells us

what these activities are, or what impact they may be having. Similarly, Mountain Valley

noted that “[n]umerous known third-party land disturbance activities (e.g., agriculture,

timber, mining, and off-road vehicle tracks) exist immediately adjacent to the aquatic

species streams and the[ir] tributaries.” J.A. 430 (emphasis added); see also J.A. 1558

(2017 Environmental Impact Statement showing mining activity along the proposed

Pipeline route in watersheds supporting the logperch). Yet the BiOp fails to evaluate the

impact of these “immediately adjacent” operations.

       Even if we were to agree that the Fish and Wildlife Service’s one-sentence recitation

of general threats to the logperch passes as an action-area analysis—and we do not—there

are several other factors it neglected to discuss. For example, the agency previously flagged

“watershed urbanization,” road development, and loss of “woody debris” due to local

deforestation as important stressors for the Roanoke and Pigg River populations generally.

J.A. 1667–70. But the Fish and Wildlife Service fails to analyze whether these population-

level stressors are still impacting logperch within the action area.

       To be sure, the Fish and Wildlife Service has a stronger argument that it properly

evaluated the environmental baseline for the candy darter. 11 The BiOp starts by describing

the species’ conservation needs, current distribution, and range-wide threats. Next, it notes

the genetic importance of the Upper Gauley River and Stony Creek populations—the two

       11
         Some of the material that follows is sourced from the Fish and Wildlife Service’s
discussion of the status of proposed critical habitat. But again, it does not matter where this
information is evaluated within the BiOp, so long as it is evaluated.

                                              20
populations the Project will impact—and describes the general health of these populations.

It also extensively describes the ecological conditions in these areas, including data on local

forest cover, water temperatures, anthropogenic impairments, invasive species, and habitat

connectivity.

       Nonetheless, the Fish and Wildlife Service’s evaluation still falls short. Though the

agency admirably describes conditions at the population level, it never narrows its analysis

to focus on the specific action area. If it had, it might have noted that the lower reaches of

Stony Creek—precisely where the Pipeline will cross—are “adjacent to a large

underground limestone mine, an associated lime plant, a railroad spur line, and a paved

road.” J.A. 1443. In addition, the “lower portions of Stony Creek dry up periodically as a

result of water leaking into a local mine”—presumably the same limestone mine. S.J.A.

1888. Yet these stressors are not expressly addressed in the BiOp.

       The Fish and Wildlife Service and Mountain Valley advance two primary

counterarguments. First, they argue that the Fish and Wildlife Service was not required to

“provide an inventory” of “each activity that has occurred or is occurring in the action

area.” Response Br. at 18; see also Intervenor’s Br. at 21–22. Rather, the definition of

“environmental baseline” requires the Fish and Wildlife Service to describe the “condition”

of the listed species and assess “impacts” of human activities in the action area. Response

Br. at 18; Intervenor’s Br. at 21. Requiring more, they contend, would “graft extra

procedural requirements onto the regulations.” Intervenor’s Br. at 22; see also Response

Br. at 18.

                                              21
       This argument is a red herring. It is true that the Endangered Species Act

implementing regulations do not require the Fish and Wildlife Service to list past and

ongoing activities. See 50 C.F.R. § 402.02. In fact, merely listing activities fails to satisfy

the agency’s regulatory responsibilities. Defs. of Wildlife v. Babbitt, 130 F. Supp. 2d 121,

128 (D.D.C. 2001) (“There must be an analysis of the status of the environmental baseline

given the listed impacts, not simply a recitation of the activities of the agencies.”). But

Petitioners are not asking for a list of past and present activities; they are asking for the

impacts of those activities to be accounted for—as required by the Act. See id. And neither

the Fish and Wildlife Service nor Mountain Valley adequately explain how the BiOp could

account for these impacts if the activities giving rise to them are never even mentioned.

       For example, how can the agency account for impacts on the logperch stemming

from the loss of “woody debris” in the Roanoke and Pigg watersheds if it never even

discusses this stressor at the action-area level? The answer, according to the Fish and

Wildlife Service’s second counterargument, lies in the magic of statistical modeling. In

essence, the agency argues that since it incorporated the results of two population and risk-

projection models—one for the logperch and one for the darter—into the BiOp, it

necessarily “account[ed] for all potential” “past and ongoing stressors in the action area.”

Response Br. at 16–17, 23 (emphasis added). Because these models reflect “the aggregate

effects of everything that has led to the current status of the affected populations,” parsing

out and analyzing “each past and ongoing activity”—like the limestone mine—“would add

no value and is not required.” Id. at 19, 23 (emphasis added).

                                              22
       The Fish and Wildlife Service stretches this argument—and these models—much

too far. To start, this explanation isn’t found anywhere in the record. The Fish and Wildlife

Service never says that it is relying on these models to evaluate the environmental baseline.

Nor do the BiOp or the studies describing the models contain any language suggesting that

these models account for “all potential stressors” or constitute “everything that has led to

the current status of the affected populations.” Thus, these explanations are no more than

impermissible post hoc rationalizations. E.g., Dow AgroSciences, 707 F.3d at 467–68 (“[A]

reviewing court may look only to these contemporaneous justifications in reviewing the

agency action.”); N.C. Wildlife Fed’n v. N.C. Dep’t of Transp., 677 F.3d 596, 604 (4th Cir.

2012) (“[A]n agency’s action must be upheld, if at all, on the basis articulated by the agency

itself,” and the “‘basis articulated by the agency’ is the administrative record, not

subsequent litigation rationalizations.” (quoting State Farm, 463 U.S. at 50)).

       Even if the Fish and Wildlife Service had adequately explained its reliance on the

models, it is hard to see how these models satisfy the agency’s burden to evaluate the

environmental baseline within the action area. Both models are general population-level

models. The 2016 logperch model was designed to calculate minimum viable population

size and related extinction risk for each of the seven logperch populations writ large. It was

not designed to assess environmental characteristics and conditions at a smaller scale.

Similarly, the 2018 darter model was created to evaluate the current and future conditions

and “resiliency” of individual populations and subpopulations. J.A. 1446. So, it is also not

well suited for evaluating conditions at the level of the action area here.

                                             23
       Sensing this disconnect, the Fish and Wildlife Service attempts to paper over this

difference in scope by suggesting that these studies reflect the “impacts of past and ongoing

stressors in the action area because the action area is within the watersheds occupied by

those populations.” Response Br. at 16–17 (emphasis added). In effect, the Fish and

Wildlife Service is saying conditions within the action area must be the same as conditions

within the larger watershed because the former is located within the latter. That is pure

speculation; it is like saying that economic conditions in Kansas are the same as those

within the United States as a whole because the former is located within the latter. Though

these models are certainly relevant predictors of conditions within the action area, because

they were calculated at a different level of generality, the Fish and Wildlife Service must

at least explain why it believes these population-level models reflect conditions within the

action area. See 50 C.F.R. § 402.02 (explaining the environmental baseline analysis must

assess “the condition of the listed species or its designated critical habitat in the action

area” (emphasis added)). The failure to do so here was arbitrary and capricious.

       Instead of acknowledging that its models may be imperfect, the Fish and Wildlife

Service argues the opposite, claiming they account for “all potential stressors” and

“everything that has led to the current status of the affected populations.” Response Br. at

19, 23 (emphasis added). But these models simply do not do what the agency claims. For

example, the “relatively simple” logperch model included just a few factors: initial

population size, population growth, environmental stochasticity, and certain catastrophe

and augmentation regimes. J.A. 1614; see J.A. 1614–18. However, only fish kills from

anthropogenic discharges—like a chemical spill—counted as “catastrophes.” J.A. 1617.

                                             24
The study explicitly excluded “floods and droughts” as catastrophes and did not consider

impacts from “non-point runoff, channelization, impoundments, impediments, and

siltation”—even though the BiOp labeled these as the “[p]rimary causes of [logperch]

habitat degradation.” J.A. 48, 72–73. Nor did it consider any sublethal effects or changes

in habitat conditions. Thus, the Fish and Wildlife Service’s claim that this model accounts

for “everything” impacting the logperch is not supported by the record.

       Similar concerns plague the candy darter model. This “semiquantitative” model

considered eight factors, including water quality and forest cover. J.A. 1478–80. In 2018,

the Fish and Wildlife Service—which developed the model—forthrightly acknowledged

that “there is uncertainty associated with this model and some of the supporting data.” J.A.

1446; see also J.A. 1432 (noting “darter demographic and genetic data” used to build out

the model “are sparse”). Fast forward three years and the agency now claims that this

limited model folds in the impacts of “all potential stressors,” including, for example, the

limestone mine. Response Br. at 23 (emphasis added). But as Petitioners point out, the

mine apparently threatens the Stony Creek darters with dewatering, not just impacts to

water chemistry. The Fish and Wildlife Service never explains how its limited model

accounts for these impacts. Nor does the agency explain how the model folds in the impacts

of other recognized causes of habitat degradation, including impoundments,

channelization, and urbanization. Thus, despite the agency’s assurances, the darter model

does not implicitly account for “all potential stressors” on the species.

       In sum, the Fish and Wildlife Service failed to adequately evaluate the “effects of

past and ongoing human and natural factors leading to the current status of the species” in

                                             25
the action area. Consultation Handbook at 4-22. Though it advances numerous post hoc

rationalizations to show it evaluated these factors, they are both impermissible and

unpersuasive.

                                             ii.

       Next, we assess whether the Fish and Wildlife Service properly evaluated

cumulative effects—“those effects of future State or private activities, not involving

Federal activities, that are reasonably certain to occur within the action area,” 50 C.F.R.

§ 402.02—impacting the Roanoke logperch and candy darter. We conclude it did not.

       The Fish and Wildlife Service’s ostensive cumulative effects analysis—for all five

studied species—is less than a page. It references a list of six future non-Federal projects

described in Mountain Valley’s 2020 Supplement to its Biological Assessment. This list

was “compiled from publicly available Construction Stormwater permits in West Virginia

and Virginia.” J.A. 567. The Fish and Wildlife Service dismisses four of these six projects

as ongoing or completed, and thus already accounted for in the environmental baseline. It

then disregards the two remaining projects because it “could find no available information”

on one and “there are no anticipated impacts on listed species” for the other. J.A. 141.

       The Fish and Wildlife Service and Mountain Valley do not argue that this analysis,

standing alone, is sufficient. Nor could they. Documents in the record—including FERC’s

2017 Environmental Impact Statement—suggest that the action area is likely to be

impacted by numerous non-Federal activities, including oil and gas extraction, mining,

logging, water withdrawals, agricultural activities, road improvement, urbanization, and

                                            26
anthropogenic discharges. 12 None of these future impacts are expressly addressed in the

BiOp or in documents that it relies on. Rather, the Fish and Wildlife Service and Mountain

Valley argue once more that they were implicitly evaluated when the agency incorporated

the logperch and darter models’ projections.

       For reasons similar to those explained above, we reject this argument. To wit, the

Fish and Wildlife Service did not say it was relying on these models to account for

cumulative impacts in the BiOp; this appears to be a post hoc rationalization. To be sure,

we must “uphold a decision of less than ideal clarity if the agency’s path may reasonably

be discerned.” Bowman Transp., Inc. v. Arkansas-Best Freight Sys., Inc., 419 U.S. 281,

286 (1974). But we fail to see how the Fish and Wildlife Service’s sparse and scattered

references to population-level analyses of “extinction risk,” J.A. 48, or “resiliency,” J.A.

53–54, were intended to pass for an evaluation of cumulative impacts within the “action

area.” Even if they were, these “relatively simple” models fail to include numerous factors

that can impact the logperch and darter, J.A. 1614, including those factors discussed above

as well as one to which we now turn: climate change.

       12
          As noted above, the prior definition of cumulative effects under NEPA is broader
than that for the Endangered Species Act. In addition, the Project’s NEPA analysis
extended far beyond the geographic boundaries of the action area. But the 2017
Environmental Impact Statement is still a helpful starting place to analyze cumulative
effects under the Endangered Species Act. See Consultation Handbook at 4-31 (“One of
the first places to seek cumulative effects information is in documents provided by the
action agency such as NEPA analyses for the action.”).

                                            27
                                              iii.

       As noted above, it is not clear whether the Fish and Wildlife Service should consider

climate change as part of the environmental-baseline analysis, the cumulative-effects

analysis, or both. But for our purposes, it makes no difference; the only question is whether

the agency properly evaluated it at all. We conclude it did not.

       In total, the BiOp spends one sentence discussing the impacts of climate change. In

its analysis of the environmental baseline for the logperch, the Fish and Wildlife Service

notes that “[c]limate change is an increasing threat to [logperch] with storm events

increasing in frequency and intensity, resulting in increased periods of higher water

volume, flow rates, and turbidity that affect the [logperch]’s abilities to forage, shelter, and

reproduce.” J.A. 49. And though other documents in the record suggest climate change

poses a “persistent threat” to the candy darter, J.A. 721, the Fish and Wildlife Service never

mentions climate change in connection with the darter in the BiOp itself.

       Perhaps wisely, neither the Fish and Wildlife Service nor Mountain Valley argue

this is a sufficient analysis. Irving, 221 F. Supp. 3d at 1233–34 (finding a “general[]”

discussion of the effects of climate change insufficient when other documents in the record

hinted at climate impacts within the action area). Rather, they argue that it was not

necessary to specifically address climate change since the logperch and darter models

implicitly account for potential climate impacts. 13 But once again, the Fish and Wildlife

       13
         Mountain Valley also argues that the impacts of climate change were extensively
discussed in the candy darter’s 2018 Species Status Assessment, which is included in the
record. Though the Fish and Wildlife Service may rely on documents in the record to

                                              28
Service never explained in the BiOp that it was relying on these models to account for the

effects of climate change. Thus, these are impermissible post hoc rationalizations. Dow

AgroSciences, 707 F.3d at 467–68.

       Even if the Fish and Wildlife Service had articulated its modeling rationale when it

issued the BiOp, we would find that evaluation arbitrary and capricious. To start, the 2016

logperch study did not even mention—much less fully account for—climate change.

Nonetheless, the agency and Mountain Valley claim that the model’s inclusion of

“environmental stochasticity” (defined as “unpredictable fluctuations in environmental

conditions”) means the study—and thus the BiOp—necessarily considered climate change.

Response Br. at 19; see Intervenor’s Br. at 28–29 (same). Yet the BiOp makes no such

claim. This argument thus stacks one post hoc rationalization upon another (that the Fish

and Wildlife Service relied on the logperch model to account for the effects of climate

change).

       At any rate, “environmental stochasticity” and climate change are not synonymous.

In the study, this stochasticity factor captured the difference between predicted and actual

population growth for a single test population—the seemingly random departures from the

model. The study assumed these differences were due to the “environment” writ large,

support its evaluation of climate change, there is no evidence it did so here. Since “the
climate change issue was not meaningfully discussed in the biological opinion, . . . it [is]
impossible to determine whether the information [in the Status Assessment] was rationally
discounted . . . or arbitrarily ignored.” Nat. Res. Def. Council v. Kempthorne, 506 F. Supp.
2d 322, 369 (E.D. Cal. 2007). And we “may not supply a reasoned basis for the agency’s
action that the agency itself has not given.” State Farm, 463 U.S. at 43 (citing SEC v.
Chenery Corp., 332 U.S. 194, 196 (1947)).

                                            29
rather than, say, errors in estimating actual population size—which it acknowledged was a

“tenuous assumption.” J.A. 1617. Critically, the study then assumed a “constant” amount

of environmental stochasticity for each model run for every population. J.A. 1614. But as

the Fish and Wildlife Service itself acknowledged, climate change is expected to be an

“increasing threat”—not a constant one. J.A. 49. Thus, even if random departures from a

simplistic model could be chalked up to “climate change,” the model failed to account for

the one thing we know about climate change: that it will get worse over time. Cf. Pac.

Coast Fed’n of Fishermen’s Ass’ns v. Gutierrez, 606 F. Supp. 2d 1122, 1184 (E.D. Cal.

2008) (finding a biological opinion failed to consider the increasing effects of climate

change by relying “on past hydrology and temperature models” that assumed constant

environmental conditions).

      A similarly arbitrary assumption undergirds the Fish and Wildlife Service’s reliance

on the darter model. That model incorporated multiple elements, including “forest cover.”

As the agency notes, forest cover can mediate the effects of water temperature increases,

including increases caused by climate change. Therefore, the agency argues that it

implicitly considered the water-warming effects of climate change by incorporating the

results of the model into the BiOp. But again, the BiOp is devoid of such an explanation,

meaning this is yet another post hoc rationalization layered upon its first post hoc

rationalization (that it considered climate change by referencing the darter model). What’s

more, increases in water temperature are not the only potential impact of climate change.

For example, climate change is also expected to increase the frequency and intensity of

flooding, and thus sedimentation. Yet there is no evidence that the darter model was

                                            30
intended to capture these effects, much less capture the “increasing threat” posed by

climate change. J.A. 49 (emphasis added).

       Ultimately, the Fish and Wildlife Service asks us to find that it evaluated the impacts

of climate change based on a series of stacked post hoc rationalizations. Yet even if those

rationalizations were contemporaneous, we would still find them arbitrary and capricious.

                                              2.

       Petitioners next contend—at the third primary step of the biological-opinion

process—that the Fish and Wildlife Service failed to incorporate its environmental-

baseline and cumulative-effects findings into its jeopardy determinations for the logperch

and darter. We agree.

       As noted above, the Endangered Species Act requires the Fish and Wildlife Service

to “[a]dd the effects of the action and cumulative effects to the environmental baseline”

when determining whether an action is likely “to reduce appreciably the likelihood of both

the survival and recovery of a listed species.” 50 C.F.R. §§ 402.02 (defining “jeopardize

the continued existence of” as used in § 402.14(g)(4)), 402.14(g)(4) (emphasis added). This

step is critical to ensure that the action is not analyzed “in a vacuum.” Nat’l Wildlife Fed’n,

524 F.3d at 929. Thus, for obvious reasons, “[s]imply reciting the activities and impacts

that constitute the baseline [and cumulative effects] and then separately addressing only

the impacts of the particular agency action in isolation is not sufficient.” Babbitt, 130 F.

Supp. 2d at 127–28; see also Am. Rivers v. Fed. Energy Regul. Comm’n, 895 F.3d 32, 47

(D.C. Cir. 2018) (finding a biological opinion arbitrarily “failed to incorporate the

environmental baseline into its jeopardy analysis”).

                                              31
       Because the Fish and Wildlife Service failed to properly evaluate the Project’s

environmental context at step two, its no-jeopardy conclusions for the Roanoke logperch

and candy darter at step three—which purport to fold these flawed evaluations into the

agency’s analysis—are necessarily arbitrary. See 50 C.F.R. §§ 402.02, 402.14(g)(4)

(requiring the Fish and Wildlife Service to determine whether the proposed action,

considered in its proper context, “is likely to jeopardize the continued existence of [the]

listed species,” meaning the action “reasonably would be expected, directly or indirectly,

to reduce appreciably the likelihood of both the survival and recovery of [that] species”).

Therefore, we find it unnecessary to further analyze Petitioners’ step-three concerns.

       On remand, the agency must ensure that it analyzes the Project “against the

aggregate effects of everything that has led to the species’ current status and, for non-

Federal activities, those things [reasonably certain] to affect the species in the future.”

Consultation Handbook at 4-35. We agree with the Fish and Wildlife Service that this does

not mean it must “include the entire environmental baseline [or cumulative effects] in the

‘agency action’ subject to review.” Response Br. at 13 (emphasis added) (quoting Nat’l

Wildlife Fed’n, 524 F.3d at 930). Under our precedent, “an agency action can only

jeopardize a species’ existence if that agency action causes some deterioration in the

species’ pre-action condition.” Defs. of Wildlife, 931 F.3d at 353 (emphasis added) (quoting

Nat’l Wildlife Fed’n, 524 F.3d at 930) (cleaned up). In other words, an agency action cannot

be barred solely because baseline conditions or cumulative effects already imperil a

species. See Ctr. for Biological Diversity v. U.S. Fish & Wildlife Serv., 807 F.3d 1031,

1052 (9th Cir. 2015).

                                            32
       But we caution that when baseline conditions or cumulative effects are “already

jeopardiz[ing] a species, an agency may not take action that deepens the jeopardy by

causing additional harm.” Defs. of Wildlife, 931 F.3d at 353 (emphasis added) (quoting

Nat’l Wildlife Fed’n, 524 F.3d at 930 (faulting the Fish and Wildlife Service for the same

error)). Put differently, if a species is already speeding toward the extinction cliff, an

agency may not press on the gas. We urge the Fish and Wildlife Service to consider this

directive carefully while reassessing impacts to the two endangered fish at issue, especially

the apparently not-long-for-this-world candy darter.

                                              B.

       Though the serious errors described above require us to vacate and remand the 2020

BiOp and Incidental Take Statement, Petitioners also identify other issues in both

documents that they claim further support vacatur. For example, Petitioners allege that the

Fish and Wildlife Service (1) arbitrarily limited the scope of the action area; (2) erroneously

excluded the Blackwater River from its logperch analysis; and (3) crafted “unlawfully

vague” incidental take limits for the logperch and darter. Opening Br. at 48. None of these

arguments have merit.

                                              1.

       Petitioners first critique the Fish and Wildlife Service’s calculation of the aquatic

action area. To define this action area, the agency used the results of a sedimentation model

prepared by Mountain Valley to determine which waterbodies might be impacted by the

Project. The Fish and Wildlife Service then expanded the action area to include stream

segments 200 meters upstream and 800 meters downstream of (1) waterbodies with an

                                              33
open-cut crossing; and (2) the confluence of unoccupied but potentially impacted

tributaries with species-occupied streams, termed “mixing zones.” J.A. 39–40. In its

analysis, the agency noted that multiple scientific studies had found that aquatic habitat

conditions were unaffected more than 500 meters downstream of pipeline crossings. “To

be protective of the” listed species and “address uncertainty” regarding the extent of the

sediment plume in mixing zones, J.A. 103–04, the Fish and Wildlife Service

“conservatively” defined the action area “as twice the maximum 500-meter area

documented in the studies, extending from 200 meters above the crossing [or confluence

with the unoccupied tributary] to 800 meters below,” Response Br. at 29.

       Petitioners quibble that an 800-meter downstream limit is arbitrary if the science

supports a 500-meter impact area. They also point out that studies assessing impacts from

crossings may not be applicable to mixing zones. But we find it hard to fault the Fish and

Wildlife Service for conservatively expanding the action area to ensure that it is capturing

all possible effects to these imperiled species, or extending the results from pipeline-

crossing studies to an analogous context. These are precisely the sort of judgment calls that

are entitled to our deference. Ctr. for Biological Diversity, 807 F.3d at 1043 (“[T]raditional

deference to the agency is at its highest where a court is reviewing an agency action that

required a high level of technical expertise.”).

       Petitioners also argue that “anecdotal” evidence from Dr. Angermeier suggests

sediment impacts may extend several kilometers downstream from a crossing. Opening Br.

at 51. But the Fish and Wildlife Service was well within its rights to ignore such

“anecdotal” evidence and instead rely on numerous published scientific studies to define

                                             34
the action area. See Ctr. for Biological Diversity, 807 F.3d at 1050 (rejecting a claim that

the agency ignored the best available science when the petitioners failed to show their

concerns “were supported by better science [than] that used in the [BiOp]”).

                                             2.

       Next, Petitioners contend that the Fish and Wildlife Service failed to justify its

exclusion of the Blackwater River from its logperch analysis. All six of the Project’s

crossings in the Blackwater River drainage contain suitable habitat for the logperch. 14 In

general, the agency assumed that logperch were present in waterbodies containing suitable

habitat. Therefore, a straightforward application of the agency’s own criteria would seem

to require the Fish and Wildlife Service to analyze impacts to the logperch within the

Blackwater River drainage. However, the agency ultimately decided to exclude the

Blackwater River crossings from consideration based on several factors: (1) traditional

survey efforts have not documented logperch presence in the watershed; (2) recent

environmental DNA (“eDNA”) sampling 15 did not detect logperch; and (3) no in-stream

work would occur at these crossings during logperch spawning season.

       14
          In total, the Project is expected to cross fourteen waterbodies that either contain
suitable habitat for the logperch or are “known to support” logperch. J.A. 69.
       15
          Though it sounds complex, eDNA sampling is elegantly simple in design.
Because fish continually release DNA molecules into the water via sloughed skin, scales,
mucus, and feces, scientists can capture and filter water from a stream and scour it for
specific species’ DNA. These results can help “corroborate or supplement existing
information indicating the probable [presence or] absence of a species in [that] area.” J.A.
70 n.4.

                                             35
         Petitioners point out that the Blackwater has been traditionally undersampled and

that the Fish and Wildlife Service itself acknowledges that eDNA analysis is not a

“definitive means for determining presence/probable absence.” J.A. 70 n.4. They also note

that time-of-year restrictions do not protect logperch from upland disturbances associated

with the Project or the long-term impacts from open-cut stream crossings. While

Petitioners’ individual critiques of each factor cited by the agency have some persuasive

heft, Petitioners do not identify anything in the record that shows logperch are in fact

present in the Blackwater River drainage. Nor do Petitioners account for how these three

factors interact synergistically. Given the absence of contrary evidence, when we consider

these factors together, we have little trouble concluding that the Fish and Wildlife Service

“provided a [sufficiently] cogent justification” for excluding the Blackwater River

watershed from further study. 16 Am. Whitewater v. Tidwell, 770 F.3d 1108, 1116 (4th Cir.

2014).

          While the agency properly justified excluding the Blackwater River drainage from
         16

its analysis, we are concerned that it did not fully follow through on that assessment. To
wit, though the Fish and Wildlife Service purported to exclude the Blackwater River
drainage from its jeopardy analysis, it later relied on suitable habitat in the Blackwater
watershed for one of the calculations supporting its recovery analysis.

       Specifically, the Fish and Wildlife Service found no impacts to logperch recovery
were likely in part because “[t]he amount of habitat to be impacted is minor (0.9%)
compared to the overall amount of [logperch] habitat available in [Virginia].” J.A. 149. But
this “overall amount” of suitable habitat includes stream miles in the Blackwater River
drainage. As Petitioners point out, this means the agency excluded the Blackwater from the
numerator—the “amount of habitat to be impacted”—but added it to the denominator—the
“overall amount” of suitable habitat in Virginia. This sounds like the agency is trying to
have it both ways. And it seems problematic to exclude an entire watershed from analysis

                                            36
                                              3.

       Petitioners also contend that the incidental take limits for the logperch and darter

are too “vague” to be enforceable. Opening Br. at 46. As noted above, an incidental take

statement must specify the “amount or extent” of incidental take. Typically, this requires

the Fish and Wildlife Service to identify the number of individual animals subject to take.

See 50 C.F.R. § 402.14(i)(1). However, a “surrogate”—such as “[a] similarly affected

species or habitat or ecological conditions”—may be used if the biological opinion: (1)

describes “the causal link between the surrogate and take of the listed species”; (2) explains

“why it is not practical to express the amount or extent of anticipated take or to monitor

take-related impacts in terms of individuals of the listed species”; and (3) “sets a clear

standard for determining when the level of anticipated take has been exceeded.” Id.

§ 402.14(i)(1)(i) (emphasis added). Here, because the Fish and Wildlife Service

determined that an individual-based limit was impractical for the logperch and darter, it

crafted take thresholds based on a sediment-concentration surrogate.

because no logperch are present then add that watershed back into the analysis to artificially
lower the percentage of habitat impacted.

       Because we already concluded that the Fish and Wildlife Service’s jeopardy
analysis—including its recovery assessment for the logperch—is arbitrary and capricious,
we find it unnecessary to further analyze this potential “having it both ways” scenario. But
we encourage the agency to explain this discrepancy on remand if it intends to continue
adding the Blackwater River to the denominator in its recovery calculations.

                                             37
       Petitioners argue that this standard isn’t “clear.” 17 Specifically, they contend that (1)

it is ambiguous whether Mountain Valley must be solely responsible for an exceedance,

and (2) it is unclear how any exceedance will be attributed to Mountain Valley as opposed

to some other source. Both arguments are nonstarters.

       To start, the Incidental Take Statement explicitly—and repeatedly—states that its

sediment-concentration thresholds are tied to “[P]roject-related” sediment releases. J.A.

169, 173 (emphasis added). It also provides that take only occurs when downstream

sediment concentrations reach certain levels “above background.” J.A. 169, 173 (emphasis

added). Thus, Mountain Valley must be solely responsible for exceeding these take

thresholds.

       Mountain Valley’s monitoring plan 18 also provides a clear mechanism for

determining responsibility for an exceedance. Specifically, Mountain Valley has installed

       17
           Petitioners also argue that the agency’s chosen surrogate—a “continuous”
sediment-concentration threshold—was an arbitrary policy change from a framework used
to measure anticipated take of bull trout in Washington State. We fail to see how a surrogate
framework for a different species in a different state prepared by a different field office is
a “policy or practice” that the Fish and Wildlife Service’s Virginia Field Office is bound
to explain its departure from. Reply Br. at 16. Even if it was a policy change, the agency
explained that its new, “continuous” threshold is more consistent with the published
scientific study underlying the bull-trout framework than the surrogate used in Washington
State was. Nevertheless, to avoid further confusion, we encourage the agency to expound
upon the reasons for its departure from the bull-trout framework on remand.
       18
           Petitioners also criticize the monitoring plan for failing to include monitoring
stations in streams where the agency’s adopted sediment model did not predict sediment
increases. However, Petitioners do not identify any fundamental flaws with this model—
in fact, they identify no flaws at all. Rather, Petitioners note that there is a “degree of
uncertainty associated with [Mountain Valley’s] modeling.” Opening Br. at 48. But
uncertainty is inherent in any model. And since Petitioners failed to establish that the

                                              38
monitoring stations above and below the action area (and even some within the action area)

to determine the background concentration entering the area and the concentration leaving

it. Whenever these stations register a potential exceedance, Mountain Valley is required to

alert FERC and the Fish and Wildlife Service; conduct an inspection of the affected stream,

monitoring equipment, and nearby erosion-and-sedimentation controls; identify potential

non-Project sources of sedimentation; “make a preliminary determination of whether

Project-related sediment in fact caused [an exceedance]”; and report all findings to the

federal agencies. J.A. 341–45.

       Petitioners complain that this gives “too much latitude” to Mountain Valley to

decide whether an exceedance was Project related. Opening Br. at 47. But under the

monitoring plan, it is the federal agencies that are responsible for making the ultimate

determination regarding responsibility for an exceedance, not Mountain Valley. See J.A.

371–72 (noting the information reported by Mountain Valley, “along with the preliminary

causation assessment that Mountain Valley is required to provide,” allow the Fish and

Wildlife Service “to independently determine whether any such exceedance is attributable

to the [P]roject, and, if so, to request that FERC immediately reinitiate Section 7

“model bears no rational relationship to the [situation] to which it is applied,” we must
defer to the agency’s choice of model. San Luis & Delta-Mendota Water Auth. v. Locke,
776 F.3d 971, 994 (9th Cir. 2014) (citation omitted).

        The model here predicted no impacts to the various additional stream segments
identified by Petitioners in their brief. Since Endangered Species Act regulations only
require monitoring where take is expected to occur, see 50 C.F.R. § 402.14(i)(3) (requiring
the action agency “to monitor the impacts of incidental take”), the agency did not err by
refusing to require Mountain Valley to monitor these additional locations.

                                            39
consultation” (emphasis added)). Petitioners counter that this still allows Mountain Valley

“to select which facts surrounding an exceedance to present to the agencies.” Reply Br. at

26 (emphasis added) (internal quotation marks omitted). If Petitioners are hinting that

Mountain Valley cannot be trusted to accurately report the facts surrounding an

exceedance, we reject that implication. Because the monitoring plan provides a “clear”

mechanism for assessing responsibility for an exceedance, as well as a clear chain of

command, we find the Fish and Wildlife Service’s selected take surrogate appropriate.

                                            III.

       While Petitioners’ more minor challenges lack merit, the serious errors detailed

above at steps two and three of the jeopardy analysis render the 2020 BiOp arbitrary and

capricious. We recognize that this decision will further delay the completion of an already

mostly finished Pipeline, but the Endangered Species Act’s directive to federal agencies

could not be clearer: “halt and reverse the trend toward species extinction, whatever the

cost.” Tenn. Valley Auth., 437 U.S. at 184. On remand, the Fish and Wildlife Service should

consider this mandate carefully, especially given the precarious state of the candy darter.

       “We have not addressed all of the [Petitioners’] complaints because, on remand,

they can be aired and addressed in the renewed agency process.” Dow AgroSciences, 707

F.3d at 475. At this point, we find it sufficient to vacate the 2020 BiOp and Incidental Take

Statement and require the Fish and Wildlife Service “to address not only the flaws we

identified but also any additional matters that may be raised on remand.” Id.

                                                             VACATED AND REMANDED

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