# 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

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A2013-19715

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** August 20, 2013
- **Citation:** 78 FR 51278

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R2-ES-2012-0035; 4500030113]
RIN 1018-AY22
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

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

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 commen
t. 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

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.

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

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 a
l. 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

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.

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

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

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.

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.

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

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

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

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

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

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

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 µg/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 µg/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 μg/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 μg/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 µg/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 µg/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

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 µg/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

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2013-19715. Public record. Not legal advice.