Endangered and Threatened Wildlife and Plants; Threatened Species Status for Pearl Darter, 64857-64868 [2016-22752]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 81, Number 183 (Wednesday, September 21, 2016)]
[Proposed Rules]
[Pages 64857-64868]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-22752]


-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2016-0037; 4500030113]
RIN 1018-BB55


Endangered and Threatened Wildlife and Plants; Threatened Species 
Status for Pearl Darter

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the Pearl darter (Percina aurora), a fish from Mississippi, as a 
threatened species under the Endangered Species Act (Act). If we 
finalize this rule as proposed, it would extend the Act's protections 
to this species. The effect of this proposed regulation will be to add 
this species to the List of Endangered and Threatened Wildlife.

DATES: We will accept comments received or postmarked on or before 
November 21, 2016. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES below) must be received by 11:59 p.m. 
Eastern Time on the closing date. We must receive requests for public 
hearings, in writing, at the address shown in FOR FURTHER INFORMATION 
CONTACT by November 7, 2016.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. In the Search box, enter FWS-R4-ES-2016-0037, 
which is the docket number for this rulemaking. Then, in the Search 
panel on the left side of the screen, under the Document Type heading, 
click on the Proposed Rules link to locate this document. You may 
submit a comment by clicking on ``Comment Now!''
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R4-ES-2016-0037; U.S. Fish and Wildlife 
Service Headquarters, MS: BPHC, 5275 Leesburg Pike, Falls Church, VA 
22041-3803.
    We request that you send comments only by the methods described 
above. We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Public Comments below for more information).

FOR FURTHER INFORMATION CONTACT: Stephen Ricks, Field Supervisor, U.S. 
Fish and Wildlife Service, Mississippi Ecological Services Field 
Office, 6578 Dogwood Parkway, Jackson, Mississippi 39213, by telephone 
601-321-1122 or by facsimile 601-965-4340. Persons who use a 
telecommunications device for the deaf (TDD) may call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, if we determine that 
a species is an endangered or threatened species throughout all or a 
significant portion of its range, we are required to promptly publish a 
proposal in the Federal Register and make a determination on our 
proposal within one year. Listing a species as an endangered or 
threatened species can only be completed by issuing a rule.
    What this document does. This document proposes the listing of the 
Pearl darter (Percina aurora) as a threatened species. The Pearl darter 
is a candidate species for which we have on file sufficient information 
on biological vulnerability and threats to support preparation of a 
listing proposal, but for which until now development of a listing 
regulation has been precluded by other higher priority listing 
activities. This proposed rule reassesses all available information 
regarding status of and threats to the Pearl darter.
    This document does not propose critical habitat for the Pearl 
darter. We have determined that critical habitat is prudent, but not 
determinable at this time.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species based on any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. We have determined that water quality decline from 
point and nonpoint source pollution continues to impact portions of 
this species' habitat. In addition, geomorphology changes attributed to 
past sand and gravel mining operations within the drainage are 
considered an ongoing threat. This species has been extirpated from the 
Pearl River watershed and is confined today to the Pascagoula River 
Basin where this species' small population size and apparent low 
genetic diversity increases its vulnerability to extirpation from 
catastrophic events.
    We will seek peer review. We will seek comments from independent 
specialists to ensure that our designation is based on scientifically 
sound data, assumptions, and analyses. We will invite these peer 
reviewers to comment on our listing proposal.

Information Requested

Public Comments

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from the public, other concerned governmental 
agencies, Native American tribes, the scientific community, industry, 
or any other interested parties concerning this proposed rule. We 
particularly seek comments concerning:
    (1) The Pearl darter's biology, range, and population trends, 
including:
    (a) Biological or ecological requirements of the species, including 
habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range including distribution patterns;
    (d) Historical and current population levels, and current and 
projected trends; and

[[Page 64858]]

    (e) Past and ongoing conservation measures for the species, its 
habitat, or both.
    (2) Factors that may affect the continued existence of the species, 
which may include habitat modification or destruction, overutilization, 
disease, predation, the inadequacy of existing regulatory mechanisms, 
or other natural or manmade factors.
    (3) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species and existing regulations 
that may be addressing those threats.
    (4) Additional information concerning the historical and current 
status, range, distribution, and population size of this species, 
including the locations of any additional populations of this species.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Please note that submissions merely stating support for or 
opposition to the action under consideration without providing 
supporting information, although noted, will not be considered in 
making a determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is a threatened or endangered 
species must be made ``solely on the basis of the best scientific and 
commercial data available.''
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    If you submit information via https://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the Web site. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on https://www.regulations.gov.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Mississippi Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT).
    Because we will consider all comments and information received 
during the comment period, our final determinations may differ from 
this proposal.

Public Hearing

    Section 4(b)(5) of the Act provides for one or more public hearings 
on this proposal, if requested. Requests must be received within 45 
days after the date of publication of this proposed rule in the Federal 
Register. Such requests must be sent to the address shown in FOR 
FURTHER INFORMATION CONTACT. We will schedule public hearings on this 
proposal, if any are requested, and announce the dates, times, and 
places of those hearings, as well as how to obtain reasonable 
accommodations, in the Federal Register and local newspapers at least 
15 days before the hearing.

Peer Review

    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), we have sought the 
expert opinions of three appropriate and independent specialists 
regarding this proposed rule. The purpose of peer review is to ensure 
that our listing determination is based on scientifically sound data, 
assumptions, and analyses. The peer reviewers have expertise in the 
Pearl darter's biology, habitat, and physical or biological factors 
that will inform our determination.

Previous Federal Actions

    We identified the Pearl darter (Pearl channel darter, Percina sp.) 
as a Category 2 Candidate in the November 21, 1991, Animal Candidate 
Review for Listing as Endangered or Threatened Species; Notice of 
Review (56 FR 58804). Category 2 Candidates were defined as species for 
which we had information that proposed listing was possibly 
appropriate, but conclusive data on biological vulnerability and 
threats were not available to support a proposed rule at the time. The 
species remained so designated in the subsequent November 15, 1994, 
annual Candidate Notice of Review (CNOR) (59 FR 58982). In the February 
28, 1996, CNOR (61 FR 7596), we discontinued the designation of 
Category 2 species as candidates; therefore, the Pearl darter was no 
longer a candidate species.
    Subsequently, in 1999, the Pearl darter was once again added to the 
candidate list (64 FR 57534, October 25, 1999). Candidates are now 
defined as those fish, wildlife, and plants for which we have on file 
sufficient information on biological vulnerability and threats to 
support preparation of a listing proposal, but for which development of 
a listing regulation is precluded by other higher priority listing 
activities. The Pearl darter was included in all of our subsequent 
annual CNORs: 66 FR 54808, October 30, 2001; 67 FR 40657, June 13, 
2002; 69 FR 24876, May 4, 2004; 70 FR 24870, May 11, 2005; 71 FR 53756, 
September 12, 2006; 72 FR 69034, December 6, 2007; 73 FR 75176, 
December 10, 2008; 74 FR 57804, November 9, 2009; 75 FR 69222, November 
10, 2010; 76 FR 66370, October 26, 2011; 77 FR 69994, November 21, 
2012; 77 FR 70104, November 22, 2013; 79 FR 72450, December 5, 2014; 80 
FR 80584, December 24, 2015.

The Pearl darter has a listing priority number of 8, which reflects a 
species with threats that are both imminent and moderate to low in 
magnitude.
    On May 11, 2004, we were sent a petition to list the Pearl darter 
by the Center for Biological Diversity. Because no new information was 
provided in the petition, and we had already determined the species 
warranted listing, no further action was taken on the petition.
    On May 10, 2011, the Service announced a work plan to restore 
biological priorities and certainty to the Service's listing process. 
As part of an agreement with one of the agency's most frequent 
plaintiffs, the Service filed a work plan with the U.S. District Court 
for the District of Columbia. The work plan enables the agency to, over 
a period of 6 years, systematically review and address the needs of 
more than 250 species listed within the 2010 CNOR, including the Pearl 
darter, to determine if these species should be added to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. This work plan 
enables the Service to again prioritize its workload based on the needs 
of candidate species, while also providing State wildlife agencies, 
stakeholders, and other partners clarity and certainty about when 
listing determinations will be made. On July 12, 2011, the Service 
reached an agreement with another frequent plaintiff group and further 
strengthened the work plan, which allows us to focus our resources on 
the species most in need of protection under the Act. These agreements 
were approved by the court on September 9, 2011. The timing of this 
proposed listing is, in part, an outcome of the work plan.

Background

Taxonomy and Species Description

    The Pearl darter (Percina aurora) is a small fish with a blunt 
snout, horizontal mouth, large eyes located high on the head, and a 
medial black spot at the base of the caudal (tail) fin (Ross 2001,

[[Page 64859]]

p. 498). Described in 1994 (Suttkus et al. 1994, pp. 13-17) from the 
Strong River in Simpson County, MS (Ross 2001, p. 500), the Pearl 
darter is one of three members of the subgenus Cottogaster. The Pearl 
darter is closely allied to the channel darter (P. copelandi) (Ross et 
al. 1989, p. 25). It is distinguished from the channel darter by its 
larger body size, lack of tubercles (small, raised, skin structures) 
and heavy pigmentation of breeding males, high number of marginal 
spines on the belly scales of breeding males, and fully scaled cheeks. 
Breeding males have two dark bands across the spinous dorsal (back) 
fin, a broad, diffuse, dusky marginal band, and a pronounced dark band 
across the fin near its base. Breeding females lack pigmentation on 
their ventral body surface. The Pearl darter reaches a maximum standard 
length (SL) of 57 millimeters (mm) (2.2 inches (in.)) in females and 64 
mm (2.5 in.) in males (Suttkus et al. 1994, p. 16).

Distribution

Historical Range
    The Pearl darter is historically known from localized sites within 
the Pearl and Pascagoula River drainages of Mississippi and Louisiana, 
based on collection records from 16 counties/parishes of Mississippi 
and Louisiana. The quantified range of the Pearl darter, expressed in 
river miles, has not been well-defined by researchers (Slack et al. 
2005, pp. 5-10; Ross 2001, p. 499; Ross et al. 2000, pp. 5-8; Bart and 
Piller 1997, pp. 3-10; Bart and Suttkus 1996, pp. 3-4, Suttkus et al. 
1994, pp. 15-18). However, a recent reanalysis of collection records 
compiled from the Mississippi Museum of Natural Science (MMNS) (2016, 
unpublished data) estimates the species' historical range to be 
approximately 708 kilometers (km) (440 miles (mi)) in the Pearl River 
and 539 km (335 mi) in the Pascagoula River system, for a total 
historical range of 1,247 km (775 mi).
    Pearl River Watershed--Examination of site records of museum fish 
collections from the Pearl River drainage (compiled from Suttkus et al. 
1994, pp. 15-18) suggest that the darter once inhabited the large 
tributaries and main channel habitats from St. Tammany Parish, LA, to 
Simpson County, MS. This area included approximately 364 km (226 mi) of 
the lower Pearl River, 21 km (13 mi) of the Strong River, and 322 km 
(200 mi) of Bogue Chitto River for a total of approximately 708 km (440 
mi), all of which is below the Ross Barnett Reservoir (compiled from 
MMNS 2016, unpublished data; Slack et al. 2005, pp. 5-10; Ross 2001, p. 
499; Ross et al. 2000, pp. 2-5, Bart and Piller 1997, pp. 3-10; Bart 
and Suttkus 1996, pp. 3-4; Suttkus et al. 1994, pp. 15-18).
    Despite annual collection efforts by Suttkus from 1958 to 1973 
(Bart and Suttkus 1996, pp. 3-4; Bart and Suttkus 1995, pp. 13-14; 
Suttkus et al. 1994, pp. 15-18), the Pearl darter was collected from 
only 14 percent of 716 fish collections from site-specific locations 
within the Pearl River drainage. There have been no records of Pearl 
darters from the Pearl River drainage since 1973, despite Suttkus' 64 
fish collections from this time through the middle 1990s from the Pearl 
River (Bart and Piller 1997, p. 1) and other various collection efforts 
in the lower Pearl River system (Roberts 2015, pers. comm.; Slack et 
al. 2005, pp. 5-10; Ross 2001, p. 499). There are no records of Pearl 
darters in the upper Pearl River system (upstream of the Ross Barnett 
Dam), and collection efforts by Schaefer and Mickel in 2011 (p. 10) 
confirmed its absence from this part of the Pearl River. A recent 
survey at the type locality in the Strong River verified its absence 
from that area also (Roberts 2015, pers. comm.). There have been no 
verifiable records of the Pearl darter from the Pearl River drainage in 
over 40 years, thus, this species is considered extirpated from that 
system, representing a 57 percent loss of its historical range.
    Pascagoula River Watershed--Site records from museum fish 
collections before 2005 suggested that the Pearl darter inhabited the 
main channels of large Pascagoula drainage tributaries from Jackson to 
Lauderdale Counties (Ross 2001, pp. 499-500). Although collection data 
from Ross (2001, p. 500), Bart and Piller (1997, p. 4), Bart and 
Suttkus (1996, p. 4), and Suttkus et al. (1994, p. 19) suggested that 
the Pearl darter was very rare in the Pascagoula River system. Bart and 
Piller (1997, p. 4) examined Suttkus' work before 1974 and found that 
only 19 Pearl darters were collected out of 19,300 total fish in 10 
Tulane University Museum of Natural History collections. Additionally, 
from the Mississippi Freshwater Fishes Database, Ross (in Bart and 
Piller 1997, p. 4) estimated the rarity of the Pearl darter within the 
Pascagoula drainage from 379 collections (81,514 fish specimens) since 
1973 and found that only one Pearl darter was collected for every 4,795 
specimens. This species' historical range within the Pascagoula River 
system totaled approximately 539 km (335 mi), which included 48 km (30 
mi) of the Pascagoula River, 11 km (7 mi) of Black Creek, 131 km (82 
mi) of the Leaf River, 34 km (21 mi) of Okatoma Creek, 262 km (163 mi) 
of the Chickasawhay River, 39 km (24 mi) of the Bouie River, and 13 km 
(8 mi) of Chunky Creek (compiled from MMNS 2016 unpublished data; Slack 
et al. 2005, pp. 5-10; Ross 2001, p. 499; Ross et al. 2000, pp. 1-28; 
Bart and Piller 1997, pp. 3-10; Bart and Suttkus 1996, pp. 3-4; Suttkus 
et al. 1994, p. 19; Ross et al. 1992, pp. 2-10).
Current Range and Population Size
    Today, Pearl darters are thought to occur only in scattered sites 
within approximately 449 km (279 mi) of the Pascagoula drainage, 
including the Pascagoula, Chickasawhay, Chunky, Leaf, and Bouie Rivers, 
and Okatoma and Black Creeks. In recent years, the species has been 
found sporadically within the Pascagoula, Chickasawhay, and Leaf 
Rivers. There have been no collecting attempts within the Bouie and 
Chunky Rivers, nor Okatoma and Black Creeks, in the last 15 years; 
thus, the status of populations in those systems is unknown.
    Collections of Pearl darters over the last 20 years in the 
Pascagoula River drainage have included: 10 Pearl darters from 4 sites 
out of 27 fish collections in 1996 and 1997 from the Pascagoula River 
(Bart and Piller 1997, p. 3); 3 specimens from the Leaf River in 1998; 
and 7 collections (total of 45 Pearl darters) in the Pascagoula River 
at the confluence with Big Black Creek (Dead Lake) and downstream of 
Dead Lake for 22 km (14 mi) (Slack et al. 2002, p. 15). Slack et al. 
(2005, p. 5) sampled for Pearl darters within the Leaf and Chickasawhay 
rivers beginning near the confluence with the Pascagoula River and 
extending through portions of the Chickasaway and Leaf Rivers. The 
species was present in 78 localities among the 2 systems but were 
typically in low abundance when present. These survey efforts by Slack 
et al. (2005, pp. 1-15) indicated range of the Pearl darter within the 
Pascagoula drainage system was further upstream than previously known.
    Over the last 15 years, Pearl darters have been found from late 
summer through fall in the upper Pascagoula River drainage (Leaf and 
Chickasawhay Rivers) and in the lower Pascagoula River proper in spring 
and summer (Clark and Schaeffer 2015, pp. 3, 9-10, 19, 23; Slack et al. 
2002, p. 8). Young of Year (YOY) (fish from the current breeding 
season) were collected in both 2013 and 2014 in the Chickasawhay and 
Leaf Rivers, indicating the existence of reproducing populations and 
recruitment in both of those systems (Clark and Schaeffer 2015, pp. 10, 
19, 23). Schaefer and Mickle (2011, pp. 1-

[[Page 64860]]

3) highlighted similarities in numbers of Pearl darters collected 
historically from the Pascagoula River Basin museum collections from 
2000 to 2009 and found them to trend closely with the CPUE (Catch per 
Unit Effort) of 1980 to 1999 collections. Clark and Schaefer (2015, pp. 
5, 9) recently resampled collection sites of Slack et al. (2005, pp. 1-
13) in the Leaf and Chickasawhay Rivers, within the upper Pascagoula 
River, and found CPUE similar between the 2004 and 2014 surveys. 
Together, Clark and Schaefer (2015, pp. 5, 9), Schaefer and Mickle 
(2011, pp. 1-3) and Slack et al. (2005, pp. 1-13) suggest a stable 
population of Pearl darters has existed within these rivers in the 
upper Pascagoula River Basin over the last decade and speculate that 
populations may exist in small numbers within the other systems not 
recently sampled (e.g., Chunky and Bouie Rivers, Okatoma and Black 
creeks).

Habitat

    The Pearl darter occurs in low-gradient, coastal plain rivers 
(Suttkus et al. 1994, p. 13). The species is considered rare and is 
infrequently collected; however, its preference for deep water, main 
channels, and its association with woody debris accumulations can make 
sampling difficult (Bart and Piller 1997, p. 1). Pearl darters have 
been collected from gravel riffles and rock outcrops; deep runs over 
gravel and sand pools below shallow riffles; swift (90 cm per sec (35 
in. per sec)), shallow water over firm gravel and cobble in mid-river 
channels; and swift water near brush piles. Slack et al. (2002, p. 10) 
found Pearl darters associated with scour holes on the inside bend of 
the river downstream from point bars and in substrata of coarse sand 
with detritus in troughs perpendicular to the shore line. Other 
collectors (Clark and Schaefer, 2015, pp. 11, 12, 19; Slack et al. 
2005, p. 9; Bart and Piller 1997, p. 10) have found Pearl darters in 
areas with finer substrate (i.e., loose sand, mud, silt), including a 
collection in loose detritus formed from a large scouring flood event 
(Clark and Schaefer 2015, p. 19). Very little aquatic vegetation was 
found in the areas where Slack et al. (2005, p. 9) collected the 
species.

Biology

    Very little is known about the reproductive biology and general 
ecology of the Pearl darter (Ross 2001, p. 499). Most Pearl darters 
mature in 1 year. Female Pearl darters are sexually mature at 39 mm 
(1.5 in) SL, while males are mature at 42 mm (1.7 in.) SL (Suttkus et 
al. 1994, pp. 19-20). Breeding males have been observed during May in 
shallow water (15 cm (5.9 in.)) over firm gravel and cobble in mid 
channel in water temperatures from 17 to 21 degrees Celsius ([deg]C) 
(62.6 to 69.8 degrees Fahrenheit ([deg]F)) (Bart and Piller 1997, p. 9; 
Suttkus et al. 1994, p. 19). It is thought that subadult Pearl darters 
migrate upstream during the fall and winter to spawn in gravel reaches 
(Bart et al. 2001, p. 14). Spawning of Pearl darters in the Pearl and 
Strong Rivers (Mississippi) has been documented during March through 
May in the upper reaches of the Bogue Chitto River (Mississippi and 
Louisiana) (Suttkus et al. 1994, pp. 19-20). YOY Pearl darters were 
collected in June from the Pearl River (Suttkus et al. 1994, p. 19). 
Bart and Pillar (1997, pp. 6-7) described the Strong River rapids area, 
near the geological outcroppings, as an important historical spawning 
habitat for the species in the Pearl River system.

Summary of Biological Status and Threats

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations in title 50 of the Code of Federal Regulations at 50 CFR 
part 424, set forth the procedures for adding species to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Under section 
4(a)(1) of the Act, we may list a species based on: (A) The present or 
threatened destruction, modification, or curtailment of its habitat or 
range; (B) overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting its continued existence. Listing actions may be warranted 
based on any of the above threat factors, singly or in combination. 
Each of these factors is discussed below:

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

    All members of Cottogaster are undergoing range contractions and 
are of potential conservation concern throughout their respective 
distributions (Dugo et al. 2008, p. 3; Warren et al. 2000, pp. 7-8; 
Goodchild 1994, pp. 433-435). The Pearl darter has been extirpated from 
the Pearl River drainage, representing an approximately 57 percent loss 
of its historical range. Suttkus et al. (1994, p. 19) attributed the 
loss of the Pearl darter in the Pearl River to increasing sedimentation 
from habitat modification caused by the removal of riparian vegetation 
and extensive cultivation near the river's edge. In addition, the 
decline of the species in the Pearl River was likely exacerbated by the 
construction of low sill dams by the West Pearl Navigation Waterway, 
which blocked fish passage and is thought to have led to the 
extirpation of the Alabama shad (Alosa alabamae) from the system 
(Mickel et al. 2010, p. 158).
Water Quality Degradation
    Similar to the Pearl River system, the Pascagoula River system 
suffers from acute and localized water quality degradation by nonpoint 
source pollution in association with land surface, stormwater, and 
effluent runoffs from urbanization and municipal areas (Mississippi 
Department of Environmental Quality (MDEQ) 2005c, p. 23; 2005d, p. 16). 
TMDLs (Total Maximum Daily Loads; regulatory term in the U.S. Clean 
Water Act describing a benchmark set for a certain pollutant to bring 
water quality up to the applicable standard) have been established for 
89 segments of the Pascagoula River Basin, many of which include 
portions of the Pearl darter's range (MDEQ 2014a, pp. 18-21). For 
sediment, one of the most pervasive pollutants, the State of 
Mississippi has TMDLs for various tributaries and main stems of the 
Leaf and Chickasawhay Rivers. To date, efforts by the State of 
Mississippi to improve water quality in the Pascagoula River basin to 
meet these TMDL benchmarks have been inadequate (MDEQ 2014a, pp. 18-
21). Thirty-nine percent of the Pascagoula River Basin tributaries are 
rated fair or poor due to pollution impacts (MDEQ 2014a, pp. 18-21; 
MDEQ 2008a, p. 17).
    Nonpoint source pollution is a localized threat to the Pearl darter 
within the drainage, and is more prevalent in areas outside those lands 
protected by The Nature Conservancy and other areas managed by the 
State of Mississippi where Best Management Practices (BMPs) are 
utilized. Most water quality threats outside of protected lands are due 
to increased sediment loads and variations in pH (MDEQ 2014a, pp. 1-51; 
2008a, pp. 13-15). Sediment in stormwater runoff increases water 
turbidity and temperature and originates locally from poorly maintained 
construction sites, timber harvest tracts, agricultural fields, 
clearing of riparian vegetation, and gravel extraction in the river 
floodplain. Excessive sediments disrupt feeding and spawning of fish 
and aquatic insects, abrade and suffocate periphyton (mixture of algae, 
bacteria, microbes, and detritus that is attached to submerged 
surfaces), and impact fish growth, survival, and reproduction (Waters 
1995, pp. 55-62). A localized

[[Page 64861]]

portion of the Chickasawhay River is on the State Section 303(d) List 
of Water Bodies as impaired due to sediment (MDEQ 2005b, p. 17).
    Additionally, some contaminants may bind with one another within 
the Pascagoula River drainage (i.e., heavy metals bind with sediments 
or other contaminants in the water column). These bound chemical 
contaminants have not been addressed in TMDLs. Only seven TMDLs for 
metals have been completed (MDEQ 2008a, pp. 1-55). The Davis Dead 
River, a tributary at the most downstream site of the Pearl darter's 
range, is considered critically impaired by mercury (MDEQ 2011, pp. 1-
29), and fish consumption advisories continue for mercury in certain 
gamefish species in the Pascagoula River main stem (MDEQ 2008a, p. 43).
    There are 15 permitted point source discharge sites within the 
Bouie River system (MDEQ 2005a, p. 6) and an unknown amount of nonpoint 
runoff sites. Municipal and industrial discharges during periods of low 
flow (i.e., no or few rain events) intensify water quality degradation 
by increasing water temperatures, lowering dissolved oxygen, and 
changing pH. Within the Pascagoula River basin, pollutants causing 
specific channel or river reach impairment, (i.e., those pollutants 
preventing the water body from reaching its applicable water quality 
standard (Environmental Protection Agency (EPA) 2012, pp. 1-9), include 
sedimentation (117 km (73 mi)); chemicals and nutrients in the water 
column (50 km (31 mi)); and various toxins, such as heavy metals like 
lead or cadmium (137 km (85 mi)). TMDLs were completed for pesticides 
such as DDT, toxaphene, dioxin, and pentachlorophenol, although much of 
the data and results are not finalized and remain unavailable for the 
designated reaches (EPA 2012, pp. 1-7; MDEQ 2003, pp. 5-10; Justus et 
al. 1999, p. 1; MDEQ 1994, pp. 1-13). No Pearl darters have been 
collected in the Bouie River (Bart et al. 2001, pp. 6-7) since 1997 
(Ross et al. 2000, p. 3), though there is no specific data correlating 
the species' decline to the presence of these toxins.
    Localized wastewater effluent into the Leaf River from the City of 
Hattiesburg is negatively impacting water quality (Hattiesburg American 
2015, pp. 1-2; Mississippi River Collaboration 2014, p. 1; The Student 
Printz 2014, pp. 1-2). Existing housing, recreational cabins, and 
trailers along the banks of the Leaf River between I-59 to the town of 
Estabutchie add nutrient loading through sewage and septic water 
effluent (Mississippi River Collaboration 2014, p. 1). In 1997, Bart 
and Piller (p. 12) noted extensive algal growth during warmer months in 
the Leaf and Bouie Rivers, indicating nutrient and organic enrichment 
and decreases in dissolved oxygen and pH changes. Today, at specific 
locations, the water quality of the Bouie and Leaf Rivers continues to 
be negatively impacted by organic enrichment, low dissolved oxygen, 
fecal coliform and elevated nutrients (MDEQ 2005a, pp. 1-26; 2004, pp. 
1-29).
Oil and Gas Development
    Nonpoint and point source pollution from oil and gas exploration, 
including drill field construction, active drilling, and pipeline 
easements, may add localized pollutants into the Pascagoula River Basin 
during stormwater runoff events if BMPs are not used. There is one 
major oil refinery within the basin along with 6 oil pumping stations, 
10 major crude pipelines, 4 major product oil pipelines, and 5 major 
gas and more than 25 lesser gas lines stretching hundreds of miles and 
crisscrossing the main stem Pascagoula, Bouie, Leaf, and Chickasawhay 
Rivers and tributaries; in addition, there are more than 100 active oil 
producing wells within the Pearl darters' watersheds (compiled from Oil 
and Gas map of Mississippi in Phillips 2013, pp. 10, 23). All have the 
potential to rupture and/or leak and cause environmental and organismal 
damage as evidenced by the Genesis Oil Co. and Leaf River oil spill of 
2000 (Environmental Science Services, Inc. 2000, pp. 1-50; Kemp 
Associates, PA, 2000, pp. 4-5; The Clarion-Ledger, December 23, 1999, 
p. 1B) and Genesis Oil spill in Okatoma Creek in February 2016 (Drennen 
pers. observ. 2016). In addition to gas pipelines, there are numerous 
railways that cross Pearl darter habitat that are subject to accidental 
and catastrophic spilling of toxins such as fuel oil, methanol, resin, 
and fertilizer (MDEQ 2014b, pp. 1-23).
    Alternative oil and gas collection methods (i.e., hydraulic 
fracturing (``fracking'') and horizontal drilling and injection) have 
allowed for the expansion of oil and gas drilling into deposits that 
were previously inaccessible (Phillips 2013, p. 21), which has led to 
increased activity within southern Mississippi, including portions of 
the Pascagoula River Basin. There are more than 100 water injection 
disposal wells and enhanced oil recovery wells within the Basin 
(compiled from Active Injection Well Map of Mississippi in Phillips 
2013, p. 49). A variety of chemicals (e.g., hydrochloric acid, 
surfactants, potassium chloride) are used during the drilling and 
fracking process (Colborn et al. 2011, pp. 1040-1042), and their wastes 
are stored in open pits (retention basins) or storage facilities. 
Spills during transport or releases due to retention basin failure or 
overflow pose a risk for surface and groundwater contamination, which 
can cause significant adverse effects to water quality and aquatic 
organisms that inhabit these watersheds (Osborn et al. 2011, pp. 8172-
8176; Kargbo et al. 2010, pp. 5680-5681; Wiseman 2009, pp. 127-142). 
There is currently no routine water quality monitoring in areas where 
the Pearl darter currently occurs, so it is unlikely that the effects 
of a leak or spill would be detected quickly to allow for a timely 
response.
Geomorphology Changes
    Pearl darters are not found in impounded waters and are intolerant 
of lentic (standing water) habitats that may be formed by gravel mining 
or other landscape-altering practices. The results of historical sand 
and gravel dredging impacts have been a concern for the Bouie and Leaf 
Rivers (MDEQ 2000, pp. 1-98). Historically, the American Sand and 
Gravel Company (ASGC) (1995, p. B4) has mined sand and gravel using a 
hydraulic suction dredge, operating within the banks or adjacent to the 
Bouie and Leaf Rivers. Large gravel bars of the river and its 
floodplain have been removed over the past 50 years, creating open-
water areas that function as deep lake systems (ASGC 1995, pp. B4-B8). 
The creation of these large, open-water areas has accelerated 
geomorphic processes, specifically headcutting (erosional feature 
causing an abrupt drop in the streambed), that has adversely affected 
the flora and fauna of many coastal plain streams (Patrick et al. 1993, 
p. 90). Mining in active river channels typically results in incision 
upstream of the mine by knickpoints (break in the slope of a river or 
stream profile caused by renewed erosion attributed to a bottom 
disturbance that may retreat upstream), sediment deposition downstream, 
and an alteration in channel morphology that can have impacts for years 
(Mossa and Coley 2004, pp. 1-20). The upstream migration of 
knickpoints, or headcutting, may cause undermining of structures, 
lowering of alluvial water tables (aquifer comprising unconsolidated 
materials deposited by water and typically adjacent to rivers), channel 
destabilization and widening, and loss of aquatic and riparian habitat. 
This geomorphic change may cause the extirpation of riparian and lotic 
(flowing water) species (Patrick et al. 1993, p. 96). Lyttle (1993, p. 
70) and Brown and Lyttle (1992, pp. 2, 46) found that

[[Page 64862]]

instream gravel mining reduces overall fish species diversity in Ozark 
streams and favors a large number of a few small fish species, such as 
the Central stoneroller (Campostoma anomalum) and most darters 
(Etheostoma sp.).
    The decline of the Pearl darter in the Bouie River and Black Creek 
may be from sedimentation caused by unstable banks and loose and 
unconsolidated streambeds (Bart and Piller 1997, p. 12). Mossa and 
Coley (2004, p. 17) determined that, of the major tributaries in the 
Pascagoula basin, the Bouie River was the least stable. Channel 
enlargement of the Bouie River showed higher than background values 
associated with avulsions (the rapid abandonment of a river channel and 
the formation of a new river channel) into floodplain pits and 
increased sedimentation. In addition, channel enlargement of 400 to 500 
percent in the Bouie River has occurred at specific sites due to 
instream gravel mining (Mossa et al. 2006, entire; Mossa and Coley 
2004, p. 17). Ayers (2014, pp. 43-45) also found significant and 
lengthy instream channel form changes in the Chickasawhay River 
floodplain. Clark and Schaefer (2015, pp. 13-14) noted a slight 
decrease in fish species richness in the upper Pascagoula River basin 
from their 2004 sampling, which they attributed to past anthropogenic 
influences such as gravel mining, bankside practices, and construction.
    In the Bogue Chitto River of the Pearl River basin, Stewart et al. 
(2005, pp. 268-270) found that the assemblages of fishes had shifted 
over 27 years. In this time period, the sedimentation rates within the 
system had increased dramatically and caused the decrease in the 
relative abundance of all fish in the family Percidae (Stewart et al. 
2005, pp. 268-270) from 35 percent to 9 percent, including the 
extirpation of Pearl darters. Ross et al. (1992, pp. 8-9) studied 
threats to the Okatoma Creek (Pascagoula Basin) fish diversity and 
predicted that geomorphic changes to the stream would reduce the fish 
habitat diversity resulting in a decline of the fish assemblages, 
including the rare Pearl darter.
Impoundments
    The proposed damming of Little and Big Cedar Creeks, tributaries to 
the Pascagoula River, for establishment of two recreational lakes 
(George County Lakes) (U.S. Army Corps of Engineers 2015, pp. 1-13) has 
prompted the American Rivers organization to recently list the 
Pascagoula River as the 10th most endangered river in the country 
(American Rivers 2016, pp. 20-21). Though the proposed project is not 
directly within known Pearl darter habitat, the lakes will decrease 
water quantity entering the lower Pascagoula Basin, and will likely 
concentrate pollutants, reduce water flow, and alter downstream food 
webs and aquatic productivity (Poff and Hart 2002, p. 660).
Summary of Factor A
    Habitat modification and resultant water quality degradation are 
occurring within the Pearl darter's current range. Increased 
sedimentation from the removal of riparian vegetation and extensive 
cultivation is thought to have led to the extirpation of the Pearl 
darter from the Pearl River drainage. Water quality degradation occurs 
locally from point and nonpoint source pollution in association with 
land surface, stormwater, and effluent runoff from urbanization and 
municipal areas. Increased sediment from a variety of sources, 
including geomorphological changes and bank instability from past 
habitat modification, appears to be the major contributor to water 
quality declines in this species' habitat. Localized sewage and waste 
water effluent also pose a threat to this species and its habitat. The 
Pearl darter's vulnerability to catastrophic events, particularly the 
release of pollutants in its habitat from oil spills, train 
derailments, and hydraulic fracturing, is also a concern due to the 
abundance of oil wells, pumping stations, gas lines, and railways 
throughout its habitat, and the increased interest in alternative oil 
and gas collection methods in the area. The proposed damming of Big and 
Little Cypress creeks may decrease water flow and increase nutrients 
and sedimentation into the Pascagoula River. These threats continue to 
impact water quality and habitat conditions through much of this 
species' current range. Therefore, we conclude that habitat degradation 
is presently a moderate threat to the Pearl darter that is expected to 
continue and possibly increase into the future.

Factor B: Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    In general, Pearl darters are unknown to the public and are not 
used for either sport or bait purposes. Therefore, collection of this 
species by the public is not currently identified as a threat. 
Scientific collecting is controlled by the State through permits; thus, 
scientific collecting and take by private and institutional collectors 
are not presently identified as threats. Therefore, overutilization for 
commercial, recreational, scientific, or educational purposes does not 
pose a threat to the Pearl darter now or in the future.

Factor C: Disease or Predation

    Predation on the Pearl darter by other fish, reptiles, and other 
organisms undoubtedly occurs; however, there is no evidence to suggest 
that any predators threaten this species. There is also no evidence 
that disease is a threat. Therefore, neither disease nor predation 
poses a threat to the Pearl darter now or in the future.

Factor D: The Inadequacy of Existing Regulatory Mechanisms

    The State of Mississippi classifies the Pearl darter as endangered 
in the State (Mississippi Natural Heritage Program 2015, p. 2), and 
prohibits the collection of the Pearl darter for scientific purposes 
without a State-issued collecting permit. However, as discussed under 
Factor B, we have no evidence to suggest that scientific collection 
poses a threat to this species. This State endangered designation 
conveys no legal protection for the Pearl darter's habitat nor 
prohibits habitat degradation, which is the primary threat to the 
species. The Pearl darter receives no protection in Louisiana, where it 
is considered historic in the State (Louisiana Department of Wildlife 
and Fisheries 2016, p. 5).
    The Pearl darter and its habitats are afforded some protection from 
water quality and habitat degradation under the Clean Water Act of 1972 
(33 U.S.C. 1251 et seq.) and the Mississippi Water Pollution Control 
Law, as amended, 1993 (Code of Mississippi, Sec. Sec.  49-17-1, et 
seq.) and regulations promulgated thereunder by the Mississippi 
Commission on Environmental Quality. Although these laws have resulted 
in some temporary enhancement in water quality and habitat for aquatic 
life, they have been inadequate in fully protecting the Pearl darter 
from sedimentation and other nonpoint source pollutants.
    The State of Mississippi maintains water-use classifications 
through issuance of National Pollutant Discharge Elimination System 
permits to industries, municipalities, and others that set maximum 
limits on certain pollutants or pollutant parameters. For water bodies 
on the Clean Water Act section 303(d) list, the State is required to 
establish a TMDL for the pollutants of concern that will improve water 
quality to the applicable standard. The establishment of TMDLs for 89 
river or stream segments and ratings of fair to poor for 39 percent of 
the tributaries within the Pascagoula basin are indicative of pollution 
impacts within the Pearl darter's habitat (MDEQ 2008a,

[[Page 64863]]

p. 17). TMDLs are not an enforced regulation, and only reflect 
benchmarks for improving water quality; they have not been successful 
in reducing water quality degradation within this species' habitat.
    Mississippi Surface Mining and Reclamation Law, Miss. Code Ann. 
Sec.  53-7-1 et seq., and Federal laws regarding oil and gas drilling 
(42 U.S.C. 6921) are generally designed to protect freshwater resources 
like the Pearl darter, but these regulatory mechanisms do not contain 
specific provisions requiring an analysis of project impacts to fish 
and wildlife resources. They also do not contain or provide for any 
formal mechanism requiring coordination with, or input from, the 
Service or the Mississippi Department of Wildlife, Fisheries and Parks 
regarding the presence of federally endangered, threatened, or 
candidate species, or other rare and sensitive species. In the case of 
surface mining, penalties may be assessed if damage is serious, but 
there is no immediate response for remediation of habitats or species. 
As demonstrated under Factor A, periodic declines in water quality and 
degradation of habitat for this species are ongoing despite these 
protective regulations. These mechanisms have been inadequate to 
protect the species from sediment runoff and turbidity within its 
habitat associated with land surface runoff and municipal/industrial 
discharges, as described under Factor A. There are currently no 
requirements within the scope of other statewide environmental laws to 
specifically consider the Pearl darter or ensure that a project will 
not significantly impact the species.
    The Pearl darter likely receives ancillary protection (i.e., water 
quality improvements, protection from geomorphological changes) where 
it co-occurs with two other federally listed species, the Gulf sturgeon 
(Acipenser oxyrhynchus desotoi) and yellow blotched map turtle 
(Graptemys flavimaculata), during the course of consultation on these 
species under section 7 of the Act. However, protective measures 
through section 7 of the Act would only be triggered for those projects 
having a Federal nexus, which would not address many of the water 
quality disturbances caused by industry, municipalities, agriculture, 
or private landowners.
    Additional ancillary protection of 53,520 hectares (ha) (132,128 
acres (ac)) within the Pascagoula basin watershed occurs due to the 
Mississippi Wildlife, Fisheries and Parks' management of six Wildlife 
Management Areas (WMAs) within the drainage for recreational hunting 
and fishing. Point and nonpoint sediment sources are decreased or 
reduced by using and monitoring BMP's during silviculture, road 
maintenance, and other landscape-altering methods. Four of the six WMAs 
(Chickasawhay and Leaf Rivers, Mason and Red Creeks) do not directly 
border the river system, but they do contain and protect parcels of 
upland buffer, wetland, and tributaries to the basin. The Pascagoula 
River and Ward Bayou WMAs include 20,329 ha (50,234 ac) consisting of 
mainly wetland buffer and river/stream reach of the basin within the 
current range of the Pearl darter, protecting approximately 106 km (66 
mi) of the Pascagoula River main stem (Stowe, pers. comm., 2015). The 
Nature Conservancy (TNC) protects 14,164 ha (35,000 ac) within the 
Pascagoula River watershed and approximately 10 km (6 mi) of the 
Pascagoula River shoreline in Jackson County, Mississippi. Of that 
amount, the Charles M. Deaton Nature Preserve (1,336 ha, 3,300 ac) 
protects the headwaters of the Pascagoula River, where the Leaf and 
Chickasawhay Rivers converge, and is part of a 19,020-ha (47,000-ac) 
swath of public lands surrounding the Pascagoula River, which includes 
approximately 8 km (5 mi) of the Chickasawhay River and approximately 7 
km (4 mi) of the Leaf River shorelines (Becky Stowe 2015, pers. comm.).
    These State-managed WMAs and TNC preserves provide a measure of 
protection for approximately 134 km (84 mi) or 30 percent of the river 
reaches within this species' current range. Even though 116 of these 
134 km (72 of 84 mi) are located within the Pascagoula River mainstem, 
only short segments of shoreline are protected in the Chickasawhay and 
Leaf Rivers. The remaining segments, not within WMA's and TNC 
preserves, are vulnerable to farming and timbering to the bankside 
edge, and construction of structures such as houses, septic facilities, 
dams, and ponds. Each land management action increases stormwater 
runoff laden with sediment and agricultural and wastewater chemicals.
Summary of Factor D
    Outside of the areas protected or managed by the State and TNC, and 
despite existing authorities, such as the Clean Water Act, pollutants 
continue to impair the water quality throughout much of the current 
range of the Pearl darter. State and Federal regulatory mechanisms have 
helped reduce the negative effects of point source and nonpoint source 
discharges, yet there is inconsistency in the implementation of these 
regulations and BMPs, which are not mandatory for all activities. Thus, 
we conclude that existing regulatory mechanisms do not adequately 
protect the Pearl darter from the impact of other threats.

Factor E: Other Natural or Manmade Factors Affecting Its Continued 
Existence

Small Population Size and Loss of Genetic Diversity
    The Pearl darter is included on the Southeastern Fishes Council 
list of the 12 most imperiled species (Kuhajda et al. 2009, pp. 17-18). 
This species has always been considered rare (Deacon et al. 1979, p. 
42) and is currently restricted to localized sites within the 
Pascagoula River drainage. Genetic diversity has likely declined due to 
fragmentation and separation of reproducing Pearl darter populations. 
Kreiser et al. (2012, p. 12) found that disjunct populations of Pearl 
darters within the Leaf and Chickasawhay Rivers showed some distinct 
alleles suggesting that gene flow between the two rivers was restricted 
and perhaps that the total gene pool diversity was declining.
    Species that are restricted in range and population size are more 
likely to suffer loss of genetic diversity due to genetic drift, 
potentially increasing their susceptibility to inbreeding depression, 
decreasing their ability to adapt to environmental changes, and 
reducing the fitness of individuals (Allendorf and Luikart 2007, pp. 
117-146; Soul[eacute] 1980, pp. 157-158). It is likely that some of the 
Pearl darter populations are below the effective population size 
required to maintain long-term genetic and population viability 
(Soul[eacute] 1980, pp. 162-164). Collecting data (Ross 2001, p. 500; 
Bart and Piller 1997, p. 4; Bart and Suttkus 1996, p. 4; Suttkus et al. 
1994, p. 19) indicate that the Pearl darter is rare in the Pascagoula 
River system, as when this species is collected it is typically in low 
numbers and a disproportionately low percentage of the total fish 
collected.
    In addition, preliminary information indicates that there may be 
low genetic diversity within the Pearl darter populations, especially 
among populations within the Leaf and Chickasawhay Rivers where it 
appears gene flow between the two rivers may be restricted (Kreiser et 
al. 2013, pp. 14-17). The long-term viability of a species is founded 
on the conservation of numerous local populations throughout its 
geographic range (Harris 1984, pp. 93-104). The presence of viable, 
separate populations is essential for a species to recover and adapt to

[[Page 64864]]

environmental change (Noss and Cooperrider 1994, pp. 264-297; Harris 
1984, pp. 93-104). Inbreeding and loss of neutral genetic variation 
associated with small population size reduce the fitness of the 
population (Reed and Frankham 2003, pp. 230-237) and accelerate 
population decline (Fagan and Holmes 2006, pp. 51-60). The species' 
small numbers within scattered locations coupled with its lack of 
genetic variability may decrease the species' ability to adapt or 
recover from major hydrological events that impact potential spawning 
habitat (Clark and Schaeffer 2015, pp. 18-22).
Hurricanes
    Fish and aquatic communities and habitat, including that of the 
Pearl darter, may be changed by hurricane influences (Schaefer et al. 
2006, pp. 62-68). In 2005, Hurricane Katrina destroyed much of the 
urban and industrial areas along the lower Pascagoula River basin and 
also impacted the ecology upriver to the confluence with the Leaf and 
Chickasawhay Rivers. Many toxic chemicals that leaked from grounded and 
displaced boats and ships, storage facilities, vehicles, septic 
systems, business sites, and other sources were reported in the rivers, 
along with saltwater intrusion from the Gulf of Mexico. Initial 
assessment identified several fish kills and increased surge of organic 
material into the waters, which lowered dissolved oxygen levels 
(Schaefer et al. 2006, pp. 62-68).
Climate Change
    The Intergovernmental Panel on Climate Change (IPCC) concluded that 
warming of the climate system is unequivocal (IPCC 2014, p. 3). 
Numerous long-term climate changes have been observed including changes 
in arctic temperatures and ice, widespread changes in precipitation 
amounts, ocean salinity, wind patterns, and aspects of extreme weather 
including droughts, heavy precipitation, heat waves, and the intensity 
of tropical cyclones (IPCC 2014, p. 4). Species that are dependent on 
specialized habitat types, limited in distribution, or at the extreme 
periphery of their range may be most susceptible to the impacts of 
climate change (see 75 FR 48911, August 12, 2010); however, while 
continued change is certain, the magnitude and rate of change is 
unknown in many cases.
    Climate change has the potential to increase the vulnerability of 
the Pearl darter to random catastrophic events (Thomas et al. 2004, pp. 
145-148; McLaughlin et al. 2002, pp. 6060-6074). An increase in both 
severity and variation in climate patterns is expected, with extreme 
floods, strong storms, and droughts becoming more common (IPCC 2014, 
pp. 58-83). Thomas et al. (2004, pp. 145-148) report that frequency, 
duration, and intensity of droughts are likely to increase in the 
Southeast as a result of global climate change. Kaushal et al. (2010, 
p. 465) reported that stream temperatures in the Southeast have 
increased roughly 0.2-0.4 [deg]C (0.3-0.7 [deg]F) per decade over the 
past 30 years, and as air temperature is a strong predictor of water 
temperature, stream temperatures are expected to continue to rise. 
Predicted impacts of climate change on fishes, related to drought, 
include disruption to their physiology (e.g., temperature tolerance, 
dissolved oxygen needs, and metabolic rates), life history (e.g., 
timing of reproduction, growth rate), and distribution (e.g., range 
shifts, migration of new predators) (Comte et al. 2013, pp. 627-636; 
Strayer and Dudgeon 2010, pp. 350-351; Heino et al. 2009, pp. 41-51; 
Jackson and Mandrak 2002, pp. 89-98). However, estimates of the effects 
of climate change using available climate models typically lack the 
geographic precision needed to predict the magnitude of effects at a 
scale small enough to discretely apply to the range of a given species. 
Therefore, there is uncertainty about the specific effects of climate 
change (and their magnitude) on the Pearl darter; however, climate 
change is almost certain to affect aquatic habitats in the Pascagoula 
River basin through increased water temperatures and more frequent 
droughts (Alder and Hostetler 2013, pp. 1-12), and species with limited 
ranges, fragmented distributions, and small population size are thought 
to be especially vulnerable to the effects of climate change (Byers and 
Norris 2011, p. 18). Thus, we consider climate change to be a threat to 
the Pearl darter.
Summary of Factor E
    Because the Pearl darter has a limited geographic range, small 
population numbers, and low genetic diversity, it is vulnerable to 
several other ongoing natural and manmade threats. These threats 
include the loss of genetic fitness, susceptibility to spills and other 
catastrophic events, and impacts from climate change. These threats are 
current and are likely to continue or increase in the future.

Cumulative Effects of Factors A Through E

    The threats that affect the Pearl darter are important on a threat-
by-threat basis but are even more significant in combination. Due to 
the loss of the species from the Pearl River system, the Pearl darter 
is now confined to a single drainage system. The species is continuing 
to experience water quality degradation from point and nonpoint source 
pollution in association with land-altering activities, discharges from 
municipalities, and geomorphological changes from past gravel mining. 
The laws and regulations directed at preventing water quality 
degradation have been ineffective at providing for the conservation of 
the Pearl darter. Furthermore, these threats and their effect on this 
species are exacerbated due to the Pearl darter's small population 
numbers and low genetic diversity, which reduce its genetic fitness and 
resilience to possible catastrophic events. Though projecting possible 
synergistic effects of climate change on the Pearl darter is somewhat 
speculative, climate change and its effects of increased water 
temperatures and more frequent droughts will have a greater negative 
impact on species with limited ranges and small population sizes, such 
as the Pearl darter. While these threats or stressors may act in 
isolation, it is more probable that many stressors are acting 
simultaneously (or in combination) on the Pearl darter.

Proposed Determination

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Pearl darter. As described in detail above, the Pearl darter has 
been extirpated from about 57 percent of its historical range and it is 
now confined to the Pascagoula River watershed. The species occurs in 
low numbers within its current range, and continues to be at risk 
throughout all of its range due to the immediacy, severity, and scope 
of threats from habitat degradation and range curtailment (Factor A) 
and other natural or manmade factors affecting its continued existence 
(Factor E). Existing regulatory mechanisms have been inadequate in 
ameliorating these threats (Factor D).
    Anthropogenic activities such as land development, agriculture, 
silviculture, oil and gas development, inadequate sewage treatment, 
stormwater runoff, past gravel mining and resultant geomorphological 
changes, and construction of dams or sills, have all contributed to the 
degradation of stream habitats and particularly water quality within 
this species' range (Factor A). These land use activities have led to 
chemical and physical changes in the mainstem rivers and tributaries 
that continue to affect the species through negative impacts to its 
habitat. Specific

[[Page 64865]]

threats include inputs of sediments, siltation of stream substrates, 
turbidity, and inputs of dissolved solids. These threats, especially 
the inputs of dissolved solids and sedimentation, have had profound 
negative effects on Pearl darter populations and have been the primary 
factor in the species' decline. Existing regulatory mechanisms (e.g., 
the Clean Water Act) have provided for some improvements in water 
quality and habitat conditions across the species' range, but these 
laws and regulations have been inadequate in protecting the species' 
habitat (Factor D), as evidenced by the extirpation of the species 
within the Pearl River basin and the number of section 303(d) listed 
streams within the species' historical range. The Pearl darter's 
vulnerability to these threats is even greater due to its reduced 
range, fragmented populations, small population sizes, and low genetic 
diversity (Factor E). The effects of certain threats, particularly 
habitat degradation and loss, increase in magnitude when population 
size is small (Primack 2012, pp. 150-152).
    The Act defines an endangered species as any species that is ``in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species as any species ``that is likely to 
become endangered throughout all or a significant portion of its range 
within the foreseeable future.'' We find that the Pearl darter is 
likely to become endangered throughout all or a significant portion of 
its range within the foreseeable future, based on the immediacy, 
severity, and scope of the threats currently impacting the species. The 
overall range has been reduced substantially and the remaining habitat 
and populations are threatened by a variety of factors acting in 
combination to reduce the overall viability of the species over time. 
The risk of becoming endangered is high because populations are 
confined to a single watershed, most are small in size, and numerous 
threats are impacting them. However, we find that endangered species 
status is not appropriate. Despite low population numbers and numerous 
threats, populations in the Chickasawhay and Leaf Rivers, which are the 
largest, appear to be stable and reproducing. In addition, the 
magnitude of threats is considered to be moderate overall, since the 
threats are having a localized impact on the species and its habitat. 
For example, water quality degradation, the most prevalent threat, is 
not as pervasive within areas protected with BMPs, and geomorphic 
changes, caused by past sand and gravel mining, are also sporadic 
within its habitat. Therefore, on the basis of the best available 
scientific and commercial information, we propose listing the Pearl 
darter as threatened in accordance with sections 3(6) and 4(a)(1) of 
the Act.
    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. Because we have determined that Pearl 
darter is threatened throughout all of its range, no portion of its 
range can be ``significant'' for purposes of the definitions of 
``endangered species'' and ``threatened species.'' See the Final Policy 
on Interpretation of the Phrase ``Significant Portion of Its Range'' in 
the Endangered Species Act's Definitions of ``Endangered Species'' and 
``Threatened Species'' (79 FR 37577, July 1, 2014).

Critical Habitat

    Section 3(5)(A) of the Act defines critical habitat as ``(i) the 
specific areas within the geographical area occupied by the species, at 
the time it is listed . . . on which are found those physical or 
biological features (I) Essential to the conservation of the species 
and (II) which may require special management considerations or 
protection; and (ii) specific areas outside the geographical area 
occupied by the species at the time it is listed . . . upon a 
determination by the Secretary that such areas are essential for the 
conservation of the species.''
    Section 4(a)(3) of the Act and implementing regulations (50 CFR 
424.12) require that we designate critical habitat at the time a 
species is determined to be an endangered or threatened species, to the 
maximum extent prudent and determinable. Our regulations (50 CFR 
424.12(a)(1)) state that designation of critical habitat is not prudent 
when one or both of the following situations exist: (1) The species is 
threatened by taking or other activity and the identification of 
critical habitat can be expected to increase the degree of threat to 
the species; or (2) such designation of critical habitat would not be 
beneficial to the species. There is currently no imminent threat of 
take attributed to collection or vandalism under Factor B for this 
species, and identification and mapping of critical habitat is not 
expected to initiate any such threat. In the absence of finding that 
the designation of critical habitat would increase threats to a 
species, if there are any benefits to a critical habitat designation, a 
finding that designation is prudent is warranted. Here, the potential 
benefits of designation include: (1) Triggering consultation under 
section 7 of the Act, in new areas for action in which there may be a 
Federal nexus where it would not otherwise occur because, for example, 
it is unoccupied; (2) focusing conservation activities on the most 
essential features and areas; (3) providing educational benefits to 
State or county governments or private entities; and (4) preventing 
inadvertent harm to the species. Accordingly, because we have 
determined that the designation of critical habitat will not likely 
increase the degree of threat to the species and may provide some 
measure of benefit, we determine that designation of critical habitat 
is prudent for the Pearl darter.
    Having determined that designation is prudent, under section 
4(a)(3) of the Act we must find whether critical habitat for the 
species is determinable. Our regulations (50 CFR 424.12(a)(2)) further 
state that critical habitat is not determinable when one or both of the 
following situations exist: (i) Information sufficient to perform 
required analysis of the impacts of the designation is lacking; or (ii) 
The biological needs of the species are not sufficiently well known to 
permit identification of an area as critical habitat.
    As discussed above, we have reviewed the available information 
pertaining to the biological needs of the species and habitat 
characteristics where the species is located. On the basis of a review 
of available information, we find that critical habitat for the Pearl 
darter is not determinable because the specific information sufficient 
to perform the required analysis of the impacts of the designation is 
currently lacking, such as information on areas to be proposed for 
designation and the potential economic impacts associated with 
designation of these areas. We are in the process of obtaining this 
information. We will make a determination on critical habitat no later 
than 1 year following any final listing determination.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened species under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing results in public awareness and 
conservation by Federal, State, Tribal, and local agencies, private 
organizations, and individuals. The Act encourages cooperation with the 
States and other countries and calls for recovery actions to be carried 
out for listed species. The protection required by Federal agencies

[[Page 64866]]

and the prohibitions against certain activities are discussed, in part, 
below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Subsection 4(f) of the Act calls for the Service to develop 
and implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed and preparation of a draft and final 
recovery plan. The recovery outline guides the immediate implementation 
of urgent recovery actions and describes the process to be used to 
develop a recovery plan. Revisions of the plan may be done to address 
continuing or new threats to the species, as new substantive 
information becomes available. The recovery plan also identifies 
recovery criteria for review of when a species may be ready for 
downlisting or delisting, and methods for monitoring recovery progress. 
Recovery plans also establish a framework for agencies to coordinate 
their recovery efforts and provide estimates of the cost of 
implementing recovery tasks. Recovery teams (composed of species 
experts, Federal and State agencies, nongovernmental organizations, and 
stakeholders) are often established to develop recovery plans. If the 
species is listed, the recovery outline, draft recovery plan, and the 
final recovery plan would be available on our Web site (https://www.fws.gov/endangered), or from our Mississippi Ecological Services 
Field Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands. 
If this species is listed, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost-share grants for non-Federal landowners, the 
academic community, and nongovernmental organizations. In addition, 
pursuant to section 6 of the Act, the State of Mississippi would be 
eligible for Federal funds to implement management actions that promote 
the protection or recovery of the Pearl darter. Information on our 
grant programs that are available to aid species recovery can be found 
at: https://www.fws.gov/grants.
    Although the Pearl darter is only proposed for listing under the 
Act at this time, please let us know if you are interested in 
participating in conservation efforts for this species. Additionally, 
we invite you to submit any new information on this species whenever it 
becomes available and any information you may have for recovery 
planning purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as an 
endangered or threatened species and with respect to its critical 
habitat, if any is designated. Regulations implementing this 
interagency cooperation provision of the Act are codified at 50 CFR 
part 402. Section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any action that is likely to jeopardize the 
continued existence of a species proposed for listing or result in 
destruction or adverse modification of proposed critical habitat. If a 
species is listed subsequently, section 7(a)(2) of the Act requires 
Federal agencies to ensure that activities they authorize, fund, or 
carry out are not likely to jeopardize the continued existence of the 
species or destroy or adversely modify its critical habitat. If a 
Federal action may affect a listed species or its critical habitat, the 
responsible Federal agency must enter into consultation with the 
Service.
    Federal agency actions within the species' habitat that may require 
conference or consultation or both as described in the preceding 
paragraph include management and any other landscape-altering 
activities on Federal lands administered by the U.S. Forest Service; 
issuance of section 404 Clean Water Act permits by the U.S. Army Corps 
of Engineers; construction and maintenance of gas and oil pipelines and 
power line rights-of-way by the Federal Energy Regulatory Commission; 
Environmental Protection Agency pesticide registration; and 
construction and maintenance of roads or highways by the Federal 
Highway Administration.
    The Act and its implementing regulations set forth a series of 
general prohibitions and exceptions that apply to threatened wildlife. 
The prohibitions of section 9(a)(1) of the Act, as applied to 
threatened wildlife and codified at 50 CFR 17.31, make it illegal for 
any person subject to the jurisdiction of the United States to take 
(which includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect; or to attempt any of these) threatened wildlife 
within the United States or on the high seas. In addition, it is 
unlawful to import; export; deliver, receive, carry, transport, or ship 
in interstate or foreign commerce in the course of commercial activity; 
or sell or offer for sale in interstate or foreign commerce any listed 
species. It is also illegal to possess, sell, deliver, carry, 
transport, or ship any such wildlife that has been taken illegally. 
Certain exceptions apply to employees of the Service, the National 
Marine Fisheries Service, other Federal land management agencies, and 
State conservation agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving threatened wildlife under certain circumstances. Regulations 
governing permits are codified at 50 CFR 17.32. With regard to 
threatened wildlife, a permit may be issued for the following purposes: 
For scientific purposes, to enhance the propagation or survival of the 
species, and for incidental take in connection with otherwise lawful 
activities. There are also certain statutory exemptions from the 
prohibitions, which are found in sections 9 and 10 of the Act.
    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a proposed 
listing on proposed and ongoing activities within the range of the 
species proposed for listing. Based on the best available information, 
the following actions are unlikely to result in a violation of section 
9, if these activities are carried out in accordance with existing 
regulations and permit requirements; this list is not comprehensive:
    (1) Normal agricultural and silvicultural practices, including

[[Page 64867]]

herbicide and pesticide use, which are carried out in accordance with 
existing regulations, permit and label requirements, and best 
management practices.
    (2) Normal residential and urban landscape activities, such as 
mowing, edging, fertilizing, etc.
    (3) Normal pipeline/transmission line easement maintenance.
    (4) Normal bridge, culvert, and roadside maintenance consistent 
with appropriate best management practices for these activities.
    Based on the best available information, the following activities 
may potentially result in a violation of section 9 of the Act; this 
list is not comprehensive:
    (1) Unauthorized handling or collecting of the species.
    (2) Introduction of nonnative fish that compete with or prey upon 
the Pearl darter.
    (3) Discharge or dumping of toxic chemicals, contaminants, 
sediments, waste water effluent, or other pollutants into waters 
supporting the Pearl darter that kills or injures individuals, or 
otherwise impairs essential life-sustaining behaviors such as spawning, 
feeding, or sheltering.
    (4) Destruction or alteration of the species' habitat (e.g., 
unpermitted instream dredging, impoundment, water diversion or 
withdrawal, channelization, discharge of fill material, modification of 
tributaries, channels, or banks) that impairs essential behaviors such 
as spawning, feeding, or sheltering, or results in killing or injuring 
a Pearl darter.
    (5) Mining, oil and gas processes, silviculture, and agricultural 
processes that result in direct or indirect destruction of riparian 
bankside habitat or in channel habitat in waters supporting the Pearl 
darter that kills or injures individuals, or otherwise impairs 
essential life-sustaining behaviors such as spawning, feeding, or 
sheltering.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the Mississippi 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Required Determinations

Clarity of the Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (1) Be logically organized;
    (2) Use the active voice to address readers directly;
    (3) Use clear language rather than jargon;
    (4) Be divided into short sections and sentences; and
    (5) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in ADDRESSES. To better help us 
revise the rule, your comments should be as specific as possible. For 
example, you should tell us the numbers of the sections or paragraphs 
that are unclearly written, which sections or sentences are too long, 
the sections where you feel lists or tables would be useful, etc.

National Environmental Policy Act

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act (42 U.S.C. 4321 et seq.), need not be prepared 
in connection with listing a species as an endangered or threatened 
species under the Endangered Species Act. We published a notice 
outlining our reasons for this determination in the Federal Register on 
October 25, 1983 (48 FR 49244).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination with Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
tribes in developing programs for healthy ecosystems, to acknowledge 
that tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to tribes. There are no tribal lands located 
within the range of this species.

References Cited

    A complete list of references cited in this proposed rulemaking is 
available on the Internet at https://www.regulations.gov and upon 
request from the Mississippi Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this proposed rule are the staff members of 
the Mississippi Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the Code of Federal Regulations, as set forth below:

PART 17--[AMENDED]

0
1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245; unless 
otherwise noted.

0
2. In Sec.  17.11(h), add an entry for ``Darter, Pearl'' to the List of 
Endangered and Threatened Wildlife in alphabetical order under FISHES 
to read as set forth below:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *

 
----------------------------------------------------------------------------------------------------------------
                                                                                          Listing citations and
           Common name              Scientific name      Where listed         Status         applicable rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
             Fishes
 

[[Page 64868]]

 
                                                  * * * * * * *
Darter, Pearl...................  Percina aurora....  Wherever found....  T              [Federal Register
                                                                                          citation when
                                                                                          published as a final
                                                                                          rule].
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------


    Dated: August 30, 2016.
James W. Kurth,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2016-22752 Filed 9-20-16; 8:45 am]
BILLING CODE 4333-15-P