[Federal Register Volume 82, Number 188 (Friday, September 29, 2017)]
[Proposed Rules]
[Pages 45551-45574]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-21052]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R5-ES-2016-0030; 4500030113]
RIN 1018-BB50


Endangered and Threatened Wildlife and Plants; Withdrawal of the 
Proposed Rule to List Kenk's Amphipod

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule; withdrawal.

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

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), withdraw the 
proposed rule to list the Kenk's amphipod (Stygobromus kenki), an 
invertebrate from the District of Columbia, Maryland, and Virginia as 
an endangered species under the Endangered Species Act (Act) as 
amended. This withdrawal is based on our conclusion that the threats to 
the species as identified in the proposed rule are not as significant 
as we previously determined and the proposed listing is not warranted. 
We base this conclusion on our analysis of new information concerning 
the results of new surveys, current and future threats, and 
conservation efforts. We find the best scientific and commercial data 
available indicate that the Kenk's amphipod does not meet the statutory 
definitions of an endangered or threatened species. Therefore, we are 
withdrawing our proposed rule to list the Kenk's amphipod as an 
endangered species.

DATES: The proposed rule that published on September 30, 2016 (81 FR 
67270), is withdrawn on September 29, 2017.

ADDRESSES: The withdrawal of our proposed rule and supplementary 
documents are available on the Internet at http://www.regulations.gov 
at Docket No. FWS-R5-ES-2016-0030, and at https://www.fws.gov/chesapeakebay/. Comments and materials we received, as well as 
supporting documentation we used in the preparation of this withdrawal, 
are available for public inspection by appointment, during normal 
business hours at: U.S. Fish and Wildlife Service, Chesapeake Bay Field 
Office, 177 Admiral Cochrane Drive, Annapolis, MD 21401, by telephone 
410-573-4577 or by facsimile 410-269-0832.

FOR FURTHER INFORMATION CONTACT: Genevieve LaRouche, Field Supervisor, 
U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177 
Admiral Cochrane Drive, Annapolis, MD 21401, by telephone 410-573-4577 
or by facsimile 410-269-0832. Persons who use a telecommunications 
device for the deaf (TDD) may call the Federal Relay Service at 800-
877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish this document. Under the Endangered Species 
Act (Act), if a species is determined to be 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 1 year. On September 30, 
2016, we issued a proposed rule to add the Kenk's amphipod as an 
endangered species to the List of Endangered and Threatened Wildlife in 
title 50 of the Code of Federal Regulations (50 CFR 17.11(h)). Our 
proposal was based on threats due to poor water quality, erosion, and 
sedimentation resulting from urban runoff at the Maryland and the 
District of Columbia locations and the effects of small population size 
and climate change at all known locations (81 FR 67270). This document 
withdraws our proposed rule to list the Kenk's amphipod as an 
endangered species under the Act because we have now determined that 
the threats to the species are not as significant as we previously 
determined and additional populations have been discovered in Virginia 
with threats that will be reduced or eliminated through conservation 
measures; therefore, listing is not warranted.
    The basis for our action. Under section 4(a)(1) of the Act, we can 
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 the threats 
to the Kenk's amphipod are not as significant and the species is more 
widely distributed than we previously determined and that listing is 
not warranted. Therefore, this document withdraws our proposed rule to 
list the Kenk's amphipod as an endangered species under the Act.
    Peer review and public comment. We sought comments from five 
independent specialists to ensure that our

[[Page 45552]]

designation is based on scientifically sound data, assumptions, and 
analyses. We invited these peer reviewers to comment on our listing 
proposal and received comments from all five. We also considered all 
comments and information received during the comment period.

Background

Previous Federal Actions

    Please refer to the proposed listing rule for the Kenk's amphipod 
(81 FR 67270; September 30, 2016) for a detailed description of 
previous Federal actions concerning this species.
    On June 7, 2017, the Department of Defense, U.S. Army Garrison, 
Fort A.P. Hill, finalized their revised Integrated Natural Resources 
Management Plan (INRMP) to include conservation measures for the Kenk's 
amphipod (Fort A.P. Hill 2017, pp. 5, 8, 8-56, 9-1- 9-4, 9-31-9-34; 
Andersen 2017a, pers. comm.; Andersen 2017b pers. comm.).

Species Description

    Please refer to the proposed listing rule for the Kenk's amphipod 
(81 FR 67270; September 30, 2016) for a detailed summary of species' 
information; however, we note key pieces of updated information below.
    The Kenk's amphipod (Stygobromus kenki) is a moderately small 
subterranean crustacean, growing to a maximum length of approximately 
0.22 inches (in) (5.5 millimeters (mm)), that can co-occur with other 
amphipods, such as the Potomac ground water amphipod (S. tenuis 
potomacus), Hay's spring amphipod (S. hayi), Tidewater amphipod (S. 
indentatus), and Rappahannock spring amphipod (S. foliatus). 
Subterranean species like the Kenk's amphipod may live for 4 to 6 
years, or even longer (Foltz and Jepson 2009, p. 2; Culver 2016, pers. 
comm.).
    Accurate identification of the Kenk's amphipod can occur only when 
a specimen is removed from the seepage spring site (hereafter referred 
interchangeably as seepage spring, seep, spring, or site depending upon 
the reference), and preserved in alcohol or other fixing agent for 
identification by a species expert who removes legs and other 
appendages from the specimen for microscopic examination. This 
identification method is the best scientific method available. Because 
the laboratory identification results in mortality, and the species co-
occurs in at least one site with the federally listed Hay's spring 
amphipod, the Service has been judicious in limiting the frequency and 
number of specimens removed from known sites.

Habitat

    Amphipods of the genus Stygobromus occur in ground water and ground 
water-related habitats (e.g., caves, seeps, small springs, wells, 
interstices, and, rarely, deep ground water lakes). The Kenk's amphipod 
is found in wooded areas where ground water emerges to form seepage 
springs (Holsinger 1978, p. 39). More specifically, Culver and Pipan 
(2014, pp. 22-23) refer to this habitat as the hypotelminorheic. 
Hypotelminorheic is described as habitats: (1) With a perched aquifer 
fed by subsurface water that creates a persistent wet spot; (2) 
underlain by a clay or other impermeable layer typically 5 to 50 
centimeters (cm) (2 to 20 in) below the surface; and (3) rich in 
organic matter compared with other aquatic subterranean habitats. The 
water supplying the springs infiltrates to the ground water from 
precipitation and runoff into the catchment (e.g., recharge or 
drainage) areas. The water exits these habitats at seepage springs. The 
shading, hydrology, and organic matter found in these woodlands are 
considered important factors in maintaining suitable habitat (i.e., for 
feeding, breeding, and sheltering) for the species.
    Springs known to currently support the Kenk's amphipod are found in 
forested areas with moderate to steep slopes, adjacent to streams, and 
overlying the Wissahickon geologic formation in the Piedmont of 
Maryland and the District of Columbia and in the Calvert formation just 
above the Nanjemoy formation in the upper Coastal Plain of Virginia. 
The Kenk's amphipod has been found in the dead leaves or fine sediment 
submerged in the waters of its seepage spring outflows (Holsinger 1978, 
p. 130). The species will move between the surface and subterranean 
portions of the spring habitat, but it is unknown when or how often 
that movement occurs (Kavanaugh 2009, p. 3).
    Our previous understanding of seepage springs drainage areas was 
that these springs typically drain an area of less than 10,000 square 
meters (2.5 acres (ac); 1 hectare (ha)). The Service contracted with 
the Maryland Geological Survey to delineate the recharge areas of the 
six Kenk's amphipod's seepage spring sites in Maryland and the District 
of Columbia (Burnt Mill Spring #6, East Spring, Kennedy Street Spring, 
Sherrill Drive Spring, Coquelin Run Spring, and Holsinger Spring) 
(Staley 2016, pp. 1-46; Staley 2017, pers. comm.). In addition, the 
Maryland Geological Survey conducted electrical resistivity surveying 
to determine elevations of bedrock or clay that may be perching the 
water table, and to detect elevation of the water table of three of the 
Washington metropolitan area seepage springs (Burnt Mill Spring #6, 
East Spring, and Kennedy Street Spring) (Staley 2016, pp. 1-46). The 
surface watershed area of the springs ranged from the largest area of 
22,055 square meters (m\2\) (237,402 square feet (ft\2\) (Holsinger 
Spring) to the smallest of 2,345 m\2\ (25,241 ft\2\) (East Spring) 
(Staley 2016, pp. 1-46; Staley 2017, pers. comm.).
    However, these watershed boundary calculations do not accurately 
reflect the extent and magnitude of the subsurface ground water flow to 
the springs, since fracture zones in the bedrock underlying the 
saturated zones may extend a spring's ground water source beyond the 
surface watershed boundaries. The saturated zones supplying water to 
these springs appear to extend to a depth of 10 meters (m) (32.8 ft) or 
more at locations near each of these springs (Staley 2016, pp. 1-46); 
they are underlain by bedrock or dense saprolite (material derived from 
weathered bedrock). This finding suggests that at some locations the 
ground water source for these seepage springs may not be as shallow as 
described by Culver and Chestnut (2006, p. 2), and could be influenced 
by a larger area than the surface catchment area. This finding may also 
mean that the Kenk's amphipod could be present at times in deeper 
subsurface water or in fractured portions of bedrock.

Distribution and Relative Abundance

Current Known Range and Distribution
    The Kenk's amphipod has been documented from a total of 13 seepage 
spring sites: East Spring, Holsinger Spring, Sherrill Drive Spring and 
Kennedy Street Spring in Rock Creek Park, managed by the National Park 
Service (NPS), in the District of Columbia; Coquelin Run Spring 
(privately owned) and Burnt Mill Spring #6 (county owned) in Montgomery 
County, MD; Upper Mill #2, Mill #4, Mill #5, Mill Creek #56, Mill Creek 
#58, and Mount Creek #2 on the U.S. Army Garrison's Fort A.P. Hill, in 
Caroline County, VA; and Voorhees Nature Preserve (owned by The Nature 
Conservancy (TNC)) in Westmoreland County, VA (see figure 1). While we 
focus our analysis on the Kenk's amphipod's known sites, we consider it 
likely that additional springs supporting the species could be found in 
Virginia because a survey of only a small portion of the potential 
suitable habitat outside of Fort A.P. Hill resulted in the

[[Page 45553]]

discovery of the Voorhees Nature Preserve site. Surveyors had access to 
only publicly owned lands; potential suitable habitat also occurs on 
private land. In Virginia, 77 springs inside Fort A.P. Hill and 22 
springs outside of Fort A.P. Hill in 3 counties (Caroline, King George, 
and Westmoreland) were surveyed. Two new sites were found on Fort A.P. 
Hill in 2017 (Mill Creek #56 and #58) with more intensive surveys. In 
Maryland, no new Kenk's amphipod sites were located during more 
widespread surveys of suitable habitat on publicly owned lands (129 
springs in 5 counties (Anne Arundel, Prince George's, Charles, Calvert, 
and St. Mary's) in 2017.
BILLING CODE 4333-15-P

[[Page 45554]]

[GRAPHIC] [TIFF OMITTED] TP29SE17.000

BILLING CODE 4333-15-C

[[Page 45555]]

Relative Abundance
    There are no reliable total population numbers for Kenk's amphipod 
sites due to sampling difficulties (e.g., flow conditions) and the lack 
of information on the portion of the population that may remain in the 
springs' ground water supply (Feller 2005, p. 10). However, because 
surveying in the Washington metropolitan area has been conducted using 
systematic and consistent methodology over many years, often by the 
same individuals, the numbers of Kenk's amphipod individuals observed 
and the number of conducted surveys required to find the species are 
considered to be the best available data and provide a reliable 
indication of the species' relative abundance.
    The species is typically found in small numbers and then only when 
ground water levels are high and springs are flowing freely, conditions 
that cause the Kenk's amphipod to be transported to the surface. These 
conditions typically occur during the spring season, except during 
especially dry years. Given the small size of the shallow ground water 
aquifers supporting the sites occupied by this species, and the known 
characteristics of subterranean invertebrates, it is probable that each 
of the Kenk's amphipod populations has always been small (Hutchins and 
Culver 2008, pp. 3-6).
    Although specimens were not collected and identified to the species 
level, Stygobromus sp., including some in the right size range for the 
Kenk's amphipod, were observed during site reconnaissance visits 
between 2004 and 2012 in several of the known Kenk's amphipod 
Washington metropolitan area spring habitats (Yeaman 2012, pers. 
comm.). In addition, visual inspections during this same time period 
indicated that most of the sites continued to appear to be suitable 
habitat, leading us to conclude that the Kenk's amphipod was extant at 
least at Burnt Mill Spring #6, Kennedy Street Spring, and East Spring 
(Feller 2015, pers. comm.). However, actual identifications of 
specimens collected during surveys conducted in 2015 and 2016 (Feller 
2016b, pers. comm.) did not result in Kenk's amphipod being found (see 
below).
    Prior to 2015, all Kenk's amphipod specimens were discovered on the 
first or second survey conducted at all known sites. In 2015 and 2016, 
the Kenk's amphipod was confirmed at only one of the Washington 
metropolitan area spring sites, Coquelin Run Spring, despite all of the 
sites being sampled multiple times during these 2 years (see table 1 
below) (Feller 2016b, pers. comm.; Feller 2016c, pers. comm.). 
Additionally, an environmental DNA (eDNA) study was conducted in 2016 
(Niemiller et al. 2016, pp. 1-7) for several amphipod species, 
including the Kenk's amphipod, to determine potential presence of the 
species in springs in the Rock Creek watershed.
    Individual Kenk's amphipods were collected from Fort A.P. Hill for 
DNA sequencing since no individuals could be found in the Washington 
metropolitan area at the time (spring/summer 2016) comparative samples 
were required for the study (Niemiller et al. 2016, p. 2). Water tested 
in the Washington metropolitan area did not detect the Kenk's amphipod 
eDNA (Niemiller et al. 2016, p. 6). However, we cannot conclude that 
Kenk's amphipods were absent at those sites. The abundance of the 
Kenk's amphipod may not be high enough in the springs to amplify DNA in 
the water samples, or the DNA from the Fort A.P. Hill animals may be 
different enough from the Washington metropolitan area animals to not 
be detected in the Rock Creek water samples. Therefore, it is unclear 
without additional survey effort whether the species may be extirpated 
at Burnt Mill Spring #6, Kennedy Street Spring, and East Spring, 
although the best available data show a decrease in observed 
individuals at these sites (see table 1).
BILLING CODE 4333-15-P

[[Page 45556]]

[GRAPHIC] [TIFF OMITTED] TP29SE17.001

BILLING CODE 4333-15-C

[[Page 45557]]

Summary of Comments and Recommendations

    In the proposed rule published on September 30, 2016 (81 FR 67270), 
we requested that all interested parties submit written comments on the 
proposal by November 29, 2016. We also contacted appropriate Federal 
and State agencies, scientific experts and organizations, and other 
interested parties and invited them to comment on the proposal. A 
newspaper notice inviting general public comment was published in USA 
Today on October 5, 2016. We did not receive any requests for a public 
hearing.
    During the 60-day public comment period (September 30, 2016, to 
November 29, 2016), we received public comments from 10 individuals or 
organizations. Of these, seven were from individuals, including five 
peer reviewers, one was from a Federal agency, and two were from 
nongovernmental organizations (NGOs). All the commenters were generally 
supportive of the proposed listing, but only 8 of the 10 provided 
substantive information. All substantive information provided during 
the comment period is summarized below and has either been incorporated 
directly into this final determination or is addressed in the response 
to comments below.

Comments From Peer Reviewers

    (1) Comment: Two peer reviewers agree with us that few if any 
studies exist that specifically examine critical thresholds for flow, 
water permanence, nutrient or contaminant loading, or the tolerance of 
close relatives of the Kenk's amphipod to pollutants and toxicants. One 
of the reviewers suggests that additional studies conducted on the 
basic biology and population size of the Kenk's amphipod would be 
helpful, noting that the more common and widespread Potomac ground 
water amphipod could be used as a surrogate species.
    Our Response: The Act requires that the Service make listing 
determinations based solely on the best scientific and commercial data 
available. When we published the proposed rule on September 30, 2016 
(81 FR 67270), we relied on the best quantitative and qualitative data 
available at that time to assess the Kenk's amphipod's status.
    (2) Comment: One peer reviewer states that the proposed listing 
underestimates the potential effect due to urbanization stress for the 
Washington metropolitan area populations, given the species' isolated 
populations. More specifically, this reviewer indicates that our 
analysis contained insufficient discussion of increased conductivity 
(salinity) and that the risk from potential sewage leakage may have 
been underestimated, in part because we did not consider that, in 
addition to increasing conductivity and nutrient loading, sewage leaks 
include ``pharmaceuticals, personal care products, and home-use 
chemicals that even at very low levels can disrupt endocrine and immune 
systems.'' Another peer reviewer provided additional references on 
several studies in the Rock Creek watershed showing the occurrence of 
pesticides, organic wastewater compounds, and metals in surface water 
and bed sediment that may be related to the degradation of habitat 
(Anderson et al. 2002; Miller et al. 2006; Koterba et al. 2010; Phelan 
and Miller 2010).
    Our Response: See the Factor A section below addressing Water 
Quality/Quantity Degradation Due to Chronic Pollution of Urban/Suburban 
Runoff for added discussion regarding the effects of conductivity and 
the presence of pharmaceuticals, personal care products, and home-use 
chemicals from sewer leaks. Additional references on several studies in 
the Rock Creek watershed showing the occurrence of pesticides, organic 
wastewater compounds, and metals in surface water and bed sediment that 
may be related to the degradation of habitat were also added to the 
final determination.
    (3) Comment: One peer reviewer states that existing regulatory 
mechanisms are inadequate to address issues related to Factor A and 
that this is largely because many of the recharge areas for the seepage 
springs in the Washington metropolitan area extend outside the 
jurisdiction of Federal agencies.
    Our Response: Many of these seepage springs have recharge areas 
extending into private lands where Federal agencies have little 
jurisdiction. While the existing regulatory mechanisms do not fully 
ameliorate the stressors affecting the species' sites in the Washington 
metropolitan area, we have concluded that those stressors do not rise 
to the level of the species being warranted for listing as an 
endangered or threatened species (See the Summary of Factor A and 
Kenk's Amphipod Determination of Status Throughout All of Its Range 
sections below).
    (4) Comment: One peer reviewer states that the proposed rule 
underestimates the potential threat of warming of the shallow ground 
water habitats supporting this amphipod ``because the impacts of 
pollutants on Kenk's amphipod may likely be compounded by even a slight 
increase in water temperature due to a potential increase of uptake of 
pollutants in concert with increased metabolic activities.''
    Our Response: We have included additional language in the final 
determination indicating the effects of increased water temperature on 
the uptake and metabolism of pollutants--see Factor E, Effects of 
Climate Change.
    (5) Comment: Two peer reviewers comment on the threat of small 
population dynamics and indicate that the proposed rule was missing a 
discussion about metapopulation structure. One reviewer states that the 
assumption of small population size and genetic isolation among Kenk's 
amphipod populations is untested and that some analyses of DNA sequence 
information will shed light on the species' metapopulation structure 
and the potential for migration of individuals among sites. The second 
reviewer states that many animal and plant species exist in low 
population numbers, but possess adequate levels of genetic diversity to 
maintain their populations. This reviewer also states that because the 
species' ability to move between sites is considered low or perhaps 
nonexistent in the opinion of species experts, as discussed in the 
proposed rule, the Kenk's amphipod may represent isolated populations 
with little potential for either recolonization or colonization of 
suitable habitat.
    Our Response: While we agree that the assumption of small 
population size and genetic isolation among Kenk's amphipod populations 
is untested, the best available data indicate that the effect of small 
population dynamics may be contributing to the species' viability, 
particularly in the Washington metropolitan area. Additionally, it is 
difficult to study the DNA sequences of Kenk's amphipods at any sites 
other than Fort A.P. Hill sites, given the paucity of individuals 
collected and the preservation method used to store the collected 
individuals.

Comments From the Public

    (6) Comment: One commenter considers the discussion of stressors 
incomplete because it does not include the ``mounting circumstantial 
evidence that seep-inhabiting Stygobromus are susceptible to changes in 
the forest canopy and understory.'' This commenter also suggests that 
the species' very shallow ground water sites are in some ways more 
connected to the forest floor than to base-level streams.
    Our Response: We have added an assessment of potential activities 
that could change the forest canopy and understory in Factor A under 
Other

[[Page 45558]]

Habitat Considerations. This issue was not mentioned in the proposed 
rule because it had not been identified as occurring at any of the 
known Kenk's amphipod sites.
    (7) Comment: One commenter, familiar with the management of Fort 
A.P. Hill, provided additional information about the identity of two 
springs, the level of stressors/threats to the Kenk's amphipod at the 
installation, and how the species would be addressed under the Sikes 
Act.
    Our Response: We have revised the final determination, as 
appropriate, to reflect these comments. The Service appreciates the 
cooperation of the Army and looks forward to working with them to 
protect this species and its habitat on Fort A.P. Hill.
    (8) Comment: One commenter indicates that a number of projects pose 
threats to the species such that the species warrants listing and that 
reinitiation of conferencing under section 7(a)(4) of the Act is 
appropriate. This commenter provides multiple documents supporting 
their position; however, only one document was new information--the 
final report on the Stygobromus eDNA study.
    Our Response: Section 7 consultations under the Act are outside the 
scope of this final listing determination. However, to the extent that 
it is relevant here, we note that we completed the appropriate level of 
consultation on the projects and concluded that there would be no 
effect to the Kenk's amphipod or its habitat. All of the commenter's 
supporting information, with the exception of their proposed rule 
comment letter and the new eDNA report referenced above, were included 
in our earlier consultations. Our subsequent review of the eDNA report, 
as part of the analysis for this final listing determination, finds 
that the report provides no evidence to support the commenter's 
position because no Kenk's amphipod DNA was detected in any of the 
action areas related to the consultations.
    (9) Comment: One commenter states that susceptibility of Kenk's 
amphipod sites to destruction by hikers on social trails near the seeps 
should be more fully discussed. The commenter also indicated that the 
NPS has taken no affirmative, proactive steps to divert hikers and 
other recreational traffic away from these seeps.
    Our Response: There is no evidence that the occasional use of 
social trails has had any effect on the Kenk's amphipod or caused any 
disturbance to the seep habitat. While the NPS has not found a 
practical way to close most social trails, they have taken steps to 
prevent designated trails from being built in areas that could affect 
the Hay's Spring or Kenk's amphipods.
    (10) Comment: One commenter raises concerns with the Service's and 
NPS's compliance with section 7 of the Act and with NPS's 
implementation of Rock Creek Enabling Legislation.
    Our Response: The Service and NPS have met our respective section 7 
regulatory obligations for the Hay's Spring and Kenk's amphipods (see 
the Water Quality/Quantity Degradation Due to Chronic Pollution of 
Urban/Suburban Runoff section of the proposed rule (81 FR 67270, 
September 30, 2016) and the Candidate Notices of Review (75 FR 69222, 
November 10, 2010; 76 FR 66370, October 26, 2011; 77 FR 69994, November 
21, 2012; 78 FR 70104, November 22, 2013; 79 FR 72450, December 5, 
2014; 80 FR 80584, December 24, 2015).
    (11) Comment: One commenter indicates that the proposed rule should 
more fully discuss agencies' failure to clean up water pollution in the 
Rock Creek watershed, specifically citing NPS's use of pesticides and 
the District of Columbia government's and NPS's use of road salt in the 
watershed.
    Our Response: We analyzed the use of pesticides in Rock Creek Park 
and determined that dimilin, which can be toxic to crustaceans, is not 
being used in the park. Other pesticides that may be toxic to amphipods 
are used on the Rock Creek Park Golf Course, but because the golf 
course is not within the recharge areas for the seepage springs known 
to support the Kenk's amphipod, this activity is not considered a 
stressor for the species. The NPS has limited or discontinued the use 
of road salts at some locations, including Sherrill Drive, Ross Drive, 
Morrow Drive, and Ridge Road, where this practice might be a problem 
for the Hay's Spring or Kenk's amphipods (Bartolomeo 2017, pers. 
comm.). The use of road salts may affect one or more locations and we 
have added additional discussion on this topic in the final listing 
determination (see Factor A, Water Quality/Quantity Degradation Due to 
Chronic Pollution of Urban/Suburban Runoff).
    (12) Comment: One commenter questioned the rationale behind being 
able to collect up to 10 specimens for scientific collection.
    Our Response: The majority of amphipods collected at sites are the 
more common species, S. tenuis. However, the Service has allowed larger 
numbers to be collected during 2016 surveys in the Washington 
metropolitan area because none of the specimens of appropriate size 
collected in the 2015 surveys have been identified to be the Kenk's 
amphipod. These protocols are followed to minimize effects to the 
species. Because the occurrence of subterranean invertebrates at spring 
emergence sites likely represents only a portion of the actual 
underground population, the Service has considered the collecting 
procedures (Feller 1997, p. 2) to be nondetrimental to the populations.

Summary of Changes From the Proposed Rule

    Based upon our review of the public comments, comments from other 
Federal and State agencies, peer review comments, and new relevant 
information that has become available since the publication of the 
proposal, we have reevaluated our proposed listing rule and made 
changes as appropriate. This document differs from the proposal in the 
following ways:
    (1) Based on our analyses of the potential threats to the Kenk's 
amphipod and additional survey data obtained in 2017, we have 
determined that the species no longer meets the definition of a 
threatened or an endangered species. This document withdraws our 
proposed rule as published on September 30, 2016 (81 FR 67270).
    (2) We have added a discussion of Ongoing and Future Conservation 
Efforts below. Fort A.P. Hill's INRMP (Fort A.P. Hill 2017, entire) is 
discussed in this section.
    (3) We have incorporated: (a) A more detailed impervious cover 
analysis using the Watershed Boundary Dataset (U.S. Geological Survey 
(USGS) 2014a, entire) and the 2011 National Land Cover Dataset (USGS 
2014b, entire); (b) reference to an eDNA study conducted in 2016 
(Niemiller et al. 2016, pp. 1-7); (c) reference to a hydrogeology 
electrical resistivity study conducted in 2016 that improves our 
understanding of the surface catchment area and the subsurface area 
surrounding the Kenk's amphipod sites (Staley 2016, pp. 1-46); (d) 
water quality sampling results conducted in 2016 and 2017 by the 
Service; and (e) results from suitable habitat surveys conducted in 
2017.

Ongoing and Future Conservation Efforts

    Below we review conservation efforts for the Kenk's amphipod, 
including those in Fort A.P. Hill's recently revised INRMP. In our 
proposed rule, we described the conservation efforts that are already 
occurring or were planned to occur in the Washington metropolitan area; 
and there are no changes to this information based on peer review and 
public comments. We have also

[[Page 45559]]

completed an analysis of the newly initiated conservation efforts at 
Fort A.P. Hill pursuant to our Policy for Evaluation of Conservation 
Efforts When Making Listing Decisions (PECE) (68 FR 15100, March 28, 
2003).
    Based on information provided in our proposed rule, Fort A.P. Hill 
revised its existing INRMP in 2017 to include the Kenk's amphipod and 
established conservation measures (i.e., expanded buffer areas) to 
address the identified threats (Fort A.P. Hill 2017, p. 9-32). The 
INRMP includes the most recent Kenk's amphipod survey information and 
establishes conservation areas that will be managed with limited 
surface disturbance and avoidance buffers (Fort A.P. Hill 2017, pp. 9-
32 to 9-34), as further described below. In addition, Fort A.P. Hill 
has agreed to include expanded buffer areas around any future new 
locations of the species. The INRMP will be revised as part of the next 
annual review process to reflect that continued implementation of 
buffers would be subject to mission requirements (Andersen 2017b, pers. 
comm.). The INRMP is comprehensively updated every 5 years, with review 
and minor amendments occurring annually. More significant updates will 
occur if and when new biological information becomes available or if 
Fort A.P. Hill's mission requirements change. The expanded buffer areas 
for the Kenk's amphipod designated in the INRMP are designed to 
maintain the species' redundancy, resiliency, and representation on 
Fort A.P. Hill, thus significantly contributing to the species' 
viability (see table 3 and the Cumulative Effects section below).
    Fort A.P. Hill consists of 76,000 acres (30,756 ha) of land with 
65,000 acres (26,304 ha) of forest (Fort A.P. Hill 2017, p. 2-1). The 
mission of the base is to ensure soldiers are fully prepared to fight 
and win the Nation's wars (Fort A.P. Hill 2017, p. 12-2). Currently, 98 
percent of the base is undeveloped operational training lands. Training 
occurs year round for both active and reserve troops of the different 
branches of the military (Fort A.P. Hill 2017, pp. 2-2 to 2-3).
    Management buffers are established around Kenk's amphipod seeps to 
ensure the integrity of surficial habitats and water quality from 
potential impacts associated with land disturbance activities. Buffers 
are site specific and are determined based on the size of the seep 
area, surrounding terrain, hydrology, and contiguity of surrounding 
habitats. The buffer areas for each seep generally exceed 200 ft (0.06 
kilometers (km)) all around, ranging in size from 1 to 6 acres (0.40 to 
2.43 ha) (average buffer area is approximately 2.3 acres (0.93 ha)). 
These buffers are also complemented by protections afforded to each 
site by adjacent wetlands and the undulating terrain of the surrounding 
landscape that provide additional habitat protections from disturbance 
activities. Within the buffers, land-disturbing activities (e.g., 
construction, land management (including pesticide application)) and 
ground-water-disturbing activities (e.g., drilling wells) are 
prohibited unless Fort A.P. Hill coordinates with the Service to 
determine ways to minimize impacts to the Kenk's amphipod (Fort A.P. 
Hill 2017, pp. 9-32 to 9-33).
    All mounted military training maneuvers (i.e., those using tracked 
and wheeled vehicles) are restricted to established roads and 
designated open areas throughout the installation, and all tactical and 
nontactical vehicles must also use established stream crossings. 
Dismounted military maneuvers (i.e., those on foot) occur throughout 
the installation, including the training areas where Kenk's amphipod 
seeps occur. Kenk's amphipod seeps occur in the most undeveloped 
portion of the installation surrounded by an abundance of natural 
habitats characterized by rolling and often steep terrain. The seeps 
themselves where the Kenk's amphipod has been found represent an 
exceptionally small fraction (0.00005 percent) of the training lands 
and are typically less often used for military training than other 
areas due to their isolated nature. Soldiers are precluded from 
bivouacking (i.e., camping) or digging within the buffer areas. Maps 
denoting the location of Kenk's amphipod buffer areas are provided to 
Range Operations for the scheduling and coordination of training 
activities in these areas. No military training operations occur in 
Kenk's amphipod seep areas or buffers that use petroleum operations 
(e.g., transport, storage, and handling) or chemical training (Fort 
A.P. Hill 2017, p. 9-33).
    Dirt and gravel trails are the primary transportation routes 
throughout the training areas where Kenk's amphipod seeps can be found. 
Tactical and nontactical vehicle traffic on these trails is 
intermittent and is typically of low duration and intensity. The trails 
do not get chemically treated in the winter months nor are these trails 
designated for or used as transportation routes for industrial 
hazardous materials (i.e., tanker trucks). Routine recurring 
maintenance activities regularly conducted on installation trails 
include tree limbing, surface grading, application of surface material 
and surface and ditch stabilization. These types of maintenance 
activities occur as needed on these already established trails within 
the buffers to ensure safe access to military lands. Stabilization 
activities are the only type of maintenance activity that requires the 
application of erosion and sediment control procedures. Where 
stabilization of trails is required within Kenk's amphipod buffers, 
stabilization efforts shall be in compliance with Virginia Erosion and 
Sediment Control procedures (VDEQ 1992). Of the six known Kenk's 
amphipod sites, only two have trails within them, and these trails 
constitute only 1.8 mi (2.89 km) (0.3 percent of total trail miles), 
half of which is closed to through traffic. Trail maintenance 
activities are anticipated to occur on trails within Kenk's amphipod 
buffers less than once every 5 years. Large-scale trail improvements 
(e.g., culvert installation/replacement, trail widening) within Kenk's 
amphipod buffers would require discussion with the Service to minimize 
impacts to the species and its habitat (Fort A.P. Hill 2017, pp. 9-32 
to-9-33).
    At Fort A.P. Hill, forest management activities, including timber 
harvest and controlled burns, occur throughout much of the facility, 
including areas along Mill Creek and Mount Creek supporting Kenk's 
amphipod sites. No land-disturbance activities such as forest 
management or vegetation/habitat management will be conducted within 
established buffers without discussion with the Service. The seeps also 
occur in the non-live-fire portion of the base, meaning that wildfires 
are significantly less of a threat to the species or its habitat 
because no live rounds are used in those areas that can serve as 
ignition sources (Applegate 2016, pers. comm.). Additionally, when 
prescribed burns are used in areas adjacent to the seeps, Fort A.P. 
Hill will keep fire out of the buffers to the extent practicable. If a 
fire entered a buffer, Fort A.P. Hill would document any impacts to the 
buffers and the seeps (Andersen 2017c, pers. comm.).
    Recreational activities are allowed within Kenk's amphipod buffer 
areas because installation regulations provide sufficient protections 
to ensure the conservation of the species. Hunting is the only 
recreational activity authorized in areas where three of the known 
Kenk's amphipod sites occur. However, strict hunting regulations 
severely limit the numbers of hunters allowed in an area at any given 
time and restrict the timing and duration for hunting. Consequently, 
Fort A.P. Hill is only available for hunting less than 16 percent of 
the year. The Kenk's amphipod sites are unlikely to

[[Page 45560]]

experience adverse effects from hunting given: The limited availability 
of the Fort A.P. Hill landscape to hunting by the public in general; 
regulations prohibiting hunters from camping, digging, or using any 
motorized transportation (e.g., all-terrain vehicles, utility-terrain 
vehicles); that the Kenk's amphipod buffers and seep areas represent an 
exceptionally small amount (0.014 percent and 0.00005 percent) of the 
huntable areas of Fort A.P. Hill, respectively; and seeps and streams 
are typically avoided by hunters due to the difficulty in traversing 
them and the adjacent slopes. Fort A.P. Hill has offered public hunting 
opportunities for decades, and there has not been any evidence of 
adverse impacts observed at any stream, seep, or wetland to date, 
including the known Kenk's amphipod sites (Fort A.P. Hill 2017, p. 9-
34).
    Fort A.P. Hill has agreed to continued commitment to the 
conservation measures (buffers) identified in the 2017 INRMP regardless 
of the Kenk's amphipod Federal listing status, pending any currently 
unknown change in mission requirements (Andersen 2017a, pers. comm.). 
However, should the species not warrant listing under the Act, some 
monitoring efforts for the species could be reduced (Andersen 2017a, 
pers. comm.; Andersen 2017b pers. comm.).
    Based on past and current primary uses of the base (forest 
management, recreational use, and military maneuvers), the acreage of 
the base, the limited area occupied by the species, including the 
buffers, and the habitat characteristics (mature forest on steep or 
rolling topography, and often adjacent to wetland areas), and the 
location of the seep sites (e.g., on isolated areas of the base), the 
Service concludes that there is a low risk of sites being adversely 
affected even if mission requirements changed.
    The INRMP would result in the protection of 6 out of the 13 (46 
percent) known Kenk's amphipod locations.

PECE Analysis

    The purpose of PECE is to ensure consistent and adequate evaluation 
of recently formalized conservation efforts when making listing 
decisions. The policy provides guidance on how to evaluate conservation 
efforts that have not yet been implemented or have not yet demonstrated 
effectiveness. The evaluation focuses on the certainty that the 
conservation efforts will be implemented and the certainty that the 
conservation efforts will be effective. The policy presents nine 
criteria for evaluating the certainty of implementation and six 
criteria for evaluating the certainty of effectiveness for conservation 
efforts. The certainty of implementation and the effectiveness of a 
formalized conservation effort may also depend on species-specific, 
habitat-specific, location-specific, and effort-specific factors. These 
criteria are not considered comprehensive evaluation criteria; we 
consider all appropriate factors in evaluating formalized conservation 
efforts. The specific circumstances will also determine the amount of 
information necessary to satisfy these criteria.
    To consider that a formalized conservation effort contributes to 
forming a basis for not listing a species, or listing a species as 
threatened rather than endangered, we must find that the conservation 
effort is sufficiently certain to be (1) implemented, and (2) 
effective, so as to have contributed to the elimination or adequate 
reduction of one or more threats to the species identified through the 
section 4(a)(1) analysis. The elimination or adequate reduction of 
section 4(a)(1) threats may lead to a determination that the species 
does not meet the definition of threatened or endangered, or is 
threatened rather than endangered. An agreement or plan may contain 
numerous conservation efforts, not all of which are sufficiently 
certain to be implemented and effective. Those conservation efforts 
that are not sufficiently certain to be implemented and effective 
cannot contribute to a determination that listing is unnecessary, or a 
determination to list as threatened rather than endangered. Regardless 
of the adoption of a conservation agreement or plan, however, if the 
best available scientific and commercial data indicate that the species 
meets the definition of an ``endangered species'' or a ``threatened 
species'' on the day of the listing decision, then we must proceed with 
appropriate rulemaking activity under section 4 of the Act. Further, it 
is important to note that a conservation plan is not required to have 
absolute certainty of implementation and effectiveness in order to 
contribute to a listing determination. Rather, we need to be certain 
that the conservation efforts will be implemented and effective such 
that the threats to the species are reduced or eliminated.
    Using the criteria in PECE (68 FR 15100, March 28, 2003), we 
evaluated the certainty of implementation (for those measures not 
already implemented) and effectiveness of conservation measures in the 
2017 Fort A.P. Hill INRMP pertaining to the Kenk's amphipod. We 
determined that the measures will be effective at eliminating or 
reducing threats to the species because they protect currently 
occupied, and any future occupied, seeps and their catchment areas from 
removal of forest canopy and the effects of poor water quality, 
erosion, and sedimentation, by instituting on-the-ground protections to 
better manage and regulate disturbance in the species' occupied 
habitat. For example, two of the sites are in an area where timber 
harvest and prescribed burns were scheduled to occur within the next 5 
years, but will not be subjected to those management actions, pending 
any currently unknown change in mission requirements, due to the 
expanded buffer areas implemented around the Kenk's amphipod sites (see 
below).
    We have a high degree of certainty that the measures will be 
implemented because Fort A.P. Hill has a track record of being good 
environmental stewards for the past 76 years since the base was 
established, and, more specifically, a track record of implementing 
conservation measures for federally listed species and species of 
concern since 1997 through their INRMPs. For example, Fort A.P. Hill 
has effectively implemented conservation measures specified in their 
INRMP for the Rappahannock spring amphipod (Stygobromus foliatus), a 
Department of Defense species at risk, including surveying its 
population and implementing avoidance buffers from ground-disturbing 
activities on the installation. In addition, during the spring of 2017, 
Fort A.P. Hill allowed access to its facility for amphipod surveys in 
potential suitable habitat.
    New conservation measures are prescribed by the 2017 INRMP for the 
Kenk's amphipod and are already being implemented, including expanded 
buffer areas. The 2017 INRMP has sufficient monitoring and reporting 
requirements to ensure that the conservation measures we deem necessary 
are implemented as planned, and are effective at removing threats to 
the Kenk's amphipod and its habitat. As specified above, the INRMP may 
be modified to reflect changes in mission requirements. Despite this 
provision, we believe that the site conditions at Fort A.P. Hill will 
continue to be adequate to conserve the Kenk's amphipod, and Fort A.P. 
Hill will discuss with the Service any changes in mission requirements 
that would affect the Kenk's amphipod and its habitat.
    Collaboration between the Service, Fort A.P. Hill, and Virginia 
Department of Game & Inland Fisheries previously occurred during 
development of the INRMP and continues to occur via discussions 
pertaining to

[[Page 45561]]

implementation throughout the year that are documented through 
electronic mail correspondence and telephone calls (Hoskin 2017, pers. 
comm.). This ongoing coordination and collaboration ensures that the 
conservation measures identified in the INRMP for all Federal and State 
listed species and species of concern are implemented. Based on Fort 
A.P. Hill's implementation of previous conservation efforts as 
specified in its INRMP, we have a high level of certainty that the 
conservation measures in the 2017 INRMP will be implemented and 
effective, and thus they can be considered as part of the basis for our 
final listing determination for the Kenk's amphipod. Our detailed PECE 
analysis is available for review at http://www.regulations.gov and 
https://www.fws.gov/chesapeakebay/.

Summary of Biological Status and Threats

    Please refer to the proposed listing rule for the Kenk's amphipod 
(81 FR 67270; September 30, 2016) for a detailed description of the 
factors affecting the species, which are summarized and updated as 
appropriate below.

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

Water Quality/Quantity Degradation Due to Chronic Pollution of Urban/
Suburban Runoff

    Habitat modification, in the form of degraded water quality and 
quantity, is one of the primary drivers of Kenk's amphipod viability. 
While the species' specific tolerances to parameters affecting water 
quality and quantity is not yet known, we do know that the Kenk's 
amphipod is at increased risk to parameters that negatively affect 
water quality and quantity because these freshwater amphipods spend 
their entire life cycle in water and are, therefore, continually 
exposed to changes in the aquatic habitat. Water quality degradation of 
ground water at spring sites located in the Washington metropolitan 
area has been previously cited as a top concern in several studies and 
reports (Feller 1997, pp. 12-13; Culver and Sereg 2004, p. 13; Feller 
2005, p. 9; Hutchins and Culver 2008, p. 6; Kavanaugh 2009, p. 60; 
Culver et al. 2012, p. 37; Culver and Pipan 2014, p. 219).
    The amount of forested buffer surrounding the seep influences the 
species' vulnerability and exposure to negative effects, and the 
smaller the buffer, the greater the risk of exposure. Buffer distance 
is important because the buffer helps filter sediment and other 
contaminants from the surface water entering the catchment areas and, 
therefore, the ground water that supports the Kenk's amphipod. The 
Washington metropolitan area amphipod sites have narrow riparian 
buffers (94 ft to 1,000 ft) (29 m to 305 m) separating them from the 
surrounding urban landscape. This urban land is characterized by 
impervious surface cover, which includes paved roads, sidewalks, 
parking lots, and buildings (Sexton et al. 2013, p. 42).
    An impervious cover analysis was conducted by the Service within 
the watersheds occupied by the Kenk's amphipod.
    We calculated the overall average value (percentage) for each 
watershed identified. We also identified three categories of impervious 
cover: (1) 0 percent impervious cover, (2) 1 to 15 percent impervious 
cover, and (3) greater than (>) 15 percent impervious cover. For each 
watershed, we then calculated the percentage of area that fell into 
each of these three categories. These percentages are presented in 
Table 2.

                                                           Table 2--Impervious Cover Estimates
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Categories of impervious cover (IC) percentage      Average
                                                                             Number of   ------------------------------------------------   impervious
 Amphipod species (total number of sites)             Watershed           amphipod sites                                                    cover (IC)
                                                                                               0% IC         1-15% IC         >15% IC       percentage
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stygobromus kenki (12)....................  Lower Rock Creek............               5              17              24              59              83
                                            Northwest Branch............               1              28              27              45              72
                                            Mount Creek.................               1              92               6               2               8
                                            Mill Creek..................               3              93               5               2               7
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Vorhees Nature Preserve was not evaluated.

    The four watersheds within the Kenk's amphipod's range have overall 
impervious cover estimates ranging from approximately 7 percent (Mill 
Creek in Virginia) to 83 percent (Lower Rock Creek in the District of 
Columbia and Montgomery County, MD). Although the data for this level 
of the impervious cover analysis were derived using the finest scale 
hydrologic units available in the National Land Cover dataset, they do 
not reference the exact location of the Kenk's amphipod spring sites in 
relation to the location of impervious cover within the watersheds 
because the spring sites and their catchment areas are at a smaller 
scale. Additionally, because the data are from 2011, there could be 
more impervious cover present than indicated in our analysis. However, 
by looking at aerial photographs from 1988 and 2014 of the areas 
surrounding the spring sites in the Washington metropolitan area, there 
has been little change in the amount of development; therefore, we 
determined that the estimates of impervious cover derived from the 2011 
dataset are sufficiently accurate for our analysis.
    To provide a general indication of how much impervious cover may be 
influencing surface water quality at individual sites, we created maps 
with the individual sites included within the impervious cover data 
layers (see Supplemental Document--Maps of Impervious cover in relation 
to spring sites in the Washington metropolitan areas and Impervious 
cover in relation to spring sites in Virginia).
    Urban impervious surfaces can result in increased surface water 
flow after storm events due to decreased opportunity for immediate or 
proximal infiltration. The surface flow waters have higher 
temperatures, higher sediment loads, and higher levels of heavy metals 
(zinc, cadmium), nitrogen, phosphorus, and fecal coliform bacteria 
(Walsh et al. 2005, pp. 706-723). In addition to affecting water 
quality, urban impervious surfaces can affect water quantity; decreased 
infiltration can result in depletion of ground water reserves and 
ultimately cause springs to dry up over time (Frazer 2005, p. 3).
    When the average impervious cover is between 10 and 15 percent 
within a watershed, sharp declines in aquatic habitat quality and 
aquatic insect

[[Page 45562]]

diversity are likely to occur, while the number of pollution-tolerant 
species increase (Schueler 1994, pp. 100-102; Boward et al. 1999, p. 
45; Center for Watershed Protection 2003, pp. 101-102 (synthesis of 30 
studies)). More recently, declines of 110 of 238 macroinvertebrate taxa 
were found in streams receiving runoff water from areas that contained 
between 0.5 to 2 percent of impervious cover (King et al. 2011, pp. 
1659-1675). These results were consistent among the three physiographic 
regions evaluated (Mountain, Piedmont, and Coastal Plain); the Piedmont 
region includes the Washington metropolitan area amphipod sites. 
Further, higher gradient, smaller catchments such as those supporting 
sites occupied by the Kenk's amphipod required less impervious cover 
than lower gradient, larger catchments to elicit a macroinvertebrate 
community response (i.e., the macroinvertebrate taxa from steeper 
sloped, smaller catchment areas showed a decline in response to 
relatively small amounts of impervious cover) (King et al. 2011, pp. 
1659-1676). This finding is relevant, given that the results of our 
impervious cover analysis indicate that Kenk's amphipod sites are 
located within areas containing 7 to 83 percent impervious cover (see 
table 2).
    The hypotelminorheic zone, the main habitat required by the Kenk's 
amphipod, may be more vulnerable to the effects of urban runoff than 
streams with respect to pollutants, erosion, and sedimentation because 
of the small size and shallow nature of the habitat. In addition, the 
aforementioned narrow buffer zones around the hypotelminorheic sites 
increase the habitat's and species' exposure to urban runoff.
    Poor water quality parameters have been documented by the USGS 
through chemical analyses of ground water, surface water, and sediments 
in the Rock Creek watershed (Anderson et al., 2002, pp. 1-99; Miller et 
al. 2006, pp. 1-48; Koterba et al. 2010, pp. 1-102; Phelan and Miller 
2010, pp. 1-80). For example, five pesticides (carbaryl, chlorpyrifos, 
diazinon, dieldrin, and malathion) were detected in Rock Creek Park 
water samples at concentrations that exceed aquatic life water quality 
criteria (Anderson et al. 2002, p. 44). Furthermore, Rock Creek 
sediments contained polycyclic aromatic hydrocarbons (PAHs), 
polychlorinated biphenyls (PCBs), organochlorine pesticides, and toxic 
metals at concentrations that approached and exceeded guidelines for 
the protection of aquatic life (Miller et al. 2006, p. 21). In a 2008 
study at five stream locations in Rock Creek Park, pharmaceuticals, 
pesticides, fragrances, flame retardants, detergents, and sterols were 
detected and attributed to low-level sources of wastewater entering the 
streams (Phelan and Miller 2010, pp. 37, 40-41).
    In the Washington metropolitan area, water quality degradation from 
urban runoff is the greatest concern for the Kenk's amphipod at the 
Sherrill Drive Spring location (Culver and Sereg 2004, p. 69). Sherrill 
Drive Spring is close (approximately 115 ft (35 m)) to the edge of Rock 
Creek Park where there is an abrupt change from forested habitat to an 
urban landscape along 16th Street Northwest, which parallels the park 
boundary. A significant amount of impervious cover routes runoff into 
the catchment area surrounding the Sherrill Drive Spring.
    While there have been no laboratory studies conducted to evaluate 
the effects and tolerance of the Kenk's amphipod or Stygobromus tenuis 
to chemical, nutrient, pesticide, or metal pollution, we know from 
published studies that amphipods may be one of the most vulnerable 
groups of organisms to chemical pollution due to their high sensitivity 
to toxicants and contaminant accumulation (Borgmann et al. 1989, p. 
756; Brumec-Turc 1989, p. 40). Sediment samples surrounding the springs 
were collected in September 2001 at East Spring and Sherrill Drive 
Spring to analyze metal and organic contaminants.
    Toxic metals were found in the sediment samples. Values were 
similar for the two sites, although East Spring had the highest values 
for all toxic metals, with the exception of zinc (Culver and Sereg 
2004, p. 65). However, because it was the springs' sediments instead of 
water samples that were analyzed, it is difficult to know whether the 
value of the metals measured in the sediments exceed aquatic life 
standards in water or any published values for freshwater amphipod 
species. Furthermore, water samples taken from the springs in Rock 
Creek Park and at Burnt Mill Spring #6 in June 2016 did not detect 
toxic metals (Pinkney 2017b, pers. comm.). Sources of trace metals in 
an urban environment may include vehicles, streets, parking lots, 
snowpacks, and rooftops (Center for Watershed Protection 2003, p. 73). 
However, although the Washington metropolitan area spring sites are 
exposed to these sources, there is no quantitative evidence that toxic 
metals are affecting the springs or the Kenk's amphipod.
    Water samples collected from 2000 to 2003 found nitrate levels as 
high as 30.8 milligrams per liter (mg/L) at Sherrill Drive Spring 
(Culver and Sereg 2004, p. 109). In 2016, nitrate concentrations at 
Sherrill Drive Spring were 3.9 mg/L and 4.2 mg/L at Burnt Mill Spring 
#6 (Pinkney 2017, pers. comm.). Statistical analysis of Maryland 
Biological Stream Survey (MBSS) data indicated that detrimental effects 
were present in fish and benthic communities at critical nitrate-N 
threshold values of 0.83 mg/L and 0.86 mg/L, respectively (Morgan et 
al. 2007, pp. 160-161). These threshold values are significantly lower 
than the values reported at Sherrill Drive Spring and Burnt Mills 
Spring #6.
    We do not know how typical the Sherrill Drive Spring or Burnt Mill 
Spring #6 nitrate concentrations are and if chronic exposure is 
occurring, but we know that Stygobromus specimens have not been 
detected at Sherrill Drive Spring since 2001 or at Burnt Mill Spring #6 
since 2005 (see table 1). We also do not know the potential source of 
the nitrate since it could come from runoff containing fertilizers or 
animal waste or from sanitary sewer leaks. However, a sanitary sewer 
line runs adjacent to the Sherrill Drive Spring, and this sewer line 
has leaked in the past (Feller 1997, p. 37; Yeaman, 2014, pers. comm.).
    Other high levels of nutrients were also evident in the June 2016 
sampling conducted by the Service's Chesapeake Bay Field Office 
(Pinkney 2017b, pers. comm.). The EPA (2000) ecoregional proposed 
criterion for stream total nitrogen of 0.69 mg/L was exceeded at the 
following seepage spring locations: Kennedy Street Spring (1.9 mg/L), 
Sherrill Drive Spring (6.5 mg/L), East Spring (9.7 mg/L), Holsinger 
Spring (20.9 mg/L), and Burnt Mill Spring #6 (24.2 mg/L). The EPA 
stream total phosphorus criterion of 0.036 mg/L was exceeded at all 
five seepage springs with a maximum concentration of 1.3 mg/L at 
Kennedy Street Spring. The MBSS thresholds were 1.3 mg/L total nitrogen 
and 0.043 mg/L total phosphorus for benthic communities (no thresholds 
were determined for fish communities) (Morgan et al. 2007, pp. 160-
161).
    Chloride levels as high as 227 mg/L were detected at Sherrill Drive 
Spring. The EPA chronic ambient water quality criterion for chloride is 
230 mg/L (EPA 2016, entire). Although we do not know the exact source 
of the elevated chloride levels at Sherrill Drive Spring, one potential 
source could be road salt. The Washington metropolitan area receives, 
on average based on 69 years of data taken at Washington National 
Airport, approximately 19.5 inches of snow annually (Southeast Regional 
Climate Center 2017, entire; Current Results 2017, entire). The 
District of Columbia Department of Public Works uses road

[[Page 45563]]

salt and other salt products to pre- and post-treat road surfaces 
before and after ice and snowfall events (District of Columbia 
Department of Public Works 2017, entire). However, the NPS has 
discontinued the use of road salts at some locations within Rock Creek 
Park (Bartolomeo 2017, pers. comm.). The widespread use of salt to 
deice roadways has led to regionally elevated chloride concentrations 
equivalent to 25 percent of the chloride concentration in seawater 
during winter. The concentrations can remain high throughout the summer 
even in less urbanized watersheds due to long-term (e.g., decades) 
accumulation of chloride in ground water (Kaushal et al. 2005, pp. 
13518-13519). This phenomenon was documented by the Service's June 2016 
detection of a chloride concentration of 227 mg/L at Sherrill Drive 
Spring (Pinkney 2017a, pers. comm.). Analyses of MBSS data on fish and 
benthic communities yielded critical chloride values of 17 mg/L for 
fish and 50 mg/L, respectively, as thresholds above which there would 
be detrimental effects on biotic communities (Morgan et al. 2007; pp. 
160-161). Thus, the concentrations measured in June 2016 (Pinkney 
2017a, pers. comm.) at Kennedy Street Spring (56.3 mg/L), Holsinger 
Spring (70.7 mg/L), Burnt Mill Spring #6 (115 mg/L), and Sherrill Drive 
Spring (237 mg/L) all exceed thresholds for benthic communities. 
Furthermore, chloride concentrations in ground water may move slower 
(e.g., dilute slower) than in surface waters and thus the effects from 
winter road salt application may be more persistent in the surrounding 
environment (Findlay and Kelly 2011, p. 66).
    At Coquelin Run Spring, ground water pollution from yard chemicals 
and road runoff (e.g., road salts, oil) could be a concern for the 
Kenk's amphipod's long-term viability. The USGS research on water 
quality degradation in other urban areas indicates that chemicals enter 
waterways and ground water primarily through runoff from rain events, 
and these chemicals have commonly been detected in streams and shallow 
ground water (USGS 1998, entire; USGS 1999a, pp. 1-3; USGS 1999b, p. 1; 
USGS 2001, p. 2). Although no water samples have been taken at the 
Coquelin Run Spring site, it is separated from backyards in this 
neighborhood by a narrow, wooded riparian strip (less than 100 ft) (30 
m) that slopes steeply down to the site. Therefore, the Coquelin Run 
Spring may be at increased risk of exposure to chemical pollutants from 
the surrounding urban development.
    The other four Washington metropolitan area sites (Burnt Mill 
Spring #6, Holsinger Spring, East Spring, and Kennedy Spring) have 
wider buffers than Sherrill Drive Spring and Coquelin Run Spring, with 
buffer distances ranging from approximately 272 ft (83 m) to 1,000 ft 
(305 m). East Spring and Kennedy Spring had much lower conductivity and 
nitrate levels than Sherrill Drive Spring in the 2000, 2001, and 2003 
sampling (Culver and Sereg 2004, pp. 55-58), but were still above 
criteria suggested by Morgan et al. (2007, p. 161). Surveys conducted 
in 2015 and 2016 did not re-confirm the Kenk's amphipod at any of these 
sites but consistently found Stygobromus tenuis at all the sites in 
higher numbers (e.g., greater than 40 observed at Burnt Mill Spring #6 
during 1 sampling event). Urban runoff can decrease biotic richness and 
favor more pollution-tolerant species in urban streams (Center for 
Watershed Protection 2003, pp. 101-102). If S. tenuis has a higher 
tolerance than the Kenk's amphipod to poor water quality parameters, 
the change in species' composition discussed in the proposed rule's (81 
FR 67270; September 30, 2016) Relative Abundance section and Factor E--
Changes in Species Composition could indicate that urban runoff is 
negatively affecting the Kenk's amphipod populations at these spring 
sites.
    The NPS manages the surrounding habitat at the four seepage spring 
sites supporting the Kenk's amphipod in Rock Creek Park. While the NPS 
uses its regulatory authority to manage water quality concerns for the 
species within Rock Creek Park, the agency has little influence over 
the protection of or effects to any seep recharge areas occurring 
outside park boundaries, and over maintenance or repair of city-owned 
infrastructure such as storm water and sewer systems located near the 
spring sites. See the proposed rule (81 FR 67270; September 30, 2016) 
for a list of laws and policies influencing NPS management.
    In Virginia, poor water quality is not likely affecting the species 
at the Fort A.P. Hill and Voorhees Nature Park because the sites are 
located in watersheds that are primarily forested with little 
impervious surface (see table 2).
    Summary of Water Quality--In total, poor water quality is believed 
to be a contributing stressor at all six of the Washington metropolitan 
area sites (i.e., 46 percent of the total known sites). Water quality 
in this area is expected to worsen due to significant runoff events 
from anticipated increases in both winter and spring precipitation and 
the frequency of high-intensity storms. (See Factor A--Excessive Storm 
Water Flows and Factor E--Effects of Climate Change sections for more 
details.) However, we find that poor water quality is not impacting the 
Virginia spring sites because the sites are located in forested areas 
with low levels of impervious cover, and we do not anticipate those 
conditions to change into the future. In addition, the measures in Fort 
A.P Hill's INRMP and the location of one site on conservation land 
provides protections to the species.

Excessive Storm Water Flows

    Runoff from impervious surfaces after heavy rain events can result 
in flooding (Frazer 2005, p. 4; NBC News 2016, entire). Flash flooding 
can also result in erosion and sedimentation (Center for Watershed 
Protection 2003, pp. 30-33), which, if it occurs in the catchment area, 
can subsequently degrade a spring site's value as habitat for the 
Kenk's amphipod.
    In the Washington metropolitan area, excessive storm water flows 
are causing significant habitat degradation at two sites--Sherrill 
Drive Spring and Coquelin Run Spring. A washout at Sherrill Drive 
Spring from 16th Street was observed in 2016 making it difficult to 
find a seep to survey (Feller 2016f, pers. comm.). Coquelin Run Spring 
is severely degraded by runoff from the surrounding Chevy Chase Lake 
Subdivision, where severe erosion was first observed at this site in 
2006 (Feller 2016h, pers. comm.). Subsequent surveys of the site found 
evidence of plastic underground pipe and sheeting, which may have been 
an attempt to address water flow and erosion at the site, in close 
proximity to the original seep and further erosion of the site (Feller 
2016a, pers. comm.; Feller 2016e, pers. comm.). A small flow was 
observed in May 2016 but was located several feet above the original 
seep documented in 2006. It is unknown what affect the pipe or plastic 
may have on the long-term hydrology of the site.
    Erosion from storm water flows has also been observed at the other 
three springs in Rock Creek Park, but not to the extent that it has 
been observed at Sherrill Drive and Coquelin Run Springs. It is unknown 
how much chronic or acute erosion and sedimentation causes a site to 
become unsuitable for the Kenk's amphipod; however, Culver and Sereg 
(2004, p. 69) found that sediment transported by storm runoff results 
in the degradation of ground water animals' habitat by clogging the 
interstices of gravels in the

[[Page 45564]]

spring seep, thereby preventing the species from using those 
interstitial spaces for shelter. It is uncertain to what extent the 
Kenk's amphipod uses those interstitial spaces, but if they do, then it 
is plausible that this type of sedimentation would cause the habitat to 
become unsuitable for the species.
    At the Virginia sites, Mill Creek #2 experiences sheet flow into 
the seep area off of a lateral slope during rainfall events due to the 
degree of slopes and close proximity to a stormwater culvert outlet 
(Applegate 2016, pers. comm.). However, erosion and sediment control 
repairs to the culvert and the surface of the associated unimproved 
trail conducted prior to the proposed rule has dramatically improved 
current conditions. Consequently, sheetflow is not considered a threat 
to the conservation of the Kenk's amphipod at this location (Applegate 
2017, pers. comm.). Sheet flow is not considered to be a problem at 
Voorhees Nature Preserve (Hobson 2017a, pers. comm.).
    Summary of Excessive Storm Water Flows--Excessive storm water flows 
are a contributing stressor at 38 percent (5 of 13) of the species' 
sites (Sherrill Drive Spring, Coquelin Run Spring, East Spring, Kennedy 
Street Spring, and Holsinger Spring).

Sewer Line Breaks and Spills

    The same riparian areas that contain the habitats of the Kenk's 
amphipod are among the principal areas where sewer lines are located in 
the Washington metropolitan area (Feller 2005, p. 2). Most of these 
sewer lines are old (most installed between 1900 and 1930 in the 
District of Columbia and between 1941 and 1971 in Montgomery County, 
MD) and subject to periodic breakage and leakage (Shaver 2011, entire; 
Kiely 2013, entire). While there have been no laboratory or field 
studies evaluating the effect of sewage leaks or spills on the Kenk's 
amphipod or the Stygobromus tenuis, adverse effects of sewage 
contamination on amphipods and other invertebrates have been documented 
(Simon and Buikema 1997, entire; de laOssa-Carretero et al. 2012, p. 
137).
    Releases of large volumes of sewage (up to 2 million gallons (gal)) 
from sanitary sewer leaks have occurred in the District of Columbia and 
Montgomery County, MD. Coquelin Run Spring, Burnt Mill Spring #6, and 
Sherrill Drive Spring are most vulnerable to sewage spills because they 
are located downhill from several sewer lines (see table 2 in the 
proposed rule (81 FR 67270; September 30, 2016) for details). The 
Washington Suburban Sanitary Commission (WSSC) has documented numerous 
large (more than 1,000 gallons) and small (more than 100 gallons) leaks 
in both the Rock Creek and Northwest Brach drainages (WSSC 2015). The 
District of Columbia does not have such detailed records, but half the 
District of Columbia's 1,800 mi (2,896 km) of sewer lines are at least 
84 years old and faulty pipes result in two dozen sewer spills every 
year (Olivio 2015). The frequency of spills is likely to increase in 
the future as the sewer lines continue to age.
    At the Virginia sites, we have no information indicating sewer 
pipelines may affect the species.
    Summary of Sewer Line Spills--In total, sewer line breaks and 
spills are a potential concern at 23 percent (3 of 13) of the species' 
sites.

Water Pipe Breaks

    Bursting of large-diameter water pipes can cause significant 
erosion of surrounding areas as a result of the large volume of fast-
moving water that exits the pipe at the break point. Bursting water 
pipes and the resulting erosion has been documented within the 
Washington metropolitan area, including areas near but not directly at 
a specific Kenk's amphipod seep site (Dudley et al. 2013, entire). The 
exposure risk of bursting water pipes at locations that could affect 
Kenk's amphipod sites is increasing given the age of the water pipe 
infrastructure (see table 2 in the proposed rule (81 FR 67270; 
September 30, 2016) for more details).
    At the Virginia sites, we have no information indicating water 
pipeline breaks may affect the species.
    Summary of Water Pipe Breaks--In total, large water pipeline breaks 
have a potential to occur at 8 percent (1 of 13) of the species' sites 
(Sherrill Drive Spring), while smaller water pipeline breaks could 
occur at 23 percent (3 of 13) of the sites (Sherrill Drive Spring, 
Coquelin Run Spring, and Burnt Mills #6 Spring).

Other Habitat Considerations

    The Kenk's amphipod is likely susceptible to changes to the forest 
canopy and understory; this theory is supported by the fact that they 
can be found in leaf litter. The more common species Stygobromus tenuis 
has been found to actively exit the hypotelminorheic under appropriate 
conditions, presumably to forage (Kavanaugh 2009, p. 3), and they are 
found only in forested areas (Culver 2016, pers. comm.).
    In the Washington metropolitan area, there have been no land-
disturbance activities such as forest management or vegetation/habitat 
management activities conducted at Rock Creek Park or at the Montgomery 
County park in the vicinity of the seeps. At Rock Creek Park, the NPS 
has taken steps to prevent designated trails from being built in areas 
that could affect the Kenk's amphipod, and there are no trails in close 
vicinity to the seep found at the county park. At the privately owned 
site, an underground pipe previously installed on the hillside where 
the seep is located was observed in 2016, and, despite the steep 
topography, there is the potential for foot traffic in the seepage area 
by the landowners. The Service is unaware of any tree removal ever 
occurring at this site.
    In general, stressors to the Kenk's amphipod habitat at the 
Virginia sites are less significant than those in the Washington 
metropolitan area because land use is primarily agriculture and forest 
with little impervious surface. See the description of Fort A.P. Hill 
under the Ongoing and Future Conservation Measures section above. With 
the possible exception of the effects of climate change and the 
potential effects of small population dynamics (see Factor E below), we 
are unaware of any stressors at Voorhees Nature Preserve (Hobson 2017a, 
pers. comm.). The preserve is located 8.5 mi (13.7 km) east across the 
Rappahannock River from Fort A.P. Hill in Westmoreland County, 
Virginia. The 729-acre (295-hectare) parcel has been owned by The 
Nature Conservancy (TNC) since 1994. The goal of the preserve is to 
protect the mature coastal plain forest and freshwater tidal marsh 
(Truslow 2017a, pers. comm.).
    As of July 2017, human activity at the preserve is limited to 
maintenance of approximately 3 mi (4.8 km) of hiking trails, white-
tailed deer management through a hunt lease with a local hunt club, and 
annual monitoring to ensure the protection goals of the property are 
being met. There is light recreational use from the 3 mi (4.8 km) of 
hiking trails located on the property. The trails are open only for 
foot travel (approximately several hundred visitors a year based on 
trail logs); no ATVs or bikes are allowed on the trails (Truslow 2017b, 
pers. comm.). Dogs are also not allowed at the preserve (TNC 2017, 
entire).
    The seep where the Kenk's amphipod was found is not impacted by the 
trail because it is located approximately 30 to 40 ft (9.1 to 12.2 m) 
down slope of the trail, at the head of a ravine, and it is surrounded 
by dense vegetation, which makes access to the site difficult (Hobson 
2017a, pers. comm.). There is also no visible erosion from the trail 
(C. Hobson 2017a, pers. comm.).

[[Page 45565]]

    The TNC developed a site-management plan upon assuming ownership. 
Timber harvesting will not occur where there is mature forest, and 
uplands will be kept in a forested condition to protect the property's 
marsh from sedimentation runoff. In addition, TNC will not use 
pesticides (e.g., dimilin) to control future gypsy moth infestations 
(TNC 1994).
    In terms of the property's protection status, TNC preserves are 
considered to be permanently protected. The deed does not contain 
restrictions on TNC selling or transferring the property; however, TNC 
policy would require that the property be transferred to an entity that 
would manage for similar conservation goals (e.g., a State natural 
resource agency or Federal agency), or that it be restricted by a 
conservation easement that would ensure permanent protection of the 
property (Truslow 2017a, pers. comm.).
    The preserve is surrounded primarily by forest, and there is 
Service-owned National Wildlife Refuge land and State-owned land west 
of the site. A soil enhancement facility was proposed in 2014 at a 
parcel approximately 1 mile (1.6 km) northeast of the seep. The purpose 
of the facility would be to compost biosolids from sewage and sell the 
compost as fertilizer. If the site was approved and constructed, it 
would not impact the Kenk's amphipod because the seep is at a higher 
elevation and in a different surface catchment area than the proposed 
soil enhancement facility.
    Summary of Factor A--Habitat modification, in the form of degraded 
water quality and quantity, is one of the primary drivers affecting 
Kenk's amphipod viability at the Washington metropolitan area sites, 
despite ongoing conservation measures. Reductions in water quality 
continue to occur at those sites primarily as a result of urbanization, 
which increases the amount of impervious cover in the watersheds 
surrounding six of the Kenk's amphipod sites. Impervious cover 
increases storm water flow velocities, decreases ground water 
filtration, and increases erosion and sedimentation. Impervious cover 
can also increase the transport of contaminants and nutrients common in 
urban environments, such as metals (zinc, cadmium), nitrogen, 
phosphorus, and fecal coliform bacteria. The Washington metropolitan 
area sites have narrow riparian buffers separating them from the 
surrounding development, increasing the sites' exposure to poor water 
quality from runoff. While poor water quality has been documented at 
Sherrill Drive Spring and is likely affecting all six sites in the 
Washington metropolitan area, the seven Virginia sites are not thought 
to be affected by poor water quality because of the large forested 
buffers on Fort A.P. Hill and Voorhees Nature Preserve.
    Excessive storm water runoff from heavy rain events can result in 
flooding, which can cause erosion and sedimentation. Habitat 
degradation due to excessive storm water flows is having effects at two 
sites--Sherrill Drive Spring and Coquelin Run Spring--but has also been 
observed at the other four springs in Rock Creek Park, and may increase 
in the future. At the Virginia sites, we have no information indicating 
excessive storm water flows affect the species.
    Sewer and water line breaks and leaks are a concern at the 
Washington metropolitan area sites because most of them are located in 
the same riparian areas that contain the habitats of the Kenk's 
amphipod. While leaks and breaks of these pipelines have not yet been 
known to directly affect the species or its habitat, the pipeline 
systems are subjected to chronic leaks and breaks, the frequency of 
which is likely to increase given the age of the infrastructure, and 
thus the exposure risk of the species to this stressor will continue to 
increase. Coquelin Run Spring, Burnt Mill Spring #6, and Sherrill Drive 
Spring are most vulnerable to sewage spills and water pipe breaks due 
to the pipe's proximity to each site and the age of the pipes. At the 
Virginia sites, we have no information indicating sewer or water 
pipeline breaks will affect the species.
    Stressors to Kenk's amphipod habitat are significantly less in 
scope and severity at Fort A.P. Hill and Voorhees Nature Preserve than 
at the Washington metropolitan area habitats, due to the location of 
the sites, the current and foreseeable mission of the managing 
entities, and the conservation measures described in the INRMP and TNC 
Management Plan. The risk is low that any disturbance to the surface 
habitat on those properties would result in adverse effects to the 
species. We acknowledge that the Washington metropolitan sites face a 
number of stressors that will continue into the future. Of the six 
Washington sites, only one site has a recent record of Kenk's amphipod. 
We cannot confirm without additional consecutive negative survey 
results, but it is possible that this species is functionally extinct 
in the Washington metropolitan area given the stressors it faces and 
the lack of specimens found in recent survey results. Conversely, the 
seven Virginia sites do not face the same stressors as the Washington 
metropolitan area sites. Habitat quality at the Virginia sites is good 
and the sites all have some form of protection, either from the 
measures in the Fort A.P. Hill INRMP or the TNC nature preserve's site-
management plan.

                      Table 3--Relative Vulnerability of Kenk's Amphipod Seep Habitat Sites
----------------------------------------------------------------------------------------------------------------
                                                                                       Current biological status
             Site name                     Location            Current seep status       of the Kenk's amphipod
----------------------------------------------------------------------------------------------------------------
Sherrill Drive Spring.............  Rock Creek Park,       Approximately 50' to road,  Extirpated? Not found in
                                     Washington, DC.        documented decrease in      recent surveys. No other
                                                            water quality (chemical     Stygobromus present.
                                                            and sedimentation),         Last detected 2001 (8
                                                            within 10' of 1924 sewer    surveys since and none
                                                            pipe and 130' of 1955       found). Niemiller et al.
                                                            30'' water pipe.            (2017) eDNA study also
                                                                                        supports extirpation of
                                                                                        all Stygobromus here.
East Spring.......................  Rock Creek Park,       Approximately 300-500'      Unknown. Not found in
                                     Washington, DC.        buffer of protected         recent surveys but other
                                                            forest, within 560' of 6-   Stygobromus present.
                                                            8'' 1921 water pipe.        Last detected 2001 (7
                                                                                        surveys in 2015-2016 and
                                                                                        none found).
Kennedy Street Spring.............  Rock Creek Park,       Approximately 500' buffer   Unknown. Not found in
                                     Washington, DC.        of protected forest,        recent surveys but other
                                                            within 860' of 6-8'' 1911   Stygobromus present.
                                                            water pipe.                 Last detected 2001 (5
                                                                                        surveys since and none
                                                                                        found).

[[Page 45566]]

 
Holsinger Spring..................  Rock Creek Park,       Approximately 700-1,000'    Historical? Not
                                     Washington, DC.        buffer of protected         documented since 1967.
                                                            forest.                     One survey in 2003 and 3
                                                                                        surveys in 2015 and none
                                                                                        found; other Stygobromus
                                                                                        species present.
Burnt Mill Spring #6..............  Northwest Branch       In county park protected    Unknown. Not found in
                                     Park, Montgomery       from further development,   recent surveys but other
                                     County, MD.            within 186' of unknown      Stygobromus species
                                                            age sewer pipe and 394'     present. Last detected
                                                            of 6-8'' 1959 water pipe.   in 2005 (10 surveys
                                                                                        since and none found).
Coquelin Run Spring...............  Private land,          Erosion problems are        Present in upslope
                                     Montgomery County,     already apparent, site      portion of seep (1
                                     MD.                    has been modified with a    individual found in
                                                            plastic pipe and plastic    2016); lower section has
                                                            material, and riparian      some erosion and species
                                                            forest is very narrow.      absent in that section
                                                            Within 220' of 1952 sewer   (3 surveys conducted in
                                                            pipe and 250' of 6-8''      2016 and none found). No
                                                            1954 water pipe.            other Stygobromus
                                                                                        species were found in
                                                                                        upper or lower portion
                                                                                        of seep in 2016.
Fort A.P. Hill (6 seeps)..........  Department of          Good habitat quality,       Present and recently
                                     Defense, Caroline      sites unaffected by         discovered. One
                                     County, VA.            urbanization. Military      individual each found at
                                                            exercises, forest           Upper Mill 2, Mill 4,
                                                            management, and             and Mount 2 in 2014 but
                                                            construction activities     not identified as the
                                                            are at low risk to affect   Kenk's amphipod until
                                                            surface habitat due to      2016; 4 individuals
                                                            the revised INRMP.          found at Mill 5 in 2014.
                                                                                        In 2017, there were 6
                                                                                        individuals found at
                                                                                        Upper Mill 2, 1
                                                                                        individual at Upper Mill
                                                                                        4, and 4 individuals at
                                                                                        Mount 2. Two new sites
                                                                                        were found in 2017: Mill
                                                                                        Creek 56 (16
                                                                                        individuals) and Mill
                                                                                        Creek 59 (8 individuals
                                                                                        found).
Voorhees Nature Preserve (1 seep).  Westmoreland County,   Good habitat quality,       Recently discovered. One
                                     VA.                    owned by TNC. Permanently   individual found in
                                                            protected as a nature       2017.
                                                            preserve.
----------------------------------------------------------------------------------------------------------------

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

    In the September 30, 2016, proposed rule (81 FR 67270), we found no 
information indicating that overutilization was a factor affecting the 
Kenk's amphipod. No new information from peer review or public comments 
indicates that overutilization is a concern for the species.

Factor C. Disease or Predation

    In the September 30, 2016, proposed rule (81 FR 67270), we found no 
information indicating that disease or predation was affecting the 
Kenk's amphipod. No new information from peer review or public comments 
indicates that disease or predation is a concern for the species.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    The following existing regulatory mechanisms were specifically 
considered and discussed as they relate to the stressors, under the 
applicable Factors, affecting the Kenk's amphipod: the Clean Water 
Act's (CWA) National Pollutant Discharge Elimination System, Rock Creek 
Park Authorization Act of 1890, and National Park Service Organic Act 
of 1916 (Factor A; summarized above in this final determination, but 
discussed in full in the proposed rule (81 FR 67270; September 30, 
2016) and Nongame and Endangered Species Conservation Act (Factor B).

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

Small Population Dynamics

    The observed small size of each of the 13 Kenk's amphipod 
populations may make each one vulnerable to natural environmental 
stochasticity and human-caused habitat disturbance, including 
relatively minor impacts in their spring recharge areas. However, there 
is significant uncertainty regarding the extent to which the number of 
Kenk's amphipods observed at the seep surface accurately reflects the 
actual population at each site given the species' known ability to move 
between the surface and subsurface habitat. We are unaware of any 
reliable method to accurately estimate the actual population size of 
the Kenk's amphipod at each of its historical and current sites. In 
addition, the multiple sites (six in the Washington metropolitan area 
and seven in Virginia) provide some protection against stochastic and 
catastrophic events affecting all sites simultaneously (see the 
Cumulative Effects section below).
    An eDNA (Niemiller et al. 2016, pp. 1-7) and a hydrogeology study 
(Staley 2016, pp. 1-46) were conducted in 2016. However, neither study 
resulted in any information that helped us better understand the Kenk's 
amphipod's genetics, distribution, or potential for dispersal (e.g., 
metapopulation structure). Therefore, unless the populations are larger 
than we know or are hydrologically connected such that individuals can 
move between sites, we maintain that these small populations are 
vulnerable to the effects of small population dynamics.
    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, 
and reducing the fitness of individuals (Soule 1980, pp. 157-158; 
Hunter 2002, pp. 162-163; Allendorf and Luikart 2007, pp. 117-146). 
Small population sizes and inhibited gene flow between populations may 
increase the likelihood of local extirpation (Gilpin and Soul[eacute] 
1986, pp. 32-34). With the exceptions for the Fort A.P. Hill 
populations of Mill Creek #2 and Mill Creek #4, which are separated by 
only approximately 360 ft (110 m), and Mill Creek #56 and #59, which 
are approximately 2,640 ft (805 m) from the other two Mill Creek sites 
and 1,056 ft (322 m) apart from each other, all the other populations 
of the Kenk's amphipod are isolated from other existing populations and 
known habitats by long distances, inhospitable upland habitat, and 
terrain that create barriers to amphipod movement. The level of 
isolation and the restricted range seen in this species, based on our

[[Page 45567]]

current knowledge of known habitat, make natural repopulation of known 
habitats (e.g., the District of Columbia sites and Burnt Mill Spring #6 
where the species' presence has not been recently confirmed) virtually 
impossible without human intervention.

Effects of Climate Change

    Climate change may result in changes in the amount and timing of 
precipitation, the frequency and intensity of storms, and air 
temperatures. All of these changes could affect the Kenk's amphipod and 
its habitat. The amount and timing of precipitation influence spring 
flow, which is an important feature of the habitat of this ground water 
species. Also, the frequency and intensity of storms affects the 
frequency, duration, and intensity of runoff events, and runoff 
transport of sediment and contaminants into catchment areas of Kenk's 
amphipod sites, especially in the Washington metropolitan area, where 
there is a substantial amount of impervious cover in close proximity to 
the habitat (see Factor A summarized above and in detail in the 
proposed rule (81 FR 67270; September 30, 2016)). Below we discuss the 
best available climate predictions for the areas supporting the Kenk's 
amphipod.
    The 2014 National Climate Assessment (Melillo et al. 2014, entire) 
predicts increasing ambient temperatures, increasing winter and spring 
precipitation, increasing frequency of heavy downpours, and increasing 
summer and fall drought risk as higher temperatures lead to greater 
evaporation and earlier winter and spring snowmelt (Horton et al. 2014, 
p. 374 In Melillo et al. 2014). Without more specific information about 
how seeps are connected underground, as well as the ability of the 
amphipods to migrate within the soil column in response to drying from 
drought conditions, it is unclear to what degree the temporary drying 
of these habitats will affect the Kenk's amphipod (Carter 2016, pers. 
comm.). Alternatively, an increase in heavy downpours will likely 
result in increased runoff and resulting erosion of surface features at 
spring sites, based on previously documented events. The 2014 National 
Climate Assessment further indicates that overall warming in the 
Northeast, including Maryland and the District of Columbia, will be 
from 3 to 10 degrees Fahrenheit ([deg]F) (1.7 to 5.6 degrees Celsius 
([deg]C)) by the 2080s (Horton et al. 2014, p. 374 In Melillo et al. 
2014). The Southeast region, which includes Virginia, is projected to 
see a regional average temperature increase of 4 to 8 [deg]F (2.2 to 
4.4 [deg]C) (Carter et al. 2014, p. 399 In Melillo et al. 2014).
    Data specific to the District of Columbia from NOAA's National 
Climate Data Center (NOAA 2017, entire) shows that the average annual 
air temperature in the District of Columbia has already increased by 
approximately 2 [deg]F (1.1[deg]C) from 1960, the decade corresponding 
to the first Kenk's amphipod surveys, to 2016. This higher rate of 
change in the District of Columbia may be due to the urban heat island 
effect (Oke 1995, p. 187), which is an increase in ambient temperature 
due to heating of impervious surfaces. This activity also results in an 
increase in temperature of rainwater that falls on heat-absorbing roads 
and parking lots. A sudden thunderstorm striking a parking lot that has 
been sitting in hot sunshine can easily result in a 10 [deg]F (5.6 
[deg]C) increase in the rainfall temperature. Menke et al. (2010, pp. 
147-148) showed that these temporary increases in temperature of storm 
water can still result in a shift in the biotic community composition 
and even accelerate changes in species distributions. Based on the work 
of Menberg et al. (2014, entire), we expect these changes in air 
temperature to be reflected in the temperature of the shallow ground 
water at all sites within a few years, but at a lower magnitude.
    Increased temperature is stressful to aquatic life through several 
mechanisms. First, at higher temperatures, the metabolic rate of 
invertebrates and fish is higher and more rapid ventilation is needed 
by the animal to obtain oxygen, which is less soluble (i.e., less 
available) in warmer versus cooler water (Schiedek et al. 2007, p. 
1846). Second, the rates that cold-blooded animals metabolize certain 
chemicals into more toxic forms increase at higher temperatures. This 
characteristic can either cause sublethal effects that inhibit the 
animal's ability to feed, breed, or escape from predators, or can be 
lethal due to increased toxicity at higher temperatures. For example, 
organophosphate insecticides are metabolically transformed into the 
more toxic oxon form. This oxon form is lethal to animals because it 
inhibits the enzyme acetylcholinesterase (Hooper et al. 2013, p. 36). 
Illustrating this toxicity, laboratory experiments exposed the Gammarus 
pseudolimnaeus amphipod to the organophosphates terbufos and 
trichlorofon (Howe et al. 1994, p. 58). In one set of experiments, 
terbufos was demonstrated to be seven times more toxic at 
62[emsp14][deg]F (17[emsp14][deg]C) than at 45[emsp14][deg]F 
(7[emsp14][deg]C). And third, ammonia, derived from wastewater, 
fertilizers, and runoff from animal wastes, is more toxic to all 
aquatic life at higher temperatures because a greater fraction exists 
in the more toxic un-ionized form (EPA 2013, p. 7). Thus, the EPA 
aquatic life criteria are temperature (and pH) dependent with lower 
limits at higher temperatures for a given pH. It is important to note 
we do not have specific temperature tolerance information for the 
Kenk's amphipod; however, there are studies of other amphipod species 
that indicate these animals have a sensitivity to elevated 
temperatures, as exhibited by reduced or eliminated egg survival at 
water temperatures above 75[emsp14][deg]F (24[emsp14][deg]C) to 
79[emsp14][deg]F (26[emsp14][deg]C) (Pockl and Humpesch 1990, pp. 445-
449).
    In summary, if current climate change predictions become reality, 
by the 2080s some increase in ground water temperatures will occur at 
sites occupied by the Kenk's amphipod, yet the magnitude and 
significance of these changes is difficult to predict.

Change in Species Composition

    At most of the Washington metropolitan area sites supporting the 
Kenk's amphipod, numbers of the Potomac ground water amphipod, which is 
the most widely distributed and abundant Stygobromus species in the 
lower Potomac drainage (Kavanaugh 2009, p. 6), have increased as 
numbers of observed Kenk's amphipods have declined (Feller 2016b, pers. 
comm.; Feller 2016c, pers. comm.). The exact cause of this change is 
not known, but it may be an indication that some stressor has led to a 
competitive advantage for the Potomac ground water amphipod (Culver et 
al. 2012, p. 29). Other than at Coquelin Run Spring, there are no 
obvious physical changes at these sites indicating a cause for the 
decline. However, as described in Factor A, impaired water quality 
could favor a more common species over a rare species. Culver and Sereg 
(2004, pp. 72-73) indicated that there is a possibility that the Kenk's 
amphipod is a poor competitor with other Stygobromus species, which may 
be a factor promoting the Kenk's amphipod's natural rarity, and that in 
cave locations Stygobromus species strongly compete with each other. 
Only one site in the Washington metropolitan area was surveyed in 2017, 
Burnt Mills Spring #6. That site continues to have a large number of S. 
tenuis and no Kenk's amphipod (Feller 2016g, pers. comm.). The more 
common species S. tenuis and S. foliatus are found at the Virginia 
sites, but they are less abundant than what has been observed in the 
Washington metropolitan area sites (Hobson 2017b, pers. comm.). While 
the Kenk's amphipod may have always been

[[Page 45568]]

naturally rare, we conclude that the species may be getting rarer at 
the Washington metropolitan area sites due to the stressors discussed 
above.
    Summary of Factor E--The believed small population size at all of 
the sites makes each one of them vulnerable to natural environmental 
stochasticity and human-caused habitat disturbance, including 
relatively minor impacts in their spring recharge areas. The believed 
small size and isolation of sites also make each population vulnerable 
to demographic stochasticity, including loss of genetic variability and 
adaptive capacity.
    The best available climate data indicate that the areas supporting 
the Kenk's amphipod will see increasing ambient temperatures, 
increasing winter and spring precipitation, increasing frequency of 
heavy downpours, and increasing summer and fall drought risk as higher 
temperatures lead to greater evaporation and earlier winter and spring 
snowmelt. Droughts could result in drying up of spring sites, while the 
increase in heavy downpours could result in erosion and sedimentation 
of sites. Ambient air temperature has increased by 3[emsp14][deg]F 
(1.7[emsp14][deg]C) since 1960, and is expected to increase by 8 to 
10[emsp14][deg]F (4.4 to 5.6[emsp14][deg]C) by the 2080s. If current 
climate change predictions become a reality, by the 2080s some increase 
in ground water temperatures will occur at sites occupied by the Kenk's 
amphipod, but the magnitude and significance of these changes is 
difficult to predict.

Cumulative Effects

    Many of the factors previously discussed are cumulatively and 
synergistically affecting the Kenk's amphipod primarily in the 
Washington metropolitan area. For example, Kenk's amphipod habitat can 
be degraded by storm water runoff when there is not adequate forest 
buffer, which is likely to increase with more frequent and intense 
storms and precipitation levels in the future. Species with larger 
populations are naturally more resilient to the stressors affecting 
individuals or local occurrences, while smaller populations or 
individuals are more susceptible to demographic or stochastic events. 
Below we discuss the Kenk's amphipod's viability as expressed through 
the conservation biology principles of representation, redundancy, and 
resiliency, which illustrate how the cumulative and synergistic effects 
are affecting the species as a whole.
    Redundancy--The species has some redundancy given its known 
historical distribution of 13 sites across 4 municipal jurisdictions 
and multiple streams. Currently, the species is known to be extant at 
one of the Washington metropolitan area sites and seven of the Virginia 
sites. We assume that the Sherrill Drive Spring site is extirpated. 
Although we cannot confirm without additional consecutive negative 
survey results, given the lack of recent positive surveys and the 
existing stressors at the five other Washington metropolitan area 
sites, it is possible that these sites are functionally extinct, which 
means that the population at each site is so reduced that the site 
population is no longer viable.
    The isolation of the two Montgomery County, MD, populations from 
other Washington metropolitan area populations and their occurrence 
along different tributary streams make it unlikely that a single 
catastrophic adverse event (e.g., a spill) will eliminate more than one 
occurrence at a time. In addition, the Virginia sites on Fort A.P. Hill 
occur in two stream areas, Mill Creek and Mount Creek, making it 
unlikely that a single military training event or other catastrophic 
event will eliminate more than one occurrence at a time. In addition, 
subsequent to the species' proposal for endangered status, it was found 
in the spring of 2017 approximately 8.5 mi (13.7 km) away and across 
the Rappahannock River from the known Fort A.P. Hill sites. This 
finding, together with the discovery of two new sites on Fort A.P. 
Hill, contributes to additional redundancy for the species.
    Representation--Based on the information about historical changes 
to the landscape across the Washington metropolitan area, we conclude 
it is likely that the species' historical distribution was larger than 
the current distribution; therefore, the species may have previously 
experienced a loss in representation. Also, because we do not yet have 
sufficient information on the genetics of these populations, we cannot 
determine whether the species possesses a single genetic identity or 
has genetic variability across populations. However, the species is now 
known to occur within habitat supported by two different geological 
formations, the Wissahickon and Nanjemoy. While we conclude that the 
species' representation has likely been reduced from historical levels, 
it may not be as limited as we thought at the time of the proposed rule 
given our expanded understanding of suitable habitat and the three new 
locations found during the spring 2017 surveys on public land.
    Resiliency--Based on the relatively small number of individuals 
found at the 13 known seeps, and the variability of stressors across 
the species' range, the resiliency of each of the Kenk's amphipod's 
populations may be low to moderate. The small size of each of the 13 
habitat areas makes each population vulnerable to natural environmental 
stochasticity and human-caused habitat disturbance, including 
relatively minor effects in the spring recharge area. As a result of 
habitat fragmentation/isolation there is a lack of connectivity and 
genetic exchange between populations and, we assume, a lack of ability 
to recolonize extirpated sites. However, the larger number of Kenk's 
amphipods found at two of the newly discovered sites, together with the 
expectation that seven of the sites will be adequately protected from 
habitat quality stressors, leads us to believe that the resiliency of 
the Kenk's amphipod at a majority of its sites is higher than we 
thought at the time of the proposed listing rule.

Determination

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations at 50 CFR part 424, set forth the procedures for 
determining whether a species is an endangered species or threatened 
species and should be included on the Federal Lists of Endangered and 
Threatened Wildlife and Plants (listed). 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.'' The 
phrase ``significant portion of its range'' (SPR) is not defined by the 
Act, and, since the Service's policy interpreting the phrase was 
vacated by the court in Center for Biological Diversity v. Jewell, No. 
14-cv-02506-RM (D. Ariz. Mar. 29, 2017), we currently do not have a 
binding interpretation that addresses: (1) The outcome of a 
determination that a species is either in danger of extinction or 
likely to become so in the foreseeable future throughout a significant 
portion of its range; or (2) what qualifies a portion of a range as 
``significant.'' We have examined the plain language of the Act and 
court decisions addressing the Service's application of the SPR phrase 
in various listing decisions, and for purposes of this rulemaking we 
are applying the following interpretation for the phrase ``significant 
portion of its range'' and its context in determining whether or not a 
species is an endangered species or a threatened species.
    Two district court decisions have evaluated whether the outcomes of 
the Service's determinations that a species is in danger of extinction 
or likely to

[[Page 45569]]

become so in the foreseeable future in a significant portion of its 
range were reasonable. Defenders of Wildlife v. Salazar, 729 F. Supp. 
2d 1207 (D. Mont. 2010) (appeal dismissed as moot because of public law 
vacating the listing, 2012 U.S. App. LEXIS 26769 (9th Cir. Nov. 7, 
2012)); WildEarth Guardians v. Salazar, No. 09-00574-PHX-FJM, 2010 U.S. 
Dist. LEXIS 105253 (D. Ariz. Sept. 30, 2010). Both courts found that, 
once the Service determines that a ``species''--which can include a 
species, subspecies, or Distinct Population Segment of a vertebrate 
species (DPS) under section 3(16) of the Act--meets the definition of 
``endangered species'' or ``threatened species,'' the species must be 
listed in its entirety and the Act's protections applied consistently 
to all members of that species (subject to modification of protections 
through special rules under sections 4(d) and 10(j) of the Act). See 
Defenders, 729 F. Supp. 2d at 1222 (delisting the Northern Rocky 
Mountain DPS of gray wolf except in the Wyoming portion of its range 
(74 FR 15123 (Apr. 2, 2009)) was unreasonable because the Act 
unambiguously prohibits listing or protecting part of a DPS); WildEarth 
Guardians, 2010 U.S. Dist. LEXIS 105253, at 15-16 (the Service's 
finding that listing the Gunnison's prairie dog in the ``montane 
portion'' of its range was warranted (73 FR 6660 (Feb. 5, 2008)) was 
unreasonable because the Service ``cannot determine that anything other 
than a species, as defined by the Act, is an endangered or threatened 
species''). The issue has not been addressed by a Federal Court of 
Appeals.
    For the purposes of this rule, we interpret the SPR phrase in the 
Act's definitions of ``endangered species'' and ``threatened species'' 
to provide an independent basis for listing a species in its entirety; 
thus there are two situations (or factual bases) under which a species 
would qualify for listing: A species may be in danger of extinction or 
likely to become so in the foreseeable future throughout all of its 
range; or a species may be in danger of extinction or likely to become 
so throughout a significant portion of its range. If a species is in 
danger of extinction throughout an SPR, it, the species, is an 
``endangered species.'' The same analysis applies to ``threatened 
species.'' Therefore, the consequence of finding that a species is in 
danger of extinction or likely to become so throughout a significant 
portion of its range is that the entire species will be listed as an 
endangered species or threatened species, respectively, and the Act's 
protections will be applied to all individuals of the species wherever 
found.
    Although there are potentially many ways to determine whether a 
portion of a species' range is ``significant,'' we conclude, for the 
purposes of this rule, that the significance of the portion of the 
range should be determined based on its biological contribution to the 
conservation of the species. For this reason, we describe the threshold 
for ``significant'' in terms of an increase in the risk of extinction 
for the species. We conclude that such a biologically based definition 
of ``significant'' best conforms to the purposes of the Act, is 
consistent with judicial interpretations, and best ensures species' 
conservation.
    For the purposes of this rule, we determine if a portion's 
biological contribution is so important that the portion qualifies as 
``significant'' by asking whether, without that portion, the species in 
the remainder of its range warrants listing (i.e., is in danger of 
extinction or likely to become so in the foreseeable future). 
Conversely, we would not consider the portion of the range at issue to 
be ``significant'' if the species would not warrant listing in the 
remainder of its range even if the population in that portion of the 
range in question became extirpated (extinct locally).
    We interpret the term ``range'' to be the general geographical area 
within which the species is currently found, including those areas used 
throughout all or part of the species' life cycle, even if not used on 
a regular basis. We consider the ``current'' range of the species to be 
the range occupied by the species at the time the Service makes a 
determination under section 4 of the Act. The phrase ``is in danger'' 
in the definition of ``endangered species'' denotes a present-tense 
condition of being at risk of a current or future undesired event. 
Hence, to say a species ``is in danger'' in an area where it no longer 
exists--i.e., in its historical range where it has been extirpated--is 
inconsistent with common usage. Thus, ``range'' must mean ``current 
range,'' not ``historical range.'' A corollary of this logic is that 
lost historical range cannot constitute a significant portion of a 
species' range where a species is in danger of extinction or likely to 
become so within the foreseeable future (i.e., it cannot be currently 
in danger of extinction in a portion of its range where it is already 
extirpated). While we conclude that a species cannot be in danger of 
extinction in its lost historical range, taking into account the 
effects of loss of historical range on a species is an important 
component of determining a species' current and future status.
    In implementing these independent bases for listing a species, as 
discussed above, we list any species in its entirety either because it 
is in danger of extinction now or likely to become so in the 
foreseeable future throughout all of its range or because it is in 
danger of extinction or likely to become so in the foreseeable future 
throughout a significant portion of its range. With regard to the text 
of the Act, we note that Congress placed the ``all'' language before 
the SPR phrase in the definitions of ``endangered species'' and 
``threatened species.'' This placement suggests that Congress intended 
that an analysis based on consideration of the entire range should 
receive primary focus. Thus, the first step in our assessment of the 
status of a species is to determine its status throughout all of its 
range. Depending on the status throughout all of its range, we will 
subsequently examine whether it is necessary to determine its status 
throughout a significant portion of its range.
    Under section 4(a)(1) of the Act, we determine whether a species is 
an endangered species or threatened species because of any of the 
following: (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. These five factors apply whether we are analyzing 
the species' status throughout all of its range or throughout a 
significant portion of its range.

Kenk's Amphipod Determination of Status Throughout All of Its Range

    Our review of the best available information indicates that the 
Kenk's amphipod is known to be extant at one of the Washington 
metropolitan area sites and seven of the Virginia sites. We assume that 
the Sherrill Drive Spring site is extirpated. Although we cannot 
confirm without additional consecutive negative survey results, given 
the lack of recent positive surveys and the existing stressors at the 
other Washington metropolitan area sites, it is possible that these 
sites are functionally extinct. Three of the Virginia sites were 
recently discovered during the 2017 surveys of suitable habitat on 
publicly owned lands. While there appears to be evidence of extirpation 
at one site (Sherrill Drive Spring) and decline of the species at four 
Washington metropolitan area sites (East Spring,

[[Page 45570]]

Kennedy Spring, Holsinger Spring, and Burnt Mill Spring #6), and one 
individual was collected at Coquelin Run Spring, the number of Kenk's 
amphipods found during the 2017 surveys was slightly higher at two of 
the previously known Fort A.P. Hill sites (Mount Creek #2 and Upper 
Mill Creek #2), the same at one previously known Fort A.P. Hill site 
(Mill Creek #4), and higher at two new sites on Fort A.P. Hill (Mill 
Creek #56 and Mill Creek #59); one of the previously known Fort A.P. 
Hill sites was not surveyed (Mill Creek #5) due to lack of spring flow. 
In addition, the species was newly discovered at the Voorhees Nature 
Preserve. It is possible that the species could be found at additional 
locations in Virginia based on the amount of yet-to-be-surveyed 
suitable habitat.
    The habitat loss and degradation (Factor A) from poor water quality 
parameters associated with urban runoff affecting the Kenk's amphipod 
at the six Washington metropolitan area sites, despite existing 
regulatory mechanisms (Factor D), are likely to be exacerbated in the 
future by the increasing risk of exposure to breaks and leaks from the 
aging sewer and water pipe infrastructure (Factor A), as well as the 
predicted more frequent and intense rainfall events, resulting in sheet 
flow events, due to the effects of climate change (Factor E). However, 
poor water quality associated with urban runoff is not affecting the 
species at the seven sites in Virginia. Interspecific competition 
(Factor E) from larger amphipod species may also be affecting the 
Kenk's amphipod at some of the Washington metropolitan area sites, but 
the available information is inconclusive, and those larger amphipod 
species, while found at some of the Virginia sites, have not been found 
in large numbers (Hobson 2017b, pers. comm.). Overutilization (Factor 
B), disease (Factor C), and predation (Factor C) are not known to be 
factors affecting the Kenk's amphipod at any site. It is possible that 
the effects of small population dynamics (Factor E) may be having an 
effect at some, if not all, of the species' locations, but there is 
some uncertainty associated with that hypothesis given the species' 
known ability to move back and forth between the ground water and 
surface areas of the seeps and given the survey data indicating the 
species can reappear, sometimes in higher numbers of individuals, after 
several years of absence. It is also possible that increasing air 
temperatures as a result of climate change (Factor E) will cause ground 
water temperatures to eventually increase, that the ground water will 
become too warm by the end of the century for the Kenk's amphipod to 
successfully reproduce, and that higher ground water temperatures will 
increase the species' exposure, and sublethal and lethal response, to 
contaminants. However, there is some uncertainty associated with that 
hypothesis given the long timeframes (e.g., more than 50 years) 
associated with the climate modelling and the unknown water temperature 
tolerance of the Kenk's amphipod.
    Although there are some stressors that are expected to continue to 
result in the degradation and loss of some habitat sites for the Kenk's 
amphipod, the risk of the species significantly declining across its 
range in the near term is very low given that it has persisted, albeit 
at decreased levels, despite historical levels of habitat loss in the 
Washington metropolitan area. Factors in favor include the species' 
presence in relatively higher numbers at the Virginia sites. 
Furthermore, the existing stressors are not likely to cause species-
level effects in the near term. The documented persistence of the 
species at one location in the Washington metropolitan area and seven 
locations in Virginia provides redundancy, resiliency, and 
representation to sustain the species beyond the near term. Therefore, 
we conclude that the risk of extinction of the Kenk's amphipod in the 
near term is sufficiently low that it does not meet the definition of 
an endangered species under the Act.
    The Act defines a threatened species as ``any species which is 
likely to become an endangered species within the foreseeable future 
throughout all or a significant portion of its range.'' A key statutory 
difference between an endangered species and a threatened species is 
the timing of when the relevant threats would begin acting upon a 
species such that it is in danger of extinction now (endangered 
species) or likely to become so in the foreseeable future (threatened 
species).
    The foreseeable future refers to the extent to which we can 
reasonably rely on predictions about the future in making 
determinations about the future conservation status of the species 
(U.S. Department of the Interior, Solicitor's Memorandum, M-37021, 
January 16, 2009). We must look not only at the foreseeability of 
threats, but also at the foreseeability of the impact of the threats on 
the species (U.S. Department of the Interior's Solicitor's Memorandum, 
M-37021, January 16, 2009).
    In considering the foreseeable future as it relates to the status 
of the Kenk's amphipod, we considered the extent to which we could 
reliably predict the species' risk of extinction over time. Our ability 
to make reliable predictions into the future for the Kenk's amphipod is 
informed by the species' survey data; the potential effects to the 
species from ongoing and predicted stressors, as well as the 
uncertainty surrounding the species' response to those stressors; and 
ongoing and future conservation measures to address the known 
stressors. The future timeframe for this analysis is 30 years, which is 
a reasonably long time to consider as the foreseeable future given the 
Kenk's amphipod's life history and the temporal scale associated with 
the patterns of survey data and the past and current stressors outlined 
in the best available data. The timeframe for foreseeable future is 
based, in part, on projecting forward. A similar timeframe encompassed 
by the historical survey results shows decades in which the species was 
present, absent, and then present again at some seep sites. This 
timeframe also captures our best professional judgment of the projected 
potential range of future conditions related to the effects of climate 
change (i.e., the period in which the species' response to the 
potential effects of climate change are reliably predictable) and 
cumulative effects.
    Since the analysis of potential effects from climate change was an 
important consideration in our analysis, it was necessary to consider a 
long enough timeframe to adequately evaluate those potential effects. 
However, we did not extend our risk assessment forecasting used in the 
listing determination process out as far as the existing climate change 
models (e.g., models that forecast effects over 80 years) discussed in 
the proposed listing rule (81 FR 67270) due to (1) the increased 
uncertainty in the model results (i.e., the confidence intervals 
associated with temperature and precipitation projections); (2) the 
higher level of uncertainty of how the species may respond to any 
potential changes in its habitat that may result from changes in 
temperature and precipitation patterns; and (3) uncertainty associated 
with how society will respond to the predicted change in climate (e.g., 
take actions that will mediate or accelerate global emissions) that far 
into the future. As an example of biological uncertainty, there are 
significant questions regarding the extent to which the number of 
Kenk's amphipods observed at the seep surface accurately reflects the 
actual population at each site given the species' known

[[Page 45571]]

ability to move between the surface and subsurface habitat.
    These uncertainties are additive and undermine the Service's 
confidence in making a risk assessment projection beyond 30 years. 
Therefore, as further described below, a projection of the threats and 
the effects to the species of 30 years represents the timeframe over 
which the Service considers a reliable prediction to be possible.
    As we concluded above, the stressors likely to have the greatest 
influence on the Kenk's amphipod's viability over time include: Changes 
in habitat quality and quantity resulting from urbanization in the 
Washington metropolitan areas and the potential for the effects of 
small population dynamics and increased ground water temperatures due 
to climate change at all sites. Given the risk factors affecting the 
species currently and/or potentially in the future, we determined the 
following:
     The best available information indicates that the risk is 
low that changes in habitat quality resulting from changes in 
temperature will result in aggregate or species-level effects in the 
foreseeable future.
     There is significant uncertainty regarding the timeframe 
in which the predicted climate-induced changes to air temperature will 
manifest in ground water (i.e., whether those changes will occur within 
the foreseeable future).
     There is significant uncertainty regarding the extent to 
which the number of Kenk's amphipods observed at the seep surface 
accurately reflects the actual population at each site given the 
species' known ability to move between the surface and subsurface 
habitat. The best available data indicate that the risk of the dynamics 
of small population size affecting the species is low because even if 
the species may exist in low numbers at most or all of the 13 known 
sites, it is very unlikely that all of the sites would be exposed to 
catastrophic or stochastic events at the same time. Therefore, the 
species is not likely to be extirpated at most or all of the sites 
within the foreseeable future.
    Taking into account the effects of the most likely stressors and 
the potential for cumulative effects to the species, our projections 
for foreseeable future conditions are that the risk is low that the 
Kenk's amphipod will not continue to be distributed across multiple 
seep sites within the species' current range. These multiple areas will 
help the Kenk's amphipod withstand catastrophic events; meaning the 
risk is low that a significant weather or other event will cause 
extirpation of the species at most or all sites. Also, we project that 
the risk is low that the species will not continue to be present in 
multiple areas, especially in Virginia, in adequate abundance to 
withstand stochastic events. For example, the risk is low that a 
training or hunting event at Fort A.P. Hill causing damage to a seep 
site will cause extirpation of the species at that site.
    Based on our analysis of the species' redundancy, resiliency, and 
representation, and our consideration of the species' future stressors 
and conservation measures to address those stressors, we conclude that 
the Kenk's amphipod is likely to remain at a sufficiently low risk of 
extinction such that it is not likely to become in danger of extinction 
in the foreseeable future and thus does not meet the definition of a 
threatened species under the Act.

Determination of Status Throughout a Significant Portion of Its Range

    Consistent with our interpretation that there are two independent 
bases for listing species as described above, after examining the 
species' status throughout all of its range, we now examine whether it 
is necessary to determine its status throughout a significant portion 
of its range. We must give operational effect to both the ``throughout 
all'' of its range language and the SPR phrase in the definitions of 
``endangered species'' and ``threatened species.'' The Act, however, 
does not specify the relationship between the two bases for listing. As 
discussed above, to give operational effect to the ``throughout all'' 
language that is referenced first in the definition, consideration of 
the species' status throughout the entire range should receive primary 
focus and we should undertake that analysis first. In order to give 
operational effect to the SPR language, the Service should undertake an 
SPR analysis if the species is neither in danger of extinction nor 
likely to become so in the foreseeable future throughout all of its 
range, to determine if the species should nonetheless be listed because 
of its status in an SPR. Thus, we conclude that to give operational 
effect to both the ``throughout all'' language and the SPR phrase, the 
Service should conduct an SPR analysis if (and only if) a species does 
not warrant listing according to the ``throughout all'' language.
    Because we determined that the Kenk's amphipod is not in danger of 
extinction or likely to become so in the foreseeable future throughout 
all of its range, we will consider whether there are any significant 
portions of its range in which the Kenk's amphipod is in danger of 
extinction or likely to become so.
    Although there are potentially many ways to determine whether a 
portion of a species' range is ``significant,'' we conclude, as noted 
above, for the purposes of this rule, that the significance of the 
portion of the range should be determined based on its biological 
contribution to the conservation of the species. For this reason, we 
describe the threshold for ``significant'' in terms of an increase in 
the risk of extinction for the species. We conclude that such a 
biologically based definition of ``significant'' best conforms to the 
purposes of the Act, is consistent with judicial interpretations, and 
best ensures species' conservation.
    We evaluate biological significance based on the principles of 
conservation biology using the concepts of redundancy, resiliency, and 
representation because decreases in the redundancy, resiliency, and 
representation of a species lead to increases in the risk of extinction 
for the species. Redundancy (having multiple resilient populations 
considering genetic and environmental diversity) may be needed to 
provide a margin of safety for the species to withstand catastrophic 
events. Resiliency describes the characteristics of a species that 
allow it to recover from stochastic events or periodic disturbance. 
Representation (the range of variation found in a species) ensures that 
the species' ability to adapt to changing environments is conserved. 
Redundancy, resiliency, and representation are not independent of each 
other, and some characteristics of a species or area may contribute to 
all three. For example, distribution across a wide variety of habitats 
is an indicator of representation, but it may also indicate a broad 
geographic distribution contributing to redundancy (decreasing the 
chance that any one event affects the entire species), and the 
likelihood that some habitat types are less susceptible to certain 
threats, contributing to resiliency (the ability of the species to 
recover from disturbance). None of these concepts is intended to be 
mutually exclusive, and a portion of a species' range may be determined 
to be ``significant'' due to its contributions under any one of these 
concepts.
    For the purposes of this rule, we determine if a portion's 
biological contribution is so important that the portion qualifies as 
``significant'' by asking whether, without that portion, the 
representation, redundancy, or resiliency of the species would be so 
impaired that the species would be in danger of extinction or likely to 
become

[[Page 45572]]

so in the foreseeable future (i.e., would be an ``endangered species'' 
or a ``threatened species''). Conversely, we would not consider the 
portion of the range at issue to be ``significant'' if there is 
sufficient resiliency, redundancy, and representation elsewhere in the 
species' range that the species would not be in danger of extinction or 
likely to become so throughout its range even if the population in that 
portion of the range in question became extirpated (extinct locally).
    We recognize that this definition of ``significant'' establishes a 
threshold that is relatively high. Given that the outcome of finding a 
species to be in danger of extinction or likely to become so in an SPR 
would be to list the species and apply protections of the Act to all 
individuals of the species wherever found, it is important to use a 
threshold for ``significant'' that is robust. It would not be 
meaningful or appropriate to establish a very low threshold whereby a 
portion of the range can be considered ``significant'' even if only a 
negligible increase in extinction risk would result from its loss. 
Because nearly any portion of a species' range can be said to 
contribute some increment to a species' viability, use of such a low 
threshold would require us to impose restrictions and expend 
conservation resources disproportionately to conservation benefit: 
Listing would be rangewide, even if only a portion of the range with 
minor conservation importance to the species is imperiled. On the other 
hand, it would be inappropriate to establish a threshold for 
``significant'' that is too high. This would be the case if the 
standard were, for example, that a portion of the range can be 
considered ``significant'' only if threats in that portion result in 
the entire species' being currently in danger of extinction or likely 
to become so. Such a high bar would not give the SPR phrase independent 
meaning, as the Ninth Circuit held in Defenders of Wildlife v. Norton, 
258 F.3d 1136 (9th Cir. 2001).
    The definition of ``significant'' used in this rule carefully 
balances these concerns. By setting a relatively high threshold, we 
minimize the degree to which restrictions would be imposed or resources 
expended that do not contribute substantially to species conservation. 
But we have not set the threshold so high that the phrase ``throughout 
a significant portion of its range'' loses independent meaning. 
Specifically, we have not set the threshold as high as it was under the 
interpretation presented by the Service in the Defenders litigation. 
Under that interpretation, the portion of the range would have to be so 
important that the species' current level of imperilment in the portion 
results in the species currently being in danger of extinction or 
likely to become so throughout all of its range.
    Under the definition of ``significant'' used in this rule, the 
portion of the range need not rise to such an exceptionally high level 
of biological significance. (We recognize that, if the portion rises to 
the higher level of biological significance and the species is in 
danger of extinction or likely to become so in the foreseeable future 
in that portion, then the species would already be in danger of 
extinction or likely to become so in the foreseeable future throughout 
all of its range. We would accordingly list the species as threatened 
or endangered throughout all of its range by virtue of the species' 
rangewide status so we would not need to rely on the SPR language for 
such a listing.) Rather, under this interpretation we ask whether the 
species would be in danger of extinction or likely to become so 
everywhere without that portion, i.e., if the species were 
hypothetically completely extirpated from that portion. In other words, 
the portion of the range need not be so important that its current 
status in that portion of its range--being merely in danger of 
extinction, or likely to become so in the foreseeable future--is 
sufficient to cause the species to be in danger of extinction or likely 
to become so in the foreseeable future throughout all of its range. 
Instead, we evaluate whether the complete extirpation (in a 
hypothetical future) of the species in that portion would at that point 
cause the species throughout its remaining range to be in danger of 
extinction or likely to become so in the foreseeable future.
    We are aware that the court in Center for Biological Diversity v. 
Jewell found that this definition of ``significant'' does not give 
sufficient independent meaning to the SPR phrase. However, that 
decision was based on two misunderstandings about the interpretation of 
``significant.'' First, the court's decision was based on its finding 
that, as with the interpretation that the court rejected in Defenders, 
the definition of ``significant'' does not allow for an independent 
basis for listing. However, this definition of ``significant'' is not 
the same as the definition applied in Defenders, which looked at the 
current status within the portion and asked what the current effect on 
the entire range of the species is. By contrast, this definition of 
``significant'' looks at a future hypothetical loss of all members 
within the portion and asks what the effect on the remainder of the 
species would be; the current status of the species in that portion is 
relevant only for determining the listing status if the portion has 
been determined to be significant. This definition of ``significant'' 
establishes a lower threshold than requiring that the species' current 
status in that portion of its range is already causing the species to 
be in danger of extinction throughout all of its range or likely to 
become so in the foreseeable future. In other words, this definition of 
``significant'' captures circumstances that would not be captured by 
the definition used in Defenders, or by analyzing whether a species is 
in danger of extinction or likely to become so throughout all of its 
range: A species that is not currently likely to become an endangered 
species in the foreseeable future, but would be if a particular 
important portion of its range is completely lost, can nonetheless be 
listed now if the species in that portion is threatened or endangered 
(as opposed to only after the portion is in fact lost, as would be the 
case if the SPR language did not exist).
    The second misunderstanding was the court's characterization of the 
listing determination for the African coelacanth as an indication that 
the Service and National Marine Fisheries Service (NMFS) have had 
difficulty accurately applying this definition of ``significant.'' 
However, in that listing determination, the conclusion was that the 
species was not in danger of extinction throughout all of its range or 
likely to become so in the foreseeable future but it did warrant 
listing because of its status in a significant portion of its range. 
The only reason for not listing the entire species was that the 
population in that portion of the range met the definition of a DPS, 
and therefore the agency listed the DPS instead of the entire species. 
The population in an SPR is not automatically a DPS so, contrary to the 
court's reasoning, the definition of ``significant'' can be applied and 
result in listing a species that would not otherwise be listed. (We 
also note another instance, in addition to the one cited in this case, 
in which this definition has been effectively applied. In the proposed 
rule to list the giant manta ray as a threatened species (82 FR 3694; 
January 12, 2017), NMFS found that the giant manta ray was not 
currently in danger of extinction or likely to become so in the 
foreseeable future throughout all of its range because the Atlantic 
populations were not experiencing the same risks as the Pacific 
populations. However, they did find that the Pacific populations 
constituted an SPR, because, without that portion, the smaller and more

[[Page 45573]]

sparsely distributed populations in the Atlantic would become 
vulnerable to demographic risks and would be likely to become in danger 
of extinction in the foreseeable future. Accordingly, the giant manta 
ray is proposed to be listed as a threatened species.) In light of 
these flaws, we are currently seeking reconsideration of the district 
court's decision.
    To undertake this analysis, we first identify any portions of the 
species' range that warrant further consideration. The range of a 
species can theoretically be divided into portions in an infinite 
number of ways. To identify only those portions that warrant further 
consideration, we determine whether there is substantial information 
indicating that there are any portions of the species' range: (1) That 
may be ``significant,'' and (2) where the species may be in danger of 
extinction or likely to become so in the foreseeable future. We 
emphasize that answering these questions in the affirmative is not a 
determination that the species is in danger of extinction or likely to 
become so in the foreseeable future throughout a significant portion of 
its range--rather, it is a step in determining whether a more-detailed 
analysis of the issue is required.
    In practice, one key part of identifying portions for further 
analysis may be whether the threats or effects of threats are 
geographically concentrated in some way. If a species is not in danger 
of extinction or likely to become so in the foreseeable future 
throughout all of its range and the threats to the species are 
essentially uniform throughout its range, then the species is not 
likely to be in danger of extinction or likely to become so in the 
foreseeable future in any portion of its range. Moreover, if any 
concentration of threats applies only to portions of the species' range 
that are not ``significant,'' such portions will not warrant further 
consideration.
    If we identify any portions (1) that may be significant and (2) 
where the species may be in danger of extinction or likely to become so 
in the foreseeable future, we engage in a more-detailed analysis to 
determine whether these standards are indeed met. The identification of 
an SPR does not create a presumption, prejudgment, or other 
determination as to whether the species is in danger of extinction or 
likely to become so in the foreseeable future in that identified SPR. 
We must go through a separate analysis to determine whether the species 
is in danger of extinction or likely to become so in the SPR. To make 
that determination, we will use the same standards and methodology that 
we use to determine if a species is in danger of extinction or likely 
to become so in the foreseeable future throughout all of its range.
    Once we have identified portions of the species' range for further 
analysis, we conduct a detailed analysis of the significance of the 
portion and the status of the species in that portion. Depending on the 
biology of the species, its range, and the threats it faces, it might 
be more efficient for us to address the significance question first or 
the status question first. If we address significance first and 
determine that a portion of the range is not ``significant,'' we do not 
need to determine whether the species is in danger of extinction or 
likely to become so in the foreseeable future there; if we address the 
status of the species in portions of its range first and determine that 
the species is not in danger of extinction or likely to become so in a 
portion of its range, we do not need to determine if that portion is 
``significant.''

Kenk's Amphipod Determination of Significant Portion of Its Range

    Applying the process described above, to identify whether any 
portions warrant further consideration, we determine whether there is 
substantial information indicating that (1) particular portions may be 
significant and (2) the species may be in danger of extinction in those 
portions or likely to become so within the foreseeable future.
    To identify portions where the species may be in danger of 
extinction or likely to become so in the foreseeable future, we 
consider whether there is substantial information to indicate that any 
threats or effects of threats are geographically concentrated in any 
portion of the species' range.
    We evaluated the current range of the Kenk's amphipod to determine 
if there are any apparent geographic concentrations of potential 
threats to the species. The risk factors that occur throughout the 
Kenk's amphipod's range include the potential for the effects of small 
population dynamics and the potential for increased ground water 
temperature resulting from the effects of climate change. Habitat loss 
and degradation from poor water quality parameters associated with 
urban runoff, however, is occurring both currently and in the 
foreseeable future solely at the six Washington metropolitan area 
sites. Thus, this one area of the species' range is subject to a type 
of habitat loss and degradation that is not affecting the species 
uniformly throughout its range. We identify the Washington metropolitan 
area sites as a portion where the species may be in danger of 
extinction or likely to become so in the foreseeable future. We next 
consider whether this portion may be significant. We can accomplish 
this by considering the biological or conservation importance of the 
portion.
    While the six Washington metropolitan area sites represent 46 
percent of the Kenk's amphipod's known populations and represent a 
diversity of sites because they occur on one of the two known 
geological formations, the risk is low that, should the species become 
extirpated in all of those locations, that loss would be sufficient to 
cause the remainder of the species to be in danger of extinction or 
likely to become so within the foreseeable future, given the Kenk's 
amphipod would still be present in 54 percent of its range (e.g., the 
seven Virginia sites). The Virginia sites are protected against the 
effects of poor water quality parameters.
    We have identified the Washington metropolitan area sites as a 
portion where the species may be in danger of extinction or likely to 
become so in the foreseeable future. However, there is not substantial 
information to indicate that this portion is significant. Therefore, 
this portion does not warrant further consideration to determine 
whether the species may be in danger of extinction or likely to become 
so in the foreseeable future in a significant portion of its range.
    To identify portions that may be significant, we consider whether 
there is substantial information to indicate that there are any natural 
divisions within the range or other areas that might be of biological 
or conservation importance. We identified the Virginia sites (spring 
seeps on Fort A.P. Hill and the Voorhees Nature Preserve) as a portion 
that may be significant. These sites are separated from the Washington 
metropolitan area sites by 60 mi (97 km). The spring sites in these 
areas occur in the Calvert geologic formation, whereas the Washington 
metropolitan area sites occur in the Wissahickon geologic formation. 
Given the separation between the Washington metropolitan sites and the 
Virginia sites and the inability of the Kenk's amphipod to travel long 
distances, we conclude that there is no genetic exchange between these 
two areas. Therefore, we find that there is substantial information 
that there are natural divisions between the Virginia and Washington 
metropolitan sites and that the Virginia site may be significant. We 
did not find substantial evidence that the Washington metropolitan 
sites are a significant portion because, without that portion, there is 
no reasonable likelihood that the remainder of the species (i.e., those 
at the Virginia

[[Page 45574]]

sites) would be in danger of extinction or likely to become so in the 
foreseeable future, due to the paucity of threats affecting the 
Virginia sites.
    We have identified the Virginia sites as a portion that may be 
significant. We next consider whether the species may be in danger of 
extinction or likely to become so in the foreseeable future in this 
portion. We can accomplish this task by considering whether there is 
substantial information indicating that there are any threats to or 
effects of threats on the species that are concentrated in that 
portion. The Virginia sites are not affected by the same threats we 
identified for the Washington metropolitan area sites (e.g., water 
quality impacts and habitat degradation), because the Virginia sites 
occur in areas where land use is primarily agriculture and forest with 
little impervious surface and spring sites are surrounded by large 
forest buffers that would filter out any potential effects of runoff 
from the agricultural areas. We do not find there is substantial 
information indicating there is a concentration of threats in the 
Virginia portion.
    We have identified that the Virginia portion may be significant. 
However, there is not substantial information to indicate that the 
species may be in danger of extinction or likely to become so in the 
foreseeable future in this portion. Therefore, this portion does not 
warrant further consideration to determine whether the species may be 
in danger of extinction or likely to become so in the foreseeable 
future in a significant portion of its range.
    Our review of the best available scientific and commercial 
information indicates that the Kenk's amphipod is not in danger of 
extinction (endangered) or likely to become endangered within the 
foreseeable future (threatened) throughout all or a significant portion 
of its range. Therefore, we find that listing the Kenk's amphipod as an 
endangered or threatened species under the Act is not warranted at this 
time.
    We request that you submit any new information concerning the 
status of, or threats to, the Kenk's amphipod to our Chesapeake Bay 
Field Office (see ADDRESSES) whenever it becomes available. New 
information will help us monitor the Kenk's amphipod and encourage its 
conservation. If an emergency situation develops for the Kenk's 
amphipod, we will act to provide immediate protection.

References Cited

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

Authors

    The primary authors of this proposed rule are the staff members of 
the Chesapeake Bay Field Office and the Northeast Regional Office.

    Dated: September 7, 2017.
James W. Kurth,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2017-21052 Filed 9-28-17; 8:45 am]
 BILLING CODE 4333-15-P