Federal Register, Volume 78 Issue 161 (Tuesday, August 20, 2013) 2013 Federal Register, 78 FR x; Centralized Library: U.S. Fish and Wildlife Service -

[Federal Register Volume 78, Number 161 (Tuesday, August 20, 2013)]
[Rules and Regulations]
[Pages 51277-51326]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-19715]

[[Page 51277]]

Vol. 78

Tuesday,

No. 161

August 20, 2013

Part II

Department of the Interior

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Fish and Wildlife Service

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50 CFR Part 17

Endangered and Threatened Wildlife and Plants; Determination of
Endangered Species Status for the Austin Blind Salamander and
Threatened Species Status for the Jollyville Plateau Salamander
Throughout Their Ranges; Final Rule

Federal Register / Vol. 78, No. 161 / Tuesday, August 20, 2013 /
Rules and Regulations

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2012-0035; 4500030113]
RIN 1018-AY22

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine
endangered species status for the Austin blind salamander (Eurycea
waterlooensis) and threatened species status for Jollyville Plateau
salamander (Eurycea tonkawae) under the Endangered Species Act of 1973
(Act), as amended. The effect of this regulation is to conserve these
salamander species and their habitats under the Act. This final rule
implements the Federal protections provided by the Act for these
species.

DATES: This rule becomes effective September 19, 2013.

ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and http://www.fws.gov/southwest/es/AustinTexas/.
Comments and materials received, as well as supporting documentation
used in preparing this final rule is available for public inspection,
by appointment, during normal business hours, at U.S. Fish and Wildlife
Service, Austin Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT: Adam Zerrenner, Field Supervisor, U.S.
Fish and Wildlife Service, Austin Ecological Services Field Office,
10711 Burnet Rd., Suite 200, Austin, TX 78758; by telephone 512-490-
0057; or by facsimile 512-490-0974. Persons who use a
telecommunications device for the deaf (TDD) may call the Federal
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule. Under the Act, a species may warrant
protection through listing if it is endangered or threatened throughout
all or a significant portion of its range. Listing a species as an
endangered or threatened species can only be completed by issuing a
rule.
This rule lists the Austin blind salamander as an endangered
species and the Jollyville Plateau salamander as a threatened species
under the Act.
The basis for our action. Under 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 Austin blind
salamander is an endangered species and the Jollyville Plateau
salamander is a threatened species under the Act due to threats faced
by the species both now and in the foreseeable future from Factors A,
D, and E.
Peer review and public comment. We sought comments from independent
specialists to ensure that our designation is based on scientifically
sound data, assumptions, and analyses. We invited these peer reviewers
to comment on our listing proposal. We also considered all comments and
information received during the comment period.

Background

Previous Federal Action

The Austin blind salamander was included in nine Candidate Notices
of Review (67 FR 40657, June 13, 2002; 69 FR 24876, May 4, 2004; 70 FR
24870, May 11, 2005; 71 FR 53756, September 12, 2006; 72 FR 69034,
December 6, 2007; 73 FR 75176, December 10, 2008; 74 FR 57804, November
9, 2009; 75 FR 69222, November 10, 2010; 76 FR 66370, October 26,
2011). The listing priority number has remained at 2 throughout the
reviews, indicating that threats to the species were both imminent and
high in impact. In addition, on May 11, 2004, the Service received a
petition from the Center for Biological Diversity to list 225 species
we previously had identified as candidates for listing in accordance
with section 4 of the Act, including the Austin blind salamander.
The Jollyville Plateau salamander was petitioned to be listed as an
endangered species on June 13, 2005, by Save Our Springs Alliance.
Action on this petition was precluded by court orders and settlement
agreements for other listing actions until 2006. On February 13, 2007,
we published a 90-day petition finding (72 FR 6699) in which we
concluded that the petition presented substantial information
indicating that listing may be warranted. On December 13, 2007, we
published the 12-month finding (72 FR 71040) on the Jollyville Plateau
salamander, which concluded that listing was warranted, but precluded
by higher priority actions. The Jollyville Plateau salamander was
subsequently included in all of our annual Candidate Notices of Review
(73 FR 75176, December 10, 2008; 74 FR 57804, November 9, 2009; 75 FR
69222, November 10, 2010; 76 FR 66370, October 26, 2011). Throughout
the four reviews, the listing priority number has remained at 8,
indicating that threats to the species were imminent, but moderate to
low in impact. On September 30, 2010, the Jollyville Plateau salamander
was petitioned to be emergency listed by Save Our Springs Alliance and
Center for Biological Diversity. We issued a petition response letter
to Save Our Springs Alliance and Center for Biological Diversity on
December 1, 2011, which stated that emergency listing a species is not
a petitionable action under the Administrative Procedure Act or the
Act; therefore, we treat a petition requesting emergency listing solely
as a petition to list a species under the Act.
On August 22, 2012, we published a proposed rule to list as
endangered and designate critical habitat for the Austin blind
salamander, Georgetown salamander (Eurycea naufragia), Jollyville
Plateau salamander, and Salado salamander (Eurycea chisholmensis) (77
FR 50768). That proposal had a 60-day comment period, ending October
22, 2012. We held a public meeting and hearing in Round Rock, Texas, on
September 5, 2012, and a second public meeting and hearing in Austin,
Texas, on September 6, 2012. On January 25, 2013, we reopened the
public comment period on the August 22, 2012, proposed listing and
critical habitat designation; announced the availability of a draft
economic analysis; and an amended required determinations section of
the proposal (78 FR 9876).
Section 4(b)(6) of the Act and its implementing regulation, 50 CFR
424.17(a), requires that we take one of three actions within 1 year of
a proposed listing: (1) Finalize the proposed listing; (2) withdraw the
proposed listing; or (3) extend the final determination by not more
than 6 months, if scientists knowledgeable about the species
substantial disagreement regarding the sufficiency

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or accuracy of the available data relevant to the determination, for
the purposes of soliciting additional data.
The public comments we have received indicate substantial
disagreement regarding the sufficiency or accuracy of the available
data that is relevant to our determination of the proposed listing of
the Georgetown and Salado salamanders. Therefore, in consideration of
these disagreements, we are publishing a 6-month extension of final
determination for the Georgetown and Salado salamanders elsewhere in
today's Federal Register. With this 6-month extension, we will make a
final determination on the proposed rule for the Georgetown and Salado
salamanders no later than February 22, 2014.
On the other hand, more research has been conducted, and,
therefore, more is known about the life history, population trends, and
threats to the Austin blind and Jollyville Plateau salamanders.
Although there may be some disagreement among scientists knowledgeable
about the Austin blind and Jollyville Plateau salamanders, the
disagreement is not substantial enough to extend the final
determination for these species. Therefore, this rule constitutes our
final determination to list the Austin blind and Jollyville Plateau
salamanders as an endangered and threatened species, respectively.

Species Information

Taxonomy
The Austin blind and Jollyville Plateau salamanders are neotenic
(do not transform into a terrestrial form) members of the family
Plethodontidae. Plethodontid salamanders comprise the largest family of
salamanders within the Order Caudata, and are characterized by an
absence of lungs (Petranka 1998, pp. 157-158). The Jollyville Plateau
salamander has very similar external morphology. Because of this, the
Jollyville Plateau salamander was previously believed to be the same
species as the Georgetown and Salado salamanders; however, molecular
evidence strongly supports that there is a high level of divergence
between the three groups (Chippindale et al. 2000, pp. 15-16). Based on
our review of these differences, and taking into account the view
expressed in peer reviews by taxonomists, we believe that the currently
available evidence is sufficient for recognizing these salamanders as
separate species.
Morphological Characteristics
As neotenic salamanders, they retain external feathery gills and
inhabit aquatic habitats (springs, spring-runs, wet caves, and
groundwater) throughout their lives (Chippindale et al. 2000, p. 1). In
other words, the Austin blind and Jollyville Plateau salamanders are
aquatic and respire through gills and permeable skin (Duellman and
Trueb 1986, p. 217). Also, adult salamanders of these species are about
2 inches (in) (5 centimeters (cm)) long (Chippindale et al. 2000, pp.
32-42; Hillis et al. 2001, p. 268).
Habitat
Each species inhabits water of high quality with a narrow range of
conditions (for example, temperature, pH, and alkalinity) maintained by
groundwater from various sources. Both the Austin blind and Jollyville
Plateau salamanders depend on water in sufficient quantity and quality
to meet their life-history requirements for survival, growth, and
reproduction. Much of this water is sourced from the Edwards Aquifer,
which is a karst aquifer characterized by open chambers such as caves,
fractures, and other cavities that were formed either directly or
indirectly by dissolution of subsurface rock formations. Water for the
salamanders is provided by infiltration of surface water through the
soil or recharge features (caves, faults, fractures, sinkholes, or
other open cavities) into the Edwards Aquifer, which discharges from
springs as groundwater (Schram 1995, p. 91). In addition, some
Jollyville Plateau salamander populations rely on water from other
sources. For instance, springs, such as Rieblin Spring, may discharge
from the Walnut formation, and some, such as Pit Spring, may discharge
from the Glen Rose formation (part of the Trinity Aquifer) (Johns 2012,
COA, pers. comm.; Johnson et al. 2012, pp. 1, 3, 46-53, 82). Other
springs, such as Lanier Spring, appear to have alluvial aquifer sources
(derived from water-bearing soil or sediments usually adjacent to
streams) (Johns 2012, pers. comm.).
The Austin blind and Jollyville Plateau salamanders spend varying
portions of their life within their surface habitats (the wetted top
layer of substrate in or near spring openings and pools as well as
spring runs) and subsurface habitats (within caves or other underground
areas of the underlying groundwater source). Although surface and
subsurface habitats are often discussed separately within this final
rule, it is important to note the interconnectedness of these areas.
Subsurface habitat does not necessarily refer to an expansive cave
underground. Rather, it may be described as the rock matrix below the
stream bed. As such, subsurface habitats are impacted by the same
threats that impact surface habitat, as the two exist as a continuum
(Bendik 2012, COA, pers. comm.).
Salamanders move an unknown depth into interstitial spaces (empty
voids between rocks) within the spring or streambed substrate that
provide foraging habitat and protection from predators and drought
conditions (Cole 1995, p. 24; Pierce and Wall 2011, pp. 16-17). They
may also use deeper passages of the aquifer that connect to the spring
opening (Dries 2011, COA, pers. comm.). This behavior makes it
difficult to accurately estimate population sizes, as only salamanders
on the surface can be regularly monitored. However, techniques have
been developed for marking individual salamanders, which allows for
better estimating population numbers using ``mark and recapture'' data
analysis techniques. These techniques have been used by the City of
Austin (COA) on the Jollyville Plateau salamander (Bendik et al. 2013,
pp. 2-7).
Range
The habitat of the Austin blind salamander occurs in the Barton
Springs Segment of the Edwards Aquifer, while the habitats of the three
other species occur in the Northern Segment of the Edwards Aquifer
(although some reside in spring locations with different groundwater
sources, as explained above). The recharge and contributing zones of
these segments of the Edwards Aquifer are found in portions of Travis,
Williamson, Blanco, Bell, Burnet, Lampasas, Mills, Hays, Coryell, and
Hamilton Counties, Texas (Jones 2003, p. 3; Mahler et al. 2006).
Diet
A stomach content analysis by the COA demonstrated that the
Jollyville Plateau salamander preys on varying proportions of aquatic
invertebrates, such as ostracods, copepods, mayfly larvae, fly larvae,
snails, water mites, aquatic beetles, and stone fly larvae, depending
on the location of the site (Bendik 2011b, pers. comm.). The feces of
one wild-caught Austin blind salamander contained amphipods, ostracods,
copepods, and plant material (Hillis et al. 2001, p. 273). Gillespie
(2013, pp. 5-9) also found that the diet of the closely related Barton
Springs salamanders consisted primarily of planarians or chironomids
(flatworms or nonbiting midge flies) depending on which was more
abundant and amphipods when planarians and chironomids were rare.

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Predation
The Austin blind and Jollyville Plateau salamanders also share
similar predators, which include centrarchid fish (carnivorous
freshwater fish belonging to the sunfish family), crayfish (Cambarus
sp.), and large aquatic insects (Pierce and Wall 2011, pp. 18-20;
Bowles et al. 2006, p. 117; Cole 1995, p. 26).
Reproduction
The detection of juveniles in all seasons suggests that
reproduction occur year-round (Bendik 2011a, p. 26; Hillis et al. 2001,
p. 273). However, juvenile abundance of Jollyville Plateau salamanders
typically increases in spring and summer, indicating that there may be
relatively more reproduction occurring in winter and early spring
compared to other seasons (Bowles et al. 2006, p. 116; Pierce 2012, pp.
10-11, 18, 20). Because eggs are very rarely found on the surface,
these salamanders likely deposit their eggs underground for protection
(O'Donnell et al. 2005, p. 18).
Population Connectivity
More study is needed to determine the nature and extent of the
dispersal capabilities of the Austin blind and Jollyville Plateau
salamanders. It has been suggested that they may be able to travel some
distance through subsurface aquifer conduits. For example, it has been
thought that Austin blind salamander can occur underground throughout
the entire Barton Springs complex (Dries 2011, COA, pers. comm.). The
spring habitats used by salamanders of the Barton Springs complex are
not connected on the surface, so the Austin blind salamander population
could extend a horizontal distance of at least 984 feet (ft) (300
meters (m)) underground, as this is the approximate distance between
the farthest two outlets within the Barton Springs complex known to be
occupied by the species. However, a mark-and-recapture study failed to
document the movement of endangered Barton Springs salamanders (Eurycea
sosorum) between any of the springs in the Barton Springs complex
(Dries 2012, COA, pers. comm.). This could indicate that individual
salamanders are not moving the distances between spring openings.
Alternatively, this could mean that the study simply failed to capture
the movement of salamanders. This study has only recently begun and is
relatively small in scope.
Due to the similar life history of the Austin blind salamander to
the other three Eurycea species considered here, it is plausible that
populations of these species could also extend 984 ft (300 m) through
subterranean habitat. However, subsurface movement is likely to be
limited by the highly dissected nature of the aquifer system, where
spring sites can be separated from other spring sites by large canyons
or other physical barriers to movement. Surface movement is similarly
inhibited by geologic, hydrologic, physical, and biological barriers
(for example, predatory fish commonly found in impoundments along
urbanized tributaries (Bendik 2012, COA, pers. comm.). Dye-trace
studies have demonstrated that some Jollyville Plateau salamander sites
located miles apart are connected hydrologically (Whitewater Cave and
Hideaway Cave) (Hauwert and Warton 1997, pp. 12-13), but it remains
unclear if salamanders are travelling between those sites. In
conclusion, some data indicate that populations could be connected
through subterranean water-filled spaces, although we are unaware of
any information available on the frequency of movements and the actual
nature of connectivity among populations.
Population Persistence
A population's persistence (ability to survive and avoid
extirpation) is influenced by a population's demographic factors (such
as survival and reproductive rates) as well as its environment. The
population needs of the central Texas salamander species are the
factors that provide for a high probability of population persistence
over the long term at a given site (for example, low degree of threats
and high survival and reproduction rates). We are unaware of detailed
studies that describe all of the demographic factors that could affect
the population persistence of the Austin blind and Jollyville Plateau
salamanders; however, we have assessed their probability of persistence
by evaluating environmental factors (threats to their surface habitats)
and what we know about the number of salamanders that occur at each
site.
To estimate the probability of persistence of each population
involves considering the predictable responses of the population to
various environmental factors (such as the amount of food available or
the presence of a toxic substance), as well as the stochasticity.
Stochasticity refers to the random, chance, or probabilistic nature of
the demographic and environmental processes (Van Dyke 2008, pp. 217-
218). Generally, the larger the population, the more likely it is to
survive stochastic events in both demographic and environmental factors
(Van Dyke 2008, p. 217). Conversely, the smaller the population, the
higher are its chances of extirpation when experiencing this
demographic and environmental stochasticity.
Rangewide Needs
We used the conservation principles of redundancy, representation,
and resiliency (Shaffer and Stein 2000, pp. 307, 309-310) to better
inform our view of what contributes to these species' probability of
persistence and how best to conserve them. ``Resiliency'' is the
ability of a species to persist through severe hardships or stochastic
events (Tear et al. 2005, p. 841). ``Redundancy'' means a sufficient
number of populations to provide a margin of safety to reduce the risk
of losing a species or certain representation (variation) within a
species, particularly from catastrophic or other events.
``Representation'' means conserving ``some of everything'' with regard
to genetic and ecological diversity to allow for future adaptation and
maintenance of evolutionary potential. Representation can be measured
through the breadth of genetic diversity within and among populations
and ecological diversity (also called environmental variation or
diversity) occupied by populations across the species' range.
A variety of factors contribute to a species' resiliency. These can
include how sensitive the species is to disturbances or stressors in
its environment, how often they reproduce and how many young they have,
how specific or narrow their habitat needs are. A species' resiliency
can also be affected by the resiliency of individual populations and
the number of populations and their distribution across the landscape.
Protecting multiple populations and variation of a species across its
range may contribute to its resiliency, especially if some populations
or habitats are more susceptible or better adapted to certain threats
than others (Service and NOAA 2011, p. 76994). The ability of
individuals from populations to disperse and recolonize an area that
has been extirpated may also influence their resiliency. As population
size and habitat quality increase, the population's ability to persist
through periodic hardships also increases.
A minimal level of redundancy is essential for long-term viability
(Shaffer and Stein 2000, pp. 307, 309-310; Groves et al. 2002, p. 506).
This provides a margin of safety for a species to withstand
catastrophic events (Service and NOAA 2011, p. 76994) by

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decreasing the chance of any one event affecting the entire species.
Representation and the adaptive capabilities (Service and NOAA
2011, p. 76994) of each of the central Texas salamander species should
also be conserved. Because a species' genetic makeup is shaped through
natural selection by the environments it has experienced (Shaffer and
Stein 2000, p. 308), populations should be protected in the array of
different environments in which the salamanders occur (surface and
subsurface) as a strategy to ensure genetic representation, adaptive
capability, and conservation of the species.
To increase the probability of persistence of each species,
populations of the Austin blind and Jollyville Plateau salamanders
should be conserved in a manner that ensures their variation and
representation. This result can be achieved by conserving salamander
populations in a diversity of environments (throughout their ranges),
including: (1) Both spring and cave locations, (2) habitats with
groundwater sources from various aquifers and geologic formations,
including the Edwards and Trinity Aquifers and the Edwards, Walnut, and
Glen Rose formations, and (3) at sites with different hydrogeological
characteristics, including sites where water flows come from artesian
pressure, a perched aquifer, or resurgence through alluvial deposits
(for example, artesian springs, Edwards and Edwards/Walnut headwater
springs, and Bull Creek alluvial resurgence areas).
Information for Austin blind and Jollyville Plateau salamanders is
discussed separately for each species in more detail below.
Austin Blind Salamander
The Austin blind salamander has a pronounced extension of the
snout, no external eyes, and weakly developed tail fins. In general
appearance and coloration, the Austin blind salamander is more similar
to the Texas blind salamander (Eurycea rathbuni) that occurs in the
Southern Segment of the Edwards Aquifer than its sympatric (occurring
within the same range) species, the Barton Springs salamander. The
Austin blind salamander has a reflective, lightly pigmented skin with a
pearly white or lavender appearance (Hillis et al. 2001, p. 271).
Before the Austin blind salamander was formally described, juvenile
salamanders were sighted occasionally in Barton Springs, and thought to
be a variation of the Barton Springs salamander. It was not until 2001
that enough specimens were available to formally describe these
juveniles as a separate species using morphological and genetic
characteristics (Hillis et al. 2001, p. 267). Given the reduced eye
structure of the Austin blind salamander, and the fact that it is
rarely seen at the water's surface (Hillis et al. 2001, p. 267), this
salamander is thought to be more subterranean than the primarily
surface-dwelling Barton Springs salamander.
The Austin blind salamander occurs in Barton Springs in Austin,
Texas. These springs are fed by the Barton Springs Segment of the
Edwards Aquifer. This segment covers roughly 155 square miles (mi) (401
square kilometers (km)) from southern Travis County to northern Hays
County, Texas (Smith and Hunt 2004, p. 7). It has a storage capacity of
more than 300,000 acre-feet of water. The contributing zone for the
Barton Springs Segment of the Edwards Aquifer that supplies water to
the salamander's spring habitat extends into Travis, Blanco, and Hays
Counties, Texas (Ross 2011, p. 3). Under drought conditions, Barton
Springs (particularly Sunken Garden/Old Mill Springs) also receives
some recharge from the Blanco River (Johnson et al. 2012, p. 82), whose
waters originate from the Trinity Aquifer.
The Austin blind salamander is found in three of the four Barton
Springs outlets in the COA's Zilker Park, Travis County, Texas:
Parthenia (Main) Springs, Eliza Springs, and Sunken Garden (Old Mill or
Zenobia) Springs where the Barton Springs salamander also occurs (Dries
2012, p. 4). Parthenia Springs provides water for the Barton Springs
Pool, which is operated by the COA as a public swimming pool. These
spring sites have been significantly modified for human use. The area
around Parthenia Springs was impounded in the late 1920s to create
Barton Springs Pool. Flows from Eliza and Sunken Garden Springs are
also retained by concrete structures, forming small pools on either
side of Barton Springs Pool (COA 1998, p. 6; Service 2005, pp. 1.6-25).
The Austin blind salamander has not been observed at the fourth Barton
Springs outlet, known as Upper Barton Springs (Hillis et al. 2001, p.
273; Dries 2012, p. 4). Upper Barton Springs flow only intermittently
(and can cease flowing for weeks or months at a time) (Dries 2012, p.
4). We are unaware of any information that suggests Main, Eliza, or
Sunken Garden Springs have ever stopped flowing.
From January 1998 to December 2000, there were only 17 documented
observations of the Austin blind salamander. During this same
timeframe, 1,518 Barton Springs salamander observations were made
(Hillis et al. 2001, p. 273). The abundance of Austin blind salamanders
increased slightly from 2002 to 2006, but fewer observations have been
made in more recent years (2009 to 2010) (COA 2011a, pp. 51-52). In
fact, during an 11-month period of drought conditions from 2008 to
2009, neither the Austin blind salamander nor the Barton Springs
salamander was seen at all (Dries 2012, p. 17), despite almost monthly
survey attempts (Dries 2012, p. 7). When they are observed, Austin
blind salamanders occur in relatively low numbers (COA 2011a, pp. 51-
52; Dries 2012, p. 4) within the surface habitat. Although the
technology to mark salamanders for individual recognition has recently
been developed (Bendik et al. 2013, p. 7), population estimates for
this species have not been undertaken. However, population estimates
are possible for aquifer-dwelling species using genetic techniques, and
one such study is planned for the Austin blind salamander in the near
future (Texas Parks and Wildlife Department (TPWD) 2011, p. 11).
Jollyville Plateau Salamander
Surface-dwelling populations of Jollyville Plateau salamanders have
large, well-developed eyes; wide, yellowish heads; blunt, rounded
snouts; dark greenish-brown bodies; and bright yellowish-orange tails
(Chippindale et al. 2000, pp. 33-34). Some cave forms of Jollyville
Plateau salamanders, which are also entirely aquatic, exhibit cave-
associated morphologies, such as eye reduction, flattening of the head,
and dullness or loss of color (Chippindale et al. 2000, p. 37). Genetic
analysis suggests a taxonomic split within this species that appears to
correspond to major geologic and topographic features of the region
(Chippindale 2010, p. 2). Chippindale (2010, pp. 5, 8) concluded that
the Jollyville Plateau salamander exhibits a strong genetic separation
between two lineages within the species: A ``Plateau'' clade that
occurs in the Bull Creek, Walnut Creek, Shoal Creek, Brushy Creek,
South Brushy Creek, and southeastern Lake Travis drainages; and a
``peripheral'' clade that occurs in the Buttercup Creek and northern
Lake Travis drainages (Chippindale 2010, pp. 5-8). The study also
suggests this genetic separation may actually represent two species
(Chippindale 2010, pp. 5, 8). However, a formal, peer-reviewed
description of the two possible species has not been published. Because
this split has not been recognized by the scientific community, we do
not recognize a

[[Page 51282]]

separation of the Jollyville Plateau salamander into two species.
The Jollyville Plateau salamander occurs in the Jollyville Plateau
and Brushy Creek areas of the Edwards Plateau in northern Travis and
southern Williamson Counties, Texas (Chippindale et al. 2000, pp. 35-
36; Bowles et al. 2006, p. 112; Sweet 1982, p. 433). Upon
classification as a species, Jollyville Plateau salamanders were known
from Brushy Creek and, within the Jollyville Plateau, from Bull Creek,
Cypress Creek, Long Hollow Creek, Shoal Creek, and Walnut Creek
drainages (Chippindale et al. 2000, p. 36). Since it was described, the
Jollyville Plateau salamander has also been documented within the Lake
Creek drainage (O'Donnell et al. 2006, p. 1). Jollyville Plateau
salamanders are known from 1 cave in the Cypress Creek drainage and 15
caves in the Buttercup Creek cave system in the Brushy Creek drainage
(Chippindale et al. 2000, p. 49; Russell 1993, p. 21; Service 1999, p.
6; HNTB 2005, p. 60). There are 106 known surface sites for the
Jollyville Plateau salamander.
The Jollyville Plateau salamander's spring-fed habitat is typically
characterized by a depth of less than 1 ft (0.3 m) of cool, well
oxygenated water (COA 2001, p. 128; Bowles et al. 2006, p. 118)
supplied by the underlying Northern Segment of the Edwards Aquifer
(Cole 1995, p. 33), the Trinity Aquifer (Johns 2012, COA, pers. comm.),
or local alluvial sources (Johns 2012, COA, pers. comm.). The main
aquifer that feeds this salamander's habitat is generally small,
shallow, and localized (Chippindale et al. 2000; p. 36; Cole 1995, p.
26). Jollyville Plateau salamanders are typically found near springs or
seep outflows and likely require constant temperatures (Sweet 1982, pp.
433-434; Bowles et al. 2006, p. 117). Salamander densities are higher
in pools and riffles and in areas with rubble, cobble, or boulder
substrates rather than on solid bedrock (COA 2001, p. 128; Bowles et
al. 2006, pp. 114-116). Surface-dwelling Jollyville Plateau salamanders
also occur in subsurface habitat within the underground aquifer (COA
2001, p. 65; Bowles et al. 2006, p. 118).
Some Jollyville Plateau salamander populations have likely
experienced decreases in abundance in recent years. Survey data
collected by COA staff indicate that four of the nine sites that were
regularly monitored by the COA between December 1996 and January 2007
had statistically significant declines in salamander abundance over 10
years (O'Donnell et al. 2006, p. 4). The average number of salamanders
counted at each of these 4 sites declined from 27 salamanders counted
during surveys from 1996 to 1999 to 4 salamanders counted during
surveys from 2004 to 2007. In 2007, monthly mark-recapture surveys were
conducted in concert with surface counts at three sites in the Bull
Creek watershed (Lanier Spring, Lower Rieblin, and Wheless Spring) over
a 6- to 8-month period to obtain surface population size estimates and
detection probabilities for each site (O'Donnell et al. 2008, p. 11).
Using these estimation techniques, surface population estimates at
Lanier Spring varied from 94 to 249, surface population estimates at
the Lower Rieblin site varied from 78 to 126, and surface population
estimates at Wheless Spring varied from 187 to 1,024 (O'Donnell et al.
2008, pp. 44-45). These numbers remained fairly consistent in more
recent population estimates for the three sites (Bendik 2011a, p. 22).
However, Bendik (2011a, pp. 5, 12-24, 26, 27) reported statistically
significant declines in Jollyville Plateau salamander counts over a 13-
year period (1996-2010) at six monitored sites with high impervious
cover (18 to 46 percent) compared to two sites with lower (less than 1
percent) impervious cover. These results are consistent with Bowles et
al. (2006, p. 111), who found lower densities of Jollyville Plateau
salamanders at urbanized sites. Based on the best available
information, these counts likely reflect changes in the salamander
populations at these sites.

Summary of Comments and Recommendations

We requested comments from the public on the proposed designation
of critical habitat for the Austin blind salamander and Jollyville
Plateau salamanders during two comment periods. The first comment
period associated with the publication of the proposed rule (77 FR
50768) opened on August 22, 2012, and closed on October 22, 2012,
during which we held public meetings and hearings on September 5 and 6,
2012, in Round Rock and Austin, Texas, respectively. We reopened the
comment period on the proposed listing rule from January 25, 2013, to
March 11, 2013 (78 FR 5385). We also contacted appropriate Federal,
State, and local agencies; scientific organizations; and other
interested parties and invited them to comment on the proposed rule and
draft economic analysis during these comment periods.
We received a total of approximately 416 comments during the open
comment period for the proposed listing, proposed critical habitat, and
associated documents. All substantive information provided during the
comment periods has been incorporated directly into the final listing
rule for the Austin blind and Jollyville Plateau salamanders and is
addressed below. Comments from peer reviewers and State agencies are
grouped separately below. Comments received are grouped into general
issues specifically relating to the proposed listing for each
salamander species. Beyond the comments addressed below, several
commenters submitted additional reports and references for our
consideration, which were reviewed and incorporated into this critical
habitat final rule as appropriate.

Peer Review

In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinions from 22 knowledgeable
individuals with scientific expertise with the hydrology, taxonomy, and
ecology that is important to these salamander species. The focus of the
taxonomists was to review the proposed rule in light of an unpublished
report by Forstner (2012) that questioned the taxonomic validity of the
Austin blind, Georgetown, Jollyville Plateau, and Salado salamanders as
separate species. We received responses from 13 of the peer reviewers.
During the first comment period we received public comments from
SWCA Environmental Consultants (SWCA) and COA that contradicted each
other. We also developed new information relative to the listing
determination. For these reasons, we conducted a second peer review on:
(1) Salamander demographics and (2) urban development and stream
habitat. The peer reviewers were provided with the contradictory
comments from SWCA and COA. During this second peer review, we
solicited expert opinions from knowledgeable individuals with expertise
in the two areas identified above, which included all of the peer
reviewers from the first comment period except the taxonomists. We
received responses from eight peer reviewers. The peer reviewers
generally concurred with our methods and conclusions and provided
additional information, clarifications, and suggestions to improve the
final listing and critical habitat rule. Peer reviewer comments are
addressed in the following summary and incorporated into the final rule
as appropriate.

[[Page 51283]]

Peer Reviewer Comments

Taxonomy
(1) Comment: Most peer reviewers stated that the best available
scientific information was used to develop the proposed rule and the
Service's analysis of the available information was scientifically
sound. Further, most reviewers stated that our assessment that the
Austin blind, Georgetown, Jollyville Plateau, and Salado salamanders
are four distinct species and our interpretation of literature
addressing threats (including reduced habitat quality due to
urbanization and increased impervious cover) to these species were well
researched. However, some researchers suggested that further research
would strengthen or refine our understanding of these salamanders. For
example, one reviewer stated that the Jollyville Plateau salamander was
supported by ``weak but suggestive evidence,'' and, therefore, it
needed more study. Another reviewer thought there was evidence of
missing descendants in the group that included the Jollyville Plateau
salamander in the enzyme analysis presented in the original species
descriptions (Chippindale et al. 2000).
Our Response: Peer reviewers' comments indicate that we used the
best available science, and we correctly interpreted that science as
recognizing the Austin blind, Georgetown, Jollyville Plateau, and
Salado salamanders as four separate species. In the final listing rule,
we continue to recognize the Austin blind and Jollyville Plateau
salamanders as distinct and valid species. However, we acknowledge that
the understanding of the taxonomy of these salamander species can be
strengthened by further research.
(2) Comment: Forstner (2012, pp. 3-4) used the size of geographic
distributions as part of his argument for the existence of fewer
species of Eurycea in Texas than are currently recognized. Several peer
reviewers commented that they saw no reason for viewing the large
number of Eurycea species with small distributions in Texas as
problematic when compared to the larger distributions of Eurycea
species outside of Texas. They stated that larger numbers and smaller
distributions of Texas Eurycea species are to be expected given the
isolated spring environments that they inhabit within an arid
landscape. Salamander species with very small ranges are common in
several families and are usually restricted to island, mountain, or
cave habitats.
Our Response: See our response to comment 1.
(3) Comment: Forstner (2012, pp. 15-16) used results from Harlan
and Zigler (2009), indicating that levels of genetic variation within
the eastern species E. lucifuga are similar to those among six
currently recognized species of Texas Eurycea, as part of his argument
that there are fewer species in Texas than currently recognized.
Several peer reviewers said that these sorts of comparisons can be very
misleading in that they fail to take into consideration differences in
the ages, effective population sizes, or population structure of the
units being compared. The delimitation of species should be based on
patterns of genetic variation that bear on the separation (or lack
thereof) of gene pools rather than on the magnitude of genetic
differences, which can vary widely within and between species.
Our Response: See our response to comment 1.
(4) Comment: Several peer reviewers stated that the taxonomic tree
presented in Forstner (2012, pp. 20, 26) is difficult to evaluate
because of the following reasons: (1) no locality information is given
for the specimens; (2) it disagrees with all trees in other studies
(which seem to be largely congruent with one another), including that
in Forstner and McHenry (2010, pp. 13-16) with regard to monophyly
(more than one member of a group sharing the same ancestor) of several
of the currently recognized species; and (3) the tree is only a gene
tree, presenting sequence data on a single gene, which provides little
or no new information on species relationships of populations.
Our Response: See our response to comment 1.
(5) Comment: Peer reviewers generally stated that Forstner (2012,
pp. 13-14) incorrectly dismisses morphological data that have been used
to recognize some of the Texas Eurycea species on the basis that it is
prone to convergence (acquisition of the same biological trait in
unrelated lineages) and, therefore, misleading. The peer reviewers
commented that it is true that similarities in characters associated
with cave-dwelling salamanders can be misleading when suggesting that
the species possessing those characters are closely related. However,
this in no way indicates that the reverse is true; that is, indicating
differences in characters is not misleading in identifying separate
species.
Our Response: See our response to comment 1.
Impervious Cover
(6) Comment: The 10 percent impervious cover threshold may not be
protective of salamander habitat based on a study by Coles et al.
(2012, pp. 4-5), which found a loss of sensitive species due to
urbanization and that there was no evidence of a resistance threshold
to invertebrates that the salamanders preyed upon. A vast amount of
literature indicates that 1 to 2 percent impervious cover can cause
habitat degradation, and, therefore, the 10 percent threshold for
impervious cover will not be protective of these species.
Our Response: We recognize that low levels of impervious cover in a
watershed may have impacts on aquatic life, and we have incorporated
results of these studies into the final listing rule. However, we are
aware of only one peer-reviewed study that examined watershed
impervious cover effects on salamanders in central Texas, and this
study found impacts on salamander density in watersheds with over 10
percent impervious cover (Bowles et al. 2006, pp. 113, 117-118).
Because this impervious cover study was done locally, we are using 10
percent as a guideline to categorize watersheds that are impacted in
terms of salamander density.
(7) Comment: While the Service's impervious cover analysis assessed
impacts on stream flows and surface habitat, it neglected to address
impacts over the entire recharge zone of the contributing aquifers on
spring flows in salamander habitat. Also, the surface watersheds
analyzed in the proposed rule are irrelevant because these salamanders
live in cave streams and spring flows that receive groundwater. Without
information on the groundwater recharge areas, the rule should be clear
that the surface watersheds are only an approximation of what is
impacting the subsurface drainage basins.
Our Response: We acknowledge that the impervious cover analysis is
limited to impacts on the surface watershed. Because the specific
groundwater recharge areas of individual springs are unknown, we cannot
accurately assess the current or future impacts on these areas.
However, we recognize subsurface flows as another avenue for
contaminants to reach the salamander sites, and we tried to make this
clearer in the final rule.
(8) Comment: Several of the watersheds analyzed for impervious
cover in the proposed rule were overestimated. The sub-basins in these
larger watersheds need to be analyzed for impervious cover impacts.
Our Response: We have refined our impervious cover analysis in this
final listing rule to clarify the surface

[[Page 51284]]

watersheds of individual spring sites. Our final impervious cover
report containing this refined analysis is available on the Internet at
http://www.regulations.gov under Docket No. FWS-R2-ES-2012-0035 and at
http://www.fws.gov/southwest/es/AustinTexas/.
Threats
(9) Comment: One peer reviewer stated that the threat to these
species from over collection for scientific purposes may be
understated.
Our Response: We have reevaluated the potential threat of
overutilization for scientific purposes and have incorporated a
discussion of this under Factor B ``Overutilization for Commercial,
Recreational, Scientific, or Educational Purposes.'' We recognize that
removing individuals from small, localized populations in the wild
without any proposed plans or regulations to restrict these activities
could increase the population's vulnerability of extinction and
decrease its resiliency and ability to withstand stochastic events.
However, we do not consider overutilization from collecting salamanders
in the wild to be a threat by itself, but it may cause significant
population declines, and could negatively impact the species in
combination with other threats.
Salamander Demographics
(10) Comment: Several peer reviewers agreed that COA's salamander
survey data were generally collected and analyzed appropriately and
that the results are consistent with the literature on aquatic species'
responses to urbanizing watersheds. Three reviewers had some
suggestions on how the data analysis could be improved, but they also
state that COA's analysis is the best scientific data available, and
alternative methods of analysis would not likely change the
conclusions.
Our Response: Because the peer reviewers examined COA's salamander
demographic data, as well as SWCA's analysis of the COA's data, and
generally agreed that the COA's data was the best information
available, we continue to rely upon this data set in the final listing
rule.
(11) Comment: Two peer reviewers pointed out that SWCA's water
samples were collected during a period of very low rainfall and,
therefore, under represent the contribution of water influenced by
urban land cover. The single sampling of water and sediment at the
eight sites referenced in the SWCA report do not compare in scope and
magnitude to the extensive studies referenced from the COA. The
numerous studies conducted (and referenced) within the known ranges of
the Austin blind and Jollyville Plateau salamanders provide scientific
support at the appropriate scale for recent and potential habitat
degradation due to urbanization. One peer reviewer pointed out that if
you sort the spring sites SWCA sampled into ``urbanized'' and ``rural''
categories, the urban sites generally have more degraded water quality
than the rural sites, in terms of nitrate, nitrite, E. coli counts, and
fecal coliform bacteria counts.
Our Response: We agree with the peer reviewers who stated that SWCA
(2012, pp. 21-24) did not present convincing evidence that overall
water quality at sites in Williamson County is good or that
urbanization is not impacting the water quality at these sites. Water
quality monitoring based on one or a few samples are not necessarily
reflective of conditions at the site under all circumstances that the
salamanders are exposed to over time. Based on this assessment, we
continued to rely upon the best scientific evidence available that
states water quality will decline as urbanization within the watershed
increases.
(12) Comment: The SWCA report indicates that increasing
conductivity is related to drought. (Note: Conductivity is a measure of
the ability of water to carry an electrical current and can be used to
approximate the concentration of dissolved inorganic solids in water
that can alter the internal water balance in aquatic organisms,
affecting the Austin blind and Jollyville Plateau salamanders'
survival. Conductivity levels in the Edwards Aquifer are naturally low.
As ion concentrations such as chlorides, sodium, sulfates, and nitrates
rise, conductivity will increase. The stability of the measured ions
makes conductivity an excellent monitoring tool for assessing the
impacts of urbanization to overall water quality. High conductivity has
been associated with declining salamander abundance.) While SWCA's
report notes lack of rainfall as the dominant factor in increased
conductivity, the confounding influence of decreases in infiltration
and increases in sources of ions as factors associated with
urbanization and changes in water quality in these areas is not
addressed by SWCA. The shift to higher conductivity associated with
increasing impervious surface is well documented in the COA references.
Higher conductivity in urban streams is well documented and was a major
finding of the U.S. Geological Survey (USGS) urban land use studies
(Coles et al. 2012). Stream conductivity increased with increasing
urban land cover in every metropolitan area studied. Conductivity is an
excellent surrogate for tracking changes in water quality related to
land use change associated with urbanization due to the conservative
nature of the ions.
Our Response: While drought may result in increased conductivity,
increased conductivity is also a reflection of increased urbanization.
We incorporated information from the study by Coles et al. (2012) in
the final listing rule, and we continued to include conductivity as a
measure of water quality in the primary constituent elements for the
Austin blind and Jollyville Plateau salamanders in the final critical
habitat rule as published elsewhere in today's Federal Register.
(13) Comment: One peer reviewer stated that SWCA's criticisms of
COA's linear regression analysis, general additive model, and
population age structure were not relevant and unsupported. In
addition, peer reviewers agreed that COA's mark-recapture estimates are
robust and highly likely to be correct. Three peer reviewers agreed
that SWCA misrepresented the findings of Luo (2010) and stated that
this thesis does not invalidate the findings of COA.
Our Response: Because the peer reviewers examined COA's data, as
well as SWCA's analysis of the COA's data, and generally agreed that
the COA's data was the best information available, we continue to rely
upon this data set in the final listing rule.
(14) Comment: One peer reviewer stated that the long-term data
collected by the COA on the Jollyville Plateau salamander were simple
counts that serve as indexes of relative population abundance, and not
of absolute abundance. This data assumes that the probability of
observing salamanders remains constant over time, season, and among
different observers. This assumption is often violated, which results
in unknown repercussions on the assessment of population trends.
Therefore, the negative trend observed in several sites could be due to
a real decrease in population absolute abundance, but could also be
related to a decrease in capture probabilities over time (or due to an
interaction between these two factors). Absolute population abundance
and capture probabilities should be estimated in urban sites using the
same methods implemented at rural sites by COA. However, even in the
absence of clear evidence of local population declines of Jollyville
Plateau salamanders, the proposed rule was correct in its assessment
because there is objective evidence that stream alterations negatively
impact the density

[[Page 51285]]

of Eurycea salamanders (Barrett et al. 2010).
Our Response: We recognize that the long-term survey data of
Jollyville Plateau salamanders using simple counts may not give
conclusive evidence on the true population status at each site.
However, based on the threats and evidence from scientifically peer-
reviewed literature, we believe the declines in counts seen at urban
Jollyville Plateau salamander sites are likely representative of real
declines in the population.
(15) Comment: One peer reviewer had similar comments on COA
salamander counts and relating them to populations. They stated that
the conclusion of a difference in salamander counts between sites with
high and low levels of impervious cover is reasonable based on COA's
data. However, this conclusion is not about salamander populations, but
instead about the counts. The COA's capture-mark-recapture analyses
provide strong evidence of both nondetection and substantial temporary
emigration, findings consistent with other studies of salamanders in
the same family as the Jollyville Plateau salamander. This evidence
cautions against any sort of analysis that relies on raw count data to
draw inferences about populations.
Our Response: See our response to previous comment.
(16) Comment: The SWCA (2012, pp. 70-76) argues that declines in
salamander counts can be attributed to declines in rainfall during the
survey period, and not watershed urbanization. However, one peer
reviewer stated that SWCA provided no statistical analysis to validate
this claim and misinterpreted the conclusions of Gillespie (2011) to
support their argument. A second peer reviewer agrees that counts of
salamanders are related to natural wet and dry cycles, but points out
that COA has taken this effect into account in their analyses. Another
peer reviewer points out that this argument contradicts SWCA's (2012)
earlier claim that COA's salamander counts are unreliable data. If the
data were unreliable, they probably would not correlate to
environmental changes.
Our Response: Although rainfall is undoubtedly important to these
strictly aquatic salamander species, the best scientific evidence
suggests that rainfall is not the only factor driving salamander
population fluctuations. In the final listing rule, we continue to rely
upon this evidence as the best scientific and commercial information
available, which suggests that urbanization is also a large factor
influencing declines in salamander counts.
Regarding comments from SWCA on the assessment of threats, peer
reviewers made the following comments:
(17) Comment: SWCA's (2012, pp. 84-85) summary understates what is
known about the ecology of Eurycea species and makes too strong of a
conclusion about the apparent ``coexistence with long-standing human
development.'' Human development and urbanization is an incredibly
recent stressor in the evolutionary history of the central Texas
Eurycea, and SWCA's assertion that the Eurycea will be ``hardy and
resilient'' to these new stressors is not substantiated with any
evidence.
(18) Comment: SWCA (2012, p. 7) states that, ``Small population
size and restricted distribution are not among the five listing
criteria and do not of themselves constitute a reason for considering a
species at risk of extinction.'' To the contrary, even though the
salamanders may naturally occur in small isolated populations, small
isolated populations and the inability to disperse between springs
should be considered under listing criteria E as a natural factor
affecting the species' continued existence. In direct contradiction,
SWCA (2012, p. 81) later states that, ``limited dispersal ability
(within a spring) may increase the species' vulnerability as
salamanders may not move from one part of the spring run to another
when localized habitat loss or degradation occurs.'' It is well known
that small population size and restricted distributions make
populations more susceptible to selection or extinction due to
stochastic events. Small population size can also affect population
density thresholds required for successful mating.
(19) Comment: SWCA (2012, p. v) contests that the Jollyville
Plateau salamander is not in immediate danger of extinction because,
``over 60 of the 90-plus known Jollyville Plateau salamander sites are
permanently protected within preserve areas. . . .'' This statement
completely ignores the entire aquifer recharge zone, which is not
included in critical habitat. Furthermore, analysis of the COA's
monitoring and water quality datasets clearly demonstrate that, even
within protected areas, there is deterioration of water quality and
decrease in population size of salamanders.
(20) Comment: SWCA (2012, p. 11) criticizes the Service and the COA
for not providing a ``direct cause and effect'' relationship between
urbanization, nutrient levels and salamander populations. There is, in
fact, a large amount of peer-reviewed literature on the effects of
pollutants and deterioration of water quality on sensitive
macroinvertebrate species as well as on aquatic amphibians. In the
proposed rule, the Service cites just a small sampling of the available
literature regarding the effects of pollutants on the physiology and
indirect effects of urbanization on aquatic macroinvertebrates and
amphibians. In almost all cases, there are synergistic and indirect
negative effects on these species that may not have one single direct
cause. There is no ecological requirement that any stressor (be it a
predator, a pollutant, or a change in the invertebrate community) must
be a direct effect to threaten the stability or long-term persistence
of a population or species. Indirect effects can be just as important,
especially when many are combined.
Our Response to Comments 17-20: We had SWCA's (2012) report peer
reviewed. The peer reviewers generally agreed that we used the best
information available in our proposed listing rule.
(21) Comment: One reviewer stated that, even though there is
detectable gene flow between populations, it may be representative of
subsurface connections in the past, rather than current population
interchange. However, dispersal through the aquifer is possible even
though there is currently no evidence that these species migrate.
Further, they stated that there is no indication of a metapopulation
structure where one population could recolonize another that had gone
extinct.
Our Response: We acknowledge that more study is needed to determine
the nature and extent of the dispersal capabilities of the Austin blind
and Jollyville Plateau salamanders. It is plausible that populations of
these species could extend through subterranean habitat. However,
subsurface movement is likely to be limited by the highly dissected
nature of the aquifer system, where spring sites can be separated from
other spring sites by large canyons or other physical barriers to
movement. Dye-trace studies have demonstrated that some Jollyville
Plateau salamander sites located miles apart are connected
hydrologically (Whitewater Cave and Hideaway Cave) (Hauwert and Warton
1997, pp. 12-13), but it remains unclear if salamanders are travelling
between those sites. There is some indication that populations could be
connected through subterranean water-filled spaces, although we are
unaware of any information available on the frequency of movements and
the actual nature of connectivity among populations.

[[Page 51286]]

Comments From States

Section 4(i) of the Act states, ``the Secretary shall submit to the
State agency a written justification for his failure to adopt
regulations consistent with the agency's comments or petition.''
Comments received from all State agencies and entities in Texas
regarding the proposal to list the Austin blind and Jollyville Plateau
salamanders are addressed below.
(22) Comment: Chippindale (2010) demonstrated that it is possible
for Jollyville Plateau salamanders to move between sites in underground
conduits. Close genetic affinities between populations in separate
watersheds on either side of the RM 620 suggest that these populations
may be connected hydrologically. Recent studies (Chippindale 2011 and
2012, in prep) indicate that gene flow among salamander populations
follows groundwater flow routes in some cases and that genetic exchange
occurs both horizontally and vertically within an aquifer segment.
Our Response: We agree that genetic evidence suggests subsurface
hydrological connectivity exist between sites at some point in time,
but we are unable to conclude if this connectivity occurred in the past
or if it still occurs today without more hydrogeological studies or
direct evidence of salamander migration from mark-recapture studies.
Also, one of our peer reviewers stated that this genetic exchange is
probably representative of subsurface connection in the past (see
comment 21 above).
(23) Comment: Very little is known about Austin blind salamander,
and COA has a plan in place to protect and improve habitat without
listing.
Our Response: We agree that more study is needed on the ecology of
the Austin blind salamander, but enough scientific and commercial data
is available on the threats to this species to make a listing
determination. We make our listing determinations based on the five
listing factors, singly or in combination, as described in section
4(a)(1) of the Act. We recognize the conservation actions made by the
COA in the final listing and critical habitat rules, but we determined
that these actions are inadequate to protect the species from threats
that are occurring from outside of the COA's jurisdiction (that is, the
surface watershed and recharge area of Barton Springs).
(24) Comment: Regarding all central Texas salamanders, there was
insufficient data to evaluate the long-term flow patterns of the
springs and creeks, and the correlation of flow, water quality,
habitat, ecology, and community response. Current research in
Williamson County indicates that water and sediment quality remain good
with no degradation, no elevated levels of toxins, and no harmful
residues in known springs.
Our Response: We have reviewed the best available scientific and
commercial information in making our final listing determination. We
sought comments from independent peer reviewers to ensure that our
designation is based on scientifically sound data, assumptions, and
analysis. And the peer reviewers stated that our proposed rule was
based on the best available scientific information. Additionally,
recent research on water quality in Williamson County springs was
considered in our listing rule. The peer reviewers agreed that these
data did not present convincing evidence that overall water quality at
salamander sites in Williamson County is good or that urbanization is
not impacting the water quality at these sites (see Comment 19 above).
(25) Comment: The listing will have negative impacts to private
development and public infrastructure.
Our Response: In accordance with the Act, we cannot make a listing
determination based on economic impacts. Section 4(b)(2) of the Act
states that the Secretary shall designate and make revisions to
critical habitat on the basis of the best available scientific data
after taking into consideration the economic impact, national security
impact, and any other relevant impact of specifying any particular area
as critical habitat. However, economic considerations are not taken
into consideration as part of listing determinations.
(26) Comment: It was suggested that there are adequate regulations
in Texas to protect the Austin blind and Jollyville Plateau
salamanders, and their respective habitats. The overall programs to
protect water quality--especially in the watersheds of the Edwards
Aquifer region--are more robust and protective than suggested by the
Service's descriptions of deficiencies. The Service overlooks the
improvements in the State of Texas and local regulatory and incentive
programs to protect the Edwards Aquifer and spring-dependent species
over the last 20 years. Texas has extensive water quality management
and protection programs that operate under State statutes and the
Federal Clean Water Act. These programs include: Surface Water Quality
Monitoring Program, Clean Rivers Program, Water Quality Standards,
Texas Pollutant Discharge Elimination System (TPDES) Stormwater
Permitting, Total Maximum Daily Load Program, Nonpoint Source Program,
Edwards Aquifer Rules, and Local Ordinances and Rules (San Marcos
Ordinance and COA Rules). Continuing efforts at the local, regional,
and State level will provide a more focused and efficient approach for
protecting these species than Federal listing.
Our Response: Section 4(b)(1)(A) of the Act requires us to take
into account those efforts being made by a State or foreign nation, or
any political subdivision of a State or foreign nation, to protect such
species, and we fully recognize the contributions of the State and
local programs. We consider relevant Federal, State, and tribal laws
and regulations when developing our threats analysis. Regulatory
mechanisms may preclude the need for listing if we determine such
mechanisms address the threats to the species such that listing is no
longer warranted. However, the best available scientific and commercial
data supports our determination that existing regulations and local
ordinances are not adequate to remove all of the threats to the Austin
blind and Jollyville Plateau salamanders. We have added further
discussion of these regulations and ordinances to Factor D in the final
listing rule.
(27) Comment: The requirement in the Edwards Rules for wastewater
to be disposed of on the recharge zone by land application is an
important and protective practice for aquifer recharge and a
sustainable supply of groundwater. Permits for irrigation of wastewater
are fully evaluated and conditioned to require suitable vegetation and
sufficient acreage to protect water quality.
Our Response: Based on the best available science, wastewater
disposal on the recharge zone by land application can contribute to
water quality degradation in surface waters and the underground
aquifer. Previous studies have demonstrated negative impacts to water
quality (increases in nitrate levels) at Barton Springs (Mahler et al.
2011, pp. 29-35) and within streams (Ross 2011, pp. 11-21) that were
likely associated with the land application of wastewater.
(28) Comment: A summary of surface water quality data for streams
in the watersheds of the Austin blind and Jollyville Plateau
salamanders was provided and a suggestion was made that sampling data
indicated high-quality aquatic life will be maintained despite
occasional instances where parameters exceeded criteria or screening
levels.

[[Page 51287]]

Our Response: In reviewing the 2010 and 2012 Texas Water Quality
Integrated Reports prepared by the Texas Commission on Environmental
Quality (TCEQ), the Service identified 14 of 28 (50 percent) stream
segments located within surface drainage areas occupied by the
salamanders, which contained measured parameters within water samples
that exceeded screening level criteria. These included ``screening
level concerns'' for parameters such as nitrate, dissolved oxygen,
impaired benthic communities, sediment toxicity, and bacteria. In
addition, as required under Sections 303(d) and 304(a) of the Clean
Water Act, 4 of 28 stream segments located within surface drainage
areas occupied by the salamanders have been identified as impaired
waters ``. . . for which effluent limitations are not stringent enough
to implement water quality standards.'' Water quality data collected
and summarized in TCEQ reports supports our concerns with water quality
degradation within the surface drainage areas occupied by the
salamanders. This information is discussed under D. The Inadequacy of
Existing Regulatory Mechanisms in this final listing rule.

Public Comments

Existing Regulatory Mechanisms
(29) Comment: Many commenters expressed concern that the Service
had not adequately addressed all of the existing regulatory mechanisms
and programs that provided protection to the salamanders. In addition,
many of the same commenters believed there were adequate Federal,
State, and local regulatory mechanisms to protect the Austin blind and
Jollyville Plateau salamanders and their aquatic habitats.
Our Response: Section 4(b)(1)(A) of the Act requires us to take
into account those efforts being made by a State or foreign nation, or
any political subdivision of a State or foreign nation, to protect such
species. Under D. The Inadequacy of Existing Regulatory Mechanisms in
the final listing rule, we provide an analysis of the inadequacy of
existing regulatory mechanisms. During the comment period, we sought
out and were provided information on several local, State, and Federal
regulatory mechanisms that we had not considered when developing the
proposed rule. We have reviewed these mechanisms and have included them
in our analysis under D. The Inadequacy of Existing Regulatory
Mechanisms in the final listing rule. Our expanded analysis still
concluded that existing regulations and local ordinances are not
effective at removing the threats to the salamanders.
Protections
(30) Comment: The Service fails to consider existing local
conservation measures and habitat conservation plans (HCPs) including
the regional permit issued to the COA and Travis County, referred to as
the Balcones Canyonlands Conservation Plan (BCCP), which benefits the
salamanders. While the salamanders are not covered in most of these
HCPs, some commenters believe that measures are in place to mitigate
any imminent threats to the species. The Service overlooks permanent
conservation actions undertaken by both public and private entities
over the last two or more decades, including preservation of caves,
which protects water quality through recharge, and the preservation of
the original Water Treatment Plant 4 site as conservation land in
perpetuity, which the COA is now managing as part of the Balcones
Canyonlands Preserve. Additionally, Travis County conducts quarterly
surveys at two permanent survey sites, and the COA monitors several
spring sites, along with additional searches for new localities within
the BCCP-managed properties. The HCPs and water quality protection
standards are sufficient to prevent significant habitat degradation.
Several commenters stated that the majority of Jollyville Plateau
salamander sites were already protected by the Balcones Canyonlands
Preserve.
Our Response: In the final listing rule, we included a section
titled ``Conservation Efforts to Reduce Habitat Destruction,
Modification, or Curtailment of Its Range'' that describes existing
conservation measures including the regional permit issued to the COA
and Travis County for the BCCP and the Williamson County Regional HCP.
These conservation efforts and the manner in which they are helping to
ameliorate threats to the species were considered in our final listing
determination. The Service considered the amount and location of
managed open space when analyzing impervious cover levels within each
surface watershed (Service 2012, 2013). We also considered preserves
when projecting how impervious cover levels within the surface
watershed of each spring site would change in the future. These
analyses included the benefits from open space as a result of several
HCPs (including, but not limited to, the BCCP, Rockledge HCP, and
Comanche Canyon HCP). Additional conservation lands considered, but not
part of, an HCP, includes the Lower Colorado River Authority (LCRA),
The Nature Conservancy of Texas, and Travis Audubon Society. While
these conservation lands contribute to the protection of the surface
and subsurface watersheds, other factors contribute to the decline of
the salamander's habitat. Other factors include, but are not limited
to: (1) Other areas within the surface watershed that have high levels
of impervious cover, which increases the overall percentage of
impervious cover within the watershed; (2) potential for groundwater
pollution from areas outside of the surface watershed; and (3)
disturbance of the surface habitat of the spring sites themselves.
With regard to the BCCP specifically, we recognize that the BCCP
system offers some water quality benefits to the Jollyville Plateau
salamander in portions of the Bull Creek, Brushy Creek, Cypress Creek,
and Long Hollow Creek drainages through preservation of open space
(Service 1996, pp. 2-28-2-29). Despite the significant conservation
measures being achieved by the BCCP and their partners, the potential
for groundwater degradation still exists from outside these preserves.
For example, eight of the nine COA monitoring sites occupied by the
Jollyville Plateau salamander within the BCCP have experienced water
quality degradation where pollution sources likely originated upstream
and outside of the preserved tracts (O'Donnell et al. 2006, pp. 29, 34,
37, 49; COA 1999, pp. 6-11; Travis County 2007, p. 4).
(31) Comment: The proposed rule directly contradicts the Service's
recent policy titled Expanding Incentives for Voluntary Conservation
Actions Under the Act (77 FR 15352, March 15, 2012), which concerns the
encouragement of voluntary conservation actions for non-listed species
and is available at http://www.gpo.gov/fdsys/pkg/FR-2012-03-15/pdf/2012-6221.pdf.
Our Response: The commenter did not specify how the proposed rule
contradicts the Service's recent policy pronouncements concerning the
encouragement of voluntary conservation actions for nonlisted species.
The recent policy pronouncements specifically state that voluntary
conservation actions undertaken are unlikely to be sufficient to affect
the need to list the species. However, if the species is listed and
voluntary conservation actions are implemented, as outlined in policy
pronouncements, the Service can provide assurances that if the
conditions of a conservation agreement are met, the landowner will not
be asked to do more, commit more resources, or be subject to further
land use restrictions than agreed

[[Page 51288]]

upon. We may also allow a prescribed level of incidental take by the
landowner.
Listing Process and Policy
(32) Comment: The Service is pushing these listings because of the
legal settlement and not basing its decision on science and the reality
of the existing salamander populations.
Our Response: We are required by court-approved settlement
agreements to remove Austin blind and Jollyville Plateau salamanders
from the candidate list within a specified timeframe. To remove these
salamanders from the candidate list means to propose them for listing
as threatened or endangered or to prepare a not-warranted finding. The
Act requires us to determine whether a species warrants listing based
on our assessment of the five listing factors described in the Act
using the best available scientific and commercial information. We
already determined, prior to the court settlement agreement, that the
Austin blind and Jollyville Plateau salamanders warranted listing under
the Act, but were precluded by the necessity to commit limited funds
and staff to complete higher priority species actions. The Austin blind
and Jollyville Plateau salamanders have been included in our annual
Candidate Notices of Review for multiple years, during which time
scientific literature and data have and continue to indicate that these
salamander species are detrimentally impacted by ongoing threats, and
we continued to find that listing each species was warranted but
precluded. While the settlement agreement has set a court-ordered
timeline for rendering our final decision, our determination is still
guided by the Act and its implementing regulations considering the five
listing factors and using the best available scientific and commercial
information.
(33) Comment: Commenters requested that the Service extend the
comment period for another 45 days after the first comment period. The
commenters were concerned about the length of the proposed listing,
which is very dense and fills 88 pages in the Federal Register and that
the public hearing was held only 2 weeks after the proposed rule was
published. The commenter does not consider this enough time to read and
digest how the Service is basing a listing decision that will have
serious consequences for Williamson County. Furthermore, the 60-day
comment period does not give the public enough time to submit written
comments to such a large proposed rule.
Our Response: The initial comment period for the proposed listing
and critical habitat designation consisted of 60 days, beginning August
22, 2012, and ending on October 22, 2012. We reopened the comment
period for an additional 45 days, beginning on January 25, 2013, and
ending on March 11, 2013. We consider the comment periods described
above an adequate opportunity for both written and oral public comment.
(34) Comment: One commenter suggested recognition of two distinct
population segments for Jollyville Plateau salamander.
Our Response: In making our listing determinations, we first decide
whether a species is endangered or threatened throughout its entire
range. Because we have already determined that the Jollyville Plateau
salamander is warranted for listing throughout its entire range, we are
not considering whether a distinct vertebrate population segment of the
species meets the definition of an endangered or threatened species.
(35) Comment: One commenter expressed concern with the use of
``unpublished'' data in the proposed rule. It is important that the
Service takes the necessary steps to ensure all data used in the
listing and critical habitat designations are reliable, verifiable, and
peer reviewed, as required by President Obama's 2009 directive for
transparency and open government. In December of 2009, the Office of
Management and Budget (OMB) issued clarification on the presentation
and substance of data used by Federal agencies and required in its
Information Quality Guidelines. Additionally under the OMB guidelines,
all information disseminated by Federal agencies must meet the standard
of ``objectivity.'' Additionally, relying on older studies instead of
newer ones conflicts with the Information Quality Guidelines.
Our Response: Our use of unpublished information and data does not
contravene the transparency and open government directive. Under the
Act, we are obligated to use the best available scientific and
commercial information, including results from surveys, reports by
scientists and biological consultants, various models, and expert
opinion from biologists with extensive experience studying the
salamanders and their habitat, whether published or unpublished. One
element of the transparency and open government directive encourages
executive departments and agencies to make information about operations
and decisions readily available to the public. Supporting documentation
used to prepare the proposed and final rules is available for public
inspection, by appointment, during normal business hours, at the U.S.
Fish and Wildlife Service, Austin Ecological Services Field Office,
10711 Burnet Rd, Suite 200, Austin, Texas 78758.
Peer Review Process
(36) Comment: One commenter requested that the Service make the
peer review process as transparent and objective as possible. The
Service should make available the process and criteria used to identify
peer reviewers. It is not appropriate for the Service to choose the
peer review experts. For the peer review to be credible, the entire
process including the selection of reviewers must be managed by an
independent and objective party. We recommend that the peer review plan
identify at least two peer reviewers per scientific discipline.
Further, the peer reviewers should be identified.
Our Response: To ensure the quality and credibility of the
scientific information we use to make decisions, we have implemented a
formal peer review process. Through this peer review process, we
followed the guidelines for Federal agencies spelled out in the Office
of Management and Budget (OMB) ``Final Information Quality Bulletin for
Peer Review,'' released December 16, 2004, and the Service's
``Information Quality Guidelines and Peer Review,'' revised June 2012.
Part of the peer review process is to provide information online about
how each peer review is to be conducted. Prior to publishing the
proposed listing and critical habitat rule for the Austin blind and
Jollyville Plateau salamanders, we posted a peer review plan on our Web
site, which included information about the process and criteria used
for selecting peer reviewers.
In regard to transparency, the OMB and Service's peer review
guidelines mandate that we not conduct anonymous peer reviews. The
guidelines state that we advise reviewers that their reviews, including
their names and affiliations, and how we respond to their comments will
be included in the official record for review, and, once all the
reviews are completed, their reviews will be available to the public.
We followed the policies and standards for conducting peer reviews as
part of this rulemaking process.
(37) Comment: The results of the peer review process should be
available to the public for review and comment well before the end of
the public comment period on the listing decision. Will the

[[Page 51289]]

public have an opportunity to participate in the peer review process?
Response: As noted above, OMB and the Service's guidelines state
that we make available to the public the peer reviewers information,
reviews, and how we respond to their comments once all reviews are
completed. The peer reviews are completed at the time the last public
comment period closes, and our responses to their comments are
completed at the time the final listing decision is published in the
Federal Register. All peer review process information is available upon
request at this time and will be made available from the U.S. Fish and
Wildlife Service, Austin Ecological Services Field Office, 10711 Burnet
Rd, Suite 200, Austin, Texas 78758.
(38) Comment: New information has been provided during the comment
period. The final listing decision should be peer reviewed.
Response: During the second public comment period, we asked peer
reviewers to comment on new and substantial information that we
received during the first comment period. We did not receive any new
information during the second comment period that we felt rose to the
level of needing peer review. Furthermore, as part of our peer review
process, we asked peer reviewers not to provide comments or
recommendations on the listing decision. Peer reviewers were asked to
comment specifically on the quality of information and analyses used or
relied on in the reviewed documents. In addition, they were asked to
identify oversights, omissions, and inconsistencies; provide advice on
reasonableness of judgments made from the scientific evidence; ensure
that scientific uncertainties are clearly identified and characterized
and that potential implications of uncertainties for the technical
conclusions drawn are clear; and provide advice on the overall
strengths and limitations of the scientific data used in the document.
(39) Comment: One commenter requested a peer review of the Austin
blind, Georgetown, Jollyville Plateau, and Salado salamanders' taxonomy
and recommended that, to avoid any potential bias, peer reviewers not
be from Texas or be authors or contributors of any works that the
Service has or is relying upon to diagnose the Austin blind,
Georgetown, Jollyville Plateau, and Salado salamanders as four distinct
species. This commenter also provided a list of four recommended
scientists for the peer review on taxonomy.
Our Response: We requested peer reviews of the central Texas
salamander taxonomy from 11 scientific experts in this field. Because
we considered the 4 recommended scientists to be qualified as
independent experts, we included the 4 experts recommended by the
commenter among the 11. Eight scientists responded to our request, and
all eight scientists agreed with our recognition of four separate and
distinct salamander species, as described in the Species Information
section of the proposed and final listing rules. The commenter also
provided an unpublished paper offering an alternative interpretation of
the taxonomy of central Texas salamanders (Forstner 2012, entire), and
that information was also provided to peer reviewers. We included two
authors of the original species descriptions of the Austin blind,
Georgetown, Jollyville Plateau, and Salado salamanders to give them an
opportunity to respond to criticisms of their work and so that we could
fully understand the taxonomic questions about these species.
(40) Comment: One commenter requested a revision to the peer review
plan to clarify whether it is a review of non-influential information
or influential information.
Our Response: We see no benefit from revising the peer review plan
to clarify whether the review was of non-influential or influential
information. The Service's ``Information Quality Guidelines and Peer
Review,'' revised June 2012, defines influential information as
information that we can reasonably determine that dissemination of the
information will have or does have a clear and substantial impact on
important policy or private sector decisions. Also, we are authorized
to define influential in ways appropriate for us, given the nature and
multiplicity of issues for which we are responsible. As a general rule,
we consider an impact clear and substantial when a specific piece of
information is a principle basis for our position.
(41) Comment: One commenter requested clarification on what type of
peer review was intended. Was it a panel review or individual review?
Did peer reviewers operate in isolation to generate individual reports
or did they work collaboratively to generate a single peer review
document.
Our Response: Peer reviews were requested individually. Each peer
reviewer who responded generated independent comments.
(42) Comment: It does not seem appropriate to ask peer reviewers,
who apparently do not have direct expertise on Eurycea or central Texas
ecological systems, to provide advice on reasonableness of judgments
made from generic statements or hyper-extrapolations from studies on
other species. The peer review plan states that reviewers will have
expertise in invertebrate ecology, conservation biology, or desert
spring ecology. The disciplines of invertebrate ecology and desert
spring ecology do not have any apparent relevance to the salamanders in
question. The Eurycea are vertebrate species that spend nearly all of
their life cycle underground. Central Texas is not a desert. The peer
reviewers should have expertise in amphibian ecology and familiarity
with how karst hydrogeology operates.
Our Response: The peer review plan stated that we sought out peer
reviewers with expertise in invertebrate ecology or desert spring
ecology, but this was an error. In the first comment period, we asked
and received peer reviews from independent scientists with local and
non-local expertise in amphibian ecology, amphibian taxonomy, and karst
hydrology. In the second comment period, we sought out peer reviewers
with local and non-local expertise in population ecology and watershed
urbanization.
(43) Comment: The peer review plan appears to ask peer reviewers to
consider only the scientific information reviewed by the Service. The
plan should include the question of whether the scientific information
reviewed constitutes the best available scientific and commercial data.
The plan should be revised to clarify that the peer reviewers are not
limited to the scientific information in the Service's administrative
record.
Our Response: The peer review plan states that we may ask peer
reviewers to identify oversights and omissions of information as well
as to consider the information reviewed by the Service. When we sent
out letters to peer reviewers asking for their review, we specifically
asked them to identify any oversights, omissions, and inconsistencies
with the information we presented in the proposed rule.
(44) Comment: The proposed peer review plan falls far short of the
OMB Guidelines (2004 Office of Management and Budget promulgated its
Final Information Quality Bulletin for Peer Review).
Our Response: This commenter failed to tell us how the plan falls
short of the OMB Guidelines. We tried to adhere to the guidelines set
forth for Federal agencies and in OMB's ``Final Information Quality
Bulletin for Peer Review,'' released December 16, 2004, and the
Service's ``Information Quality Guidelines and Peer Review,'' revised
June 2012. While the draft peer review plan had some errors, we believe
we satisfied the intent of the guidelines and

[[Page 51290]]

that the errors did not affect the rigor of the actual peer review that
occurred.
Salamander Populations
(45) Comment: Studies indicate that there are healthy populations
of Jollyville Plateau salamanders in many locations, including highly
developed areas such as State Highway 45 at RM 620 and along Spicewood
Springs Road between Loop 1 and Mesa Drive.
Our Response: We are unaware of long-term monitoring studies that
have demonstrated healthy populations of Jollyville Plateau salamanders
over time in highly developed areas. Furthermore, the fact that some
heavily urbanized areas still have salamanders in them does not
indicate the probability of population stability. In the case of the
Spicewood Spring site mentioned by the commenter, salamander monitoring
by COA since 1996 has consistently found low numbers of salamanders
(Bendik 2011a, pp. 14, 19-20).
(46) Comment: A recent study by SWCA proposes that the COA's data
is inadequate to assess salamander population trends and is not
representative of environmental and population control factors (such as
seasonal rainfall and drought). The study also states that there is
very little evidence linking increased urban development to declining
water quality.
Our Response: We have reviewed the report by SWCA and COA's data
and determined that it is reasonable to conclude that a link between
increased urban development, declining water quality, and declining
salamander populations exists for these species. Peer reviewers have
also generally agreed with this assessment.
(47) Comment: Given the central Texas climate and the general
geology and hydrology of the Edwards Limestone formation north of the
Colorado River, the description ``surface-dwelling'' or ``surface
residing'' overstates the extent and frequency that the Jollyville
Plateau salamander utilizes surface water. The phrase ``surface
dwelling population'' in the proposed rule appears to be based on two
undisclosed and questionable assumptions pertaining to Jollyville
Plateau salamander species: (1) There are a sufficient number of these
salamanders that have surface water available to them for sufficient
periods of times so that the group could be called a ``population;''
and (2) there are surface-dwelling Jollyville Plateau salamander
populations that are distinct from subsurface dwelling Jollyville
Plateau salamander populations. Neither assumption can be correct
unless the surface area is within a spring-fed impoundment that
maintains water for a significant portion of a year. The notion of
Jollyville Plateau salamander being a ``surface dwelling Eurycea'' most
likely stems from an early description of the Barton Springs salamander
adopted by the Service. Characterizing the Barton Springs salamander as
``predominately surface dwelling'' is highly questionable. The history
of the Barton Springs Pool provides a tremendous amount of information
regarding the life history of the Barton Springs salamander (and other
Texas Eurycea), the relative importance of surface habitat areas, and
the absolute necessity for underground habitat.
Our Response: In the proposed rule, we did not mean to imply or
assume that ``surface-dwelling populations'' are restricted to surface
habitat only. In fact, we made clear in the proposed rule that these
populations need access to subsurface habitat. In addition, we also
considered the morphology of these species in our description of their
habitat use. The morphology of the Jollyville Plateau salamander serves
as indicators of surface and subsurface habitat use. The Jollyville
Plateau salamander's surface populations have large, well-developed
eyes. In addition, the Jollyville Plateau salamanders have yellowish
heads and dark greenish-brown bodies. Subterranean populations of this
species have reduced eyes and dullness of color, indicating adaptation
to subsurface habitat. In contrast, the Austin blind salamander has no
external eyes and has lightly pigmented skin, indicating it is more
subterranean than surface-dwelling.
Threats
(48) Comment: One commenter described an experiment at Barton
Springs Pool in 1998 designed to measure the impacts on the Barton
Springs salamander from lowering the water level during pool cleanings.
At the time, the substrate of the beach area was described by the
Service as ``basically silt and sediment with algae on top'' and ``like
concrete.'' In other words, it was nothing like the habitat in the
proposed rule, which emphasized the need for interstitial spaces (the
space between the rocks) free from sediments. Despite this
untraditional habitat, 23 Barton Springs salamanders were found in the
beach area, and prey items such as amphipods were also found. Later,
the COA removed the silt and algae substrate, restricting salamander
habitat to the rocky substrate. The events of 1998 demonstrate that
unobstructed interstitial space is not necessarily critical to
impounded habitats. Constant water impoundments (Barton Springs Pool
and Spring Lake in San Marcos) are a unique type of habitat (pond) for
Eurycea distinct from ephemeral spring flow areas and underground
areas. The San Marcos salamander uses aquatic vegetation as cover. It
is noteworthy that Spring Lake has a significantly higher density of
salamanders than does Barton Springs Pool. Threats the Service
associates with sediment must be assessed differently for impounded
areas compared to ephemeral spring flow areas.
Our Response: We recognize that these salamanders can use habitat
types other than rocky substrate. Jollyville Plateau salamanders have
been found under leaf litter, vegetation, and in open areas (Bowles et
al. 2006, pp. 114-116). Pierce et al. (2010, p. 295) observed closely
related Georgetown salamanders in open spaces and under sticks, leaf
litter, and other structural cover. However, these peer-reviewed
studies also came to the conclusion that salamanders are much more
likely to be under rocks than other cover objects and that they select
rocks with larger surface areas (Pierce et al. 2010, p. 296; Bowles et
al. 2006, p. 118). These results are consistent with studies on other
aquatic salamanders nationwide (Davic and Orr 1987; Parker 1991; Welsh
and Ollivier 1998; Smith and Grossman 2003). Therefore, based on the
best available information, we consider habitat containing substrates
other than large rocks to be suboptimal habitat for the Austin blind
and Jollyville Plateau salamanders. Regarding sediment, we explain the
impacts that sedimentation has on salamanders in the proposed and final
listing rules under Factor A. The assessment of this threat is based on
a number of studies, which peer reviewers have agreed comprise the best
available information. Impoundments promote sedimentation and generally
suboptimal habitat for salamanders, as described under Factor A of the
proposed and final listing rules. Despite the persistence of salamander
species at impounded locations, these are not natural habitat types in
which the species have evolved and would be unlikely to persist in
perpetuity if restricted to sites like this.
(49) Comment: The Service appears reluctant to distinguish between
what are normal, baseline physical conditions (climate, geology, and
hydrology) found in central Texas and those factors outside of the norm
that might actually threaten the survival of the Austin blind and
Jollyville Plateau salamanders species. Cyclical droughts and regular
flood events are part of the normal

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central Texas climate and have been for thousands of years. The Service
appears very tentative about accepting the obvious adaptive behaviors
of the salamanders to survive floods and droughts.
Our Response: The final listing rule acknowledges that drought
conditions are common to the region, and the ability to retreat
underground may be an evolutionary adaptation to such natural
conditions (Bendik 2011a, pp. 31-32). However, it is important to note
that, although salamanders may survive a drought by retreating
underground, this does not necessarily mean they are resilient to
future worsening drought conditions in combination with other
environmental stressors. For example, climate change, groundwater
pumping, decreased water infiltration to the aquifer, potential
increases in saline water encroachments in the aquifer, and increased
competition for spaces and resources underground all may negatively
affect their habitat (COA 2006, pp. 46-47; TPWD 2011, pp. 4-5; Bendik
2011a, p. 31; Miller et al. 2007; p. 74; Schueler 1991, p. 114). These
factors may exacerbate drought conditions to the point where
salamanders cannot survive. In addition, we recognize threats to
surface habitat at a given site may not extirpate populations of these
salamander species in the short term, but this type of habitat
degradation may severely limit population growth and increase a
population's overall risk of extirpation from cumulative impacts of
other stressors occurring in the surface watershed of a spring.
(50) Comment: The Service cited two COA studies (COA 2001, p.15;
COA 2010a, p. 16) within the proposed rule to support the finding of
water quality degradation in the Bull Creek watershed. To the extent
that the 2001 study is superseded by the 2010 study, the 2001 study
should be excluded. The COA 2001 report (p. 16) states that ``Although
this study found some evidence of a negative shift in the Bull Creek
watershed, many COA watershed health measures, including the habitat
quality index, the TCEQ aquatic life use score, the number of
macroinvertebrate taxa, and the three diatom community metrics, all
continue to indicate an overall healthy creek.'' The use of the 2010
study without providing a full disclosure or analysis of the overall
findings of this study does not meet the objectivity standard of the
Information Quality Guidelines.
Our Response: We cited the COA 2010 study twice in the proposed
rule: once to state that sensitive macroinvertebrate species were lost
in Bull Creek (77 FR 50778), and once to state that Tributary 5 of Bull
Creek increased in conductivity, chloride, and sodium and decreased in
invertebrate diversity from 1996 to 2008 (77 FR 50779). We do not
believe that these statements were misleading or misrepresenting the
results of the study. In addition, the COA 2010 report (p. 16)
summarized their study by stating that ``currently Bull Creek ranks
highest out of all sampled creeks in the COA; however, spatial
differences between sites coupled with temporal shifts over the past
decade indicate negative changes in the watershed, particularly in the
headwater tributaries.'' This statement is followed by a list of water
quality declines found in headwater tributaries 5 and 6. This is the
area of Bull Creek where Jollyville Plateau salamander habitat is
located.
Further, the Service has relied on other data to support the
conclusion that water quality is degrading in the Bull Creek watershed.
For example, O'Donnell et al. (2006, p. 45) state that despite the
amount of preserve land in the watershed, ``the City of Austin has
reported significant declines in Jollyville Plateau salamander
abundance at one of their Jollyville Plateau salamander monitoring
sites within Bull Creek even though our analysis found that 61 percent
of the land within this watershed has 0 percent impervious cover.''
O'Donnell et al. (2006, p. 46) state, ``Poor water quality, as measured
by high specific conductance and elevated levels of ion concentrations,
is cited as one of the likely factors leading to statistically
significant declines in salamander abundance at the COA's long-term
monitoring sites.''
(51) Comment: The Service cites a 2005 COA study (Turner 2005a, p.
6) that reported ``significant changes over time'' for several chemical
constituents (77 FR 50779). The proposed rule does not disclose the
following finding from this study: ``No significant trends at the 0.05
level were found when the data from the last five years was
eliminated.'' Also not disclosed were the study's author's admonition
regarding the limitations of the study and statement that the study
should not be used to predict future water quality concentrations.
Finally, the proposed rule did not disclose the last sentence of this
report: ``Significance and presence of trends is variable depending on
flow conditions (`baseflow vs. stormflow, recharge vs. non-
recharge').'' Such non-disclosures do not comport with the Information
Quality Guidelines.
Our Response: We do not believe that our characterization of this
study was misleading or misrepresenting the results of the study. The
fact that significant trends were not found when the last 5 years of
data (from 1995 through 1999) were excluded from the analysis supports
our conclusion that recent urbanization in the surrounding areas was
driving declines in water quality. The author states that their
regression model should not be used to predict future water quality
concentrations (Turner 2005, p. 6). We made no such predictions based
on this model in the proposed rule. Regarding the last point made by
the commenter, the proposed rule did in fact state that, ``The
significance and presence of trends in other pollutants were variable
depending on flow conditions (baseflow vs. stormflow, recharge vs. non-
recharge) (Turner 2005a, p. 20)'' (see 77 FR 50779).
(52) Comment: The Tonkawa Springs and Great Oaks neighborhoods in
Williamson County, Texas, had their water supply contaminated in 1995
after gasoline from a nearby gas station leaked into water wells for
the two neighborhoods. These water wells had to be decommissioned and
another water supplier found.
Our Response: We agree that leaking underground storage tanks and
other sources of hazardous materials pose a threat to salamanders. The
final listing rules cite this type of hazardous spill as a threat.
(53) Comment: One commenter contests the idea that land application
irrigation from wastewater treatment plants increases pollutants in the
aquifer.
Our Response: No citation is provided by the commenter to support
this view; however, Ross (2011, pp. 11-18) reported that residential
irrigation with wastewater effluent had led to excessive nutrient input
into the recharge zone of the Barton Springs Segment of the Edwards
Aquifer. Mahler et al. (2011, p. 35) also cites land application of
treated wastewater as the likely source of excess nutrients, and
possibly wastewater compounds, detected in tributaries recharging
Barton Springs. This information has been updated in the final listing
rule.
(54) Comment: City of Round Rock is extending its contract for the
third time to build a fire station next to Krienke Spring in Jollyville
Plateau salamander critical habitat Unit 1. No detention facilities
have been proposed, and none appear possible because of topography
without excavation into karst rock layer. The City of Round Rock had a
geological assessment and geotechnical studies done as well as an
engineering feasibility study, which includes logs of boring with lab
test data, boring location

[[Page 51292]]

plan, and preliminary foundation and pavement design information.
Copies were provided in the comment letter.
Our Response: The final listing rule cites population growth and
urban development as a primary threat to salamanders. To achieve
recovery of these salamander species, we will seek cooperative
conservation efforts on private, State, and other lands.
(55) Comment: Through measuring water-borne stress hormones,
researchers found that salamanders from urban sites had significantly
higher corticosterone stress hormone levels than salamanders from rural
sites. This finding serves as evidence that chronic stress can occur as
development encroaches upon these spring habitats.
Our Response: We are aware that researchers are pursuing this
relatively new approach to evaluate salamander health based on
differences in stress hormones between salamanders from urban and
nonurban sites. Stress levels that are elevated due to natural or
unnatural (that is, anthropogenic) environmental stressors can affect
an organism's ability to meet its life-history requirements, including
adequate foraging, predator avoidance, and reproductive success. We
encourage continued development of this and other nonlethal scientific
methods to improve our understanding of salamander health and habitat
quality.
(56) Comment: Information in the proposed rule does not discern
whether water quality degradation is due to development or natural
variation in flood and rainfall events. Fundamental differences in
surface counts of salamanders between sites are due to a natural
dynamic of an extended period of above-average rainfall followed by
recent drought.
Our Response: We recognize that aquatic-dependent organisms such as
the Austin blind and Jollyville Plateau salamanders will respond to
local weather conditions; however, the best available science indicates
that rainfall alone does not explain lower salamander densities at
urban sites monitored by the COA. Furthermore, there is scientific
consensus among numerous studies on the impacts of urbanization that
conclude species diversity and abundance consistently declines with
increasing levels of development, as described under Factor A in the
final listing rule.
(57) Comment: Studies carried out by the Williamson County
Conservation Foundation (WCCF) do not support the Service's assertions
that habitat for the salamanders is threatened by declining water
quality and quantity. New information from water quality studies
performed within the past 3 months at Jollyville Plateau salamander
sites indicate that aquifer water is remarkably clean and that water
quality protection standards already in place throughout the county are
working.
Our Response: The listing process requires the Service to consider
both ongoing and future threats to the species. Williamson County has
yet to experience the same level of population growth as Travis County,
but is projected to have continued rapid growth in the foreseeable
future. Therefore, it is not surprising that some areas where the
Jollyville Plateau salamanders occur in Williamson County may exhibit
good water quality. However, our peer reviewers concluded that the
water quality data referenced by the commenter is not enough evidence
to conclude that water quality at salamander sites in Williamson County
is sufficient for the Jollyville Plateau salamander. The best available
science indicates that water quality and species diversity consistently
declines with increasing levels of urban development. Existing
regulatory programs designed to protect water quality are often not
adequate to preserve native ecosystem integrity. Although some springs
support larger salamander populations compared to others, among the
Jollyville Plateau salamander sites for which we have long-term
monitoring data, there is a strong correlation between highly urbanized
areas and lower salamander densities. According to COA, densities of
Jollyville Plateau salamanders are an average of three times lower at
urban sites compared to rural streams.
(58) Comment: Aerial photography in the Travis County soil survey
indicates that the entire surface watershed of Indian Spring was built
out as primarily single-family residential subdivisions before 1970 in
the absence of any water quality regulations. Impervious cover levels
in the watershed have remained above 40 percent for more than 40 years.
Despite nearly 75 years of contiguous development and habitat
modification to Indian Spring, the salamanders have persisted and
appear to thrive.
Our Response: We were provided no references in support of the
comment ``. . . Indian Spring . . . salamanders have persisted and
appear to thrive.'' Our records indicate the status of the salamander
population at Indian Springs is currently unknown. As stated in our
response to comment 62 above, we are unaware of long-term monitoring
studies that have demonstrated stable populations of Jollyville Plateau
salamanders over time in highly developed areas. Furthermore, the fact
that some heavily urbanized areas still have salamanders in them does
not indicate the probability of population persistence over the long
term.
Hydrology
(59) Comment: The Service homogenizes ecosystem characteristics
across central Texas salamander species. The proposed rule often
assumes that the ``surface habitat'' characteristics of the Barton
Springs salamander and Austin blind salamander (year-round surface
water in manmade impoundments) apply to the Jollyville Plateau
salamanders, which live in very different geologic and hydrologic
habitat. The Jollyville Plateau salamander lives in water contained
within a ``perched'' zone of the Edwards Limestone formation that is
relatively thin and does not retain or recharge much water when
compared to the Barton Springs segment of the Edwards Aquifer. Many of
the springs where Jollyville Plateau salamanders are found are more
ephemeral due to the relatively small drainage basins and relatively
quick discharge of surplus groundwater after a rainfall event. Surface
water at several of the proposed creek headwater critical habitat units
is generally short lived following a rain event. The persistence of
Jollyville Plateau salamanders at these headwater locations
demonstrates that this species is not as dependent on surface water as
occupied impoundments suggest.
Our Response: The Service recognizes that the Austin blind
salamander is more subterranean than the other three species of
salamander. However, the Jollyville Plateau salamander spends large
portions of its life in subterranean habitat. Further, the Jollyville
Plateau salamander has cave-associated forms. The Austin blind and
Jollyville Plateau salamander species are within the same genus,
entirely aquatic throughout each portion of their life cycles, respire
through gills, inhabit water of high quality with a narrow range of
conditions, depend on water from the Edwards Aquifer, and have similar
predators. The Barton Springs salamander shares these same
similarities. Based on this information, the Service has determined
that these species are suitable surrogates for each other.
Exactly how much these species depend on surface water is unclear,
but the best available information suggests that the productivity of
surface habitat is important for individual growth. For example, a
recent study showed that Jollyville Plateau salamanders had negative
growth in body length and tail width while using subsurface habitat
during a drought and that growth did

[[Page 51293]]

not become positive until surface flow returned (Bendik and Gluesenkamp
2012, pp. 3-4). In addition, the morphological variation found in these
salamander populations may provide insight into how much time is spent
in subsurface habitat compared to surface habitat.
(60) Comment: Another commenter stated that salamander use of
surface habitat is entirely dependent on rainfall events large enough
to generate sufficient spring and stream flow. Even after large
rainfall events, stream flow decreases quickly and dissipates within
days. As a result, the salamanders are predominately underground
species because groundwater is far more abundant and sustainable.
Our Response: See our response to previous comment.
(61) Comment: Several commenters stated that there is insufficient
data on long-term flow patterns of the springs and creek and on the
correlation of flow, water quality, habitat, ecology, and community
response to make a listing determination. Commenters propose that
additional studies be conducted to evaluate hydrology and surface
recharge area, and water quality.
Our Response: We agree that there is a need for more study on the
hydrology of salamander sites, but there is enough data available on
the threats to these species to make a listing determination. We make
our listing determinations based on the five listing factors, singly or
in combination, as described in section 4(a)(1) of the Act.
Pesticides
(62) Comment: Claims of pesticides posing a significant threat are
unsubstantiated. The references cited in the proposed rule are in some
cases misquoted, and others are refuted by more robust analysis. The
water quality monitoring reports, as noted in the proposed rule,
indicate that pesticides were found at levels below criteria set in the
aquatic life protection section of the Texas Surface Water Quality
Standards, and they were most often at sites with urban or partly urban
watersheds. This information conflicts with the statement that the
frequency and duration of exposure to harmful levels of pesticides have
been largely unknown or undocumented.
Our Response: We recognize there are uncertainties about the degree
to which different pesticides may be impacting water quality and
salamander health across the range of the Austin blind and Jollyville
Plateau salamanders, but the very nature of pesticides being designed
to control unwanted organisms through toxicological mechanisms and
their persistence in the environment makes them pose an inherent risk
to nontarget species. Numerous studies have documented the presence of
pesticides in water, particularly areas impacted by urbanization and
agriculture, and there is ample evidence that full life-cycle and
multigenerational exposures to dozens of chemicals, even at low
concentrations, contribute to declines in the abundance and diversity
of aquatic species. Few pesticides or their breakdown products have
been tested for multigenerational effects to amphibians, and many do
not have an applicable State or Federal water quality standard. For
these reasons, we maintain that commercial and residential pesticide
use contributes to habitat degradation and poses a threat to the Austin
blind and Jollyville Plateau salamanders, as well as the aquatic
organisms that comprise their diet.
(63) Comment: There were no detections of insecticides or
fungicides in a USGS monitoring program that analyzed for 52 soluble
pesticide residues in the Barton Springs aquifer from 2003 through 2005
(Maher et al. 2006). This same study found the highest atrazine
concentrations detected was about 0.08 [micro]g/L in a sample from
Upper Spring, indicated as 40 times lower than levels of concern (Maher
et al. 2006). The maximum value of 0.44 [micro]g/L cited from older
USGS monitoring data, though still lower than levels of concern,
appears to be abnormally high and not representative of actual
exposure. The body of evidence available strongly suggests that
historical levels of pesticide residues in the aquifers inhabited by
the Austin blind and Jollyville Plateau salamanders have always been
low and are diminishing.
Our Response: We agree that levels of pesticides documented in
Barton Springs and other surface water bodies of the Edwards Aquifer
often occur at relatively low concentrations; nevertheless, we believe
they are capable of negatively impacting habitat quality and salamander
health. Barton Springs in particular is an artesian spring with high
flows that would serve to dilute pollutants that are introduced to the
system via storm events, irrigation runoff, or other non-point sources
and may, therefore, not be representative of pesticide concentrations
in springs throughout the range of the Austin blind and Jollyville
Plateau salamanders. Furthermore, persistent compounds that
bioaccumulate could enter aquatic systems at low levels, but
nevertheless reach levels of concern in sediments and biological
tissues over time. We agree that pesticide residues would be expected
to be low historically in the aquifer, but we disagree that pesticides
are decreasing. No citation was provided by the commenter to
substantiate this claim. We believe that, with projected human
population growth, the frequency and concentration of pesticides in the
environment will increase in the future.
(64) Comment: The Service cites Rohr et al. (2003, p. 2,391)
indicating that carbaryl causes mortalities and deformities in
streamside salamanders (Ambystoma barbouri). However, Rohr et al.
(2003, p. 2,391) actually found that larval survival was reduced by the
highest concentrations of carbaryl tested (50 [mu]g/L) over a 37-day
exposure period. Rohr et al. (2003, p. 2,391) also found that embryo
survival and growth was not affected, and hatching was not delayed in
the 37 days of carbaryl exposure. In the same study, exposure to 400
[mu]g/L of atrazine over 37 days (the highest dose tested) had no
effect on larval or embryo survival, hatching, or growth. A Scientific
Advisory Panel (SAP) of the Environmental Protection Agency (EPA)
reviewed available information regarding atrazine effects on
amphibians, including the Hayes (2002) study cited by the Service, and
concluded that atrazine appeared to have no effect on clawed frog
(Xenopus laevis) development at atrazine concentrations ranging from
0.01 to 100 [micro]g/L. These studies do not support the Service's
conclusions.
Our Response: We do not believe that our characterization of Rohr
et al. (2003) misrepresented the results of the study. In their
conclusions, Rohr et al. (2003, p. 2,391) state, ``Carbaryl caused
significant larval mortality at the highest concentration and produced
the greatest percent of malformed larvae, but did not significantly
affect behavior relative to controls. Although atrazine did not induce
significant mortality, it did seem to affect motor function.'' This
study clearly demonstrates that these two pesticides can have an impact
on amphibian biology and behavior. In addition, the EPA (2007, p. 9)
also found that carbaryl is likely to adversely affect the Barton
Springs salamander both directly and indirectly through reduction of
prey.
Regarding the Hayes (2002) study, we acknowledge that an SAP of the
EPA reviewed this information and concluded that atrazine
concentrations less than 100 [micro]g/L had no effects on clawed frogs
in 2007. However, the 2012 SAP did reexamine the conclusions of the
2007 SAP using a meta-analysis of published studies along with
additional studies on more species (EPA 2012, p. 35). The 2012 SAP
expressed concern

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that some studies were discounted in the 2007 SAP analysis, including
studies like Hayes (2002) that indicated that atrazine is linked to
endocrine disruption in amphibians (EPA 2012, p. 35). In addition, the
2007 SAP noted that their results on clawed frogs are insufficient to
make global conclusions about the effects of atrazine on all amphibian
species (EPA 2012, p. 33). Accordingly, the 2012 SAP has recommended
further testing on at least three amphibian species before a conclusion
can be reached that atrazine has no effect on amphibians at
concentrations less than 100 [micro]g/L (EPA 2012, p. 33). Due to
potential differences in species sensitivity, exposure scenarios that
may include dozens of chemical stressors simultaneously, and
multigenerational effects that are not fully understood, we continue to
view pesticides in general, including carbaryl, atrazine, and many
others to which aquatic organisms may be exposed, as a potential threat
to water quality, salamander health, and the health of aquatic
organisms that comprise the diet of salamanders.
Impervious Cover
(65) Comment: One commenter stated that, in the draft impervious
cover analysis, the Service has provided no data to prove a cause and
effect relationship between impervious cover and the status of surface
salamander sites or the status of underground habitat.
Our Response: Peer reviewers agreed that we used the best available
scientific information in regard to the link between urbanization,
water quality, and salamander populations.
(66) Comment: On page 18 of the draft impervious cover analysis,
the Service dismisses the role and effectiveness of water quality
controls to mitigate the effects of impervious cover: ``. . . the
effectiveness of storm water runoff measures, such as passive filtering
systems, is largely unknown in terms of mitigating the effects of
watershed-scale urbanization.'' The Service recognized the
effectiveness of such storm water runoff measures in the final rule
listing the Barton Springs salamander as endangered in 1997. Since
1997, the Service has separately concurred that the water quality
controls imposed in the Edwards Aquifer area protect the Barton Springs
salamander.
Our Response: Since 1997, water quality and Jollyville Plateau
salamander counts have declined at several salamander sites, as
described under Factor A in the final listing rule. This is in spite of
water quality control measures implemented in the Edwards Aquifer area.
Further discussion of these measures can be found under Factor D in
this final listing rule.
(67) Comment: The springshed, as defined in the draft impervious
cover analysis, is a misnomer because the so-called springsheds
delineated in the study are not the contributing or recharge area for
the studied springs. Calling a surface area that drains to a specific
stretch of a creek a springshed is disingenuous and probably misleading
to less informed readers.
Our Response: We acknowledge that the term springshed may be
confusing to readers, and we have thus replaced this term with the
descriptors ``surface drainage area of a spring'' or ``surface
watershed of a spring'' throughout the final listing rule and
impervious cover analysis document.
(68) Comment: Page 18 of the draft impervious cover analysis
states, ``. . . clearly-delineated recharge areas that flow to specific
springs have not been identified for any of these spring sites;
therefore, we could not examine impervious cover levels on recharge
areas to better understand how development in those areas may impact
salamander habitat.'' This statement is not accurate with respect to
the springs in which the Austin Blind salamander has been observed.
Numerous studies, including several dye studies, have been conducted on
the recharge area for these springs. Enclosed with this letter are
seven studies that describe the ``springshed'' for these springs.
Further, Barton Springs Pool is largely isolated from Barton Creek due
to dams and bypass structures except during larger rainfall events when
the creek tops the upstream dam. That the draft impervious cover
analysis misses these obvious and widely known facts indicates a
fundamental misunderstanding of how the Barton Springs segment of the
Edwards Aquifer operates.
Our Response: We acknowledge that the recharge area for Barton
Springs is much better studied compared to springs for other central
Texas salamanders, and we have incorporated this information in the
final impervious cover analysis. We are also aware of the upstream dam
above Barton Springs. However, this dam does not isolate the springs
from threats occurring within the surface watershed. We believe the
surface watershed of Barton Springs does play a role in determining the
overall habitat quality of this site. For example, development in the
surface watershed may increase the frequency and severity of flood
events that top the upstream dam. These floods contain contaminants and
sediments that accumulate in Barton Springs (Geismar 2005, p. 2; COA
2007a, p. 4).
(69) Comment: During the first public comment period, many entities
submitted comments and information directing the Service's attention to
the actual data on water quality in the affected creeks and springs.
Given the amount of water quality data available to the Service and the
public, the Texas Salamander Coalition is concerned that the Service
continues to ignore local data and instead focuses on impervious cover
and impervious cover studies conducted in other parts of the country
without regard to existing water quality regulations. Why use models,
generic data, and concepts when actual data on the area of concern is
readily available?
Our Response: The Service has examined and incorporated all water
quality data submitted during the public comment periods. However, the
vast majority of salamander sites are still lacking long-term
monitoring data that are necessary to make conclusions on the status of
the site's water quality. The impervious cover analysis allows us to
quantify this specific threat for sites where information is lacking.
(70) Comment: Spicewood Springs, proposed critical habitat Unit 31
for the Jollyville Plateau salamander, was fully built out prior to
1995. No open space exists within Unit 31 aside from the narrow wooded
area along an unnamed tributary. Impervious cover in Unit 31 exceeds 55
percent. Impervious cover within the Spicewood Springs surface
watershed exceeds 50 percent. Development has almost certainly led to
bank erosion, increased velocity, decreased water depths, fill from
construction activities, and stream maintenance and stabilization.
These modifications have altered the natural and traditional character
of the tributary in which Spicewood Springs are located. Extensive,
historic impervious cover in the watershed (55 percent) and the
subsequent baseline water quality has not eliminated Jollyville Plateau
salamander at the spring, documenting that the threat of the habitat
degradation is absent in Unit 31. By the criteria in the proposed rule,
the Jollyville Plateau salamander should no longer occupy Spicewood
Springs because the impervious cover is greater than 15 percent and has
been for 30 years. However, Jollyville Plateau salamanders have been
found by the COA in 1996 after which most of the development in the
area was complete. Further, recent water quality sampling by SWCA shows
baseline levels of almost all contaminants. Any future added impervious
cover is not likely to significantly reduce the current amount

[[Page 51295]]

of groundwater recharging. Groundwater depletion may also result from
groundwater extraction. Review of the Texas Water Development Board
data indicates no Edwards formation water wells are in the area.
Our Response: Numerous variables affect the extent to which any
given spring may be impacted by surrounding land uses and human
activities that occur both within the immediate watershed and in areas
of groundwater recharge. Some springs may be more resistant or
resilient to increased pollution loading due to high flow volume,
extensive subsurface habitat, or other physical, chemical, or
biological features that ameliorate the effects of environmental
stressors. Impervious cover estimates are a useful tool to indicate the
likelihood of injury to aquatic resources, but there are exceptions.
However, the scientific literature overwhelmingly indicates a strong
pattern of lower water quality and aquatic biodiversity in the presence
of increasing levels of impervious cover.
Disease
(71) Comment: The Service concludes in the proposed rule that
chytrid fungus is not a threat to any of the salamanders. The Service's
justification for this conclusion is that they have no data to indicate
whether impacts from this disease may increase or decrease in the
future. There appears to be inconsistency in how the information
regarding threats is used.
Our Response: Threats are assessed by their imminence and
magnitude. Currently, we have no data to indicate that chytrid fungus
is a significant threat to the species. The few studies that have
looked for chytrid fungus in central Texas Eurycea found the fungus,
but no associated pathology was found within several populations and
among different salamander species.
(72) Comment: The statement about chytrid fungus having been
documented on Austin blind salamanders in the wild is incorrect.
Chytrid fungus has only been documented on captive Austin blind
salamanders. The appropriate citation for this is Chamberlain 2011,
COA, (pers. comm.), not O'Donnell et al. 2006, as cited in the proposed
rule.
Our Response: This statement has been corrected in the final
listing rule.
Climate Change
(73) Comment: Climate change has already increased the intensity
and frequency of extreme rainfall events globally (numerous references)
and in central Texas. This increase in rainfall extremes means more
runoff possibly overwhelming the capacity of recharge features. This
has implications for water storage. Implications are that the number of
runoff events recharging the aquifer with a higher concentration of
toxic pollutants than past events will be occurring more frequently,
likely in an aquifer with a lower overall volume of water to dilute
pollutants. Understanding high concentration toxicity needs to be
evaluated in light of this.
Our Response: We agree that climate change will likely result in
less frequent recharge, affecting both water quantity and quality of
springs throughout the aquifer. We have added language in the final
listing rule to further describe the threat of climate change and
impacts to water quality.
(74) Comment: The section of the proposed rule addressing climate
change fails to include any consideration or description of a baseline
central Texas climate. The proposed rule describes flooding and drought
as threats, but fails to provide any serious contextual analysis of the
role of droughts and floods in the life history of the central Texas
salamanders.
Our Response: The proposed and final listing rules discuss the
threats of drought conditions and flooding, both in the context of
naturally occurring weather patterns and as a result of anthropogenic
activities.
(75) Comment: The flooding analysis is one of several examples in
the proposed rule in which the Service cites events measured on micro-
scales of time and area, and fails to comprehend the larger ecosystem
at work. For example, the proposed rule describes one flood event
causing ``erosion, scouring the streambed channel, the loss of large
rocks, and creation of several deep pools.'' Scouring and depositing
sediment are both normal results of the intense rainfall events in
central Texas.
Our Response: While we agree that scouring and sediment deposition
are normal hydrologic processes, when the frequency and intensity of
these events is altered by climate change, urbanization, or other
anthropogenic forces, the resulting impacts to ecosystems can be more
detrimental than what would occur naturally.
Other Threats
(76) Comment: The risk of extinction is negatively or inversely
correlated with population size. Also, small population size, in and of
itself, can increase the risk of extinction due to demographic
stochasticity, mutation accumulation, and genetic drift. The
correlation between extinction risk and population size is not
necessarily indirect (that is, due to an additional extrinsic factor
such as environmental perturbation).
Our Response: Although we do not consider small population sizes to
be a threat in and of itself to any of the Austin blind and Jollyville
Plateau salamanders, we do believe that small population sizes make
them more vulnerable to extinction from other existing or potential
threats, such as major stochastic events.
Taxonomy
(77) Comment: The level of genetic divergence among the Jollyville
Plateau, Georgetown, and Salado salamanders is not sufficiently large
to justify recognition of three species. The DNA papers indicate a
strong genetic relationship between individual salamanders found across
the area. Such a strong relationship necessarily means that on an
ecosystem-wide basis, the salamanders are exchanging genetic material
on a regular basis. There is no evidence that any of these salamanders
are unique species.
Our Response: The genetic relatedness of the Georgetown salamander,
Jollyville Plateau salamander, and Salado salamanders is not disputed.
The three species are included together on a main branch of the tree
diagrams of mtDNA data (Chippindale et al. 2000, Figs. 4 and 6). The
tree portraying relationships based on allozymes (genetic markers based
on differences in proteins coded by genes) is concordant with the mtDNA
trees (Chippindale et al. 2000, Fig. 5). These trees support the
evolutionary relatedness of the three species, but not their identity
as a single species. The lack of sharing of mtDNA haplotype markers,
existence of unique allozyme alleles in each of the three species, and
multiple morphological characters diagnostic of each of the three
species are inconsistent with the assertion that they are exchanging
genetic material on a regular basis. The Austin blind salamander is on
an entirely different branch of the tree portraying genetic
relationships among these species based on mtDNA and has diagnostic,
morphological characters that distinguish it from other Texas
salamanders (Hillis et al. 2001, p. 267). Based on our review of these
differences, and taking into account the views expressed in peer
reviews by expert taxonomists, we believe that the currently available
evidence is sufficient for recognizing these salamanders as four
separate species.
(78) Comment: A genetics professor commented that Forstner's report
(2012) disputing the taxonomy of the Austin

[[Page 51296]]

blind, Georgetown, Jollyville Plateau, and Salado salamanders
represents a highly flawed analysis that has not undergone peer review.
It is not a true taxonomic analysis of the Eurycea complex and does not
present any evidence that call into question the current taxonomy of
the salamanders. Forstner's (2012) report is lacking key information
regarding exact methodology and analysis. It is not entirely clear what
resulting length of base pairs was used in the phylogenetic analysis
and the extent to which the data set was supplemented with missing or
ambiguous data. The amount of sequence data versus missing data is
important for understanding and interpreting the subsequent analysis.
It also appears as though Forstner included all individuals with
available, unique sequence when, in fact, taxonomic sampling--that is,
the number of individuals sampled within a particular taxon compared
with other taxa--can also affect the accuracy of the resulting
topology. The Forstner (2012) report only relies on mitochondrial DNA
whereas the original taxonomic descriptions of these species relied on
a combination of nuclear DNA, mitochondrial DNA, as well as morphology
(Chippindale et al. 2000, Hillis et al. 2001). Forstner's (2012) report
does not consider non-genetic factors such as ecology and morphology
when evaluating taxonomic differences. Despite the limitations of a
mitochondrial DNA-only analysis, Forstner's (2012) report actually
contradicts an earlier report by the same author that also relied only
on mtDNA.
Our Response: This comment supports the Service's and our peer
reviewers' interpretation of the best available data (see Responses to
Comments 1 through 5 above).
(79) Comment: Forstner (2012) argues that the level of genetic
divergence among the three species of Texas Eurycea is not sufficiently
large to justify recognition of three species. A genetics professor
commented that this conclusion is overly simplistic. It is not clear
that the populations currently called Eurycea lucifuga in reality
represent a single species, as Forstner (2012) assumes. Almost all
cases of new species in the United States for the last 20 years (E.
waterlooensis is a rare exception) have resulted from DNA techniques
used to identify new species that are cryptic, meaning their similarity
obscured the genetic distinctiveness of the species. One could view the
data on Eurycea lucifuga as supporting that cryptic species are also
present. Moreover, Forstner's (2012) comparison was made to only one
species, rather than to salamanders generally. Moreover, there is
perhaps a problem with the Harlan and Zigler (2009) data. They
sequenced 10 specimens of E. lucifuga, all from Franklin County,
Tennessee; 9 of these show genetic distances between each other from
0.1 to 0.3 percent, which is very low. One specimen shows genetic
distance to all other nine individuals from 1.7 to 1.9 percent, an
order of magnitude higher. This single specimen is what causes the high
level of genetic divergence to which Forstner compares the Eurycea.
This discrepancy is extremely obvious in the Harlan and Zigler (2009)
paper, but was not mentioned by Forstner (2012). A difference of an
order of magnitude in 1 specimen of 10 is highly suspect, and,
therefore, these data should not be used as a benchmark in comparing
Eurycea.
The second argument in Forstner (2012) is that the phylogenetic
tree does not group all individuals of a given species into the same
cluster or lineage. Forstner's (2012) conclusions are overly
simplistic. The failure of all sequences of Eurycea tonkawae to cluster
closely with each other is due to the amount of missing data in some
sequences. It is well known in the phylogenetics literature that
analyzing sequences with very different data (in other words, large
amounts of missing data) will produce incorrect results because of this
artifact. As an aside, why is there missing data? The reason is that
these data were produced roughly 5 years apart. The shorter sequences
were made at a time when lengths of 350 bases for cytochrome b were
standard because of the limitations of the technology. As improved and
cheaper methods were available (about 5 to 6 years later), it became
possible to collect sequences that were typically 1,000 to 1,100 bases
long. It is important to remember that the data used to support the
original description of the three northern species by Chippindale et
al. (2000) were not only cytochrome b sequences, but also data from a
different, but effective, analysis of other genes, as well as analysis
of external characteristics. Forstner's (2012) assessment of the
taxonomic status (species or not) of the three species of the northern
group is not supported by the purported evidence that he presents (much
of it unpublished).
Our Response: This comment supports the Service's and our peer
reviewers' interpretation of the best available data (see Responses to
Comments 1 through 5 above).
(80) Comment: Until the scientific community determines the
appropriate systematic approach to identify the number of species, it
seems imprudent to elevate the salamanders to endangered.
Our Response: The Service must base its listing determinations on
the best available scientific and commercial information, and such
information includes considerations of correct taxonomy. To ensure the
appropriateness of our own analysis of the relevant taxonomic
literature, we sought peer reviews from highly qualified taxonomists,
particularly with specialization on salamander taxonomy, of our
interpretation of the available taxonomic literature and unpublished
reports. We believe that careful analysis and peer review is the best
way to determine whether any particular taxonomic arrangement is likely
to be generally accepted by experts in the field. The peer reviews that
we received provide overall support, based on the available
information, for the species that we accept as valid in the final
listing rule.
Technical Information
(81) Comment: Clarify whether the distance given for the Austin
blind salamander extending ``at least 984 feet (ft) (300 meters (m)
underground'' is a vertical depth or horizontal distance.
Our Response: It is a horizontal distance. This has been clarified
in the final listing rule.
(82) Comment: The Service made the following statement in the
proposed rule: ``Therefore, the status of subsurface populations is
largely unknown, making it difficult to assess the effects of threats
on the subsurface populations and their habitat.'' In fact, the
difficulty of assessing threats for subsurface populations depends upon
the threats. One can more easily assess threats of chemical pollutants,
for example, because subterranean populations will be affected
similarly to surface ones because they inhabit the same or similar
water.
Our Response: The statement above was meant to demonstrate the
problems associated with not knowing how many salamanders exist in
subsurface habitat rather than how threats are identified. We have
removed the statement in the final listing rule to eliminate this
confusion.
(83) Comment: In addition to the references cited in the proposed
rule, Bowles et al. (2006) also documents evidence of reproduction
throughout the year in Jollyville Plateau salamanders.
Our Response: We examined the published article by Bowles et al.
(2006, pp. 114, 116, 118), and found that, while there were juvenile
salamanders observed nearly year-round, there was

[[Page 51297]]

also evidence of a seasonal reproduction pattern among their study's
findings. We have included this information in the final listing rule.
(84) Comment: Geologists with the COA have extensively reviewed the
possibility that a small test well caused the dewatering of Moss Gully
Spring, as discussed in the proposed rule, and have been unable to
substantiate that theory. In fact, the boring was drilled near the
spring in 1985, and the spring was found to have significant flow and a
robust Jollyville Plateau salamander population in the early 1990s.
Reduction in flow and a smaller salamander population was observed at
Moss Gully Spring around 2005 or 2006, but there had been no changes to
the boring. Subsequent groundwater tracing also failed to delineate a
definitive connection between the well and the spring.
Our Response: Given the existing uncertainty that dewatering at
this site was caused by the 1985 test well, we have removed the
discussion of Moss Gully Spring from the final listing rule.
(85) Comment: The discussion of the COA's Water Treatment Plant 4
project in the proposed rule could be misconstrued as posing a threat
to the Jollyville Plateau salamander.
Our Response: We agree that construction and operation of the
Jollyville Transmission Main tunnel, including associated vertical
shafts, is unlikely to adversely affect the Jollyville Plateau
salamander due to best management practices and environmental
monitoring implemented by the COA. We have modified this discussion in
the final listing rule to clarify our assessment.

Changes From Proposed Listing Rule

On August 22, 2012 (77 FR 50768), we published a proposed rule to
list the Jollyville Plateau salamander as endangered. Based on
additional information we received during the comment period on the
proposed rule and after further analysis of the magnitude and imminence
of threats to the species, we are listing the Jollyville Plateau
salamander as a threatened species in this final rule. For more
detailed information, please see Listing Determination for the
Jollyville Plateau Salamander below.

Summary of Factors Affecting the Species

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

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

Habitat modification, in the form of degraded water quality and
quantity and disturbance of spring sites, is the primary threat to the
Austin blind and Jollyville Plateau salamanders. Water quality
degradation in salamander habitat has been cited as the top concern in
several studies (Chippindale et al. 2000, pp. 36, 40, 43; Hillis et al.
2001, p. 267; Bowles et al. 2006, pp. 118-119; O'Donnell et al. 2006,
pp. 45-50). These salamanders spend their entire life cycle in water.
All of the species have evolved under natural aquifer conditions both
underground and as the water discharges from natural spring outlets.
Deviations from high water quality and quantity have detrimental
effects on salamander ecology because the aquatic habitat can be
rendered unsuitable for salamanders by changes in water chemistry and
flow patterns. Substrate modification is also a major concern for the
salamander species (COA 2001, pp. 101, 126; Geismar 2005, p. 2;
O'Donnell et al. 2006, p. 34). Unobstructed interstitial space is a
critical component to the surface habitat for the Austin blind and
Jollyville Plateau salamanders, because it provides cover from
predators and habitat for their macroinvertebrate prey items within
surface sites. When the interstitial spaces become compacted or filled
with fine sediment, the amount of available foraging habitat and
protective cover for salamanders is reduced (Welsh and Ollivier 1998,
p. 1,128).
Threats to the habitat of the Austin blind and Jollyville Plateau
salamanders (including those that affect water quality, water quantity,
or the physical habitat) may affect only the surface habitat, only the
subsurface habitat, or both habitat types. For example, substrate
modification degrades the surface springs and spring-runs, but does not
impact the subsurface environment, while water quality degradation can
impact both the surface and subsurface habitats, depending on whether
the degrading elements are moving through groundwater or are running
off the ground surface into a spring area (surface watershed). Our
assessment of water quality threats from urbanization is largely
focused on surface watersheds. Impacts to subsurface areas are also
likely to occur from urbanization over recharge zones within the
Edwards Aquifer region; however, these impacts are more difficult to
assess given the limited information available on subsurface flows and
drainage areas that feed into these subsurface flows to the springs and
cave locations. These recharge areas are additional pathways for
impacts to the Austin blind and Jollyville Plateau salamanders to occur
that we are not able to precisely assess at each known salamander site.
However, we can consider urbanization and various other sources of
impacts to water quality and quantity over the larger recharge zone to
the aquifer (as opposed to individual springs) to assess the potential
for impacts at salamander sites.
The threats under Factor A will be presented in reference to
stressors and sources. We consider a stressor to be a physical,
chemical, or biological alteration that can induce an adverse response
from an individual salamander. These alterations can act directly on an
individual or act indirectly on an individual through impacts to
resources the species requires for feeding, breeding, or sheltering. A
source is the origin from which the stressor (or alteration) arises.
The majority of the discussion below under Factor A focuses on
evaluating the nature and extent of stressors and their sources related
to urbanization, the primary source of water quality degradation,
within the ranges of the Austin blind and Jollyville Plateau
salamanders. Additionally, other stressors causing habitat destruction
and modification, including water quantity degradation and physical
disturbance to surface habitat, will be addressed.

Water Quality Degradation

Urbanization
Urbanization is the concentration of human populations into
discrete areas, leading to transformation of land for residential,
commercial, industrial, and transportation purposes. It is one of the
most significant sources of water quality degradation that can affect
the future survival of central Texas salamanders (Bowles et al. 2006,
p. 119; Chippindale and Price 2005, pp. 196-197). Urban development
leads to various stressors

[[Page 51298]]

on spring systems, including increased frequency and magnitude of high
flows in streams, increased sedimentation, increased contamination and
toxicity, and changes in stream morphology and water chemistry (Coles
et al. 2012, pp. 1-3, 24, 38, 50-51). Urbanization can also impact
aquatic species by negatively affecting their invertebrate prey base
(Coles et al. 2012, p. 4).
The ranges of the Austin blind and Jollyville Plateau salamanders
reside within increasingly urbanized areas of Travis and Williamson
Counties that are experiencing rapid human population growth. For
example, the population of the COA grew from 251,808 people in 1970 to
656,562 people in 2000. By 2007, the population had grown to 735,088
people (COA 2007b, p. 1). This represents a 192 percent increase over
the 37-year period. Population projections from the Texas State Data
Center (2012, pp. 496-497) estimate that Travis County will increase in
population from 1,024,266 in 2010, to 1,990,820 in 2050. This would be
a 94 percent increase in the human population size over this 40-year
period. The Texas State Data Center also estimates an increase in human
population in Williamson County from 422,679 in 2010 to 2,015,294 in
2050, exceeding the size of Travis County. This would represent a 477
percent increase over a 40-year timeframe. All human population
projections from the Texas State Data Center presented here are under a
high growth scenario, which assumes that migration rates from 2000 to
2010 will continue through 2050 (Texas State Data Center and the Office
of the State Demographer 2012, p. 9). By comparison, the national
United States' population is expected to increase from 310,233,000 in
2010, to 439, 010,000 in 2050, which is about a 42 percent increase
over the 40-year period (U.S. Census Bureau 2008, p. 1). Growing human
populations increase demand for residential and commercial development,
drinking water supply, wastewater disposal, flood control, and other
municipal goods and services that alter the environment, often
degrading salamander habitat by changing hydrologic regimes, and
affecting the quantity and quality of water resources.
As development increases within the watersheds where the Austin
blind and Jollyville Plateau salamanders occur, more opportunities
exist for the detrimental effects of urbanization to impact salamander
habitat. A comprehensive study by the USGS found that, across the
United States, contaminants, habitat destruction, and increasing
streamflow flashiness (rapid response of large increases of streamflow
to storm events) resulting from urban development have been associated
with the disruption of biological communities, particularly the loss of
sensitive aquatic species (Coles et al. 2012, p. 1).
Several researchers have also examined the negative impact of
urbanization on stream salamander habitat by making connections between
salamander abundances and levels of development within the watershed.
In 1972, Orser and Shure (p. 1,150) were among the first biologists to
show a decrease in stream salamander density with increasing urban
development. A similar relationship between salamanders and
urbanization was found in North Carolina (Price et al. 2006, pp. 437-
439; Price et al. 2012, p. 198), Maryland, and Virginia (Grant et al.
2009, pp. 1,372-1,375). Willson and Dorcas (2003, pp. 768-770)
demonstrated the importance of examining disturbance within the entire
watershed as opposed to areas just adjacent to the stream by showing
that salamander abundance is most closely related to the amount and
type of habitat within the entire watershed. In central Texas, Bowles
et al. (2006, p. 117) found lower Jollyville Plateau salamander
densities in tributaries with developed watersheds as compared to
tributaries with undeveloped watersheds. Developed tributaries also had
higher concentrations of chloride, magnesium, nitrate-nitrogen,
potassium, sodium, and sulfate (Bowles et al. 2006, p. 117).
The impacts that result from urbanization can affect the physiology
of individual salamanders. An unpublished study (Gabor 2012, Texas
State University, pers. comm.) has demonstrated that Jollyville Plateau
salamanders in disturbed habitats have greater stress levels than those
in undisturbed habitats, as determined by measurements of water-borne
stress hormones in disturbed (urbanized) and undisturbed streams (Gabor
2012, Texas State University, pers. comm.). Chronic stress can decrease
survival of individuals and may lead to a decrease in reproduction.
Both of these factors may partially account for the decrease in
abundance of salamanders in streams within disturbed environments
(Gabor 2012, Texas State University, pers. comm.).
Urbanization occurring within the watersheds of the Austin blind
and Jollyville Plateau salamanders could cause irreversible declines or
extirpation of salamander populations with continuous exposure over a
relatively short time span. We consider this to be an ongoing threat of
high impact for the Jollyville Plateau salamander that is expected to
increase in the future as development within its range expands.
Impervious cover is another source of water quality degradation and
is directly correlated with urbanization (Coles et al. 2012, p. 30).
For this reason, impervious cover is often used as a surrogate for
urbanization (Schueler et al. 2009, p. 309), even though it does not
account for many sources of water quality degradation associated with
urbanization, including human population density, fertilizer and
pesticide use, septic tanks, and fuel storage and transport. Impervious
cover is any surface material that prevents water from filtering into
the soil, such as roads, rooftops, sidewalks, patios, paved surfaces,
or compacted soil (Arnold and Gibbons 1996, p. 244). Once vegetation in
a watershed is replaced with impervious cover, rainfall is converted to
surface runoff instead of filtering through the ground (Schueler 1991,
p. 114). Such urbanized development in a watershed may: (1) Alter the
hydrology or movement of water through a watershed, (2) increase the
inputs of contaminants to levels that greatly exceed those found
naturally in streams, and (3) alter habitats in and near streams that
provide living spaces for aquatic species (Coles et al. 2012, p. 38),
such as the Austin blind and Jollyville Plateau salamanders. During
periods of high precipitation levels, stormwater runoff in urban areas
can enter recharge areas of the Edwards Aquifer and rapidly transport
sediment, fertilizer nutrients, and toxic contaminants (such as
pesticides, metals, and petroleum hydrocarbons) to salamander habitat.
Both nationally and locally, consistent relationships between
impervious cover and water quality degradation through contaminant
loading have been documented. In a study of contaminant input from
various land use areas in Austin, stormwater runoff loads were found to
increase with increasing impervious cover (COA 1990, pp. 12-14). This
study also found that contaminant input rates of the more urbanized
watersheds were higher than those of the small suburban watersheds.
Soeur et al. (1995, p. 565) determined that stormwater contaminant
loading positively correlated with development intensity in Austin. In
a study of 38 small watersheds in the Austin area, several different
contaminants were found to be positively correlated with impervious
cover (5-day biochemical oxygen demand, chemical oxygen demand,
ammonia, dissolved phosphorus, copper, lead, and zinc)

[[Page 51299]]

(COA 2006, p. 35). Using stream data from 1958 to 2007 at 24 Austin-
area sites, some of which are located within watersheds occupied by
Austin blind salamanders and Jollyville Plateau salamanders, Glick et
al. (2009, p. 9) found that the COA's water quality index had a strong
negative correlation with impervious cover. Veenhuis and Slade (1990,
pp. 18-61) also reported mean concentrations of most water quality
constituents, such as total suspended solids and other pollutants, are
lower in undeveloped watersheds than those for urban watersheds.
Impervious cover has demonstrable impacts on biological communities
within streams. Schueler (1994, p. 104) found that sites receiving
runoff from high impervious cover drainage areas had sensitive aquatic
macroinvertebrate species replaced by species more tolerant of
pollution and hydrologic stress (high rate of changes in discharges
over short periods of time). An analysis of nine regions across the
United States found considerable losses of algal, invertebrate, and
fish species in response to stressors brought about by urban
development (Coles et al. 2012, p. 58). In an analysis of 43 North
Carolina streams, Miller et al. (2007, pp. 78-79) found a strong
negative relationship between impervious cover and the abundance of
larval southern two-lined salamanders (Eurycea cirrigera). The COA
cited five declining salamander populations from 1997 to 2006: Balcones
District Park Spring, Tributary 3, Tributary 5, Tributary 6, and
Spicewood Tributary (O'Donnell et al. 2006, p. 4). All of these
populations occur within surface watersheds containing more than 10
percent impervious cover (Service 2013, pp. 9-11). Springs with
relatively low amounts of impervious cover (6.77 and 0 percent for
Franklin and Wheless Springs, respectively) in their surface drainage
areas tend to have generally stable or increasing salamander
populations (Bendik 2011a, pp. 18-19). Bendik (2011a, pp. 26-27)
reported statistically significant declines in Jollyville Plateau
salamander populations over a 13-year period at six monitored sites
with high impervious cover (18 to 46 percent) compared to two sites
with low impervious cover (less than 1 percent). These results are
consistent with Bowles et al. (2006, p. 111), who found lower densities
of Jollyville Plateau salamanders at urbanized sites compared to non-
urbanized sites.
We recognize that the long-term survey data of Jollyville Plateau
salamanders using simple counts may not give conclusive evidence on the
long-term trend of the population at each site. However, based on the
threats and evidence from the literature, the declines in counts seen
at urban Jollyville Plateau salamander sites are likely real declines
in the population. We expect downward trends in salamander populations
to continue into the future as human population growth and urbanization
drive further declines in habitat quality and quantity.
Impervious Cover Analysis
For this final rule, we calculated impervious cover within the
watersheds occupied by the Austin blind and Jollyville Plateau
salamanders. In this analysis, we delineated the surface areas that
drain into spring sites and which of these sites may be experiencing
habitat quality degradation as a result of impervious cover in the
surface drainage area. However, we only examined surface drainage areas
for each spring site for the Jollyville Plateau salamander because we
did not know the recharge area for specific spring or cave sites. This
information was available for the Austin blind salamander and the
Barton Springs system. Another limitation of this analysis is that we
did not account for riparian (stream edge) buffers or stormwater runoff
control measures, both of which have the potential to mitigate some of
the effects of impervious cover on streams (Schueler et al. 2009, pp.
312-313). Please see the Service's Refined Impervious Cover Analysis
(Service 2013, pp. 2-7) for a description of the methods used to
conduct this analysis. This analysis is most likely an underestimation
of current impervious cover because small areas of impervious cover may
have gone undetected at the resolution of our analysis and additional
areas of impervious cover may have been added since 2006, which is the
year the impervious-cover data for our analysis was generated. We
compared our results with the results of similar analyses completed by
SWCA and COA, and impervious-cover percentages at individual sites from
both analyses were generally higher than our own (Service 2013,
Appendix C).

Impervious Cover Categories

We examined studies that report ecological responses to watershed
impervious- cover levels based on a variety of degradation measurements
(Service 2013, Table 1, p. 4). Most studies examined biological
responses to impervious cover (for example, aquatic invertebrate and
fish diversity), but several studies measured chemical and physical
responses as well (for example, water quality parameters and stream
channel modification). The most commonly reported impervious cover
level at which noticeable degradation to aquatic ecosystems begins to
occur is approximately 10 percent, with more recent studies reporting
levels of 10 percent and lower. Recent studies in the eastern United
States have reported large declines in aquatic macroinvertebrates (the
prey base of salamanders) at impervious-cover levels as low as 0.5
percent (King and Baker 2010, p. 1002; King et al. 2011, p. 1664).
Bowles et al. (2006, pp. 113, 117-118) found lower Jollyville Plateau
salamander densities in watersheds with more than 10 percent impervious
cover. To our knowledge, this is the only peer-reviewed study that
examined watershed impervious-cover effects on salamanders in our study
area. This is also in agreement with the Center for Watershed
Protection's impervious-cover model, which predicts that stream health
begins to decline at 5 to 10 percent impervious cover in small
watersheds (Schueler et al. 2009, pp. 309, 313). Their prediction is
based on a meta-analysis of 35 recent research studies (Schueler et al.
2009, p. 310). However, a USGS investigation found immediate declines
in aquatic invertebrate communities as soon as the percentage of
developed land increased from background levels, including areas with
less than 10 percent impervious cover (Coles et al. 2012, p. 64).
Various levels of impervious cover within watersheds have been
cited as having detrimental effects to water quality and biological
communities within streams (Schueler et al. 2009, pp. 312-313; Coles et
al. 2012, p. 65). An impervious-cover model generated using data from
relevant literature by Schueler et al. (2009, p. 313) indicates that
stream degradation generally increases as impervious cover increases,
and occurs at impervious cover of 5 to 10 percent. This model predicts
that streams transition from an ``impacted'' status (clear signs of
declining stream health) to a ``nonsupporting'' status (no longer
support their designated uses in terms of hydrology, channel stability,
habitat, water quality, or biological diversity) at impervious-cover
levels from 20 to 25 percent. However, a recent national-scale
investigation of the effects of urban development on stream ecosystems
revealed that degradation of invertebrate communities can begin at the
earliest levels of urban development (Coles et al. 2012, p. 64),
thereby contradicting the resistance thresholds described by Schueler
(1994, pp. 100-102). Therefore, the lack of a resistance

[[Page 51300]]

threshold in biological responses indicates that no assumptions can be
made with regard to a ``safe zone'' of impervious cover less than 10
percent (Coles et al. 2012, p. 64). In light of these studies, we
created the following impervious cover categories:

None: 0 percent impervious cover in the watershed
Low: Greater than 0 percent to 10 percent impervious cover
in the watershed
Medium: Greater than 10 percent to 20 percent impervious
cover in the watershed
High: Greater than 20 percent impervious cover in the
watershed
Sites in the Low category may still be experiencing impacts from
urbanization, as cited in studies such as Coles et al. (2012, p. 64),
King et al. (2011, p. 1664), and King and Baker (2010, p. 1002). In
accordance with the findings of Bowles et al. (2006, pp. 113, 117-118),
sites in the Medium category are likely experiencing impacts from
urbanization that are negatively impacting salamander densities. Sites
in the High category are so degraded that habitat recovery will either
be impossible or very difficult (Schueler et al. 2009, pp. 310, 313).

Results of Our Impervious Cover Analysis

We estimated impervious cover percentages for each surface drainage
area of a spring known to have at least one population of either an
Austin blind or Jollyville Plateau salamander (cave locations were
omitted). These estimates and maps of the surface drainage area of
spring locations are provided in our refined impervious cover analysis
(Service 2013, pp. 1-25). A total of 114 watersheds were analyzed,
encompassing a total of 543,269 acres (ac) (219,854 hectares (ha)).
The Austin blind salamander had three watersheds delineated, one
for each of the springs where the species is found. Eliza and Parthenia
Springs had nearly identical large surface drainage areas, while the
watershed of Sunken Garden (Old Mill) was found to be a much smaller
area. Even though the level of impervious cover was Low in Eliza and
Parthenia watersheds, most of the impervious cover occurs within 5 mi
(8 km) of the springs.
We also calculated the impervious cover levels for the contributing
and recharge zones of the Barton Springs Segment of the Edwards
Aquifer. Unlike the known locations for the Jollyville Plateau
salamander, the sources of subsurface water feeding the sites of Austin
blind salamander (Barton Springs complex) are fairly well-delineated.
Barton Springs is the principal discharge point for the Barton Springs
Segment of the Edwards Aquifer, and recharge throughout most of the
aquifer converges to this discharge point (Slade et al. 1986, p. 28;
Johnson et al. 2012, p. 2). Most of the water recharging the Barton
Springs Segment of the Edwards Aquifer was believed to be derived from
percolation through six creeks that cross the recharge zone (Slade et
al. 1986, pp. 43, 51), but more recent work shows that a significant
amount of recharge occurs in the upland areas (Hauwert 2009, pp. 212-
213). Approximately 75 percent of the Barton Springs Segment of the
recharge zone has no impervious cover. Overall, the recharge zone of
the Barton Springs Segment of the Edwards Aquifer has 6.9 percent
impervious cover. The contributing zone of the Barton Springs Segment
has 1.81 percent impervious cover overall.
For the Jollyville Plateau salamander, a total of 93 watersheds
were delineated, representing 106 surface sites. The watersheds varied
greatly in size, ranging from the 3-ac (1-ha) watershed of Cistern
(Pipe) Spring to the 49,784-ac (20,147-ha) watershed of Brushy Creek
Spring. Impervious cover also varied greatly among watersheds. Twelve
watersheds had no impervious cover. Eighty-one of the 93 watersheds had
some level of impervious cover, with 31 watersheds categorized as High,
26 as Medium, and 21 as Low. The highest level of impervious cover (48
percent) was found in the watershed of Troll Spring.
Based on our analysis of impervious-cover levels in land draining
across the surface into salamander surface habitat (Service 2013, pp.
1-25), the Jollyville Plateau salamander had a high proportion of
watersheds (47 of 93 analyzed) with medium and high levels of
impervious cover. Conversely, the watersheds encompassing the Austin
blind salamander were relatively low in impervious cover. No watersheds
for the Austin blind salamander were classified as medium or high (that
is, greater than 10 percent impervious cover). In addition, the
recharge and contributing zones of the Barton Springs segment of the
Edwards Aquifer were classified as low.
Although some watersheds in our analysis were classified as low, it
is important to note that low levels of impervious cover (that is, less
than 10 percent) may degrade salamander habitat. Recent studies in the
eastern United States have reported large declines in aquatic
macroinvertebrates (the prey base of salamanders) at impervious cover
levels as low as 0.5 percent (King and Baker 2010, p. 1002; King et al.
2011, p. 1,664). Several authors have argued negative effects to stream
ecosystems are seen at low levels of impervious cover and gradually
increase as impervious cover increases (Booth et al. 2002, p. 838;
Groffman et al. 2006, pp. 5-6; Schueler et al. 2009, p. 313; Coles et
al. 2012, pp. 4, 64).
Although general percentages of impervious cover within a watershed
are helpful in determining the general level of impervious cover within
watersheds, it does not tell the complete story of how urbanization may
be affecting salamanders or their habitat. Understanding how a
salamander might be affected by water quality degradation within its
habitat requires an examination of where the impervious cover occurs
and what other threats to water quality (for example, non-point-source
runoff, highways and other sources of hazardous materials, livestock
and feral hogs, and gravel and limestone mining) are present within the
watershed.
In addition, several studies have demonstrated that the spatial
arrangement of impervious cover has impacts on aquatic ecosystems. An
analysis of 42 watersheds in the State of Washington found that certain
urban pattern variables, such as land use intensity, land cover
composition, landscape configuration, and connectivity of the
impervious area are important in predicting effects to aquatic
ecosystems (Alberti et al. 2007, pp. 355-359). King et al. (2005, pp.
146-147) found that the closer developed land was to a stream in the
Chesapeake Bay watershed, the larger the effect it had on stream
macroinvertebrates. On a national scale, watersheds with development
clustered in one large area (versus being interspersed throughout the
watershed), and development located closer to streams had higher
frequency of high-flow events (Steuer et al. 2010, pp. 47-48, 52).
Based on these studies, it is likely that the way development is
situated in the landscape of a surface drainage area of a salamander
spring site plays a large role in how that development impacts
salamander habitat.
One major limitation of this analysis is that we only examined
surface drainage areas (watersheds) for each spring site for the
Jollyville Plateau salamander. In addition to the surface habitat, this
salamander uses the subsurface habitat. Moreover, the base flow of
water discharging from the springs on the surface comes from
groundwater sources, which are in turn replenished by recharge features
on the surface. As Shade et al. (2008, pp. 3-4)

[[Page 51301]]

points out, ``. . . little is known of how water recharges and flows
through the subsurface in the Northern Segment of the Edwards Aquifer.
Groundwater flow in karst is often not controlled by surface topography
and crosses beneath surface water drainage boundaries, so the sources
and movements of groundwater to springs and caves inhabited by the
Jollyville Plateau salamander are poorly understood. Such information
is critical to evaluating the degree to which Jollyville Plateau
salamander sites can be protected from urbanization.'' So a recharge
area for a spring may occur within the surface watershed, or it could
occur many miles away in a completely different watershed. A site
completely surrounded by development may still contain unexpectedly
high water quality because that spring's base flow is coming from a
distant recharge area that is free from impervious cover. While some
dye tracer work has been done in the Northern Segment (Shade et al.
2008, p. 4), clearly delineated recharge areas that flow to specific
springs in the Northern Segment have not been identified for any of
these spring sites; therefore, we could not examine impervious-cover
levels on recharge areas to better understand how development in those
areas may impact salamander habitat.
Impervious cover by itself within the watersheds of the Austin
blind and Jollyville Plateau salamanders could cause irreversible
declines or extirpation of populations with continuous exposure to
water quality degradation stressors over a relatively short timespan.
Given the current levels of impervious cover within the surface
watersheds for the Jollyville Plateau salamander, we consider this to
be a threat of high impact for this species that is expected to
increase in the future as development within its range expands.
Although the impervious cover level for the Austin blind salamander
remains relatively low at the present time, impacts from this threat
could increase in the future as urbanization expands.
Hazardous Material Spills
The Edwards Aquifer is at risk from a variety of sources of
contaminants and pollutants (Ross 2011, p. 4), including hazardous
materials that have the potential to be spilled or leaked, resulting in
contamination of both surface and groundwater resources (Service 2005,
pp. 1.6-14-1.6-15). For example, a number of point-sources of
pollutants exist within the Jollyville Plateau salamander's range.
Utility structures such as storage tanks or pipelines (particularly gas
and sewer lines) can accidentally discharge. Any activity that involves
the extraction, storage, manufacture, or transport of potentially
hazardous substances, such as fuels or chemicals, can contaminate water
resources and cause harm to aquatic life. Spill events can involve a
short release with immediate impacts, such as a collision that involves
a tanker truck carrying gasoline. Alternatively, the release can be
long term, involving the slow release of chemicals over time, such as a
leaking underground storage tank.
A peer reviewer for the proposed rule provided information from the
National Response Center's database of incidents of chemical and
hazardous materials spills (http://www.nrc.uscg.mil/foia.html) from
anthropogenic activities including, but not limited to, automobile or
freight traffic accidents, intentional dumping, storage tanks, and
industrial facilities. The number of incidents is likely to be an
underestimate of the total number of incidents because not all
incidents are discovered or reported. The database produced 450 records
of spill events (145 that directly affected a body of water) in Travis
County between 1990 and 2012 and 189 records of spill events (33 that
directly affected a body of water) in Williamson County during the same
time period. Spills that did not directly affect aquatic environments
may have indirectly done so by contaminating soils or lands that drain
to water bodies (Gillespie 2012, University of Texas, pers. comm.). The
risk of this type of contamination is currently ongoing and expected to
increase with increasing activities associated with urbanization in
central Texas.
Hazardous material spills pose a significant threat to the Austin
blind and Jollyville Plateau salamanders, and impacts from spills could
increase substantially under drought conditions due to lower dilution
and buffering capability of impacted water bodies. Spills under low
flow conditions are predicted to have an impact at much smaller volumes
(Turner and O'Donnell 2004, p. 26). For example, it is predicted that
at low flows (10 cubic feet per second (cfs)) a spill of 360 gallons
(1,362.7 liters) of gasoline 3 mi (4.8 km) from Barton Springs could be
catastrophic for the Austin blind salamander population (Turner and
O'Donnell 2004, p. 26).
A significant hazardous materials spill within stream drainages of
the Austin blind salamander could have the potential to threaten its
long-term survival and sustainability of multiple populations or
possibly the entire species. Because the Austin blind salamander
resides in only one spring system, a catastrophic spill in its surface
and subsurface habitat could cause the extinction of this species in
the wild. However, because the Jollyville Plateau salamander occurs in
106 surface and 16 cave populations over a broad range, the potential
for a catastrophic hazardous materials spill to cause the extinction of
this species in the wild is highly unlikely. Even so, a hazardous
materials spill has the potential to cause localized Jollyville Plateau
salamander populations to be extirpated. In combination with the other
threats identified in this final rule, a catastrophic hazardous
materials spill could contribute to the Jollyville Plateau salamanders'
risk of extinction by reducing its overall probability of persistence.
Furthermore, we consider hazardous material spills to be a potential
significant threat to the Austin blind salamanders due to their limited
distributions, the number of potential sources, and the amount of
damage that could be done by a single event.

Underground Storage Tanks

The risk of hazardous material spills from underground storage
tanks is widespread in Texas and is expected to increase as
urbanization continues to occur. As of 1996, more than 6,000 leaking
underground storage tanks in Texas had resulted in contaminated
groundwater (Mace et al. 1997, p. 2). In 1993, approximately 6,000
gallons (22,712 liters) of gasoline leaked from an underground storage
tank located near Krienke Springs in southern Williamson County, Texas,
which is known to be occupied by the Jollyville Plateau salamander
(Manning 1994, p. 1).
Leaking underground storage tanks have been documented as a problem
within the Jollyville Plateau salamander's range (COA 2001, p. 16). The
threat of water quality degradation from an underground storage tank
could by itself cause irreversible declines or extirpation in local
populations or significant declines in habitat quality of the Austin
blind and Jollyville Plateau salamanders with only one exposure event.
This is considered to be an ongoing threat of high impact to the
Jollyville Plateau salamander. Although we are unaware of any
information that indicates underground storage tanks have resulted in
spills within the vicinity of Austin blind salamander sites, they are
likely present within the watersheds that recharge Barton Springs given
its urbanized environment. We expect this to become a more significant

[[Page 51302]]

threat in the future as urbanization continues to expand.

Highways

The transport of hazardous materials is common on many highways,
which are major transportation routes (Thompson et al. 2011, p. 1).
Every year, thousands of tons of hazardous materials are transported
over Texas highways (Thompson et al. 2011, p. 1). Transporters of
hazardous materials (such as gasoline, cyclic hydrocarbons, fuel oils,
and pesticides) carry volumes ranging from a few gallons up to 10,000
gallons (37,854 liters) or more of hazardous material (Thompson et al.
2011, p. 1). An accident involving hazardous materials can cause the
release of a substantial volume of material over a very short period of
time. As such, the capability of standard stormwater management
structures (or best management practices) to trap and treat such
releases might be overwhelmed (Thompson et al. 2011, p. 2).
Interstate Highway 35 crosses the watersheds that contribute
groundwater to spring sites occupied by the Austin blind and Jollyville
Plateau salamanders. A catastrophic spill could occur if a transport
truck overturned and its contents entered the recharge zone of the
Northern or Barton Springs Segments of the Edwards Aquifer.
Transportation accidents involving hazardous materials spills at bridge
crossings are of particular concern because recharge areas in creek
beds can transport contaminants directly into the aquifer (Service
2005, pp. 1.6-14). The threat of water quality degradation from
highways could by itself cause irreversible declines or extirpation in
local populations or significant declines in habitat quality of the
Austin blind and Jollyville Plateau salamanders with only one exposure
event. We consider this to be an ongoing threat to the Austin blind and
Jollyville Plateau salamanders.

Energy Pipelines

Energy pipelines are another source of potential hazardous material
spills. They carry crude oil and refined products made from crude oil,
such as gasoline, home heating oil, diesel fuel, and kerosene.
Liquefied ethylene, propane, butane, and some petrochemicals are also
transported through energy pipelines (U.S. Department of Transportation
Pipeline and Hazardous Materials Safety Administration 2013, p. 1).
Austin blind salamander habitat is at risk from hazardous material
spills that could contaminate groundwater. There is potential for a
catastrophic spill in the Barton Springs Segment of the Edwards
Aquifer, due to the presence of the Longhorn pipeline (Turner and
O'Donnell 2004, pp. 2-3). Although a number of mitigation measures were
employed to reduce the risk of a leak or spill from the Longhorn
pipeline, such a spill could enter the aquifer and result in the
contamination of salamander habitat at Barton Springs (EPA 2000, pp. 9-
29-9-30).
A contaminant spill could travel quickly through the aquifer to
Barton Springs, where it could impact Austin blind salamander
populations. Depending on water levels in the aquifer, groundwater flow
rates through the Barton Springs Segment of the Edwards Aquifer can
range from 0.6 mi (1 km) per day to over 4 mi (6 km) per day. The
relatively rapid movement of groundwater under any flow conditions
provides little time for mitigation efforts to reduce potential damage
from a hazardous spill anywhere within the Barton Springs Segment of
the Edwards Aquifer (Turner and O'Donnell 2004, pp. 11-13).
The threat of water quality degradation from energy pipelines could
by itself cause irreversible declines, extirpation, or significant
declines in habitat quality of the Austin blind salamander with only
one exposure event. Because the Austin blind salamander is found only
at one location and can be extirpated by one catastrophic energy
pipeline leak, we consider this to be an ongoing threat of high impact
that will likely continue in the future. However, we are unaware of any
information that indicates energy pipelines are located within the
range of the Jollyville Plateau salamander and, therefore, do not
consider this to be a threat for this species at this time.

Water and Sewage Lines

Multiple municipality water lines also run through the surrounding
areas of Barton Springs. A water line break could potentially flow
directly into Barton Springs, exposing salamanders to chlorine
concentrations that are potentially toxic (Herrington and Turner 2009,
pp. 5, 6). Sewage spills are the most common type of spill within the
Barton Springs watershed and represent a potential catastrophic threat
(Turner and O'Donnell 2004, p. 27). Sewage spills often include
contaminants such as nutrients, polycyclic aromatic hydrocarbons
(PAHs), metals, pesticides, pharmaceuticals, and high levels of fecal
coliform bacteria. Increased ammonia levels and reduced dissolved
oxygen are the most likely impacts of a sewage spill that could cause
rapid mortality of large numbers of salamanders (Turner and O'Donnell
2004, p. 27). Fecal coliform bacteria cause diseases in salamanders and
their prey base (Turner and O'Donnell 2004, p. 27). Approximately 7,600
wastewater main pipelines totaling 349 mi (561.6 km) are present in the
Barton Springs Segment of the Edwards Aquifer (Herrington et al. 2010,
p. 16). In addition, there are 9,470 known septic facilities in the
Barton Springs Segment as of 2010 (Herrington et al. 2010, p. 5), up
from 4,806 septic systems in 1995 (COA 1995, pp. 3-13). In one COA
survey of these septic systems, over 7 percent were identified as
failing (no longer functioning properly, causing water from the septic
tank to leak) (COA 1995, pp. 3-18).
Sewage spills from pipelines also have been documented in
watersheds supporting Jollyville Plateau salamander populations (COA
2001, pp. 16, 21, 74). For example, in 2007, a sewage line overflowed
an estimated 50,000 gallons (190,000 liters) of raw sewage into the
Stillhouse Hollow drainage area of Bull Creek (COA 2007c, pp. 1-3).
Because the location of the spill was a short distance downstream of
currently known salamander locations, no salamanders were thought to be
affected.
The threat of water quality degradation from water and sewage lines
could by itself cause irreversible declines or extirpation in local
populations or significant declines in habitat quality of the Austin
blind and Jollyville Plateau salamanders with only one exposure event.
We consider this to be an ongoing threat of high impact to the Austin
blind and Jollyville Plateau salamanders that is likely to increase in
the future as urbanization expands within the ranges of these species.

Swimming Pools

If water from swimming pools is drained into waterways or storm
drains without dechlorination, impacts to Eurycea salamanders could
occur (COA 2001, p. 130). This is due to the concentrations of chlorine
commonly used in residential swimming pools, which far exceed the
lethal concentrations observed in experiments with the San Marcos
salamander (Eurycea nana) (COA 2001, p. 130). Saltwater pools have also
grown in popularity and pose a similar risk to water quality, because
saltwater can be harmful to freshwater organisms (Duellman and Trueb
1986, p. 165; Ingersoll et al. 1992, pp. 507-508; Bendik 2012, COA,
pers. comm.). Residential swimming pools can be found throughout the
watersheds of

[[Page 51303]]

several Jollyville Plateau salamander sites and may pose a risk to the
salamanders if discharged into the storm drain system or waterways.
Water quality degradation from swimming pools in combination with
other impacts could contribute to significant declines in habitat
quality. Although swimming pools occur throughout the range of the
Jollyville Plateau salamander, using 2012 Google Earth aerial images we
identified only two sites for this species (Krienke Spring and Long Hog
Hollow Tributary) with swimming pools located within 50 m (164 ft). We
did not identify any other swimming pools within 50 m (164 ft) of any
other salamander site. Therefore, we do not consider this to be an
ongoing threat to the Austin blind or Jollyville Plateau salamanders at
this time.
Construction Activities
Short-term increases in pollutants, particularly sediments, can
occur during construction in areas of new development. When vegetation
is removed and rain falls on unprotected soils, large discharges of
suspended sediments can erode from newly exposed areas resulting in
increased sedimentation in downstream drainage channels (Schueler 1987,
pp. 1-4; Turner 2003, p. 24; O'Donnell et al. 2005, p. 15). This
increased sedimentation from construction activities has been linked to
declines in Jollyville Plateau salamander counts at multiple sites
(Turner 2003, p. 24; O'Donnell et al. 2006, p. 34).
Cave sites are also impacted by construction, as Testudo Tube Cave
(Jollyville Plateau salamander habitat) showed an increase in nickel,
calcium, nitrates, and nitrites after nearby road construction (Richter
2009, pp. 6-7). Barton Springs (Austin blind salamander habitat) is
also under the threat of pollutant loading due to its proximity to
construction activities and the spring's location at the downstream
side of the watershed (COA 1997, p. 237). The COA (1995, pp. 3-11)
estimated that construction-related sediment and in-channel erosion
accounted for approximately 80 percent of the average annual sediment
load in the Barton Springs watershed. In addition, the COA (1995, pp.
3-10) estimated that total suspended sediment loads have increased 270
percent over predevelopment loadings within the Barton Springs Segment
of the Edwards Aquifer. Construction is intermittent and temporary, but
it affects both surface and subsurface habitats. Therefore, we have
determined that this threat is ongoing and will continue to affect the
Austin blind and Jollyville Plateau salamanders and their habitats.
Also, the physical construction of pipelines, shafts, wells, and
similar structures that penetrate the subsurface has the potential to
negatively affect subsurface habitat for salamander species. It is
known that these salamanders inhabit the subsurface environment and
that water flows through the subsurface to the surface habitat.
Tunneling for underground pipelines can destroy potential habitat by
removing subsurface material, thereby destroying subsurface spaces/
conduits in which salamanders can live, grow, forage, and reproduce.
Additional material can become dislodged and result in increased
sediment loading into the aquifer and associated spring systems. In
addition, disruption of water flow to springs inhabited by salamanders
can occur through the construction of tunnels and vertical shafts to
access them. Because of the complexity of the aquifer and subsurface
structure and because detailed maps of the underground conduits that
feed springs in the Edwards Aquifer are not available, tunnels and
shafts have the possibility of intercepting and severing those conduits
(COA 2010b, p. 28). Affected springs could rapidly become dry and would
not support salamander populations. The closer a shaft or tunnel
location is to a spring, the more likely that the construction will
impact a spring (COA 2010b, p. 28). Even small shafts pose a threat to
nearby spring systems. We consider subsurface construction to be a
threat to the surface and subsurface habitat of the Austin blind and
Jollyville Plateau salamanders.
Examples of recent subsurface construction activities that had the
potential to pose a threat to salamander surface and subsurface habitat
are the Water Treatment Plant No. 4 pipeline and shaft construction and
the Barton Springs Pool bypass tunnel repairs. In 2011, construction
began on the Jollyville Transmission Main (JTM), a tunnel designed to
transport treated drinking water from Water Treatment Plant No. 4 to
the Jollyville Reservoir. The project also includes four working shafts
along the tunnel route (COA 2010b, p. 1) that provide access points
from the surface down to the tunnel. While this type of project has the
potential to impact salamanders and their habitat, the COA took the
salamanders into consideration and designed measures to avoid or
minimize impacts. Because the tunnel is being constructed below the
Edwards Aquifer and below the permeable portion of the Glen Rose
formation (COA 2010b, p. 42; Toohey 2011, p. 1; COA 2011c, pp. 36, 46),
the threat to the salamander from this particular tunnel is considered
low.
Of the four Water Treatment Plant No. 4 shafts, only the one at the
Four Points location appeared to be a potential threat to any
Jollyville Plateau salamanders. However, construction on this shaft is
now completed, and there have been no observed impacts to any springs
or other downstream Jollyville Plateau habitat (COA 2012, pers. comm.).
Within 1 mi (1.6 km) of the Four Points shaft location are 8 of 92
known Jollyville Plateau salamander sites. The closest locations
(Spring 21 and Spring 24) are about 2,000 ft (610 m) or greater from
the shaft. Best management practices designed to protect groundwater
resources have been implemented into the design and construction of the
Jollyville Transmission Main shafts. These practices include, but are
not limited to: monitoring groundwater quality and spring flow,
minimizing sediment discharges during construction, developing a
groundwater impact contingency plan, locating working shafts in areas
where the chance of encountering conduits to salamander springs is
reduced, relocating the treatment plant from its original location near
Jollyville Plateau salamander sites to within an area that has no known
Jollyville Plateau salamander sites, dedicating 102 ac (41 ha) that was
originally purchased for the Water Treatment Plant No. 4 project as
conservation land in perpetuity as part of the Balcones Canyonlands
Preserve system, creating contingency plans for unexpectedly high
groundwater inflow to the shafts during their construction, and
rerouting conduit flow paths around the shaft if encountered (COA
2010b, pp. 51-55).
In 2012, the COA began construction in Barton Springs Pool to
repair and stabilize a bypass tunnel that allows both normal flow from
Barton Creek and frequent small floods to bypass the swimming area to
protect water quality within the pool. This project had the potential
to affect both Barton Springs and Austin blind salamanders by directly
injuring individuals found within the construction area, drying out
areas of habitat during pool drawdowns, and subjecting them to
potentially harmful chemicals and sediment (Service 2011, p. 27).
However, the COA took the Barton Springs and Austin blind salamanders
into careful consideration when planning this project and ultimately
implemented a variety of protective measures to minimize threats to
these species. Some

[[Page 51304]]

of these measures included, but are not limited to: (1) Regular
monitoring of water depth, water quality and temperature, discharge of
the Barton Springs complex, and salamander habitat; (2) limiting
drawdown to only 2 ft (0.6 m) under conditions of 40 cfs or greater;
(3) daily surveying for salamanders to ensure none were present in an
area where construction activities would be conducted; (4) relocating
salamanders found during these surveys to undisturbed habitat areas;
(5) carefully evaluating the types of materials used during
construction and choosing those that were the least toxic to the
aquatic ecosystem; and (6) using sediment and pollution control
measures, such as silt fences, containment booms, and turbidity
curtains (Service 2011, pp. 14-18). Because the COA implemented these
protective measures, impacts to the Barton Springs and Austin blind
salamanders were minimized.
The threat of water quality degradation from construction
activities could by itself cause irreversible declines or extirpation
in local populations or significant declines in habitat quality of the
Austin blind and Jollyville Plateau salamanders with only one exposure
event (if subsurface flows were interrupted or severed) or with
repeated exposure over a relatively short timespan. From information
available in our files and provided to us during the peer review and
public comment period for the proposed rule, we found that all of the
Austin blind salamander sites have been known to have had construction
on their perimeters. Likewise, we are aware of physical habitat
modification from construction activities at one of the known
Jollyville Plateau surface sites. Therefore, we consider construction
activities to be an ongoing threat of medium impact to the Austin blind
salamander and low impact to Jollyville Plateau salamanders given their
low exposure risk.

Quarries

Construction activities within rock quarries can permanently alter
the geology and groundwater hydrology of the immediate area and
adversely affect springs that are hydrologically connected to impacted
sites (Ekmekci 1990, p. 4; van Beynan and Townsend 2005, p. 104;
Humphreys 2011, p. 295). Limestone rock is an important raw material
that is mined in quarries all over the world due to its popularity as a
building material and its use in the manufacture of cement (Vermeulen
and Whitten 1999, p. 1). The potential environmental impacts of
quarries include destruction of springs or collapse of karst caverns,
as well as impacts to water quality through siltation and
sedimentation, and impacts to water quantity through water diversion,
dewatering, and reduced flows (Ekmekci 1990, p. 4; van Beynan and
Townsend 2005, p. 104). The mobilization of fine materials from
quarries can lead to the occlusion of voids and the smothering of
surface habitats for aquatic species downstream (Humphreys 2011, p.
295). Quarry activities can also generate pollution in the aquatic
ecosystem through leaks or spills of waste materials from mining
operations (such as petroleum products) (Humphreys 2011, p. 295). For
example, in 2000, a spill of almost 3,000 gallons (11,356 liters) of
diesel from an above-ground storage tank occurred on a limestone quarry
in New Braunfels, Texas (about 4.5-mi (7.2 km) from Comal Springs in
the Southern Segment of the Edwards Aquifer) (Ross et al. 2005, p. 14).
Quarrying of limestone is another activity that has considerable
potential to negatively affect the physical environments where
salamanders are known to occur. Quarrying and mineral extractions are
known to cause the downstream mobilization of sediment (Humphreys 2011,
p. 295), which can occlude the interstitial spaces that salamanders use
for protective cover. Quarrying can alter landforms, reduce spring
discharge, cause drawdown of the water table, produce sinkholes, and
destroy caves (van Beynen and Townsend 2005, p. 104). As quarries
continue to expand, the risk of impacting salamander habitat increases.
One quarry occurs in one of the surface watersheds (Brushy Creek
Spring) where Jollyville Plateau salamanders are known to occur. This
assessment was based on examining Google Earth 2012 aerial photos of
each site from the surface drainage basins (surface watersheds) of each
surface site. There may be additional avenues of potential impacts to
the springs or cave sites through subsurface drainage basins that were
not documented through this analysis.
The threat of physical modification of surface habitat from
quarrying by itself could cause irreversible declines in population
sizes or habitat quality at any of the Austin blind or Jollyville
Plateau salamander sites. It could also work in combination with other
threats to contribute to significant declines of salamander populations
or habitat quality. Currently quarries are located in the surface
watersheds of 1 of the 106 assessed Jollyville Plateau salamander
surface sites. Therefore, we consider this an ongoing threat of low
impact given the low exposure risk to the Jollyville Plateau salamander
that could increase in the future. Physical modification of surface
habitat from quarries is not considered an ongoing threat to the Austin
blind salamander at this time. The Austin blind salamander's range is
located in downtown Austin, and there are no active limestone quarries
within the species' range or in its surface watershed.
Contaminants and Pollutants
Contaminants and pollutants are stressors that can affect
individual salamanders or their habitats or their prey. These stressors
find their way into aquatic habitat through a variety of ways,
including stormwater runoff, point (a single identifiable source) and
non-point (coming from many diffuse sources) discharges, and hazardous
material spills (Coles et al. 2012, p. 21). For example, sediments
eroded from soil surfaces can concentrate and transport contaminants
(Mahler and Lynch 1999, p. 165). The Austin blind and Jollyville
Plateau salamanders and their prey species are directly exposed to
sediment-borne contaminants present within the aquifer and discharging
through the spring outlets. For example, in addition to sediment, trace
metals such as arsenic, cadmium, copper, lead, nickel, and zinc were
found in Barton Springs in the early 1990s (COA 1997, pp. 229, 231-
232). Such contaminants associated with sediments are known to
negatively affect survival and growth of an amphipod species, which are
part of the prey base of the Austin blind and Jollyville Plateau
salamanders (Ingersoll et al. 1996, pp. 607-608; Coles et al. 2012, p.
50). As a karst aquifer system, the Edwards Aquifer is more vulnerable
to the effects of contamination due to: (1) A large number of conduits
that offer no filtering capacity, (2) high groundwater flow velocities,
and (3) the relatively short amount of time that water is inside the
aquifer system (Ford and Williams 1989, pp. 518-519). These
characteristics of the aquifer allow contaminants entering the
watershed to enter and move through the aquifer more easily, thus
reaching salamander habitat within spring sites more quickly than other
types of aquifer systems. Various industrial and municipal activities
result in the discharge of treated wastewater or unintentional release
of industrial contaminants as point source pollution. Urban
environments are host to a variety of human activities that generate
many types of sources for contaminants and pollutants. These
substances, especially when combined, often degrade nearby

[[Page 51305]]

waterways and aquatic resources within the watershed (Coles et al.
2012, pp. 44-53).
Amphibians, especially their eggs and larvae (which are usually
restricted to a small area within an aquatic environment), are
sensitive to many different aquatic pollutants (Harfenist et al. 1989,
pp. 4-57). Contaminants found in aquatic environments, even at
sublethal concentrations, may interfere with a salamander's ability to
develop, grow, or reproduce (Burton and Ingersoll 1994, pp. 120, 125).
Central Texas salamanders are particularly vulnerable to contaminants,
because they have evolved under very stable environmental conditions,
remain aquatic throughout their entire life cycle, have highly
permeable skin, have severely restricted ranges, and cannot escape
contaminants in their environment (Turner and O'Donnell 2004, p. 5). In
addition, macroinvertebrates, such as small freshwater crustaceans
(amphipods and copepods), that aquatic salamanders feed on are
especially sensitive to water pollution (Phipps et al. 1995, p. 282;
Miller et al. 2007, p. 74; Coles et al. 2012, pp. 64-65). Studies in
the Bull Creek watershed in Austin, Texas, found a loss of some
sensitive macroinvertebrate species, potentially due to contaminants of
nutrient enrichment and sediment accumulation (COA 2001, p. 15; COA
2010a, p. 16). Below, we discuss specific contaminants and pollutants
that may be impacting the Austin blind and Jollyville Plateau
salamanders.

Petroleum Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a common form of
aquatic contaminants in urbanized areas that could affect salamanders,
their habitat, or their prey. This form of pollution can originate from
petroleum products, such as oil or grease, or from atmospheric
deposition as a byproduct of combustion (for example, vehicular
combustion). These pollutants accumulate over time on impervious cover,
contaminating water supplies through urban and highway runoff (Van
Metre et al. 2000, p. 4,067; Albers 2003, pp. 345-346). The main source
of PAH loading in Austin-area streams is parking lots with coal tar
emulsion sealant, even though this type of lot only covers 1 to 2
percent of the watersheds (Mahler et al. 2005, p. 5,565). A recent
analysis of the rate of wear on coal tar lots revealed that the
sealcoat wears off relatively quickly and contributes more to PAH
loading than previously thought (Scoggins et al. 2009, p. 4,914).
Petroleum and petroleum byproducts can adversely affect living
organisms by causing direct toxic action, altering water chemistry,
reducing light, and decreasing food availability (Albers 2003, p. 349).
Exposure to PAHs at levels found within the Jollyville Plateau
salamander's range can cause impaired reproduction, reduced growth and
development, and tumors or cancer in species of amphibians, reptiles,
and other organisms (Albers 2003, p. 354). Coal tar pavement sealant
slowed hatching, growth, and development of a frog (Xenopus laevis) in
a laboratory setting (Bryer et al. 2006, pp. 244-245). High
concentrations of PAHs from coal tar sealant negatively affected the
righting ability (amount of time needed to flip over after being placed
on back) of adult eastern newts (Notophthalmus viridescens) and may
have also damaged the newt's liver (Sparling et al. 2009, pp. 18-20).
For juvenile spotted salamanders (Ambystoma maculatum), PAHs reduced
growth in the lab (Sparling et al. 2009, p. 28). In a lab study using
the same coal tar sealant once used by the COA, Bommarito et al. (2010,
pp. 1,151-1,152) found that spotted salamanders displayed slower growth
rates and diminished swimming ability when exposed to PAHs. These
contaminants are also known to cause death, reduced survival, altered
physiological function, inhibited reproduction, and changes in
community composition of freshwater invertebrates (Albers 2003, p.
352). Due to their similar life histories, it is reasonable to assume
that effects of PAHs on other species of amphibians, reptiles, and
other organisms could also occur in Austin blind and Jollyville Plateau
salamanders.
Limited sampling by the COA has detected PAHs at concentrations of
concern at multiple sites within the range of the Jollyville Plateau
salamander. Most notable were the levels of nine different PAH
compounds at the Spicewood Springs site in the Shoal Creek drainage
area, which were above concentrations known to adversely affect aquatic
organisms (O'Donnell et al. 2005, pp. 16-17). The Spicewood Springs
site is located within an area with greater than 30 percent impervious
cover and down gradient from a commercial business that changes vehicle
oil. This is also one of the sites where salamanders have shown
declines in abundance (from an average of 12 individuals per visit in
1997 to an average of 2 individuals in 2005) during the COA's long-term
monitoring studies (O'Donnell et al. 2006, p. 47). Another study found
several PAH compounds in seven Austin-area streams, including Barton,
Bull, and Walnut Creeks, downstream of coal tar sealant parking lots
(Scoggins et al. 2007, p. 697). Sites with high concentrations of PAHs
(located in Barton and Walnut Creeks) had fewer macroinvertebrate
species and lower macroinvertebrate density (Scoggins et al. 2007, p.
700). This form of contamination has also been detected at Barton
Springs, which is the Austin blind salamander's habitat (COA 1997, p.
10).
The threat of water quality degradation from PAH exposure could by
itself cause irreversible declines or extirpation in local populations
or significant declines in habitat quality of the Austin blind and
Jollyville Plateau salamanders with continuous or repeated exposure. In
some instances, exposure to PAH contamination could negatively impact a
salamander population in combination with exposure to other sources of
water quality degradation, resulting in significant habitat declines or
other significant negative impacts (such as loss of invertebrate prey
species). We consider this to be a threat of high impact to the Austin
blind and Jollyville Plateau salamanders now and in the future as
urbanization increases within these species' surface watersheds.

Pesticides

Pesticides (including herbicides and insecticides) are also
associated with urban areas. Sources of pesticides include lawns, road
rights-of-way, and managed turf areas, such as golf courses, parks, and
ballfields. Pesticide application is also common in residential,
recreational, and agricultural areas. Pesticides have the potential to
leach into groundwater through the soil or be washed into streams by
stormwater runoff.
Some of the most widely used pesticides in the United States--
atrazine, carbaryl, diazinon, and simazine (Mahler and Van Metre 2000,
p. 1)--were documented within the Austin blind salamander's habitat
(Barton Springs Pool and Eliza Springs) in water samples taken at
Barton Springs during and after a 2-day storm event (Mahler and Van
Metre 2000, pp. 1, 6, 8). They were found at levels below criteria set
in the aquatic life protection section of the Texas Surface Water
Quality Standards (Mahler and Van Metre 2000, p. 4). In addition,
elevated concentrations of organochlorine pesticides were found in
Barton Springs sediments (Ingersoll et al. 2001, p. 7). A later water
quality study at Barton Springs from 2003 to 2005 detected

[[Page 51306]]

several pesticides (atrazine, simazine, prometon, and deethylatrazine)
in low concentrations (Mahler et al. 2006, p. 63). The presence of
these contaminants in Barton Springs indicates the vulnerability of
salamander habitat to contamination.
Another study by the USGS detected insecticides (diazinon and
malathion) and herbicides (atrazine, prometone, and simazine) in
several Austin-area streams, most often at sites with urban and partly
urban watersheds (Veenhuis and Slade 1990, pp. 45-47). Twenty-two of
the 42 selected synthetic organic compounds analyzed in this study were
detected more often and in larger concentrations at sites with more
urban watersheds compared to undeveloped watersheds (Veenhuis and Slade
1990, p. 61). Other pesticides (dichlorodiphenyltrichloroethane,
chlordane, hexachlorobenzene, and dieldrin) have been detected at
multiple Jollyville Plateau salamander sites (COA 2001, p. 130).
While pesticides have been detected at Austin blind salamander and
Jollyville Plateau salamander sites, we do not know the extent to which
pesticides and other waterborne contaminants have affected salamander
survival, development, and reproduction, or their prey. However,
pesticides are known to impact amphibian species in a number of ways.
For example, Reylea (2009, p. 370) demonstrated that diazinon reduces
growth and development in larval amphibians. Another pesticide,
carbaryl, causes mortality and deformities in larval streamside
salamanders (Ambystoma barbouri) (Rohr et al. 2003, p. 2,391). The
Environmental Protection Agency (EPA) (2007, p. 9) also found that
carbaryl is likely to adversely affect the Barton Springs salamander
both directly and indirectly through reduction of prey. Additionally,
atrazine has been shown to impair sexual development in male amphibians
(clawed frogs (Xenopus laevis)) at concentrations as low as 0.1 parts
per billion (Hayes 2002, p. 5,477). Atrazine levels were found to be
greater than 0.44 parts per billion after rainfall in Barton Springs
Pool (Mahler and Van Mere 2000, pp. 4, 12).
We acknowledge that in 2007 a Scientific Advisory Panel (SAP) of
the Environmental Protection Agency (EPA) reviewed the available
information on atrazine effects on amphibians and concluded that
atrazine concentrations less than 100 [mu]g[sol]L had no effects on
clawed frogs. However, the 2012 SAP is currently reexamining the
conclusions of the 2007 SAP using a meta-analysis of published studies
along with additional studies on more species (EPA 2012, p. 35). The
2012 SAP expressed concern that some studies were discounted in the
2007 SAP analysis, including studies like Hayes (2002) that indicated
that atrazine is linked to endocrine (hormone) disruption in amphibians
(EPA 2012, p. 35). In addition, the 2007 SAP noted that their results
on clawed frogs are insufficient to make global conclusions about the
effects of atrazine on all amphibian species (EPA 2012, p. 33).
Accordingly, the 2012 SAP has recommended further testing on at least
three amphibian species before a conclusion can be reached that
atrazine has no effect on amphibians at concentrations less than 100
[mu]g/L (EPA 2012, p. 33). Due to potential differences in species
sensitivity, exposure scenarios that may include dozens of chemical
stressors simultaneously, and multigenerational effects that are not
fully understood, we continue to view pesticides, including carbaryl,
atrazine, and many others to which aquatic organisms may be exposed, as
a potential threat to water quality, salamander health, and the health
of aquatic organisms that comprise the diet of salamanders.
The threat of water quality degradation from pesticide exposure
could by itself cause irreversible declines or extirpation in local
populations or significant declines in habitat quality of the Austin
blind and Jollyville Plateau salamanders with continuous or repeated
exposure. In some instances, exposure to pesticide contamination could
negatively impact a salamander population in combination with exposure
to other sources of water quality degradation, resulting in significant
habitat declines or other significant negative impacts (such as loss of
invertebrate prey species). We consider this an ongoing threat of high
impact for the Austin blind salamander because this species occurs only
in one location. For the Jollyville Plateau salamanders, this is
currently a threat of low impact that is likely to increase in the
future.

Nutrients

Nutrient input (such as phosphorus and nitrogen) to watershed
drainages, which often results in abnormally high organic growth in
aquatic ecosystems, can originate from multiple sources, such as human
and animal wastes, industrial pollutants, and fertilizers (from lawns,
golf courses, or croplands) (Garner and Mahler 2007, p. 29). As the
human population grows and subsequent urbanization occurs within the
ranges of the Austin blind and Jollyville Plateau salamanders, they
likely become more susceptible to the effects of excessive nutrients
within their habitats because their exposure increases. To illustrate,
an estimated 102,262 domestic dogs and cats (pet waste is a potential
source of excessive nutrients) were known to occur within the Barton
Springs Segment of the Edwards Aquifer in 2010 (Herrington et al. 2010,
p. 15). Their distributions were correlated with human population
density (Herrington et al. 2010, p. 15). Feral hogs have also been
cited as a source of elevated bacteria, nitrates, and phosphorus in
streams in the Austin area (Timmons et al. 2011, pp. 1-2). Finally,
livestock grazing near streams can negatively affect stream systems by
influencing nutrients, bacteria, and aquatic species diversity (COA
1995, pp. 3-62).
Various residential properties and golf courses are known to use
fertilizers to maintain turf grass within watersheds where Jollyville
Plateau salamander populations are known to occur (COA 2003, pp. 1-7).
Analysis of water quality attributes conducted by the COA (1997, pp. 8-
9) showed significant differences in nitrate, ammonia, total dissolved
solids, total suspended solids, and turbidity concentrations between
watersheds dominated by golf courses, residential land, and rural land.
Golf course tributaries were found to have higher concentrations of
these constituents than residential tributaries, and both golf course
and residential tributaries had substantially higher concentrations for
these five water quality attributes than rural tributaries (COA 1997,
pp. 8-9).
Residential irrigation of wastewater effluent is another source
leading to excessive nutrient input into the recharge and contributing
zones of the Barton Springs Segment of the Edwards Aquifer (Ross 2011,
pp. 11-18; Mahler et al. 2011, pp. 16-23). Wastewater effluent permits
do not require treatment to remove metals, pharmaceutical chemicals, or
the wide range of chemicals found in body care products, soaps,
detergents, pesticides, or other cleaning products (Ross 2011, p. 6).
These chemicals remaining in treated wastewater effluent can enter
streams and the aquifer and alter water quality within salamander
habitat. A USGS study found nitrate concentrations in Barton Springs
and the five streams that provide most of its recharge much higher
during 2008 to 2010 than before 2008 (Mahler et al. 2011, pp. 1-4).
Additionally, nitrate levels in water samples collected between 2003
and 2010 from Barton Creek tributaries exceeded TCEQ screening levels
and were identified as

[[Page 51307]]

screening level concerns (TCEQ 2012b, p. 344). The rapid development
over the Barton Springs contributing zone since 2000 was associated
with an increase in the generation of wastewater (Mahler et al. 2011,
p. 29). Septic systems and land-applied treated wastewater effluent are
likely sources contributing nitrate to the recharging streams (Mahler
et al. 2011, p. 29). As of November 2010, the permitted volume of
irrigated flow in the contributing zone of the Barton Springs Segment
of the Edwards Aquifer was 3,300,000 gallons (12,491 kiloliters) per
day. About 95 percent of that volume was permitted during 2005 to 2010
(Mahler et al. 2011, p. 30).
Excessive nutrient input into aquatic systems can increase plant
growth (including algae blooms), which pulls more oxygen out of the
water when the dead plant matter decomposes, resulting in less oxygen
being available in the water for salamanders to breathe (Schueler 1987,
pp. 1.5-1.6; Ross 2011, p. 7). A reduction in dissolved oxygen
concentrations could not only affect respiration in salamander species,
but also lead to decreased metabolic functioning and growth in
juveniles (Woods et al. 2010, p. 544), or death (Ross 2011, p. 6).
Excessive plant material can also reduce stream velocities and increase
sediment deposition (Ross 2011, p. 7). When the interstitial spaces
become compacted or filled with fine sediment, the amount of available
foraging habitat and protective cover is reduced (Welsh and Ollivier
1998, p. 1,128). Studies in the Bull Creek watershed found a loss of
some sensitive macroinvertebrate species, potentially due to nutrient
enrichment and sediment accumulation (COA 2001b, p. 15).
Increased nitrate levels have been known to affect amphibians by
altering feeding activity and causing disequilibrium and physical
abnormalities (Marco et al. 1999, p. 2,837). Poor water quality,
particularly elevated nitrates, may also be a cause of morphological
deformities in individual Jollyville Plateau salamanders. The COA has
documented very high levels of nitrates (averaging over 6 milligrams
per liter (mg L^-1) with some samples exceeding 10 mg
L^-1) and high conductivity at two monitoring sites in the
Stillhouse Hollow drainage area (O'Donnell et al. 2006, pp. 26, 37).
Additionally, as reported in the 2012 Texas Integrated Report of
Surface Water Quality, nitrate levels in water samples collected
between 2003 and 2010 from Stillhouse Hollow, Barrow Preserve, and
Spicewood stream segments exceeded TCEQ screening levels and were
identified as screening level concerns (TCEQ 2012b, p. 38, 41). For
comparison, nitrate levels in undeveloped Edwards Aquifer springs
(watersheds without high levels of urbanization) are typically close to
1 mg L^-1 (O'Donnell et al. 2006, p. 26). The source of the
nitrates in Stillhouse Hollow is thought to be lawn fertilizers (Turner
2005b, p. 11). Salamanders observed at the Stillhouse Hollow monitoring
sites have shown high incidences of deformities, such as curved spines,
missing eyes, missing limbs or digits, and eye injuries (O'Donnell et
al. 2006, p. 26). These deformities often result in the salamander's
inability to feed, reproduce, or survive. The Stillhouse Hollow
location was also cited as having the highest observation of dead
salamanders (COA 2001, p. 88). Although no statistical correlations
were found between the number of deformities and nitrate concentrations
(O'Donnell et al. 2006, p. 26), environmental toxins are the suspected
cause of salamander deformities (O'Donnell et al. 2006, p. 25). Nitrate
toxicity studies have indicated that salamanders and other amphibians
are sensitive to these pollutants (Marco et al. 1999, p. 2,837). Some
studies have indicated that concentrations of nitrate between 1.0 and
3.6 mg/L can be toxic to aquatic organisms (Rouse 1999, p. 802; Camargo
et al. 2005, p. 1,264; Hickey and Martin 2009, pp. ii, 17-18).
The threat of water quality degradation from excessive nutrient
exposure could by itself cause irreversible declines or extirpation in
local populations or significant declines in habitat quality of the
Austin blind and Jollyville Plateau salamanders with continuous or
repeated exposure. At least five surface watersheds of the known
Jollyville Plateau salamander's surface sites contain golf courses that
could be contributing to excessive nutrient loads. In some instances,
exposure to excessive nutrient exposure could negatively impact a
salamander population in combination with exposure to other sources of
water quality degradation, resulting in significant habitat declines or
other significant negative impacts (such as loss of morphological
deformities). We consider this an ongoing threat of medium impact for
the Austin blind salamander and low impact for the Jollyville Plateau
salamanders that will likely increase in the future.
Changes in Water Chemistry

Conductivity

Conductivity is a measure of the ability of water to carry an
electrical current and can be used to approximate the concentration of
dissolved inorganic solids in water that can alter the internal water
balance in aquatic organisms, affecting the Austin blind and Jollyville
Plateau salamanders' survival. Conductivity levels in the Edwards
Aquifer are naturally low, ranging from approximately 550 to 700 micro
Siemens per centimeter ([mu]S cm^-1) (derived from several
conductivity measurements in two references: Turner 2005a, pp. 8-9;
O'Donnell et al. 2006, p. 29). As ion concentrations such as chlorides,
sodium, sulfates, and nitrates rise, conductivity will increase. These
compounds are the chemical products, or byproducts, of many common
pollutants that originate from urban environments (Menzer and Nelson
1980, p. 633), which are often transported to streams via stormwater
runoff from impervious cover. This, combined with the stability of the
measured ions, makes conductivity an excellent monitoring tool for
assessing the impacts of urbanization to overall water quality.
Measurements by the COA between 1997 and 2006 found that conductivity
averaged between 550 and 650 [mu]S cm^-1 at rural springs
with low or no development and averaged between 900 and 1000 [mu]S
cm^-1 at monitoring sites in watersheds with urban
development (O'Donnell et al. 2006, p. 37).
Conductivity can be influenced by weather. Rainfall serves to
dilute ions and lower conductivity while drought has the opposite
effect. The trends of increasing conductivity in urban watersheds were
evident under baseflow conditions and during a period when
precipitation was above average in all but 3 years, so drought was not
a factor (NOAA 2013, pp. 1-7). The COA also monitored water quality as
impervious cover increased in several subdivisions with known
Jollyville Plateau salamander sites between 1996 and 2007. They found
increasing ions (calcium, magnesium, and bicarbonate) and nitrates with
increasing impervious cover at four Jollyville Plateau salamander sites
and as a general trend during the course of the study from 1997 to 2006
(Herrington et al. 2007, pp. 13-14). These results indicate that
developed watersheds can alter the water chemistry within salamander
habitats.
High conductivity has been associated with declining salamander
abundance. For example, three of the four sites with statistically
significant declining Jollyville Plateau salamander counts from 1997 to
2006 are cited as having high conductivity readings (O'Donnell et al.
2006, p. 37). Similar correlations

[[Page 51308]]

were shown in studies comparing developed and undeveloped sites from
1996 to 1998 (Bowles et al. 2006, pp. 117-118). This analysis found
significantly lower numbers of salamanders and significantly higher
measures of specific conductance at developed sites as compared to
undeveloped sites (Bowles et al. 2006, pp. 117-118). Tributary 5 of
Bull Creek has had an increase in conductivity, chloride, and sodium
and a decrease in invertebrate diversity from 1996 to 2008 (COA 2010a,
p. 16). Only one Jollyville Plateau salamander has been observed here
from 2009 to 2010 in quarterly surveys (Bendik 2011a, p. 16). A
separate analysis found that ions such as chloride and sulfate
increased in Barton Creek despite the enactment of city-wide water
quality control ordinances (Turner 2007, p. 7). Poor water quality, as
measured by high specific conductance and elevated levels of ion
concentrations, is cited as one of the likely factors leading to
statistically significant declines in salamander counts at the COA's
long-term monitoring sites (O'Donnell et al. 2006, p. 46). h
The threat of water quality degradation from high conductivity
could by itself cause irreversible declines or extirpation in local
populations or significant declines in habitat quality of the Austin
blind and Jollyville Plateau salamanders with continuous or repeated
exposure. In some instances, exposure to high conductivity could
negatively impact a salamander population in combination with exposure
to other sources of water quality degradation, resulting in significant
habitat declines. We consider this an ongoing threat of high impact for
the Jollyville Plateau salamander that is likely to increase in the
future. Although we are unaware of any information that indicates
increased conductivity is occurring within the ranges of the Austin
blind salamander, we expect this to become a significant threat in the
future for this species as urbanization continues to expand within its
surface watersheds.

Salinity

As groundwater levels decline, a decrease in hydrostatic pressure
occurs and saline water is able to move into groundwater flow paths of
the aquifer (Pavlicek et al. 1987, p. 2). Water quality in the Barton
Springs Segment of the Edwards Aquifer has been degraded in the past
due to saline water encroachment (Slade et al. 1986, p. 62). This water
quality degradation occurred when Barton Springs discharge was less
than 30 cfs (Slade et al. 1986, p. 64). An analysis of more recent data
found similar declines in water quality as the flow of Barton Springs
dropped into the 20 to 30 cfs range (Johns 2006, pp. 6-7). As mentioned
earlier, reduced groundwater levels would also increase the
concentration of pollutants in the aquifer. Flows at Barton Springs
dropped below 17 cfs as recently as mid-November 2011 (Barton Springs/
Edwards Aquifer Conservation District 2011, p. 1), and no Austin blind
salamanders were observed during surveys at any of their three known
locations during this time.
This saline water encroachment is detrimental to the freshwater
biota in the springs and the aquifer, including the Austin blind and
Jollyville Plateau salamanders and their prey. Most amphibian larvae
cannot survive saline conditions (Duellman and Trueb 1986, p. 165).
Ingersoll et al. (1992, pp. 507-508) found that increased salinity
caused mortality in amphipods and some freshwater fish species. Saline
conditions in the Edwards Aquifer could, therefore, pose a risk to the
salamanders and their prey species.
The threat of water quality degradation from saline water
encroachments could by itself cause irreversible declines or
extirpation in local populations or significant declines in habitat
quality of the Austin blind and Jollyville Plateau salamanders with
continuous or repeated exposure. In some instances, exposure to saline
conditions could negatively impact a salamander population in
combination with exposure to other sources of water quality
degradation, resulting in significant habitat declines or another
significant negative impact (such as loss of prey species). We consider
this an ongoing threat of high impact for the Austin blind salamander
that will continue in the future. At this time, we are unaware of any
information that indicates low saline water encroachment is occurring
within the range of the Jollyville Plateau salamander.

Dissolved Oxygen

In an analysis performed by the COA (Turner 2005a, p. 6),
significant changes over time were reported for several chemical
constituents and physical parameters in Barton Springs Pool, which
could be attributed to impacts from watershed urbanization.
Conductivity, turbidity, sulfates, and total organic carbon increased
over a 20- to 25-year time period while the concentration of dissolved
oxygen decreased (Turner 2005a, pp. 8-17). A similar analysis by
Herrington and Hiers (2010, p. 2) examined water quality at Barton
Springs Pool and other Barton Springs outlets where Austin blind
salamanders are found (Sunken Gardens and Eliza Springs) over a general
period of the mid-1990s to the summer of 2009. Herrington and Hiers
(2010, pp. 41-42) found that dissolved oxygen decreased over time in
the Barton Springs Pool, while conductivity and nitrogen increased.
However, this decline in water quality was not seen in Sunken Gardens
Spring or Eliza Spring (Herrington 2010, p. 42).
Low dissolved oxygen can affect salamanders and other amphibians by
reducing respiratory efficiency, metabolic energy, reproductive rate,
and ultimately survival (Norris et al. 1963, p. 532; Hillman and
Withers 1979, p. 2,104; Boutilier et al. 1992, pp. 81-82). The
screening level for dissolved oxygen (5.0 mg/L) that is used by TCEQ
for their analysis of water quality samples is similar to that
recommended by the Service in 2006 to be protective of federally listed
salamanders (White et al. 2006, p. 51). In 2012, the TCEQ reported that
stream segments located within watersheds occupied by the Austin blind
(Barton Spring pool) and Jollyville Plateau (Bull Creek) salamanders
had depressed dissolved oxygen levels that were not meeting screening
level criteria (TCEQ 2012b, pp. 35-36; 2012c, p. 733).
The threat of water quality degradation from low dissolved oxygen
could by itself cause irreversible declines or extirpation in local
populations or significant declines in habitat quality of the Austin
blind and Jollyville Plateau salamanders with continuous or repeated
exposure. In some instances, exposure to low dissolved oxygen could
negatively impact a salamander population in combination with exposure
to other sources of water quality degradation, resulting in significant
habitat declines. We consider this an ongoing threat of high impact for
the Austin blind salamander due to their limited range. However, we
consider this to be a threat of low impact to the Jollyville Plateau
salamanders given the low risk of exposure.

Water Quantity Degradation

Water quantity decreases and spring flow declines are considered
threats to Eurycea salamanders (Corn et al. 2003, p. 36; Bowles et al.
2006, p. 111), because drying spring habitats can cause salamanders to
be stranded, resulting in death of individuals (O'Donnell et al. 2006,
p. 16). It is also known that prey availability for carnivores is low
underground due to the lack of primary production (Hobbs and Culver
2009, p.

[[Page 51309]]

392). Therefore, relying entirely on subsurface habitat during dry
conditions on the surface may negatively impact the salamanders'
feeding abilities and slow individual and population growth, which can
exacerbate the risk of extirpation in the face of other threats
occurring at the site.
Urbanization
Increased urbanization in the watershed has been cited as one
factor, particularly in combination with drought that causes declines
in spring flows (COA 2006, pp. 46-47; TPWD 2011, pp. 4-5). This is
partly due to reductions in baseflow due to impervious cover.
Urbanization removes the ability of a watershed to allow slow
filtration of water through soils following rain events. Instead
rainfall runs off impervious surfaces and into stream channels at
higher rates, increasing downstream ``flash'' flows and decreasing
groundwater recharge and subsequent baseflows from springs (Miller et
al. 2007, p. 74; Coles et al. 2012, pp. 2, 19). Urbanization can also
impact water quantity by increasing groundwater pumping and altering
the natural flow regime of streams. These stressors are discussed in
more detail below.
Urbanization can also result in increased groundwater pumping,
which has a direct impact on spring flows, particularly under drought
conditions. Groundwater availability models demonstrate that 1 cfs of
pumping will diminish Barton Springs flow by 1 cfs under drought-of-
record (1950s drought) conditions (Smith and Hunt 2004, pp. 24, 36).
Under the same conditions, these models suggest that present-day
pumping rates will temporarily cease Barton Springs flow for at least a
4-month period under a repeat of drought-of-record conditions (Smith
and Hunt 2004, pp. 24, 36).
From 1980 to 2000, groundwater pumping in the Northern Segment of
the Edwards Aquifer nearly doubled (TWDB 2003, pp. 32-33). Total water
use for Williamson County where the Jollyville Plateau salamander
occurs was 82,382 acre feet (ac ft) in 2010, and is projected to
increase to 109,368 ac ft by 2020, and to 234,936 ac ft by 2060,
representing a 185 percent increase over the 50-year period (TWDB 2011,
p. 78). Similarly, a 91 percent increase in total groundwater use over
the same 50-year period is expected in Travis County (TWDB 2011, pp. 5,
72).
While the demand for water is expected to increase with human
population growth, one prediction of future groundwater use in this
area suggests a large drop in pumping as municipalities convert from
groundwater to surface water supplies (TWDB 2003, p. 65). To meet the
increasing water demand, the 2012 State Water Plan recommends more
reliance on surface water, including existing and new reservoirs,
rather than groundwater (TWDB 2012, p. 190). For example, one
recommended project conveys water from Lake Travis to Williamson County
(TWDB 2012, pp. 192-193). Another recommendation would augment the
surface water of Lake Granger in Williamson County with groundwater
from Burleson County and the Carrizo-Wilcox Aquifer (TWDB 2012, pp.
164, 192-193). However, it is unknown if this reduction in groundwater
use will occur, and if it does, how that will affect spring flows for
salamanders.
The COA found a negative correlation between urbanization and
spring flows at Jollyville Plateau salamander sites (Turner 2003, p.
11). Field studies have also shown that a number of springs that
support Jollyville Plateau salamanders have already gone dry
periodically and that spring waters resurface following rain events
(O'Donnell et al. 2006, pp. 46-47). Through a site-by-site assessment
from information available in our files and provided during the peer
review and public comment period for the proposed rule, we found that
51 out of the 106 Jollyville Plateau salamander surface sites have gone
dry for some period of time. Because we lack flow data for some of the
spring sites, it is possible that even more sites have gone dry for a
period of time as well.
Flow is a major determining factor of physical habitat in streams,
which in turn, is a major determining factor of aquatic species
composition within streams (Bunn and Arthington 2002, p. 492). Various
land-use practices, such as urbanization, conversion of forested or
prairie habitat to agricultural lands, excessive wetland draining, and
overgrazing can reduce water retention within watersheds by routing
rainfall quickly downstream, increasing the size and frequency of flood
events and reducing baseflow levels during dry periods (Poff et al.
1997, pp. 772-773). Over time, these practices can degrade in-channel
habitat for aquatic species (Poff et al. 1997, p. 773).
Baseflow is defined as that portion of streamflow that originates
from shallow, subsurface groundwater sources, which provide flow to
streams in periods of little rainfall (Poff et al. 1997, p. 771). The
land-use practices mentioned above can cause streamflow to shift from
predominately baseflow, which is derived from natural filtration
processes, to predominately stormwater runoff. With increasing
stormwater runoff, the amount of baseflow available to sustain water
supplies during drought cycles is diminished and the frequency and
severity of flooding increases (Poff et al. 1997, p. 773). The
increased quantity and velocity of runoff increases erosion and
streambank destabilization, which in turn, leads to increased sediment
loadings, channel widening, and detrimental changes in the morphology
and aquatic ecology of the affected stream system (Hammer 1972, pp.
1,535-1,536, 1,540; Booth 1990, pp. 407-409, 412-414; Booth and Reinelt
1993, pp. 548-550; Schueler 1994, pp. 106-108; Pizzuto et al. 2000, p.
82; Center for Watershed Protection 2003, pp. 41-48; Coles et al. 2012,
pp. 37-38).
Changes in flow regime can have a direct impact on salamander
populations. For example, Barrett et al. (2010, pp. 2,002-2,003)
observed that the density of aquatic southern two-lined salamanders
(Eurycea cirrigera) declined more drastically in streams with urbanized
watersheds compared to streams with forested or pastured watersheds. A
statistical analysis indicated that this decline in urban streams was
due to an increase in flooding frequency from stormwater runoff.
Barrett et al. (2010, p. 2,003) also used artificial stream experiments
to demonstrate that salamander larvae were flushed from sand-based
sediments at significantly lower velocities, as compared to gravel,
pebble, or cobble-based sediments. Sand-based substrates are common to
urban streams due to high sedimentation rates (see ``Sedimentation''
section above). The combined effects of increased sand-based substrates
due to high sedimentation rates and increased flow velocities from
impervious cover result in effectively flushing salamander larvae from
their habitat.
The Service has determined that impervious cover due to
urbanization in the salamanders' watersheds causes streamflow to shift
from predominately baseflow to predominately stormwater runoff. For
example, an examination of 24 stream sites in the Austin area revealed
that increasing impervious cover in the watersheds resulted in
decreased base flow, increased high-flow events of shorter duration,
and more rapid rises and falls of the stream flow (Glick et al. 2009,
p. 9). Increases in impervious cover within the Walnut Creek watershed
(Jollyville Plateau salamander habitat) have likely caused a shift to
more rapid rises and falls of that stream flow (Herrington 2010, p.
11).

[[Page 51310]]

The threat of water quantity degradation from urbanization could by
itself cause irreversible declines in population sizes or habitat
quality for the Austin blind and Jollyville Plateau salamanders. Also,
it could by itself cause irreversible declines or the extirpation of a
salamander population at a site with continuous exposure. We consider
this to be an ongoing threat of high impact for the Austin blind and
Jollyville Plateau salamanders that is likely to increase in the
future.
Drought
Drought conditions cause lowered groundwater tables and reduced
spring flows. The Northern Segment of the Edwards Aquifer, which
supplies water to the Jollyville Plateau salamander's habitat, is
vulnerable to drought (Chippindale et al. 2000, p. 36). In particular,
the portion of the Edwards Aquifer underlying the Jollyville Plateau is
relatively shallow with a high elevation, thus being unlikely to
sustain spring flows during periods of drought (Cole 1995, pp. 26-27).
Drought has been cited as causing declines in spring flows within
Jollyville Plateau and Austin blind salamander habitat (O'Donnell et
al. 2006, pp. 46-47; Bendik 2011a, p. 31; Hunt et al. 2012, pp. 190,
195). A drought lasting from 2008 to 2009 was considered one of the
worst droughts in central Texas history and caused numerous Jollyville
Plateau salamander sites to go dry (Bendik 2011a, p. 31). An even more
pronounced drought throughout Texas began in 2010, with the period from
October 2010 through September 2011 being the driest 12-month period in
Texas since rainfall records began (Hunt et al. 2012, p. 195). Rainfall
in early 2012 lessened the intensity of drought conditions, but 2012
monthly summer temperatures continued to be higher than average (NOAA
2013, p. 6). Moderate to extreme drought conditions have continued into
2013 in the central Texas region (LCRA 2013, p. 1). Weather forecasts
call for near to slightly less than normal rainfall across Texas
through August, but not enough rain to break the drought is expected
(LCRA 2013, p. 1).
Low flow conditions during drought also have negative impacts to
the Austin blind salamander and its ecosystem in the Edwards Aquifer
and at Barton Springs. The long-term average flow at the Barton Springs
outlets is approximately 53 cfs (1.5 cubic meters per second) (COA
1998, p. 13; Smith and Hunt 2004, p. 10; Hunt et al. 2012, p. 194). The
lowest flow recorded at Barton Springs was about 10 cfs (0.2 cubic
meters per second) during a record, multiyear drought in the 1950s (COA
1998, p. 13). During the 2011 drought, 10-day average flows at Barton
Springs reached 20 cfs (0.5 cubic meters per second) (Hunt et al. 2012,
pp. 190, 195). Discharge at Barton Springs decreases as water levels in
the Barton Springs Segment of the Edwards Aquifer drop. Decreased
discharge is associated with increases in water temperature, decreases
in spring flow velocity, and increases in sedimentation (COA 2011d, pp.
19, 24, 27).
The specific effects of low flow on central Texas salamanders can
be inferred by examining studies on the Barton Springs salamander.
Drought decreases spring flow and dissolved oxygen levels and increases
temperature in Barton Springs (Turner 2004, p. 2; Turner 2009, p. 14).
Low dissolved oxygen levels decrease reproduction in Barton Springs
salamanders (Turner 2004, p. 6; 2009, p. 14). Turner (2009, p. 14) also
found that Barton Springs salamander counts decline with decreasing
discharge. The number of Barton Springs salamanders observed during
surveys decreased during a prolonged drought from June 2008 through
September 2009 (COA 2011d, pp. 19, 24, 27). The drought in 2011 also
resulted in dissolved oxygen concentrations so low that COA used an
aeration system to maintain oxygenated water in Eliza and Sunken
Gardens Springs (Dries 2011, COA, pers. comm.). Drought also lowered
water quality in Barton Springs due to saline water encroachments in
the Barton Springs Segment of the Edwards Aquifer (Slade et al. 1986,
p. 62; Johns 2006, p. 8).
The Austin blind and Jollyville Plateau salamanders may be able to
persist through temporary surface habitat degradation because of their
ability to retreat to subsurface habitat. Drought conditions are common
to the region, and the ability to retreat underground may be an
evolutionary adaptation to such natural conditions (Bendik 2011a, pp.
31-32). However, it is important to note that, although salamanders may
survive a drought by retreating underground, this does not necessarily
mean they are resilient to long-term drought conditions (particularly
because sites may already be affected by other, significant stressors,
such as water quality declines).
Drought may also affect surface habitats that are important for
prey availability as well as individual and population growth.
Therefore, sites with suitable surface flow and adequate prey
availability are likely able to support larger population densities
(Bendik 2012, COA, pers. comm.). Prey availability for carnivores, such
as these salamanders, is low underground due to the lack of sunlight
and primary production (Hobbs and Culver 2009, p. 392). Complete loss
of surface habitat may lead to the extirpation of predominately
subterranean populations that depend on surface flows for biomass input
(Bendik 2012, COA, pers. comm.). In addition, length measurements taken
during a COA mark-recapture study at Lanier Spring demonstrated that
individual Jollyville Plateau salamanders exhibited negative growth
(shrinkage) during a 10-month period of retreating to the subsurface
from 2008 to 2009 (Bendik 2011b, COA, pers. comm.; Bendik and
Gluesenkamp 2012, pp. 3-4). The authors of this study hypothesized that
the negative growth could be the result of soft tissue contraction and/
or bone loss, but more research is needed to determine the physical
mechanism with which the shrinkage occurs (Bendik and Gluesenkamp 2012,
p. 5). Although this shrinkage in body length was followed by positive
growth when normal spring flow returned, the long-term consequences of
catch-up growth are unknown for these salamanders (Bendik and
Gluesenkamp 2012, pp. 4-5). Therefore, threats to surface habitat at a
given site may not extirpate populations of these salamander species in
the short term, but this type of habitat degradation may severely limit
population growth and increase a population's overall risk of
extirpation from other stressors occurring in the surface watershed.
The threat of water quantity degradation from drought by itself
could cause irreversible declines in population sizes or habitat
quality for the Austin blind and Jollyville Plateau salamanders. Also,
it could negatively impact salamander populations in combination with
other threats and contribute to significant declines in the size of the
populations or habitat quality. For example, changes in water quantity
will have direct impacts on the quality of that water, in terms of
concentrations of contaminants and pollutants. Therefore, we consider
this to be a threat of high impact for the Austin blind and Jollyville
Plateau salamanders now and in the future.
Climate Change
The effects of climate change could potentially lead to detrimental
impacts on aquifer-dependent species, especially coupled with other
threats on water quality and quantity. Recharge, pumping, natural
discharge, and saline intrusion of groundwater systems could all be
affected by climate change (Mace

[[Page 51311]]

and Wade 2008, p. 657). According to the Intergovernmental Panel on
Climate Change (IPCC 2007, p. 1), ``warming of the climate system is
unequivocal, as is now evident from observations of increases in global
averages of air and ocean temperatures, widespread melting of snow and
ice, and rising global average sea level.'' Localized projections
suggest the southwestern United States may experience the greatest
temperature increase of any area in the lower 48 States (IPCC 2007, p.
8), with warming increases in southwestern States greatest in the
summer. The IPCC also predicts hot extremes, heat waves, and heavy
precipitation will increase in frequency (IPCC 2007, p. 8). Evidence of
climate change has been observed in Texas, such as the record-setting
drought of 2011, with extreme droughts becoming much more probable than
they were 40 to 50 years ago (Rupp et al. 2012, pp. 1053-1054).
Climate change could compound the threat of decreased water
quantity at salamander spring sites. An increased risk of drought could
occur if evaporation exceeds precipitation levels in a particular
region due to increased greenhouse gases in the atmosphere (CH2M HILL
2007, p. 18). The Edwards Aquifer is also predicted to experience
additional stress from climate change that could lead to decreased
recharge (Lo[aacute]iciga et al. 2000, pp. 192-193). CH2M HILL (2007,
pp. 22-23) identified possible effects of climate change on water
resources within the Lower Colorado River Watershed (which contributes
recharge to Barton Springs). A reduction of recharge to aquifers and a
greater likelihood for more extreme droughts, such as the droughts of
2008 to 2009 and 2011 mentioned above, were identified as potential
impacts to water resources (CH2M HILL 2007, p. 23).
Furthermore, climate change could affect rainfall and ambient
temperatures, which are factors that may limit salamander populations.
Different ambient temperatures in the season that rainfall occurs can
influence spring water temperature if aquifers have fast transmission
of rainfall to springs (Martin and Dean 1999, p. 238). Gillespie (2011,
p. 24) found that reproductive success and juvenile survivorship in the
Barton Springs salamander, which occurs at the three spring sites where
the Austin blind salamander is known to occur, may be significantly
influenced by fluctuations in mean monthly water temperature. This
study also found that groundwater temperature is influenced by the
season in which rainfall events occur over the recharge zone of the
aquifer. When recharging rainfall events occur in winter when ambient
temperature is low, mean monthly water temperature at Barton Springs
and Eliza Spring can drop as low as 65.5[emsp14][deg]F (18.6 [deg]C)
and remain below the annual average temperature of 70.1[emsp14][deg]F
(21.2 [deg]C) for several months (Gillespie 2011, p. 24).
The threat of water quantity degradation from climate change could
negatively impact a population of any of the Austin blind and
Jollyville Plateau salamanders in combination with other threats and
contribute to significant declines in population sizes or habitat
quality. We consider this to be a threat of moderate impact for the
Austin blind and Jollyville Plateau salamanders now and in the future.

Physical Modification of Surface Habitat

The Austin blind and Jollyville Plateau salamanders are sensitive
to direct physical modification of surface habitat from sedimentation,
impoundments, flooding, feral hogs, livestock, and human activities.
Direct mortality to salamanders can also occur as a result of these
threats, such as being crushed by feral hogs, livestock, or humans.
Sedimentation
Elevated mobilization of sediment (mixture of silt, sand, clay, and
organic debris) is a stressor that occurs as a result of increased
velocity of water running off impervious surfaces (Schram 1995, p. 88;
Arnold and Gibbons 1996, pp. 244-245). Increased rates of stormwater
runoff also cause increased erosion through scouring in headwater areas
and sediment deposition in downstream channels (Booth 1991, pp. 93,
102-105; Schram 1995, p. 88). Waterways are adversely affected in urban
areas, where impervious cover levels are high, by sediment loads that
are washed into streams or aquifers during storm events. Sediments are
either deposited into layers or become suspended in the water column
(Ford and Williams 1989, p. 537; Mahler and Lynch 1999, p. 177).
Sediment derived from soil erosion has been cited as the greatest
single source of pollution of surface waters by volume (Menzer and
Nelson 1980, p. 632).
Excessive sediment from stormwater runoff is a threat to the
physical habitat of salamanders because it can cover substrates
(Geismar 2005, p. 2). Sediments suspended in water can clog gill
structures in aquatic animals, which can impair breathing and reduce
their ability to avoid predators or locate food sources due to
decreased visibility (Schueler 1987, p. 1.5). Excessive deposition of
sediment in streams can physically reduce the amount of available
habitat and protective cover for aquatic organisms, by filling the
interstitial spaces of gravel and rocks where they could otherwise
hide. As an example, a California study found that densities of two
salamander species were significantly lower in streams that experienced
a large infusion of sediment from road construction after a storm event
(Welsh and Ollivier 1998, pp. 1,118-1,132). The vulnerability of the
salamander species in this California study was attributed to their
reliance on interstitial spaces in the streambed habitats (Welsh and
Ollivier 1998, p. 1,128).
Excessive sedimentation has contributed to declines in Jollyville
Plateau salamander populations in the past. Monitoring by the COA found
that, as sediment deposition increased at several sites, salamander
abundances significantly decreased (COA 2001, pp. 101, 126).
Additionally, the COA found that sediment deposition rates have
increased significantly along one of the long-term monitoring sites
(Bull Creek Tributary 5) as a result of construction activities
upstream (O'Donnell et al. 2006, p. 34). This site has had significant
declines in salamander abundance, based on 10 years of monitoring, and
the COA attributes this decline to the increases in sedimentation
(O'Donnell et al. 2006, pp. 34-35). The location of this monitoring
site is within a large preserved tract. However, the headwaters of this
drainage are outside the preserve and the development in this area
increased sedimentation downstream and impacted salamander habitat
within the preserved tract.
Effects of sedimentation on the Austin blind salamander is expected
to be similar to the effects on the Jollyville Plateau salamander based
on similarities in their ecology and life history needs. Analogies can
also be drawn from data on the Barton Springs salamander. Barton Spring
salamander population numbers are adversely affected by high turbidity
and sedimentation (COA 1997, p. 13). Sediments discharge through Barton
Springs, even during baseflow conditions (not related to a storm event)
(Geismar 2005, p. 12). Storms can increase sedimentation rates
substantially (Geismar 2005, p. 12). Areas in the immediate vicinity of
the spring outflows lack sediment, but the remaining bedrock is
sometimes covered with a layer of sediment several inches thick
(Geismar 2005, p. 5). Sedimentation is a direct threat for the Austin
blind salamander because its

[[Page 51312]]

surface habitat in Barton Springs would fill with sediment if it were
not for regular maintenance and removal (Geismar 2005, p. 12). Further
development in the Barton Creek watershed, which contributes recharge
to Barton Springs, will most likely be associated with diminished water
clarity and a reduction in biodiversity of flora (COA 1997, p. 7).
Additional threats from sediments as a source of contaminants were
discussed in the ``Contaminants and Pollutants'' under the ``Water
Quality Degradation'' section above.
The threat of physical modification of surface habitat from
sedimentation by itself could cause irreversible declines in population
sizes or habitat quality for any of the Austin blind and Jollyville
Plateau salamanders' populations. It could also negatively impact the
species in combination with other threats to contribute to significant
declines. We consider this to be an ongoing threat of high impact for
the Austin blind and Jollyville Plateau salamanders that is likely to
increase in the future.
Impoundments
Impoundments can alter the salamanders' physical habitat in a
variety of ways that are detrimental. They can alter the natural flow
regime of streams, increase siltation, and support larger, predatory
fish (Bendik 2011b, COA, pers. comm.), leading to a variety of impacts
to the salamanders and their surface habitats. For example, a low-water
crossing on a tributary of Bull Creek occupied by the Jollyville
Plateau salamander resulted in sediment buildup above the impoundment
and a scour hole below the impoundment that supported predaceous fish
(Bendik 2011b, COA, pers. comm.). As a result, Jollyville Plateau
salamanders were not found in this degraded habitat after the
impoundment was constructed. When the crossing was removed in October
2008, the sediment buildup was removed, the scour hole was filled, and
salamanders were later observed (Bendik 2011b, COA, pers. comm.). Many
low-water crossings are present near other Jollyville Plateau
salamander sites (Bendik 2011b, COA, pers. comm.).
All spring sites for the Austin blind salamander (Main, Eliza, and
Sunken Garden Springs) have been impounded for recreational use. These
sites were impounded in the early to mid-1900s. For example, a
circular, stone amphitheater was built around Eliza Springs in the
early 1900s. A concrete bottom was installed over the natural substrate
at this site in the 1960s. It now discharges from 7 openings (each 1 ft
(0.3 m) in diameter) in the concrete floor and 13 rectangular vents
along the edges of the concrete, which were created by the COA to help
restore flow. While the manmade structures help retain water in the
spring pools during low flows, they have altered the salamander's
natural environment. The impoundments have changed the Barton Springs
ecosystem from a stream-like system to a more lentic (still water)
environment, thereby reducing the water system's ability to flush
sediments downstream and out of salamander habitat. Although a natural
surface flow connection between Sunken Gardens Spring and Barton Creek
has been restored recently (COA 2007a, p. 6), the Barton Springs system
as a whole remains highly modified.
The threat of physical modification of surface habitat from
impoundments by itself may not be likely to cause significant
population declines, but it could negatively impact the species in
combination with other threats and contribute to significant declines
in the population size or habitat quality. We consider impoundments to
be an ongoing threat of moderate impact to the Austin blind and
Jollyville Plateau salamanders and their surface habitats that will
likely continue in the future.
Flooding
Flooding as a result of rainfall events can considerably alter the
substrate and hydrology of salamander habitat. Extreme flood events
have occurred in the Austin blind and Jollyville Plateau salamander's
surface habitats (Pierce 2011a, p. 10; TPWD 2011, p. 6; Turner 2009, p.
11; O'Donnell et al. 2005, p. 15). The increased flow rate from
flooding causes unusually high dissolved oxygen concentrations, which
may exert direct or indirect, sublethal effects (reduced reproduction
or foraging success) on salamanders (Turner 2009, p. 11). Salamanders
also may be flushed from the surface habitat by strong flows during
flooding. Bowles et al. (2006, p. 117) observed no Jollyville Plateau
salamanders in riffle habitat at one site during high water velocities
and hypothesized that individual salamanders were either flushed
downstream or retreated to the subsurface.
An increase in the frequency of flood events causes streambank and
streambed erosion (Coles et al. 2012, p. 19), which can deposit
sediment into salamander habitat. For example, Geismar (2005, p. 2)
found that flooding increases contaminants and sediments in Barton
Springs. In 2007, flooding resulted in repeated accumulation of
sediment in the Barton Springs Pool that was so rapid that cleaning by
COA staff was not frequent enough to keep the surface habitat from
becoming embedded (COA 2007a, p. 4).
Flooding can alter the surface salamander habitat by deepening
stream channels, which may increase habitat for predaceous fish. Much
of the Austin blind and Jollyville Plateau salamanders' surface habitat
is characterized by shallow water depth (COA 2001, p. 128; Pierce
2011a, p. 3), with the exception of the Austin blind salamander at Main
and Sunken Garden Springs. However, deep pools are sometimes formed
within stream channels from the scouring of floods. Tumlison et al.
(1990, p. 172) found that the abundance of one Eurycea species
decreased as water depth increased. This relationship may be caused by
an increase in predation pressure, as deeper water supports predaceous
fish populations. However, several central Texas Eurycea species are
able to survive in deep water environments in the presence of many
predators. For example, San Marcos salamander in Spring Lake, Eurycea
sp. in Landa Lake, and Barton Springs salamander in Barton Springs
Pool. All of these sites have vegetative cover, which may allow
salamanders to avoid predation. Anti-predator behaviors may allow these
species to co-exist with predaceous fish, but the effectiveness of
these behaviors may be species-specific (reviewed in Pierce and Wall
2011, pp. 18-19) and many of the shallow, surface habitats of the
Jollyville Plateau salamander do not have much vegetative cover.
The threat of physical modification of surface habitat from
flooding by itself may not be likely to cause significant population
declines, but it could negatively impact the species in combination
with other threats and contribute to significant declines in the
population size or habitat quality. We consider this to be a threat of
moderate impact to the Austin blind and Jollyville Plateau salamanders
that may increase in the future as urbanization and impervious cover
increases within the surface watersheds of these species, causing more
frequent and more intense streamflow flash flooding (see discussion in
the ``Urbanization'' section under ``Water Quality Degradation''
above).
Feral Hogs
There are between 1.8 and 3.4 million feral hogs (Sus scrofa) in
Texas (Texas A&M University (TAMU) 2011, p. 2), which is another source
of physical habitat disturbance to salamander surface sites. They
prefer to live around moist areas, including riparian areas near
streams, where they can dig into the soft ground for food and wallow in

[[Page 51313]]

mud to keep cool (Mapson 2004, pp. 11, 14-15). Feral hogs disrupt these
ecosystems by decreasing plant species diversity, increasing invasive
species abundance, increasing soil nitrogen, and exposing bare ground
(TAMU 2012, p. 4). Feral hogs negatively impact surface salamander
habitat by digging and wallowing in spring heads, which increases
sedimentation downstream (O'Donnell et al. 2006, pp. 34, 46). This
activity can also result in direct mortality of amphibians (Bull 2009,
p. 243).
Feral hogs have become abundant in some areas where the Jollyville
Plateau salamander occurs. O'Donnell et al. (2006, p. 34) noted that
feral hog activity was increasing in the Bull and Cypress Creeks
watersheds. Fortunately, feral hogs cannot access Austin blind
salamander sites due to fencing and their location in downtown Austin.
The threat of physical modification of surface habitat from feral
hogs by itself may not be likely to cause significant population
declines, but it could negatively impact the species in combination
with other threats and contribute to significant declines in the
population size or habitat quality. We consider this to be an ongoing
threat of moderate impact to the Jollyville Plateau salamander that
will likely continue in the future. We do not consider physical habitat
modification from feral hogs to be a threat to the Austin blind
salamander at this time or in the future.
Livestock
Similar to feral hogs, livestock can negatively impact surface
salamander habitat by disturbing the substrate and increasing
sedimentation in the spring run where salamanders are often found.
Poorly managed livestock grazing results in changes in vegetation (from
grass-dominated to brush-dominated), which leads to increased erosion
of the soil profile along stream banks (COA 1995, pp. 3-59) and
sediment in salamander habitat. However, the Austin blind salamander's
habitat is inside a COA park, and livestock are not allowed in the
spring areas. Also, much of the Jollyville Plateau salamander habitat
is in suburban areas, and we are not aware of livestock access to or
damage in those areas. Therefore, we do not consider physical habitat
modification from livestock to be a threat to the Austin blind or
Jollyville Plateau salamanders at this time or in the future.
Other Human Activities
Some sites of the Austin blind and Jollyville Plateau salamanders
have been directly modified by human-related activities. Frequent human
visitation of sites occupied by the Austin blind and Jollyville Plateau
salamanders may negatively affect the species and their habitat.
Documentation from the COA of disturbed vegetation, vandalism, and the
destruction of travertine deposits (fragile rock formations formed by
deposit of calcium carbonate on stream bottoms) by foot traffic has
been documented at one of their Jollyville Plateau salamander
monitoring sites in the Bull Creek watershed (COA 2001, p. 21) and may
have resulted in direct destruction of small amounts of the
salamander's habitat. Other Jollyville Plateau salamander sites have
also been impacted. Both Stillhouse Hollow Spring and Balcones District
Park regularly receive visitors that modify the available cover habitat
(by removing or arranging substrates). Balcones District Park is also
regularly disturbed by off-leash dog traffic (Bendik 2012, COA, pers.
comm.). Eliza Spring and Sunken Garden Spring, two of the three
locations of the Austin blind salamander, also experience vandalism,
despite the presence of fencing and signage (Dries 2011, COA, pers.
comm.). The deep water of the third location (Parthenia Springs) likely
protects the Austin blind salamander's surface habitat from damage from
frequent human recreation. All of these activities can reduce the
amount of cover available for salamander breeding, feeding, and
sheltering.
The threat of physical modification of surface habitat from human
visitation, recreation, and alteration by itself may not be likely to
cause significant population declines, but it could negatively impact
the species in combination with other threats and contribute to
significant declines in the population size or habitat quality. We
consider this to be an ongoing threat of moderate impact to the Austin
blind and Jollyville Plateau salamanders that will likely continue in
the future.
Conservation Efforts To Reduce Habitat Destruction, Modification, or
Curtailment of Its Range
When considering the listing determination of species, it is
important to consider conservation efforts that have been made to
reduce or remove threats, such as the threats to the Austin blind and
Jollyville Plateau Texas salamanders' habitat. A number of efforts have
aimed at minimizing the habitat destruction, modification, or
curtailment of the salamanders' ranges.
In a separate undertaking, and with the help of a grant funded
through section 6 of the Act, the WCCF developed the Williamson County
Regional HCP to obtain a section 10(a)(1)(B) permit for incidental take
of federally listed endangered species in Williamson County, Texas.
This HCP became final in October 2008. Although Jollyville Plateau
salamanders present in southern Williamson County are likely influenced
by the Edwards Aquifer Recharge Zone in northern Williamson County, the
Williamson County Regional HCP does not include considerations for this
species. However, in 2012, the WCCF began contracting to gather
information on the Jollyville Plateau salamander in Williamson County.
Travis County and COA also have a regional HCP (the Balcones
Canyonlands Conservation Plan) and section 10(a)(1)(B) permit that
covers incidental take of federally listed species in Travis County.
While the Jollyville Plateau salamander is not a covered species under
that permit, the Balcones Canyonlands Preserve system offers some
benefits to the Jollyville Plateau salamander in portions of the Bull
Creek, Brushy Creek, Cypress Creek, and Long Hollow Creek drainages
through preservation of open space (Service 1996, pp. 2-28, 2-29).
Sixty-seven of 106 surface sites for the Jollyville Plateau salamander
are within Balcones Canyonlands Preserves. However, eight of the nine
COA monitoring sites occupied by the Jollyville Plateau salamander
within the Balcones Canyonlands Preserve have experienced water quality
degradation from disturbances occurring upstream and outside of the
preserved tracts (O'Donnell et al. 2006, pp. 29, 34, 37, 49; COA 1999,
pp. 6-11; Travis County 2007, p. 4).
Additionally, the Buttercup Creek HCP was established to avoid,
minimize, and mitigate for the potential negative effects of
construction and operation of single and multifamily residences and a
school near and adjacent to currently occupied habitat of the
endangered Tooth Cave ground beetle (Rhadine persephone) and other rare
cave and karst species, including the Jollyville Plateau salamander,
and to contribute to conservation of the listed and non-listed cave or
karst fauna. The Buttercup HCP authorizes incidental take of endangered
karst invertebrates, if encountered during construction. Under the
Buttercup HCP, mitigation for take of the karst invertebrates was
implemented by setting aside 12 separate cave preserves (130 ac (53
ha), 37 caves) and two greenbelt flood plains (33 ac (13 ha)) for a
total of 163 ac (66 ha), which remain in a natural

[[Page 51314]]

undisturbed condition and are preserved in perpetuity for the benefit
of the listed and non-listed species. There are 21 occupied endangered
karst invertebrate caves and 10 Jollyville Plateau salamander caves in
the preserves. The shape and size of each preserve was designed to
include surface drainage basins for all caves, the subsurface extent of
all caves, and connectivity between nearby caves and features.
Additionally, for those more sensitive cave preserves, particularly
with regard to recharge, 7 of the 12 preserves are to be fenced off to
restrict access for only maintenance, monitoring, and research. All
preserves are regularly monitored, fences and gates are checked and
repaired, and red imported fire ants (Solenopsis invicta) controlled.
Surface water drainage from streets and parking areas will be diverted
by permanent diversion structures to treatment systems and detention
ponds or will discharge down-gradient of the cave preserves. An
additional 3 to 4 in (76 to 102 mm) of topsoil are added in yards and
landscaped areas for additional filtration and absorption of
fertilizers, pesticides, and other common constituents, and an
education and outreach program informs homeowners about the proper use
of fertilizers and pesticides, the benefits of native landscaping, and
the disposal of household hazardous waste.
In addition, several individual 10(a)(1)(B) permit holders in
Travis County have established preserves and included provisions that
are expected to benefit the Jollyville Plateau salamander. Twelve of
the 16 known caves for the Jollyville Plateau salamander are located
within preserves. Similar to the Williamson County Regional HCP and
Balcones Canyonlands Conservation Plan, there is potential for adverse
effects to salamander sites from land use activities outside the
covered areas under the HCPs.
Furthermore, the COA is implementing the Barton Springs Pool HCP to
avoid, minimize, and mitigate incidental take of the Barton Springs
salamander resulting from the continued operation and maintenance of
Barton Springs Pool and adjacent springs (COA 1998, pp. 1-53). Many of
the provisions of the plan also benefit the Austin blind salamander.
These provisions include: (1) Training lifeguard and maintenance staff
to protect salamander habitat, (2) controlling erosion and preventing
surface runoff from entering the springs, (3) ecological enhancement
and restoration, (4) monthly monitoring of salamander numbers, (5)
public outreach and education, and (6) establishment and maintenance of
a captive-breeding program, which includes the Austin blind salamander.
As part of this HCP, the COA completed habitat restoration of Eliza
Spring and the main pool of Barton Springs in 2003 and 2004. A more
natural flow regime was reconstructed in these habitats by removing
large obstructions to flow. This HCP has recently been proposed for
revision to include coverage for the Austin blind salamander and to
extend the COA's permit for another 20 years (78 FR 23780, April 22,
2013).
Although these conservation efforts likely contribute water quality
benefits to surface flow, surface habitats can be influenced by land
use throughout the recharge zone of the aquifer that supplies its
spring flow. Furthermore, the surface areas influencing subsurface
water quality (that is draining the surface and flowing to the
subsurface habitat) is not clearly delineated for many of the sites
(springs or caves) for the Austin blind or Jollyville Plateau
salamanders. Because we are not able to precisely assess additional
pathways for negative impacts to these salamanders to occur, many of
their sites may be affected by threats that cannot be mitigated through
the conservation efforts that are currently ongoing.
Conclusion of Factor A
Degradation of habitat, in the form of reduced water quality and
quantity and disturbance of spring sites (physical modification of
surface habitat), is the primary threat to the Austin blind and
Jollyville Plateau salamanders. This threat may affect only the surface
habitat, only the subsurface habitat, or both habitat types. In
consideration of the stressors currently impacting the salamander
species and their habitats along with their risk of exposure to
potential sources of this threat, we have found the threat of habitat
destruction and modification within the ranges of the Austin blind and
Jollyville Plateau salamanders to have severe impacts on these species,
and we expect this threat to continue into the future.

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

There is little available information regarding overutilization of
the Austin blind and Jollyville Plateau salamanders for commercial,
recreational, scientific, or educational purposes, although we are
aware that some individuals of these species have been collected from
their natural habitat for a variety of purposes. Collecting individuals
from populations that are already small enough to experience reduced
reproduction and survival due to inbreeding depression or become
extirpated due to environmental or demographic stochasticity and other
catastrophic events (see the discussion on small population sizes under
Factor E--Other Natural or Manmade Factors Affecting Its Continued
Existence below) can pose a risk to the continued existence of these
populations. Additionally, there are no regulations currently in place
to prevent or restrict the collections of salamanders from their
habitat in the wild for scientific or other purposes, and we know of no
plans within the scientific community to limit the amount or frequency
of collections at known salamander locations. We recognize the
importance of collecting for scientific purposes, such as for research,
captive assurance programs, taxonomic analyses, and museum collections.
However, removing individuals from small, localized populations in the
wild, without any proposed plans or regulations to restrict these
activities, could increase the population's vulnerability and decrease
its resiliency and ability to withstand stochastic events.
Currently, we do not consider overutilization from collecting
salamanders in the wild to be a threat by itself, but it may contribute
to significant population declines, and could negatively impact the
species in combination with other threats.

C. Disease or Predation

Chytridiomycosis (chytrid fungus) is a fungal disease that is
responsible for killing amphibians worldwide (Daszak et al. 2000, p.
445). The chytrid fungus has been documented on the feet of Jollyville
Plateau salamanders from 15 different sites in the wild (O'Donnell et
al. 2006, pp. 22-23; Gaertner et al. 2009, pp. 22-23) and on Austin
blind salamanders in captivity (Chamberlain 2011, COA, pers. comm.).
However, the salamanders are not displaying any noticeable health
effects (O'Donnell et al. 2006, p. 23). We do not consider
chytridiomycosis to be a threat to the Austin blind and Jollyville
Plateau salamanders at this time. We have no data to indicate that
impacts from this disease may increase or decrease in the future.
A condition affecting Barton Springs salamanders may also affect
the Austin blind salamander. In 2002, 19 Barton Springs salamanders,
which co-occur with the Austin blind salamander, were found at Barton
Springs with bubbles of gas occurring throughout their bodies
(Chamberlain and O'Donnell 2003, p.

[[Page 51315]]

17). Three similarly affected Barton Springs salamanders also were
found in 2003 (Chamberlain and O'Donnell 2003, pp. 17-18). Of the 19
salamanders affected in 2002, 12 were found dead or died shortly after
they were found. Both adult and juvenile Barton Springs salamanders
have been affected (Chamberlain and O'Donnell 2003, pp. 10, 17).
The incidence of gas bubbles in salamanders at Barton Springs is
consistent with a disorder known as gas bubble disease, or gas bubble
trauma, as described by Weitkamp and Katz (1980, pp. 664-671). In
animals with gas bubble trauma, bubbles below the surface of the body
and inside the cardiovascular system produce lesions and dead tissue
that can lead to secondary infections (Weitkamp and Katz 1980, p. 670).
Death from gas bubble trauma is apparently related to an accumulation
of internal bubbles in the cardiovascular system (Weitkamp and Katz
1980, p. 668). Pathology reports on affected animals at Barton Springs
found that the symptoms were consistent with gas bubble trauma
(Chamberlain and O'Donnell 2003, pp. 17-18). The cause of gas bubble
trauma is unknown, but its incidence has been correlated with water
temperature. Gas bubble trauma has been observed in wild Barton Springs
salamanders only on rare occasions (Chamberlain, unpublished data) and
has been observed in Austin blind salamanders in captivity only when
exposed to water temperatures approaching 80[emsp14][deg]F (26.7
[deg]C) (Chamberlain 2011, COA, pers. comm.). Given these limited
observations, we do not consider gas bubble trauma to be a threat to
the Austin blind salamander now or in the future.
To our knowledge, gas bubble trauma has not been observed in
Jollyville Plateau salamanders. However, if an increase in water
temperature is a causative factor, this species may also be at risk
during droughts or other environmental stressors that result in
increases in water temperature.
Regarding predation, COA biologists found Jollyville Plateau
salamander abundances were negatively correlated with the abundance of
predatory centrarchid fish (carnivorous freshwater fish belonging to
the sunfish family), such as black bass (Micropterus spp.) and sunfish
(Lepomis spp.) (COA 2001, p. 102). Predation of a Jollyville Plateau
salamander by a centrarchid fish was observed during a May 2006 field
survey (O'Donnell et al. 2006, p. 38). However, Bowles et al. (2006,
pp. 117-118) rarely observed these predators in Jollyville Plateau
salamander habitat. Centrarchid fish are currently present in two of
three Austin blind salamander sites (Gillespie 2011, p. 87). Crayfish
(another predator) occur in much of the habitat occupied by Jollyville
Plateau salamanders. Both the Austin blind and Jollyville Plateau
salamanders have been observed retreating into gravel substrate after
cover was moved, suggesting these salamanders display antipredation
behavior (Bowles et al. 2006, p. 117). Another study found that San
Marcos salamanders (Eurycea nana) have the ability to recognize and
show antipredator response to the chemical cues of introduced and
native centrarchid fish predators (Epp and Gabor 2008, p. 612).
However, we do not have enough data to indicate whether predation is a
significant limiting factor for the Austin blind and Jollyville Plateau
salamanders.
In summary, while disease and predation may be affecting
individuals of these salamander species, these are not significant
factors affecting the species' continued existence in healthy, natural
ecosystems. Neither disease nor predation is occurring at a level that
we consider to be a threat to the continued existence of the Austin
blind and Jollyville Plateau salamanders now or in the future.

D. The Inadequacy of Existing Regulatory Mechanisms

The primary threats to the Austin blind and Jollyville Plateau
salamanders are habitat degradation related to a reduction of water
quality and quantity and disturbance at spring sites (see discussion
under Factor A above). Therefore, regulatory mechanisms that protect
water from the Trinity and Edwards Aquifers are crucial to the future
survival of these species. Federal, State, and local laws and
regulations have been insufficient to prevent past and ongoing impacts
to the Austin blind and Jollyville Plateau salamanders and their
habitats from water quality degradation, reduction in water quantity,
and surface disturbance of spring sites, and are unlikely to prevent
further impacts to the species in the future.
State and Federal Regulations
Laws and regulations pertaining to endangered or threatened animal
species in the State of Texas are contained in Chapters 67 and 68 of
the Texas Parks and Wildlife Department (TPWD) Code and Sections
65.171-65.176 of Title 31 of the Texas Administrative Code (T.A.C.).
TPWD regulations prohibit the taking, possession, transportation, or
sale of any of the animal species designated by State law as endangered
or threatened without the issuance of a permit. The Austin blind and
Jollyville Plateau salamanders are not listed on the Texas State List
of Endangered or Threatened Species (TPWD 2013, p. 3). Even if they
were, State threatened and endangered species laws do not contain
protective provisions for habitat. At this time, these species are
receiving no direct protection from State of Texas regulations.
Under authority of the T.A.C. (Title 30, Chapter 213), the TCEQ
regulates activities having the potential for polluting the Edwards
Aquifer and hydrologically connected surface streams through the
Edwards Aquifer Protection Program or ``Edwards Rules.'' The Edwards
Rules require a number of water quality protection measures for new
development occurring in the recharge, transition, and contributing
zones of the Edwards Aquifer. The Edwards Rules were enacted to protect
existing and potential uses of groundwater and maintain Texas Surface
Water Quality Standards. Specifically, a water pollution abatement plan
(WPAP) must be submitted to the TCEQ in order to conduct any
construction-related or post-construction activities on the recharge
zone. The WPAP must include a description of the site and location
maps, a geologic assessment conducted by a geologist, and a technical
report describing, among other things, temporary and permanent best
management practices (BMPs).
However, the permanent BMPs and measures identified in the WPAP are
designed, constructed, operated, and maintained to remove 80 percent of
the incremental increase in annual mass loading of total suspended
solids from the site caused by the regulated activity. This necessarily
results in some level of water quality degradation since up to 20
percent of total suspended solids are ultimately discharged from the
site into receiving waterways. Separate Edwards Aquifer protection
plans are required for organized sewage collection systems, underground
storage tank facilities, and aboveground storage tank facilities.
Regulated activities exempt from the requirements of the Edwards Rules
are: (1) The installation of natural gas lines; (2) the installation of
telephone lines; (3) the installation of electric lines; (4) the
installation of water lines; and (5) the installation of other utility
lines that are not designed to carry and will not carry pollutants,
storm water runoff, sewage effluent, or treated effluent from a
wastewater treatment facility.
Temporary erosion and sedimentation controls are required to be
installed and

[[Page 51316]]

maintained for any exempted activities located on the recharge zone.
Individual land owners who seek to construct single-family residences
on sites are exempt from the Edwards Aquifer protection plan
application requirements provided the plans do not exceed 20 percent
impervious cover. Similarly, the Executive Director of the TCEQ may
waive the requirements for permanent BMPs for multifamily residential
subdivisions, schools, or small businesses when 20 percent or less
impervious cover is used at the site.
The best available science indicates that measurable degradation of
stream habitat and loss of biotic integrity occurs at levels of
impervious cover within a watershed much less than this (see Factor A
discussion above). The single known location of the Austin blind
salamander and half of the known Jollyville Plateau salamander
locations occur within those portions of the Edwards Aquifer regulated
by the TCEQ. The TCEQ regulations do not address land use, impervious
cover limitations, some nonpoint-source pollution, or application of
fertilizers and pesticides over the recharge zone (30 TAC 213.3). In
addition, these regulations were not intended or designed specifically
to be protective of the salamanders. We are unaware of any water
quality ordinances more restrictive than the TCEQ's Edwards Rules in
Travis or Williamson Counties outside the COA.
Texas has an extensive program for the management and protection of
water that operates under State statutes and the Federal Clean Water
Act (CWA). It includes regulatory programs such as the following: Texas
Pollutant Discharge Elimination System, Texas Surface Water Quality
Standards, and Total Maximum Daily Load Program (under Section 303(d)
of the CWA).
In 1998, the State of Texas assumed the authority from the
Environmental Protection Agency (EPA) to administer the National
Pollutant Discharge Elimination System. As a result, the TCEQ's TPDES
program has regulatory authority over discharges of pollutants to Texas
surface water, with the exception of discharges associated with oil,
gas, and geothermal exploration and development activities, which are
regulated by the Railroad Commission of Texas. In addition, stormwater
discharges as a result of agricultural activities are not subject to
TPDES permitting requirements. The TCEQ issues two general permits that
authorize the discharge of stormwater and non-stormwater to surface
waters in the State associated with: (1) small municipal separate storm
sewer systems (MS4) (TPDES General Permit TXR040000) and (2)
construction sites (TPDES General Permit TXR150000). The MS4
permit covers small municipal separate storm sewer systems that were
fully or partially located within an urbanized area, as determined by
the 2000 Decennial Census by the U.S. Census Bureau, and the
construction general permit covers discharges of storm water runoff
from small and large construction activities impacting greater than 1
acre of land. In addition, both of these permits require new discharges
to meet the requirements of the Edwards Rules.
To be covered under the MS4 general permit, a municipality must
submit a Notice of Intent (NOI) and a copy of their Storm Water
Management Program (SWMP) to TCEQ. The SWMP must include a description
of how that municipality is implementing the seven minimum control
measures, which include the following: (1) Public education and
outreach; (2) public involvement and participation; (3) detection and
elimination of illicit discharges; (4) construction site stormwater
runoff control (when greater than 1 ac (0.4 ha) is disturbed); (5)
post-construction stormwater management; (6) pollution prevention and
good housekeeping for municipal operations; and (7) authorization for
municipal construction activities (optional). Municipalities located
within the range of the Austin blind and Jollyville Plateau salamanders
that are covered under the MS4 general permit include the Cities of
Cedar Park, Round Rock, Austin, Leander, and Pflugerville, as well as
Travis and Williamson Counties.
To be covered under the construction general permit, an applicant
must prepare a stormwater pollution and prevention plan (SWP3) that
describes the implementation of practices that will be used to
minimize, to the extent practicable, the discharge of pollutants in
stormwater associated with construction activity and non-stormwater
discharges. For activities that disturb greater than 5 ac (2 ha), the
applicant must submit an NOI to TCEQ as part of the approval process.
As stated above, the two general permits issued by the TCEQ do not
address discharge of pollutants to surface waters from oil, gas, and
geothermal exploration and geothermal development activities,
stormwater discharges associated with agricultural activities, and from
activities disturbing less than 5 acres (2 ha) of land. Despite the
significant value the TPDES program has in regulating point-source
pollution discharged to surface waters in Texas, it does not adequately
address all sources of water quality degradation, including nonpoint-
source pollution and the exceptions mentioned above, that have the
potential to negatively impact the Austin blind and Jollyville Plateau
salamanders.
In reviewing the 2010 and 2012 Texas Water Quality Integrated
Reports prepared by the TCEQ, the Service identified 14 of 28 (50
percent) stream segments located within surface watersheds occupied by
the Austin blind and Jollyville Plateau salamanders where parameters
within water samples exceeded screening level criteria (TCEQ 2010a, pp.
546-624; TCEQ 2010b, pp. 34-68; TCEQ 2012b, pp. 35-70; TCEQ 2012c, pp.
646-736). Four of these 28 (14 percent) stream segments have been
identified as impaired waters as required under sections 303(d) and
304(a) of the Clean Water Act ``. . .for which effluent limitations are
not stringent enough to implement water quality standards'' (TCEQ
2010c, pp. 77, 82-83; TCEQ 2012d, pp. 67, 73). The analysis of surface
water quality monitoring data collected by TCEQ indicated ``screening
level concerns'' for nitrate, dissolved oxygen, impaired benthic
communities, sediment toxicity, and bacteria. The TCEQ screening level
for nitrate (1.95 mg/L) is within the range of concentrations (1.0 to
3.6 mg/L) above which the scientific literature indicates may be toxic
to aquatic organisms (Camargo et al. 2005, p. 1,264; Hickey and Martin
2009, pp. ii, 17-18; Rouse 1999, p. 802). In addition, the TCEQ
screening level for dissolved oxygen (5.0 mg/L) is similar to that
recommended by the Service in 2006 to be protective of federally listed
salamanders (White et al. 2006, p. 51). Therefore, water quality data
collected and summarized by the TCEQ supports our concerns with the
adequacy of existing regulations to protect the Austin blind and
Jollyville Plateau salamanders from the effects of water quality
degradation.
To discharge effluent onto the land, the TCEQ requires wastewater
treatment systems within the Barton Springs Segment of the Edwards
Aquifer recharge and contributing zones to obtain Texas Land
Application Permits (TLAP) (Ross 2011, p. 7). Although these permits
are designed to protect the surface waters and underground aquifer,
studies have demonstrated reduced water quality downstream of TLAP
sites (Mahler et al. 2011, pp. 34-35; Ross 2011, pp. 11-18). Ross
(2011, pp. 18-21) attributes this to the TCEQ's failure to conduct
regular soil monitoring for nutrient accumulation on TLAP sites and the
failure to conduct in-depth reviews of TLAP applications. A study

[[Page 51317]]

by the U.S. Geological Survey concluded that baseline water quality in
the Barton Springs Segment of the Edwards Aquifer, which is occupied by
the Austin blind salamander, in terms of nitrate had shifted upward
between 2001 and 2010 and was at least partially the result of an
increase in the land application of treated wastewater (Mahler et al.
2011, pp. 34-35).
Local Ordinances and Regulations
The COA's water quality ordinances (COA Code, Title 25, Chapter 8)
provide some water quality regulatory protection to the Austin blind
and Jollyville Plateau salamander's habitat within Travis County. Some
of the protections include buffers around critical environmental
features and waterways (up to 400 ft (122 m)), permanent water quality
control structures (sedimentation and filtration ponds), wastewater
system restrictions, and impervious cover limitations (COA Code, title
25, Chapter 8; Turner 2007, pp. 1-2). The ordinances range from
relatively strict controls in its Drinking Water Protection Zones to
lesser controls in its Desired Development Zones. For example, a 15
percent impervious cover limit is in place for new developments within
portions of the Barton Springs Zone, one of the Drinking Water
Protection Zones, while up to 90 percent impervious cover is permitted
within the Suburban City Limits Zone, one of the Desired Development
Zones.
In the period after the COA passed water quality ordinances in 1986
and 1991, sedimentation and nutrients decreased in the five major
Austin-area creeks (Turner 2007, p. 7). Peak storm flows were also
lower after the enactment of the ordinances, which may explain the
decrease in sedimentation (Turner 2007, p. 10). Likewise, a separate
study on the water quality of Walnut Creek (Jollyville Plateau
salamander habitat) from 1996 to 2008 found that water quality has
either remained the same or improved (Scoggins 2010, p. 15). These
trends in water quality occurred despite a drastic increase in
construction and impervious cover during the same time period (Turner
2007, pp. 7-8; Scoggins 2010, p. 4), indicating that the ordinances are
effective at mitigating some of the impacts of development on water
quality. Another study in the Austin area compared 18 sites with
stormwater controls (retention ponds) in their watersheds to 20 sites
without stormwater controls (Maxted and Scoggins 2004, p. 8). In sites
with more than 40 percent impervious cover, more contaminant-sensitive
macroinvertebrate species were found at sites with stormwater controls
than at sites without controls (Maxted and Scoggins 2004, p. 11).
Local ordinances have not been completely effective at protecting
water quality to the extent that sedimentation, contaminants,
pollution, and changes in water chemistry no longer impact salamander
habitat (see ``Stressors and Sources of Water Quality Degradation''
discussion under Factor A above). A study conducted by the COA of four
Jollyville Plateau salamander spring sites within two subdivisions
found that stricter water quality controls (wet ponds instead of
standard sedimentation/filtration ponds) did not necessarily translate
into improved groundwater quality (Herrington et al. 2007, pp. 13-14).
In addition, water quality data analyzed by the COA showed significant
increases in conductivity, nitrate, and sodium between 1997 and 2005 at
two Jollyville Plateau salamander long-term monitoring sites, which
also had significant declines in salamander counts (O'Donnell et al.
2006, p. 12).
In addition, Title 7, Chapter 245 of the Texas Local Government
Code permits ``grandfathering'' of certain local regulations.
Grandfathering allows developments to be exempted from new requirements
for water quality controls and impervious cover limits if the
developments were planned prior to the implementation of such
regulations. However, these developments are still obligated to comply
with regulations that were applicable at the time when project
applications for development were first filed (Title 7, Chapter 245 of
the Texas Local Government Code, p. 1).
On January 1, 2006, the COA banned the use of coal tar sealant
(Scoggins et al. 2009, p. 4909), which has been shown to be the main
source of PAHs in Austin-area streams (Mahler et al. 2005, p. 5,565).
However, historically applied coal tar sealant lasts for several years
and can remain a source of PAHs to aquatic systems (DeMott et al. 2010,
p. 372). A study that examined PAH concentrations in Austin streams
before the ban and 2 years after the ban found no difference,
indicating that either more time is needed to see the impact of the
coal tar ban, or that other sources (for example, airborne and
automotive) are contributing more to PAH loadings (DeMott et al. 2010,
pp. 375-377). Furthermore, coal tar sealant is still legal outside of
the COA's jurisdiction and may be contributing PAH loads to northern
portions of the Jollyville Plateau salamander's habitat.
The LCRA Highland Lakes Watershed Ordinance applies to lands
located within the Lake Travis watershed in northwestern Travis County,
as well as portions of Burnet and Llano Counties. This ordinance was
implemented by LCRA beginning in 2006 to protect water quality in the
Highland Lakes region. There are 14 Jollyville Plateau salamander sites
located within the northwestern portion of Travis County covered by
this ordinance. Development in this area is required to protect water
quality by: (1) Providing water quality volume based on the 1-year
storm runoff in approved best management practices (BMPs) (practices
that effectively manage stormwater runoff quality and volume), (2)
providing buffer zones around creeks that remain free of most
construction activities, (3) installing temporary erosion and sediment
control, (4) conducting water quality education, and (5) requiring
water quality performance monitoring of certain BMPs. However, as with
TPDES permitting discussed above, agricultural activities are exempt
from the water quality requirements contained in the Highland Lakes
Watershed Ordinance (LCRA 2005, pp. 8-21).
The Cities of Cedar Park and Round Rock, and Travis and Williamson
Counties have some jurisdiction within watersheds occupied by either
the Austin blind or Jollyville Plateau salamanders. The Service has
reviewed ordinances administered by each of these municipalities to
determine if they contain measures protective of salamanders above and
beyond those already required through other regulatory mechanisms
(Clean Water Act, T.A.C., etc.). Each of the cities has implemented
their own ordinances that contain requirements for erosion control and
the management of the volume of stormwater discharged from developments
within their jurisdictions. However, as discussed above under Factor A,
measurable degradation of stream habitat and loss of biotic integrity
can occur at low levels of impervious cover within a watershed, and
there are no impervious cover limit restrictions in Travis or
Williamson Counties or for development within the municipalities of
Cedar Park and Round Rock where the Jollyville Plateau salamander
occurs.
Groundwater Conservation Districts
The Barton Springs/Edwards Aquifer Conservation District permits
and regulates most wells on the Barton Springs segment of the Edwards
Aquifer, subject to the limits of the State of Texas law. They have
established two desired future conditions for the Freshwater Edwards
Aquifer within the Northern Subdivision of Groundwater

[[Page 51318]]

Management Area 10: (1) An extreme drought desired future condition of
6.5 cubic feet per second (cfs) (0.18 cubic meter per second (cms))
measured at Barton Springs, and (2) an ``all-conditions'' desired
future condition of 49.7 cfs (1.41 cms) measured at Barton Springs.
These desired future conditions are meant to assure an adequate supply
of freshwater for well users and adequate flow for endangered species.
There are no groundwater conservation districts in northern Travis or
southern Williamson Counties, so groundwater pumping continues to be
unregulated in these areas (TPWD 2011, p. 7).
Conclusion of Factor D
Surface water quality data collected by TCEQ and COA indicates that
water quality degradation is occurring within many of the surface
watersheds occupied by the Austin blind and Jollyville Plateau
salamanders despite the existence of numerous State and local
regulatory mechanisms to manage stormwater and protect water quality
(Turner 2005a, pp. 8-17, O'Donnell et al. 2006, p. 29, TCEQ 2010a, pp.
546-624; TCEQ 2010b, pp. 34-68; TCEQ 2010c, pp. 77, 82-83; TCEQ 2012b,
pp. 35-70; TCEQ 2012c, pp. 646-736; TCEQ 2012d, pp. 67, 73). No
regulatory mechanisms are in place to manage groundwater withdrawals in
northern Travis or southern Williamson Counties. Human population
growth and urbanization in Travis and Williamson Counties are projected
to continue into the future as well as the associated impacts to water
quality and quantity (see Factor A discussion above). Therefore, we
conclude that the existing regulatory mechanisms are not providing
adequate protection for the Austin blind and Jollyville Plateau
salamanders or their habitats either now or in the future.

E. Other Natural or Manmade Factors Affecting Their Continued Existence

Small Population Size and Stochastic Events
The Austin blind and Jollyville Plateau salamanders may be more
susceptible to threats and impacts from stochastic events because of
their small population sizes (Van Dyke 2008, p. 218). The risk of
extinction for any species is known to be highly inversely correlated
with population size (O'Grady et al. 2004, pp. 516, 518; Pimm et al.
1988, pp. 774-775). In other words, the smaller the population, the
greater the overall risk of extinction. Population size estimates that
take into account detection probability have not been generated at most
sites for these species, but mark-recapture studies at some of the
highest quality sites for Jollyville Plateau salamanders estimated
surface populations as low as 78 and as high as 1,024 (O'Donnell et al.
2008, pp. 44-45).
At small population levels, the effects of demographic
stochasticity (the variability in population growth rates arising from
random differences among individuals in survival and reproduction
within a season) alone greatly increase the risk of local extinctions
(Van Dyke 2008, p. 218). Although it remains a complex field of study,
conservation genetics research has demonstrated that long-term
inbreeding depression (a pattern of reduced reproduction and survival
as a result of genetic relatedness) can occur within populations with
effective sizes of 50 to 500 individuals and may also occur within
larger populations as well (Frankham 1995, pp. 305-327; Latter et al.
1995, pp. 287-297; Van Dyke 2008, pp. 155-156).
Current evidence from integrated work on population dynamics shows
that setting conservation thresholds at only a few hundred individuals
does not properly account for the synergistic impacts of multiple
threats facing a population (Traill et al. 2010, p. 32). Studies across
taxonomic groups have found both the evolutionary and demographic
constraints on populations require sizes of at least 5,000 adult
individuals to ensure long-term persistence (Traill et al. 2010, p.
30). Only one site for the Jollyville Plateau salamanders at Wheless
Spring has an average population estimate of greater than 500
individuals based on results of a mark-recapture study (O'Donnell et
al. 2008, p. 46).
Through a review of survey information available in our files and
provided to us during the peer review and public comment period for the
proposed rule, we noted the highest number of individuals counted
during survey events that have occurred over the last 10 years. We used
these survey counts as an index of salamander population health and
relative abundance. We recognize these counts do not represent true
population counts or estimates because they are reflective of only the
number of salamanders observed in the surface habitat at a specific
point in time. However, the data provide the best available information
to consider relative population sizes of salamanders.
Through this assessment, we determined that surveys at many sites
have never yielded as many as 50 individuals. In fact, 33 of the 106
(31 percent) Jollyville Plateau salamander surface sites have not
yielded as many as 5 individuals at any one time in the last 10 years.
Furthermore, surveys or salamander counts of only 8 of the 106 (8
percent) Jollyville Plateau salamander surface sites have resulted in
more than 50 individuals at a time over the last 10 years. We also
found that many of the salamander population counts have been low or
unknown.
For the Austin blind salamander, the highest count observed at a
single site over the last 10 years was 34 individuals; however, numbers
this high are very rare for this species. Counts of three individuals
or less have been reported most frequently since 1995. Because most of
the sites occupied by the Austin blind and Jollyville Plateau
salamanders are not known to have many individuals, any of the threats
described in this final rule or even stochastic events that would not
otherwise be considered a threat could extirpate populations. As
populations are extirpated, the overall risk of extinction of the
species is increased.
Small population sizes can also act synergistically with other
traits (such as being a habitat specialist and having limited
distribution, as is the case with the Austin blind and Jollyville
Plateau salamanders) to greatly increase risk of extinction (Davies et
al. 2004, p. 270). Stochastic events from either environmental factors
(random events such as severe weather) or demographic factors (random
causes of births and deaths of individuals) may also heighten the
effect of other threats to the salamander species because of their
limited range and small population sizes (Melbourne and Hastings 2008,
p. 100).
In conclusion, we do not consider small population size to be a
threat in and of itself to the Austin blind or Jollyville Plateau
salamanders, but their small population sizes make them more vulnerable
to extinction from other existing or potential threats, such as a major
stochastic event. We consider the level of impacts from stochastic
events to be moderate for the Jollyville Plateau salamander, because
this species has more populations over a broader range. On the other
hand, recolonization following a stochastic event is not likely for the
Austin blind salamander due to its limited distribution and low
numbers. Therefore, the impact from a stochastic event for the Austin
blind salamander is a significant threat.
Ultraviolet Radiation
Increased levels of ultraviolet-B (UV-B) radiation, due to
depletion of the stratospheric ozone layers, may lead to declines in
amphibian populations

[[Page 51319]]

(Blaustein and Kiesecker 2002, pp. 598-600). For example, research has
demonstrated that UV-B radiation causes significant mortality and
deformities in developing long-toed salamanders (Ambystoma
macrodactylum) (Blaustein et al. 1997, p. 13,735). Exposure to UV-B
radiation reduces growth in clawed frogs (Xenopus laevis) (Hatch and
Burton, 1998, p. 1,783) and lowers hatching success in Cascades frogs
(Rana cascadae) and western toads (Bufo boreas) (Kiesecker and
Blaustein 1995, pp. 11,050-11,051). In lab experiments with spotted
salamanders, UV-B radiation diminished their swimming ability
(Bommarito et al. 2010, p. 1151). Additionally, UV-B radiation may act
synergistically (the total effect is greater than the sum of the
individual effects) with other factors (for example, contaminants, pH,
pathogens) to cause declines in amphibians (Alford and Richards 1999,
p. 141; see ``Synergistic and Additive Interactions among Stressors''
below). Some researchers have indicated that future increases in UV-B
radiation will have significant detrimental impacts on amphibians that
are sensitive to this radiation (Blaustein and Belden 2003, p. 95).
The effect of increased UV-B radiation on the Austin blind and
Jollyville Plateau salamanders is unknown. It is unlikely the few cave
populations of Jollyville Plateau salamanders that are restricted
entirely to the subsurface are exposed to UV-B radiation. In addition,
exposure of the Austin blind salamander may be limited because they
largely reside underground. Surface populations of these species may
receive some protection from UV-B radiation through shading from trees
or from hiding under rocks at some spring sites. Substrate alteration
may put these species at greater risk of UV-B exposure and impacts.
Because eggs are likely deposited underground (Bendik 2011b, COA, pers.
comm.), UV-B radiation may have no impact on the hatching success of
these species.
In conclusion, the effect of increased UV-B radiation has the
potential to cause deformities or developmental problems to
individuals, but we do not consider this stressor to significantly
contribute to the risk of extinction of the Austin blind and Jollyville
Plateau salamanders at this time. However, UV-B radiation could
negatively affect any of the Austin blind and Jollyville Plateau
salamanders' surface populations in combination with other threats
(such as water quality or water quantity degradation) and contribute to
significant declines in population sizes.
Deformities in Jollyville Plateau Salamanders
Jollyville Plateau salamanders observed at the Stillhouse Hollow
monitoring sites have shown high incidences of deformities, such as
curved spines, missing eyes, missing limbs or digits, and eye injuries
(O'Donnell et al. 2006, p. 26). The Stillhouse Hollow location was also
cited as having the highest observation of dead Jollyville Plateau
salamanders (COA 2001, p. 88). Although water quality is relatively low
in the Stillhouse Hollow drainage (O'Donnell et al. 2006, pp. 26, 37),
no statistical correlations were found between the number of
deformities and nitrate concentrations (O'Donnell et al. 2006, p. 26).
Environmental toxins are the suspected cause of salamander deformities
(COA 2001, pp. 70-74; O'Donnell et al. 2006, p. 25), but deformities in
amphibians can also be the result of genetic mutations, parasitic
infections, UV-B radiation, or the lack of an essential nutrient. More
research is needed to elucidate the cause of these deformities. We
consider deformities to be a low-level impact to the Jollyville Plateau
salamander at this time because this stressor is an issue at only one
site, is not affecting the entire population there, and does not appear
to be an issue for the other salamander species.
Other Natural Factors
The highly restricted ranges of the salamanders and entirely
aquatic environment make them extremely vulnerable to threats such as
decreases in water quality and quantity. This is especially true for
the Austin blind salamander, which is found in only one locality
comprising three hydrologically connected springs of Barton Springs.
Due to its limited distribution, the Austin blind salamander is
sensitive to stochastic incidences, such as storm events (which can
dramatically affect dissolved oxygen levels), catastrophic contaminant
spills, and leaks of harmful substances. One catastrophic spill event
in Barton Springs could potentially cause the extinction of the Austin
blind salamander in the wild.
Although rare, catastrophic events pose a significant threat to
small populations because they have the potential to eliminate all
individuals in a small group (Van Dyke 2008, p. 218). In the proposed
rule, we discussed that the presence of several locations of Jollyville
Plateau salamanders close to each other provides some possibility for
natural recolonization for populations of these species if any of these
factors resulted in a local extirpation event (Fagan et al. 2002, p.
3,255). Although it may be possible for Eurycea salamanders to travel
through aquifer conduits from one surface population to another, or
that two individuals from different populations could breed in
subsurface habitat, there is no direct evidence that they currently
migrate from one surface population to another on a regular basis. Just
because there is detectable gene flow between two populations does not
necessarily mean that there is current or routine dispersal between
populations that could allow for recolonization of a site should the
population be extirpated by a catastrophic event (Gillespie 2012,
University of Texas, pers. comm.).
In conclusion, restricted ranges could negatively affect any of the
Austin blind and Jollyville Plateau salamanders' populations in
combination with other threats (such as water quality or water quantity
degradation) and lead to the species being at a higher risk of
extinction. We consider the level of impacts from stochastic events to
be moderate for the Jollyville Plateau salamander, because even though
this species has more populations over a broader range, the range is
still restricted and the species' continued existence could be
compromised by a common event. On the other hand, recolonization
following a stochastic event is less likely for the Austin blind
salamander due to its limited distribution and low numbers. Therefore,
the impact from a stochastic event for the Austin blind salamander is a
significant threat.
Synergistic and Additive Interactions Among Stressors
The interactions among multiple stressors (contaminants, UV-B
radiation, pathogens) may be contributing to amphibian population
declines (Blaustein and Kiesecker 2002, p. 598). Multiple stressors may
act additively or synergistically to have greater detrimental impacts
on amphibians compared to a single stressor alone. Kiesecker and
Blaustein (1995, p. 11,051) found a synergistic effect between UV-B
radiation and a pathogen in Cascades frogs and western toads.
Researchers demonstrated that reduced pH levels and increased levels of
UV-B radiation independently had no effect on leopard frog (Rana
pipiens) larvae; however, when combined, these two caused significant
mortality (Long et al. 1995, p. 1,302). Additionally, researchers
demonstrated that UV-B radiation increases the toxicity of PAHs, which
can cause mortality and deformities on developing amphibians (Hatch and
Burton 1998, pp. 1,780-

[[Page 51320]]

1,783). Beattie et al. (1992, p. 566) demonstrated that aluminum
becomes toxic to amphibians at low pH levels. Also, disease outbreaks
may occur only when there are contaminants or other stressors in the
environment that reduce immunity (Alford and Richards 1999, p. 141).
For example, Christin et al. (2003, pp. 1,129-1,132) demonstrated that
mixtures of pesticides reduced the immunity to parasitic infections in
leopard frogs.
Currently, the effect of synergistic stressors on the Austin blind
and Jollyville Plateau salamanders is not fully known. Furthermore,
different species of amphibians differ in their reactions to stressors
and combinations of stressors (Kiesecker and Blaustein 1995, p. 11,051;
Relyea et al. 2009, pp. 367-368; Rohr et al. 2003, pp. 2,387-2,390).
Studies that examine the effects of interactions among multiple
stressors on the Austin blind and Jollyville Plateau salamanders are
lacking. However, based on the number of examples in other amphibians,
the possibility of synergistic effects on these salamanders cannot be
discounted.
Conclusion of Factor E
The effect of increased UV-B radiation is an unstudied stressor to
the Austin blind and Jollyville Plateau salamanders that has the
potential to cause deformities or development problems. The effect of
this stressor is low at this time. Deformities have been documented in
the Jollyville Plateau salamander, but at only one location (Stillhouse
Hollow). We do not know what causes these deformities, and there is no
evidence that the incidence rate is increasing or spreading. Therefore,
the effect of UV-B radiation is low. Finally, small population sizes at
most of the sites for the salamanders increases the risk of local
extirpation events. We do not necessarily consider small population
size to be a threat in and of itself to the Austin blind and Jollyville
Plateau salamanders, but their small population sizes make them more
vulnerable to extirpation from other existing or potential threats,
such as stochastic events. Thus, we consider the level of impacts from
stochastic events to be moderate for the Jollyville Plateau salamander
and high for the Austin blind salamanders due to its more limited
distribution and low numbers.
Conservation Efforts To Reduce Other Natural or Manmade Factors
Affecting Its Continued Existence
We have no information on any conservation efforts currently under
way to reduce the effects of UV-B radiation, deformities, small
population sizes, or limited ranges on the Austin blind and Jollyville
Plateau salamanders.
Cumulative Impacts

Cumulative Effects From Factors A Through E

Some of the threats discussed in this finding could work in concert
with one another to cumulatively create situations that impact the
Austin blind and Jollyville Plateau salamanders. Some threats to the
species may seem to be of low significance by themselves, but when
considered with other threats that are occurring at each site, such as
small population sizes, the risk of extirpation is increased.
Furthermore, we have no direct evidence that salamanders currently
migrate from one population to another on a regular basis, and many of
the populations are situated in a way (that is, they are isolated from
one another) where recolonization of extirpated sites is very unlikely.
Cumulatively, as threats to the species increase over time in tandem
with increasing urbanization within the surface watersheds of these
species, more and more populations will be lost, which will increase
the species' risk of extinction.
Overall Threats Summary
The primary factor threatening the Austin blind and Jollyville
Plateau salamanders is the present or threatened destruction,
modification, or curtailment of its habitat or range (Factor A).
Degradation of habitat, in the form of reduced water quality and
quantity and disturbance of spring sites (surface habitat), is the
primary threat to the Austin blind and Jollyville Plateau salamanders.
Reductions in water quality occur primarily as a result of
urbanization, which increases the amount of impervious cover in the
watershed and exposes the salamanders to more hazardous material
sources. Impervious cover increases storm flow, erosion, and
sedimentation. Impervious cover also changes natural flow regimes
within watersheds and increases the transport of contaminants common in
urban environments, such as oils, metals, and pesticides. Expanding
urbanization results in an increase of contaminants, such as
fertilizers and pesticides, within the watershed, which degrades water
quality at salamander spring sites. Additionally, urbanization
increases nutrient loads at spring sites, which can lead to decreases
in dissolved oxygen levels. Construction activities are a threat to
both water quality and quantity because they can increase sedimentation
and exposure to contaminants, as well as dewater springs by
intercepting aquifer conduits.
Various other threats to habitat exist for the Austin blind and
Jollyville Plateau salamanders as well. Drought, which may be
compounded by the effects of global climate change, also degrades water
quantity and reduces available habitat for the salamanders. Water
quantity can also be reduced by groundwater pumping and decreases in
baseflow due to increases in impervious cover. Flood events contribute
to the salamanders' risks of extinction by degrading water quality
through increased contaminants levels and sedimentation, which may
damage or alter substrates, and by removing rocky substrates or washing
salamanders out of suitable habitat. Impoundments are also a threat to
the Austin blind and Jollyville Plateau salamanders. Feral hogs are a
threat to Jollyville Plateau salamanders, because they can physically
alter their surface habitat and increase nutrients. Additionally,
catastrophic spills and leaks remain a threat for many salamander
locations. All of these threats are projected to increase in the future
as the human population and development increases within watersheds
that provide habitat for these salamanders. Some of these threats are
moderated, in part, by ongoing conservation efforts, such as HCPs,
preserves, and other programs in place to protect land from the effects
of urbanization and to gather water quality data that would be helpful
in designing conservation strategies for the salamander species.
Overall, we consider the combined threats of Factor A to be ongoing and
with a high degree of impact to the Austin blind and Jollyville Plateau
salamanders and their habitats.
Another factor affecting these salamander species is Factor D, the
inadequacy of existing regulatory mechanisms. Surface water quality
data collected by TCEQ indicates that water quality degradation is
occurring within many of the surface watersheds occupied by the Austin
blind and Jollyville Plateau salamanders despite the existence of
numerous State and local regulatory mechanisms to manage stormwater and
protect water quality. Human population growth and urbanization in
Travis and Williamson Counties are projected to continue into the
future as well as the associated impacts to water quality and quantity
(see Factor A discussion above). Because existing regulations are not
providing adequate protection for the salamanders or their habitats, we
consider the existing regulatory mechanisms inadequate to protect the

[[Page 51321]]

Austin blind and Jollyville Plateau salamanders now and in the future.
Under Factor E we identified several stressors that could
negatively impact the Austin blind and Jollyville Plateau salamanders,
including the increased risk of local extirpation events due to small
population sizes, UV-B radiation, and deformities. Although none of
these stressors rose to the level of being considered a threat by
itself, small population sizes and restricted ranges make the Austin
blind and Jollyville Plateau salamanders more vulnerable to extirpation
from other existing or potential threats, such as stochastic events.
Thus, we consider the level of impacts from stochastic events to be
high for the Austin blind and Jollyville Plateau salamanders due to
their low numbers, and especially high for the Austin blind salamander
due to its limited distributions.

Determination

Standard for Review

Section 4 of the Act, and its implementing regulations at 50 CFR
part 424, set forth the procedures for adding species to the Federal
Lists of Endangered and Threatened Wildlife and Plants. Under section
4(b)(1)(a), the Secretary is to make threatened or endangered
determinations required by subsection 4(a)(1) solely on the basis of
the best scientific and commercial data available to her after
conducting a review of the status of the species and after taking into
account conservation efforts by States or foreign nations. The
standards for determining whether a species is threatened or endangered
are provided in section 3 of the Act. An endangered species is any
species that is ``in danger of extinction throughout all or a
significant portion of its range.'' A threatened species is any species
that is ``likely to become an endangered species within the foreseeable
future throughout all or a significant portion of its range.'' Per
section 4(a)(1) of the Act, in reviewing the status of the species to
determine if it meets the definitions of threatened or endangered, we
determine whether any species is an endangered species or a threatened
species because of any of the following 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; and (E) other natural or manmade
factors affecting its continued existence.
We evaluated whether the Austin blind and Jollyville Plateau
salamanders are in danger of extinction now (that is, an endangered
species) or are likely to become in danger of extinction in the
foreseeable future (that is, a threatened species). The foreseeable
future refers to the extent to which the Secretary can reasonably rely
on predictions about the future in making determinations about the
future conservation status of the species. A key statutory difference
between a threatened species and an endangered species is the timing of
when a species may be in danger of extinction, either now (endangered
species) or in the foreseeable future (threatened species).

Listing Status Determination for the Austin Blind Salamander

Based on our review of the best available scientific and commercial
information, we conclude that the Austin blind salamander is in danger
of extinction now throughout all of its range and, therefore, meets the
definition of an endangered species. This finding, explained below, is
based on our conclusions that this species has only one known
population that occurs at three spring outlets in Barton Springs, the
habitat of this population has experienced impacts from threats, and
these threats are expected to increase in the future. We find the
Austin blind salamander is at an elevated risk of extinction now, and
no data indicate that the situation will improve without significant
additional conservation intervention. We, therefore, find that the
Austin blind salamander warrants an endangered species listing status
determination.
Present and future degradation of habitat (Factor A) is the primary
threat to the Austin blind salamander. This threat has primarily
occurred in the form of reduced water quality from introduced and
concentrated contaminants (for example, PAHs, pesticides, nutrients,
and trace metals), increased sedimentation, and altered stream flow
regimes. These stressors are primarily the result of human population
growth and subsequent urbanization within the watershed and recharge
and contributing zones of the Barton Springs Segment of the Edwards
Aquifer. Urbanization is currently having impacts on Austin blind
salamander habitat. For example, a study by the U.S. Geological Survey
concluded that baseline water quality in the Barton Springs Segment of
the Edwards Aquifer, in terms of nitrate, had shifted upward between
2001 and 2010 and was at least partially the result of an increase in
the land application of treated wastewater (Mahler et al. 2011, pp. 34-
35). Based on our analysis of impervious cover, the surface watershed
and groundwater recharge and contributing zones of Barton Springs have
levels of impervious cover that are likely causing habitat degradation.
As a result, the best available information indicates that habitat
degradation from urbanization is causing a decline in the Austin blind
salamander population throughout the species' range now and will cause
population declines in the future, putting this population at an
elevated risk of extirpation.
Further degradation of water quality within the Austin blind
salamander's habitat is expected to continue into the future, primarily
as a result of an increase in urbanization. Substantial human
population growth is ongoing within this species' range, indicating
that the urbanization and its effects on Austin blind salamander
habitat will increase in the future. The Texas State Data Center (2012,
pp. 496-497) has reported a population increase of 94 percent for
Travis County, Texas, from the year 2010 to 2050. Data indicate that
water quality degradation at Barton Springs continues to occur despite
the existence of current regulatory mechanisms in place to protect
water quality; therefore, these mechanisms are not adequate to protect
this species and its habitat now, nor do we anticipate them to
sufficiently protect the species in the future (Factor D).
An additional threat to the Austin blind salamander is hazardous
materials that could be spilled or leaked potentially resulting in the
contamination of both surface and groundwater resources. For example, a
number of point-sources of pollutants exist within the Austin blind
salamander's range, including 7,600 wastewater mains and 9,470 known
septic facilities in the Barton Springs Segment of the Edwards Aquifer
as of 2010 (Herrington et al. 2010, pp. 5, 16). Because this species
occurs in only one population in Barton Springs, a single but
significant hazardous materials spill within stream drainages of the
Austin blind salamander has the potential to cause this species to go
extinct.
In addition, construction activities resulting from urban
development may negatively impact both water quality and quantity
because they can increase sedimentation and dewater springs by
intercepting aquifer conduits. It has been estimated that total
suspended sediment loads have increased 270 percent over predevelopment
loadings within the Barton Springs Segment of the Edwards Aquifer (COA
1995, pp. 3-10). The risk of a hazardous material spill and effects
from construction activities will increase as urbanization

[[Page 51322]]

within the range of the Austin blind salamander increases.
The habitat of Austin blind salamanders is sensitive to direct
physical habitat modification, particularly due to human vandalism of
the springs and the Barton Springs impoundments. Eliza Spring and
Sunken Garden Spring, two of the three spring outlets of the Austin
blind salamander, experience vandalism, despite the presence of fencing
and signage (Dries 2011, COA, pers. comm.). Also, the impoundments have
changed the Barton Springs ecosystem from a stream-like system to a
more lentic (still-water) environment, thereby reducing the water
system's ability to flush sediments downstream and out of salamander
habitat. In combination with the increased threat from urbanization,
these threats are likely driving the Austin blind salamander to the
brink of extinction now.
Future climate change could also affect water quantity and spring
flow for the Austin blind salamander. Climate change could compound the
threat of decreased water quantity at salamander spring sites by
decreasing precipitation, increasing evaporation, and increasing the
likelihood of extreme drought events. The Edwards Aquifer is projected
to experience additional stress from climate change that could lead to
decreased recharge and low or ceased spring flows given increasing
pumping demands (Lo[aacute]iciga et al. 2000, pp. 192-193). Evidence of
climate change has been observed in Texas, such as the record-setting
drought of 2011, with extreme droughts becoming much more probable than
they were 40 to 50 years ago (Rupp et al. 2012, pp. 1053-1054). Drought
lowers water quality in Barton Springs due to saline water
encroachments in the Barton Springs Segment of the Edwards Aquifer
(Slade et al. 1986, p. 62; Johns 2006, p. 8). Recent droughts have
negatively impacted Austin blind salamander abundance (Dries 2012, pp.
16-18), reducing the resiliency of the sole population. Therefore,
climate change is an ongoing threat to this species and contributes to
the likelihood of the Austin blind salamander becoming extinct now.
Other natural or manmade factors (Factor E) affecting the Austin
blind salamander population include UV-B radiation, small population
sizes, stochastic events (such as floods or droughts), and synergistic
and additive interactions among the stressors mentioned above. While
these factors are not threats to the existence of the Austin blind
salamander in and of themselves, in combination with the threats
summarized above, these factors make the Austin blind salamander
population less resilient and more vulnerable to extinction now.
Because of the fact-specific nature of listing determinations,
there is no single metric for determining if a species is ``in danger
of extinction'' now. In the case of the Austin blind salamander, the
best available information indicates that habitat degradation has
occurred throughout the only known Austin blind salamander population.
The threat of urbanization indicates that this Austin blind salamander
population is currently at an elevated risk of extinction now and will
continue to be at an elevated risk in the future. These impacts are
expected to increase in severity and scope as urbanization within the
range of the species increases. Also, the combined result of increased
impacts to habitat quality and inadequate regulatory mechanisms leads
us to the conclusion that Austin blind salamanders are in danger of
extinction now. This Austin blind salamander population has become
degraded from urbanization, low resiliency and is subsequently at an
elevated risk from climate change impacts and catastrophic events (for
example, drought, floods, hazardous material spills). Therefore,
because the only known Austin blind salamander population is at an
elevated risk of extinction, the Austin blind salamander is in danger
of extinction throughout all of its range now, and appropriately meets
the definition of an endangered species (that is, in danger of
extinction now).
Under the Act and our implementing regulations, a species may
warrant listing if it is threatened or endangered throughout all or a
significant portion of its range. The threats to the survival of this
species occur throughout its range and are not restricted to any
particular significant portion of its range. Accordingly, our
assessments and determinations apply to this species throughout its
entire range.
In conclusion, as described above, the Austin blind salamander is
subject to significant threats now, and these threats will continue to
become more severe in the future. After a review of the best available
scientific information as it relates to the status of the species and
the five listing factors, we find the Austin blind salamander is
currently on the brink of extinction. Therefore, on the basis of the
best available scientific and commercial information, we list the
Austin blind salamander as an endangered species in accordance with
section 3(6) of the Act. We find that a threatened species status is
not appropriate for the Austin blind salamander because the overall
risk of extinction is high at this time. The one existing population is
not sufficiently resilient or redundant to withstand present and future
threats, putting this species in danger of extinction now.

Listing Determination for the Jollyville Plateau Salamander

In the proposed rule (77 FR 50768, August 22, 2012), the Jollyville
Plateau salamander species was proposed as endangered, rather than
threatened, because at that time, we determined the threats to be
imminent, and their potential impacts to the species would be
catastrophic given the very limited range of the species. For this
final determination, we took into account data that was made available
after the proposed rule published, information provided by commenters
on the proposed rule, and further discussions within the Service to
determine whether the Jollyville Plateau salamander should be
classified as endangered or threatened. Based on our review of the best
available scientific and commercial information, we conclude that the
Jollyville Plateau salamander is likely to become in danger of
extinction in the foreseeable future throughout all of its range and,
therefore, meets the definition of a threatened species, rather than
endangered. This finding, explained below, is based on our conclusions
that many populations of the species have begun to experience impacts
from threats to its habitat, and these threats are expected to increase
in the future. As the threats increase, we expect Jollyville Plateau
salamander populations to be extirpated, reducing the overall
representation and redundancy across the species' range and increasing
the species' risk of extinction. We find the Jollyville Plateau
salamander will be at an elevated risk of extinction in the future, and
no data indicate that the situation will improve without significant
additional conservation intervention. We, therefore, find that the
Jollyville Plateau salamander warrants a threatened species listing
status determination.
Present and future degradation of habitat (Factor A) is the primary
threat to the Jollyville Plateau salamander. This threat has primarily
occurred in the form of reduced water quality from introduced and
concentrated contaminants (for example, PAHs, pesticides, nutrients,
and trace metals), increased sedimentation, and altered stream flow
regimes. These stressors are primarily the result of human population
growth and subsequent urbanization within the watersheds and

[[Page 51323]]

recharge and contributing zones of the groundwater supporting spring
and cave sites. Urbanization affects both surface and subsurface
habitat and is currently having impacts on Jollyville Plateau
salamander counts. For example, Bendik (2011a, pp. 26-27) demonstrated
that declining trends in counts are correlated with high levels of
impervious cover. Based on our analysis of impervious cover (which we
use as a proxy for urbanization) throughout the range of the Jollyville
Plateau salamander, 81 of the 93 surface watersheds occupied by
Jollyville Plateau salamanders have levels of impervious cover that are
likely causing habitat degradation. As a result, the best available
information indicates that habitat degradation from urbanization is
causing declines in Jollyville Plateau salamander populations
throughout most of the species' range now or will cause population
declines in the future, putting these populations at an elevated risk
of extirpation.
Further degradation of water quality within the Jollyville Plateau
salamander's habitat is expected to continue into the future, primarily
as a result of an increase in urbanization. Substantial human
population growth is ongoing within this species' range, indicating
that the urbanization and its effects on Jollyville Plateau salamander
habitat will increase in the future. The Texas State Data Center (2012,
pp. 496-497, 509) has reported a population increase of 94 percent and
477 percent for Travis and Williamson Counties, Texas, respectively,
from the year 2010 to 2050. Data indicate that water quality
degradation in sites occupied by Jollyville Plateau salamanders
continues to occur despite the existence of current regulatory
mechanisms in place to protect water quality; therefore, these
mechanisms are not adequate to protect this species and its habitat
now, nor do we anticipate them to sufficiently protect the species in
the future.
Adding to the likelihood of the Jollyville Plateau salamander
becoming endangered in the future is the risk from hazardous materials
that could be spilled or leaked, potentially resulting in the
contamination of both surface and groundwater resources. For example, a
number of point-sources of pollutants exist within the Jollyville
Plateau salamander's range, including leaking underground storage tanks
and sewage spills from pipelines (COA 2001, pp. 16, 21, 74). A
significant hazardous materials spill within stream drainages of the
Jollyville Plateau salamander has the potential to threaten the long-
term survival and sustainability of multiple populations.
In addition, construction activities resulting from urban
development may negatively impact both water quality and quantity
because they can increase sedimentation and dewater springs by
intercepting aquifer conduits. Increased sedimentation from
construction activities has been linked to declines in Jollyville
Plateau salamander counts at multiple sites (Turner 2003, p. 24;
O'Donnell et al. 2006, p. 34). The risk of a hazardous material spill
and effects from construction activities will increase as urbanization
within the range of the Jollyville Plateau salamander increases.
The habitat of Jollyville Plateau salamanders is sensitive to
direct physical habitat modification, such as those resulting from
human recreational activities, impoundments, feral hogs, and livestock.
Destruction of Jollyville Plateau salamander habitat has been
attributed to vandalism (COA 2001, p. 21), human recreational use (COA
2001, p. 21), impoundments (O'Donnell et al. 2008, p. 1; Bendik 2011b,
pers. comm.), and feral hog activity (O'Donnell et al. 2006, pp. 34,
46). Because these threats are impacting a limited number of sites,
they are not causing the Jollyville Plateau salamander to be on the
brink of extinction now. However, in combination with the increased
threat from urbanization, these threats are likely to drive the
Jollyville Plateau salamander to the brink of extinction in the
foreseeable future.
Future climate change could also affect water quantity and spring
flow for the Jollyville Plateau salamander. Climate change could
compound the threat of decreased water quantity at salamander spring
sites by decreasing precipitation, increasing evaporation, and
increasing the likelihood of extreme drought events. The Edwards
Aquifer is predicted to experience additional stress from climate
change that could lead to decreased recharge and low or ceased spring
flows given increasing pumping demands (Lo[aacute]iciga et al. 2000,
pp. 192-193). Climate change could cause spring sites with small
amounts of discharge to go dry and no longer support salamanders,
reducing the overall redundancy and representation for the species.
Evidence of climate change has been observed in Texas, such as the
record-setting drought of 2011, with extreme droughts becoming much
more probable than they were 40 to 50 years ago (Rupp et al. 2012, p.
1,053-1,054). Therefore, climate change is an ongoing threat to this
species and will add to the likelihood of the Jollyville Plateau
salamander becoming endangered within the foreseeable future.
Other natural or manmade factors (Factor E) affecting all
Jollyville Plateau salamander populations include UV-B radiation, small
population sizes, stochastic events (such as floods or droughts), and
synergistic and additive interactions among the stressors mentioned
above. While these factors are not threats to the existence of the
Jollyville Plateau salamander in and of themselves in combination with
the threats summarized above, these factors make Jollyville Plateau
salamander populations less resilient and more vulnerable to population
extirpations in the foreseeable future.
Because of the fact-specific nature of listing determinations,
there is no single metric for determining if a species is ``in danger
of extinction'' now. In the case of the Jollyville Plateau salamander,
the best available information indicates that habitat degradation has
resulted in measureable impacts on salamander counts. But, given that
there are 106 surface and 16 cave populations, it is unlikely that any
of the current threats are severe enough to impact all of the sites and
result in overall species extirpation in the near future. The
Jollyville Plateau salamander's risk of extinction now is not high (it
is not in danger of extinction now). However, the threat of
urbanization will cause the Jollyville Plateau salamander to be at an
elevated risk of extirpation in the future. Also, the combined result
of increased impacts to habitat quality and inadequate regulatory
mechanisms leads us to the conclusion that Jollyville Plateau
salamanders will likely be in danger of extinction within the
foreseeable future. As Jollyville Plateau salamander populations become
more degraded, isolated, or extirpated from urbanization, the species
will lose resiliency and be at an elevated risk from climate change
impacts and catastrophic events, such as drought, floods, and hazardous
material spills. These events will affect all known extant populations,
putting the Jollyville Plateau salamander at a high risk of extinction.
Therefore, because the resiliency of populations is expected to
decrease in the foreseeable future, the Jollyville Plateau salamander
will be danger of extinction throughout all of its range in the
foreseeable future, and appropriately meets the definition of a
threatened species (that is, in danger of extinction in the foreseeable
future).
After a review of the best available scientific information as it
relates to the status of the species and the five listing factors, we
find the Jollyville Plateau salamander is not currently in danger of
extinction, but will be in danger of extinction in the future
throughout all of

[[Page 51324]]

its range. Therefore, on the basis of the best available scientific and
commercial information, we are listing the Jollyville Plateau
salamander as a threatened species, in accordance with section 3(6) of
the Act. We find that an endangered species status is not appropriate
for the Jollyville Plateau salamander because the species is not in
danger of extinction at this time. While some threats to the Jollyville
Plateau salamander are occurring now, the impacts from these threats
are not yet at a level that puts this species in danger of extinction
now. Habitat degradation and associated salamander count declines have
been observed at urbanized sites. Furthermore, some Jollyville Plateau
salamander sites are located within preserves and receive some
protections from threats occurring to the species now. While the
populations within preserves are not free from the impacts of
urbanization, they are at a lower risk of extirpation because of the
protections in place. Even so, with future urbanization outside of the
preserves and the added effects of climate change, we expect habitat
degradation to continue into the foreseeable future to the point where
the species has an increased risk of extinction.
Under the Act and our implementing regulations, a species may
warrant listing if it is threatened or endangered throughout all or a
significant portion of its range. The threats to the survival of this
species occur throughout its range and are not restricted to any
particular significant portion of its range. Accordingly, our
assessments and determinations apply to this species throughout its
entire range.

Available Conservation Measures

Conservation measures provided to species listed as endangered or
threatened species under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness and
conservation by Federal, State, tribal, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
States and requires that recovery actions be carried out for all listed
species. The protection required by Federal agencies and the
prohibitions against certain activities are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Subsection 4(f) of the Act requires the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The recovery planning process involves the
identification of actions that are necessary to halt or reverse the
decline in the species' status by addressing the threats to its
survival and recovery. The goal of this process is to restore listed
species to a point where they are secure, self-sustaining, and
functioning components of their ecosystems.
Recovery planning includes the development of a recovery outline
shortly after a species is listed and preparation of a draft and final
recovery plan. The recovery outline guides the immediate implementation
of urgent recovery actions and describes the process to be used to
develop a recovery plan. Revisions of the plan may be done to address
continuing or new threats to the species, as new substantive
information becomes available. The recovery plan identifies site-
specific management actions that set a trigger for review of the five
factors that control whether a species remains endangered or may be
downlisted or delisted, and methods for monitoring recovery progress.
Recovery plans also establish a framework for agencies to coordinate
their recovery efforts and provide estimates of the cost of
implementing recovery tasks. Recovery teams (comprising species
experts, Federal and State agencies, nongovernmental organizations, and
stakeholders) are often established to develop recovery plans. When
completed, the recovery outline, draft recovery plan, and the final
recovery plan will be available on our Web site (http://www.fws.gov/endangered), or from our Austin Ecological Services Field Office (see
FOR FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, tribes, nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (for example, restoration of native vegetation), research,
captive propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires
cooperative conservation efforts on private, State, tribal, and other
lands.
Once these species are listed, funding for recovery actions will be
available from a variety of sources, including Federal budgets, State
programs, and cost-share grants for non-Federal landowners, the
academic community, and nongovernmental organizations. In addition,
pursuant to section 6 of the Act, the State of Texas will be eligible
for Federal funds to implement management actions that promote the
protection or recovery of the Austin blind and Jollyville Plateau
salamanders. Information on our grant programs that are available to
aid species recovery can be found at: http://www.fws.gov/grants.
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is proposed or listed as
endangered or threatened and with respect to its critical habitat, if
any is designated. Regulations implementing this interagency
cooperation provision of the Act are codified at 50 CFR Part 402.
Section 7(a)(4) of the Act requires Federal agencies to confer with the
Service on any action that is likely to jeopardize the continued
existence of a species proposed for listing or result in destruction or
adverse modification of proposed critical habitat. If a species is
listed subsequently, section 7(a)(2) of the Act requires Federal
agencies to ensure that activities they authorize, fund, or carry out
are not likely to jeopardize the continued existence of the species or
destroy or adversely modify its critical habitat. If a Federal action
may affect a listed species or its critical habitat, the responsible
Federal agency must enter into formal consultation with the Service.
Federal agency actions within the species habitat that may require
conference or consultation or both as described in the preceding
paragraph include management, construction, and any other activities
with the possibility of altering aquatic habitats, groundwater flow
paths, and natural flow regimes within the ranges of the Austin blind
and Jollyville Plateau salamanders. Such consultations could be
triggered through the issuance of section 404 Clean Water Act permits
by the Army Corps of Engineers or other actions by the Service, U.S.
Geological Survey, and Bureau of Reclamation; construction and
maintenance of roads or highways by the Federal Highway Administration;
landscape-altering activities on Federal lands administered by the
Department of Defense; and construction and management of gas pipelines
and power line rights-of-way by the Federal Energy Regulatory
Commission.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply

[[Page 51325]]

to all endangered wildlife. The prohibitions of section 9(a)(2) of the
Act, codified at 50 CFR 17.21 for endangered wildlife, in part, make it
illegal for any person subject to the jurisdiction of the United States
to take (includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect; or to attempt any of these), import, export, ship
in interstate commerce in the course of commercial activity, or sell or
offer for sale in interstate or foreign commerce any listed species.
Under the Lacey Act (18 U.S.C. 42-43; 16 U.S.C. 3371-3378), it is also
illegal to possess, sell, deliver, carry, transport, or ship any such
wildlife that has been taken illegally. Certain exceptions apply to
agents of the Service and State conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving endangered and threatened wildlife species under certain
circumstances. Regulations governing permits are codified at 50 CFR
17.22 for endangered wildlife, and at 50 CFR 17.32 for threatened
wildlife. With regard to endangered wildlife, a permit must be issued
for the following purposes: for scientific purposes, to enhance the
propagation or survival of the species, and for incidental take in
connection with otherwise lawful activities.

Required Determinations

Regulatory Planning and Review (Executive Orders 12866 and 13563)

Executive Order 12866 provides that the Office of Information and
Regulatory Affairs in the Office of Management and Budget (OMB) will
review all significant rules. The Office of Information and Regulatory
Affairs has determined that this rule is not significant.
Executive Order 13563 reaffirms the principles of E.O. 12866 while
calling for improvements in the nation's regulatory system to promote
predictability, to reduce uncertainty, and to use the best, most
innovative, and least burdensome tools for achieving regulatory ends.
The executive order directs agencies to consider regulatory approaches
that reduce burdens and maintain flexibility and freedom of choice for
the public where these approaches are relevant, feasible, and
consistent with regulatory objectives. E.O. 13563 emphasizes further
that regulations must be based on the best available science and that
the rulemaking process must allow for public participation and an open
exchange of ideas. We have developed this rule in a manner consistent
with these requirements.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

This rule does not contain any new collections of information that
require approval by OMB under the Paperwork Reduction Act. This rule
will not impose recordkeeping or reporting requirements on State or
local governments, individuals, businesses, or organizations. An agency
may not conduct or sponsor, and a person is not required to respond to,
a collection of information unless it displays a currently valid OMB
control number.

National Environmental Policy Act

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

Data Quality Act

In developing this rule, we did not conduct or use a study,
experiment, or survey requiring peer review under the Data Quality Act
(Pub. L. 106-554).

References Cited

A complete list of all references cited in this rule is available
on the Internet at http://www.regulations.gov or upon request from the
Field Supervisor, Austin Ecological Services Field Office (see
ADDRESSES).

Author(s)

The primary author of this document is staff from the Austin
Ecological Services Field Office (see ADDRESSES) with support from the
Arlington, Texas, Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as follows:

PART 17--[AMENDED]

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

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

0
2. Amend Sec. 17.11(h) by adding entries for ``Salamander, Austin
blind'' and ``Salamander, Jollyville Plateau'' in alphabetical order
under AMPHIBIANS to the List of Endangered and Threatened Wildlife to
read as follows:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *
(h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
-------------------------------------------------------- population where Critical Special
Historic range endangered or Status When listed habitat rules
Common name Scientific name threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *
Amphibians

* * * * * * *
Salamander, Austin blind......... Eurycea U.S.A.............. Entire............. E 817 17.95(d) NA
waterlooensis. (TX)...............

* * * * * * *
Salamander, Jollyville Plateau... Eurycea tonkawae.... U.S.A.............. Entire............. T 817 17.95(d) NA
(TX)...............

* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 51326]]

* * * * *

Dated: August 5, 2013.
Dan Ashe,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2013-19715 Filed 8-19-13; 8:45 am]
BILLING CODE 4310-55-P