Endangered and Threatened Wildlife and Plants; Endangered Status for the Ozark Hellbender Salamander, 61956-61978 [2011-25690]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 76, Number 194 (Thursday, October 6, 2011)]
[Rules and Regulations]
[Pages 61956-61978]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-25690]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R3-ES-2009-0009; MO 92210-0-0008-B2]
RIN 1018-AV94


Endangered and Threatened Wildlife and Plants; Endangered Status 
for the Ozark Hellbender Salamander

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine 
endangered status under the Endangered Species Act of 1973 (Act), as 
amended, for the Ozark Hellbender (Cryptobranchus alleganiensis 
bishopi), a subspecies found in northern Arkansas and southern 
Missouri. This final rule implements the Federal protections provided 
by the Act for this species. We have also determined that the 
designation of critical habitat for the Ozark Hellbender is not 
prudent. The final rule for the CITES Appendix III listing for the 
Ozark and Eastern Hellbender is being published concurrently in today's 
Federal Register.

DATES: This final rule is effective November 7, 2011.

ADDRESSES: The final rule is available on the Internet at https://www.regulations.gov and at the

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Columbia Missouri Ecological Services Field Office. Comments and 
materials received, as well as supporting documentation used in the 
preparation of this rule, will be available for public inspection, by 
appointment, during normal business hours at: U.S. Fish and Wildlife 
Service, Columbia Missouri Ecological Services Field Office, 101 Park 
De Ville Dr., Suite A, Columbia, MO 65203; telephone: 573-234-2132; 
facsimile: 573-234-2181.

FOR FURTHER INFORMATION CONTACT: Charles Scott, Field Supervisor, at 
the U.S. Fish and Wildlife Service, Columbia Missouri Ecological 
Services Field Office (see ADDRESSES section). If you use a 
telecommunications device for the deaf (TDD), please call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    The Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 
1531 et seq.) is a law that was passed to prevent extinction of species 
by providing measures to help alleviate the loss of species and their 
habitats. Before a plant or animal species can receive the protection 
provided by the Act, it must first be added to the Federal Lists of 
Threatened and Endangered Wildlife and Plants; section 4 of the Act and 
its implementing regulations at 50 CFR part 424 set forth the 
procedures for adding species to these lists. We published a proposed 
rule (75 FR 54561) to list the Ozark Hellbender (Cryptobranchus 
alleganiensis bishopi) as endangered under the Endangered Species Act, 
as amended (Act; 16 U.S.C. 1531 et seq.) on September 8, 2010, with a 
60-day public comment period.

Previous Federal Action

    Federal actions for this species prior to September 8, 2010, are 
outlined in our proposed rule for this action (75 FR 54561). We 
implemented the Service's peer review process and opened a 60-day 
comment period to solicit scientific and commercial information on the 
species from all interested parties following publication of the 
proposed rule. Because collection for trade is considered a primary 
threat, we coordinated with our Division of Management Authority to 
develop, concurrent with that proposal, a proposal to list the Ozark 
Hellbender as well as the Eastern Hellbender in Appendix III of the 
Convention on International Trade in Endangered Species of Wild Fauna 
and Flora (CITES) (75 FR 54579). The final rule for the CITES Appendix 
III listing is being published concurrently in today's Federal 
Register.

Species Description

    The Ozark Hellbender is a large, strictly aquatic salamander 
endemic to streams of the Ozark Plateau in southern Missouri and 
northern Arkansas. Its dorso-ventrally flattened body form enables 
movements in the fast-flowing streams it inhabits (Nickerson and Mays 
1973a, p. 1). Ozark Hellbenders have a large, keeled tail and tiny 
eyes. An adult may attain a total length of 11.4 to 22.4 inches (in) 
(29 to 57 centimeters (cm)) (Dundee and Dundee 1965, pp. 369-370; 
Johnson 2000, p. 41). Numerous fleshy folds along the sides of the body 
provide surface area for respiration (Nickerson and Mays 1973a, pp. 26-
28) and obscure their poorly developed costal grooves (grooves in the 
inner border of the ribs; Dundee 1971, p. 101.1). Ozark Hellbenders are 
distinguishable from Eastern Hellbenders (Cryptobranchus alleganiensis 
alleganiensis) by their smaller body size, dorsal blotches, increased 
skin mottling, heavily pigmented lower lip, smooth surfaced lateral 
line system, and reduced spiracular openings (openings where water is 
expelled out of the body) (Grobman 1943, p. 6; Dundee 1971, p. 101.3; 
Peterson et al. 1983, pp. 227-231; LaClaire 1993, pp. 1-2). Despite 
these distinguishing characteristics, the two subspecies are not easily 
or readily distinguishable absent the presence of both subspecies or 
when encountered outside of their subspecies' range.

Taxonomy

    The Ozark Hellbender was originally described as Cryptobranchus 
bishopi by Grobman (1943, pp. 6-9) from a specimen collected from the 
Current River in Carter County, Missouri. Based on the slight 
morphological and ecological variation within the genus Cryptobranchus, 
Dundee and Dundee (1965, pp. 369-370) determined subspecific status for 
Ozark and Eastern hellbenders as within the hellbender, C. 
alleganiensis complex sensu lato (which means, ``in the broad sense'' 
and is used when two subspecies are derived from a single species 
within a broader context). Subsequent genetic analyses by Merkle et al. 
(1977, pp. 550-552) and Shaffer and Breden (1989, pp. 1017-1022) 
supported the classification of the Ozark and Eastern hellbender as 
subspecies. In 1991 Collins (1991, pp. 42-43) attempted to revive the 
designation of C. bishopi, due to the lack of intergradation between 
the Eastern and Ozark Hellbenders, primarily a result of the taxa 
occurring in separate, nonoverlapping geographic areas (Dundee 1971, p. 
101.1). However, despite some phenotypic and genetic differences 
between Ozark and Eastern hellbenders (Grobman 1943, pp. 6-9; Dundee 
and Dundee 1965, p. 370; Dundee 1971, p. 101.1; Routman 1993, pp. 410-
415; Kucuktas et al. 2001, p. 127), the suggestion to elevate Ozark and 
Eastern hellbenders to species status was never accepted by other 
taxonomists (Crother et al. 2008, p. 15). We will continue to use the 
nomenclature C. a. bishopi for the Ozark Hellbender, which is the 
taxonomy currently recognized by the Committee on Standard English and 
Scientific Names (Crother et al. 2008, p. 15). Although discussion 
continues over the taxonomic status of the Ozark Hellbender, the 
designation of the Ozark Hellbender as a species or subspecies does not 
affect its qualification for listing under the Act (16 U.S.C. 1531 et 
seq.).

Habitat and Life History

    Eastern and Ozark hellbenders are similar in habitat selection, 
movement, and reproductive biology (Nickerson and Mays 1973a, pp. 44-
55). Published works on the Eastern Hellbender provide insights into 
Ozark Hellbender ecology. Adult Ozark Hellbenders are frequently found 
beneath large rocks, typically limestone or dolomite, and in moderate 
to deep (less than 3 feet (ft) to 9.8 ft (less than 1 meter (m) to 3 
m)), rocky, fast-flowing streams in the Ozark Plateau (Johnson 2000, p. 
42; Fobes and Wilkinson 1995, pp. 5-7). In spring-fed streams, Ozark 
Hellbenders will often concentrate downstream of the spring, where 
there is little water temperature change throughout the year (Dundee 
and Dundee 1965, p. 370). Adults are nocturnal, remaining beneath cover 
during the day and emerging to forage at night, primarily on crayfish. 
They are diurnal during the breeding season (Nickerson and Mays 1973a, 
pp. 40-41; Noeske and Nickerson 1979, pp. 92, 94). Ozark Hellbenders 
are territorial and will defend occupied cover from other hellbenders 
(Nickerson and Mays 1973a, pp. 42-43). This species migrates little 
throughout its life. For example, one tagging study revealed that 70 
percent of marked individuals moved less than 100 ft (30 m) from the 
site of original capture (Nickerson and Mays 1973b, p. 1165). Home 
ranges average 91.9 square (sq) ft (28 sq m) for females and 265.7 sq 
ft (81 sq m) for males (Peterson and Wilkinson 1996, p. 126).
    Hellbenders are habitat specialists that depend on consistent 
levels of dissolved oxygen, temperature, and flow (Williams et al. 
1981, p. 97). The lower

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dissolved-oxygen levels found in warm or standing water do not provide 
for the hellbender's respiratory needs. In fact, hellbenders have been 
observed rocking or swaying in still, warm water (Williams et al. 1981, 
p. 97) to increase their exposure to oxygen. Hutchison and Hill (1976, 
p. 327) found that the hellbender exhibits a preferred mean water 
temperature of 52.9 [deg]F (11.6 [deg]C), 63.9 [deg]F (17.7 [deg]C), 
and 71.1 [deg]F (21.7 [deg]C) for individuals acclimatized to 
temperatures of 41 [deg]F (5 [deg]C), 59 [deg]F (15 [deg]C), and 77 
[deg]F (25 [deg]C), respectively. Hutchison et al. (1973, p. 807) found 
the mean critical thermal maxima (the temperature at which animals lose 
their organized locomotory ability and are unable to escape from 
conditions that would promptly lead to their death) of Ozark 
Hellbenders was 90.9 [deg]F (32.7 [deg]C) at 41 [deg]F (5 [deg]C) 
acclimation, 91.2 [deg]F (32.9 [deg]C) at 59 [deg]F (15 [deg]C), and 
97.7 [deg]F (36.5 [deg]C) at 77[deg] F (25 [deg]C).
    Hellbenders are long-lived, capable of living 25 to 30 years in the 
wild (Peterson et al. 1983, p. 228). Hellbenders may live up to 29 
years in captivity (Nigrelli 1954, p. 297). Individuals mature sexually 
at 5 to 8 years of age (Bishop 1941, pp. 49-50; Dundee and Dundee 1965, 
p. 370), and males normally mature at a smaller size and younger age 
than females. Female hellbenders are reported to be sexually mature at 
a total length of 14.6 to 15.4 in (37 to 39 cm), or at an age of 
approximately 6 to 8 years (Nickerson and Mayes 1973a, p. 54; Peterson 
et al. 1983, p. 229; Taber et al. 1975, p. 638). Male hellbenders have 
been reported to reach sexual maturity at a total length of 11.8 in (30 
cm), or at an age of approximately 5 years (Taber et al. 1975, p. 638).
    Breeding generally occurs between mid-September and early October 
(Johnson 2000, p. 42). Males prepare nests beneath large flat rocks or 
submerged logs. Ozark Hellbenders mate via external fertilization, and 
males will guard the fertilized eggs from predation by other 
hellbenders (Nickerson and Mays 1973a, pp. 42, 48). Clutch sizes vary 
from 138 to 450 eggs per nest (Dundee and Dundee 1965, p. 369), and 
eggs hatch after approximately 80 days (Bishop 1941, p. 47). Larvae and 
small individuals hide beneath small stones in gravel beds or under 
large rocks, similar to those occupied by adults (Nickerson and Mays 
1973a, p. 12; LaClaire 1993, p. 2). Although there is little 
information on the diet of larval hellbenders, it is generally believed 
that aquatic insects comprise their primary food source. In one of the 
few studies on larval diet, Pitt and Nickerson (2006, p. 69) found that 
the stomach of a larval Eastern Hellbender from the Little River in 
Tennessee exclusively contained aquatic insects.
    During or shortly after eggs are laid, males and females may prey 
upon their own and other individuals' clutches. Most hellbenders 
examined during the breeding season contain between 15 and 25 eggs in 
their stomachs (Smith 1907, p. 26). Males frequently regurgitate eggs 
(King 1939, p. 548; Pfingsten 1990, p. 49), and females sometimes eat 
their own eggs while ovipositing (laying) them (Nickerson and Mays 
1973a, p. 46). Topping and Ingersol (1981, p. 875) found that up to 24 
percent of the gravid (egg-bearing) females examined from the Niangua 
River in Missouri retained their eggs and eventually reabsorbed them.

Range

    Ozark Hellbenders are endemic to the White River drainage in 
northern Arkansas and southern Missouri (Johnson 2000, pp. 40-41), 
historically occurring in portions of the Spring, White, Black, Eleven 
Point, and Current Rivers and their tributaries (North Fork White 
River, Bryant Creek, and Jacks Fork) (LaClaire 1993, p. 3). Currently, 
populations of Ozark Hellbenders are known to occur in the North Fork 
of the White River, the Eleven Point River, and the Current River.
    The other subspecies of hellbender, the Eastern Hellbender, occurs 
in central and eastern Missouri (in portions of the Missouri drainage 
in south-central Missouri and the Meramec (Mississippi drainage)), but 
its range does not overlap with that of the Ozark Hellbender. The 
Eastern Hellbender's range extends eastward to New York, Georgia, and 
the States in between.

Population Estimates and Status

    Evidence indicates Ozark Hellbenders are declining throughout their 
range (Wheeler et al. 2003, pp. 153, 155), and no populations appear to 
be stable.
    At the request of the Saint Louis Zoo's Wildcare Institute, the 
Conservation Breeding Specialist Group (CBSG) facilitated a Population 
and Habitat Viability Analysis (PHVA) for Ozark and Eastern Hellbenders 
in August 2006. Thirty workshop participants explored threats to 
hellbender populations and developed management actions aimed at 
understanding and halting their decline. Using the software program 
Vortex (v9.61), the CBSG team prepared and presented a baseline model 
for hellbender populations and worked through the input parameters with 
the participants to optimize the model and determine current and 
projected mean population sizes for all current populations in 75 years 
(Briggler et al. 2007, pp. 8, 80-86). The results of the model are 
presented in the river-specific population accounts below.
    A description of what we know about Ozark Hellbender populations 
follows, including current population estimates from the hellbender 
PHVA (Briggler et al. 2007, pp. 83-84).
    White River--There are only two Ozark Hellbender records from the 
main stem of the White River. In 1997, an Ozark Hellbender was recorded 
in Baxter County, Arkansas (Irwin 2008a, pers. comm.). No hellbenders 
were found during a 2001 survey of the lower portion of the White 
River, but in 2003, an angler caught a specimen in Independence County, 
Arkansas (Irwin 2008a, pers. comm.). We do not know whether a viable 
population exists (or whether hellbenders are able to exist) in the 
main stem of the White River or if the individuals captured are members 
of a relic population that was separated from the North Fork White 
River population by Norfork Reservoir. Much of the potentially occupied 
hellbender habitat was destroyed by the series of dams constructed in 
the 1940s and 1950s on the upper White River, including Beaver, Table 
Rock, Bull Shoals, and Norfork Reservoirs.
    North Fork White River--The North Fork White River (North Fork) 
historically contained a considerable Ozark Hellbender population. In 
1973, results of a mark-recapture study indicated that there were 
approximately 1,150 hellbenders within a 1.7-mile (mi) (2.7-kilometer 
(km)) reach of the North Fork in Ozark County, Missouri, with an 
estimated density of one individual per 26.2 to 32.8 sq ft (8 to 10 sq 
m; Nickerson and Mays 1973b, p. 1165). Ten years later, hellbender 
density in a 2.9-mi (4.6-km) section of the North Fork in the same 
county remained high, with estimated densities between one per 19.7 sq 
ft (6 sq m) and one per 52.5 sq ft (16 sq m; Peterson et al. 1983, p. 
230). Individuals caught in this study also represented a range of 
lengths from 6.8 to 21.7 in (172 to 551 millimeters (mm)), indicating 
that reproduction was occurring in this population, and most 
individuals measured between 9.8 and 17.7 in (250 and 449 mm). In a 
1992 qualitative study in Ozark County, Missouri, 122 hellbenders were 
caught during 49 person-hours of searching the North Fork (Ziehmer and 
Johnson 1992, p. 2). Those individuals ranged in length from 10 to 18 
in (254 to 457 mm), and no average length was included in that 
publication.
    Until the 1992 study, the North Fork population appeared to be 
relatively healthy. However, in a 1998 study of the same reach of river 
that was censused in

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1983 (Peterson et al. 1983, pp. 225-231) and that used the same 
collection methods, only 50 hellbenders were captured (Wheeler et al. 
1999, p. 18). These individuals ranged in length from 7.9 to 20.0 in 
(200 to 507 mm), with most measuring between 15.7 and 19.7 in (400 and 
500 mm), and the average length was significantly greater than the 
average length of those collected 20 years earlier (Wheeler 1999, p. 
15). This shift in length distribution was not a result of an increase 
in maximum length of individuals; instead, there were fewer individuals 
collected in the smaller size classes.
    As a way to compare relative abundance of hellbenders in the late 
1990s to historic numbers, Wheeler et al. (2003, pp.152-153) obtained 
raw data used in the Peterson et al. (1983) study to calculate numbers 
of individuals caught per day. Other Ozark Hellbender population 
studies not included in that conversion are converted here for further 
comparison of relative abundance between historic and more recent 
studies (Ziehmer and Johnson 1992, pp. 1-5). For comparison purposes, 
one search day is defined as 8 hours of searching by 3 people (or 24 
person-hours). However, converting person-hours to a search day metric 
may underestimate actual search effort and overestimate relative 
hellbender abundance as person-hours usually only include time spent in 
the water searching (as opposed to total number of hours spent on the 
river). It should also be noted that because search effort was not 
standardized among all studies, comparison of hellbender captures per 
search day is a general, rather than a quantitative, comparison. Using 
this metric for the North Fork, approximately 55 hellbenders were 
caught per search day in 1983 (Peterson et al. 1983, pp. 225-231). In 
1992, 60 hellbenders per search day were caught (Ziehmer and Johnson 
1992, p. 2), and in 1998, 17 hellbenders per search day were caught 
(Wheeler 2003, p. 153).
    Another comparison of Ozark Hellbenders captures between historic 
and recent years provides further evidence of a decline. A 16.2-mi (25-
km) section of stream in the North Fork (overlapping with some sites 
sampled in the previous studies) was surveyed during 1969-1979 and 
again during 2005-2006 (Nickerson and Briggler 2007, pp. 212-213). 
Between 1969 and 1979, researchers caught 8 to 12 hellbenders per hour 
(64 to 96 hellbenders per search day); whereas in 2005 and 2006 
researchers averaged 0.5 hellbenders per hour (4 hellbenders per search 
day) (Nickerson and Briggler 2007, p. 213).
    In 2006, hellbender experts estimated the current population in the 
North Fork to be 200 individuals (Briggler et al. 2007, p. 83). The 
North Fork had been considered the stronghold of the species in 
Missouri, and the populations inhabiting this river were considered 
stable by Ziehmer and Johnson (1992, p. 3) and LaClaire (1993, pp. 3-
4). However, the studies cited above indicate that these populations 
now appear to be experiencing declines similar to those in other 
streams. The collection of young individuals has become rare, 
indicating that there is little recruitment. Although Briggler (2011c, 
pers. comm.) occasionally found some younger hellbenders in this river 
during surveys between 2005 and 2010, no larvae have been found despite 
extensive effort. In species such as the hellbender, which are long 
lived and mature at a relatively late age, detecting declines related 
to insufficient recruitment can take many years, as recruitment under 
healthy population conditions is typically low (Nickerson and Mays 
1973a, p. 54). Based on the comparisons of relative abundance and lack 
of observed recruitment, it appears that a severe decline has occurred 
in the North Fork.
    Bryant Creek-- Bryant Creek is a tributary of the North Fork in 
Ozark County, Missouri, which flows into Norfork Reservoir. Ziehmer and 
Johnson (1992, p. 2) expected to find Ozark Hellbenders in this stream 
during an initial survey, but none were captured or observed after 22 
person-hours (0.9 search days). This apparent absence of the species 
conflicted with previous reports from Missouri Department of 
Conservation (MDC) personnel and an angler who reported observations of 
fairly high numbers of hellbenders in Bryant Creek during the winter 
months (Ziehmer and Johnson 1992, p. 3). A subsequent survey of the 
creek resulted in the capture of six hellbenders (Wheeler et al. 1999, 
p. 7) and confirmed the existence of a population in this tributary, at 
least through 1998. This population, however, is isolated from the 
other North Fork White River populations by the Norfork Reservoir, 
which could contribute to this population's apparent small size due to 
fragmentation of habitat. During MDC surveys conducted in 2007, no 
individuals were found in areas where the six individuals were found in 
1998. However, five individuals were found in areas of Bryant Creek 
that were not surveyed in 1998. This population has been historically 
low and is not considered to be viable (Briggler 2008b, pers. comm.).
    Black River--There is one documented record of an Ozark Hellbender 
in the Black River above its confluence with the Strawberry River on 
the Independence-Jackson County line (Arkansas) in 1978 (Irwin 2008a, 
pers. comm.). Portions of the Black River in Missouri were surveyed in 
1999 by researchers at Arkansas State University, but no hellbenders 
were observed (Wheeler et al. 1999, p. 18). Currently, the Black River 
does not appear to have conditions suitable for Ozark Hellbenders, 
although it may have been occupied before intensive agriculture was 
initiated in the area (Irwin 2008b, pers. comm.). The Black River is 
presumed to be part of the historical range of the subspecies, because 
Ozark Hellbenders have been documented in several of its tributaries, 
including the Spring, Current, and Eleven Point rivers (Firschein 1951, 
p. 456; Trauth et al. 1992, p. 83). In 2004, MDC surveyed areas in 
Missouri that had been searched in 1999 (Wheeler et al. 1999, p. 18), 
as well as areas not searched in 1999 that had anecdotal reports of 
hellbenders. No hellbenders were found during this 2-day survey. The 
habitat was considered less than ideal because it was predominantly 
composed of igneous rocks, which lack the cracks and crevices necessary 
for hellbender inhabitance. Parts of the Black River, with suitable 
dolomite rock, might have contained a small population at one time 
(Briggler 2008b, pers. comm.).
    Spring River--The Spring River, a tributary of the Black River, 
flows from Oregon County, Missouri, south into Arkansas. Ozark 
Hellbender populations have been found in the Spring River near Mammoth 
Spring in Fulton County, Arkansas (LaClaire 1993, p. 3). In the early 
1980s, 370 individuals were captured during a mark-recapture study 
along 4.4-mi (7-km) of stream south of Mammoth Spring (Peterson et al. 
1988, p. 293). Hellbender density at each of the two surveyed sites was 
fairly high (approximately one per 75.5 square (sq) ft (23 sq m) and 
one per 364 sq ft (111 sq m), respectively). These individuals were 
considerably larger than hellbenders captured from other streams during 
the same time period, with 74 percent of Spring River hellbenders 
having a total length of more than 17.7 in (450 mm), with a maximum 
length of 23.6 in (600 mm) (Peterson et al. 1988, p. 294). Although 
other factors may be involved in the observed length differences, it 
has been hypothesized that Spring River populations are genetically 
distinct from other hellbender populations. This

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speculation was upheld by the conclusions of a genetic study of the 
populations in the Spring, Current, and Eleven Point rivers (Kucuktas 
et al. 2001, pp. 131-135). In 1991, surveyors searched 10 sites for 
hellbenders along a 16.2-mi (26-km) stream reach but observed only 20 
individuals during 41 person-hours (11.7 hellbenders per search day) 
over a 6-month period (Trauth et al. 1992, pp. 84-85). This 6-month 
survey included the two sites surveyed in the early to mid-1980s in 
which surveyors captured 370 hellbenders, along with eight additional 
sites upstream and downstream (Peterson et al. 1988, pp. 291-303; 
Trauth et al. 1992, p. 83). No size class information is available, 
although the large sizes of captures reported in Peterson et al. (1988, 
p. 294) may be indicative of a population experiencing little 
recruitment.
    Researchers with Arkansas State University surveyed the Spring 
River from autumn 2003 through winter 2004, performing 74 hours of 
search effort and found only 12 Ozark Hellbenders (3.9 hellbenders per 
search day) (Hiler 2005, p. 186). Nine of these animals exhibited 
severe physical abnormalities and were removed from the river to be 
housed at the Mammoth Spring National Fish Hatchery but have since 
died. All nine have since died, however, possibly due to water quality 
issues at the hatchery or from health issues that were observed when 
they were captured (i.e., lesions, raw limbs). Arkansas State 
University researchers found four and one individual during 2005 and 
2006 surveys, respectively. Hellbenders have declined in this stream 
from unknown causes. Possible reasons for the decline include water 
quality degradation, aquatic vegetation encroachment, collection for 
scientific purposes, and illegal commercial collection (Irwin 2008b, 
pers. comm.). Experts estimated the population in the Spring River to 
be at most 10 individuals, considered the population in this river to 
be functionally extirpated, and considered there to be minimal 
possibility of this stream being reinhabited under present conditions 
because of the magnitude of habitat degradation (Briggler et al. 2007, 
p. 83; Irwin 2008b, pers. comm.).
    Eleven Point River--The Eleven Point River, a tributary of the 
Black River that occurs in Missouri and Arkansas, has been surveyed 
several times since the 1970s. Wheeler (1999, p. 10) analyzed 
historical data and reported that in 1978, 87 Ozark Hellbenders were 
captured in Oregon County, Missouri, over a 3-day period, yielding an 
average of 29 hellbenders per search day. From 1980 to 1982, 314 
hellbenders were captured in the same area in 9 collection days, 
yielding an average of 35 hellbenders per search day; hellbender body 
lengths over that period ranged from 4.7 to 17.8 in (119 to 451 mm) 
(Wheeler 1999, p. 10). In 1988, Peterson et al. (1988, p. 293) captured 
211 hellbenders from the Eleven Point River and estimated hellbender 
density to be approximately one per 65.6 sq ft (20 sq m). Total lengths 
of these individuals ranged from 4.7 to 17.7 in (120 to 450 mm), with 
most between 9.8 and 13.8 in (250 and 350 mm). The average number of 
hellbenders captured per hour was 8.4 and 8.8 for the two sites 
sampled, or 67 and 70 hellbenders captured per search day (using the 
search day conversion method presented in the North Fork White River 
discussion). As noted previously, the abundance of hellbenders per 
search day is likely an overestimate, and may be better approximated as 
35-40 hellbenders per search day since the reported capture rates do 
not appear to be relative to the number of surveyors.
    In 1998, Wheeler (1999, p. 10) captured 36 Ozark Hellbenders over 4 
days from the same localities as Peterson et al. (1988, p. 292), for an 
average of nine hellbenders per search day. These hellbenders were 
larger than those captured previously, with total lengths of 12.8 to 
18.0 in (324 to 457 mm), and there were considerably fewer individuals 
in the smaller size classes. For comparison, a survey of localities in 
2005 by Peterson et al. (1988, p. 293) resulted in a total of 31 
hellbenders captured and yielded an average of 2.6 hellbenders captured 
per search day. Population declines and reduced recruitment in the 
Eleven Point River in Missouri are indicated by the results of survey 
data (Briggler 2011b, pers. comm.), although hellbenders are 
consistently reported during surveys in the Eleven Point River in 
Arkansas (Irwin 2011a, pers. comm.).
    Recently in Arkansas (2005 and 2007), however, no more than two or 
three individuals were caught per search day. Specifically, the catch 
per person-hour in 2005 was 1.1 hellbenders and in 2007 the capture 
rate was 0.9 hellbenders per person-hour for surveys conducted on the 
Eleven Point River in Arkansas (Irwin 2008a, pers. comm.). In 2006, 
hellbender experts estimated the current Eleven Point River population 
to be 200 individuals in Arkansas and 100 individuals in Missouri 
(Briggler et al. 2007, p. 83).
    Current River--The Current River was not surveyed extensively until 
the 1990s. Nickerson and Mays (1973a, p. 63) reported a large Ozark 
Hellbender population in this stream, but no numbers were recorded. In 
1992, Ziehmer and Johnson (1992, p. 2) found 12 hellbenders in 60 
person-hours in Shannon County, Missouri, or approximately 5 
hellbenders per search day (using the same search day conversion as 
presented in the North Fork White River discussion). These individuals 
ranged in length from 4.5 in (115 mm) to more than 15.0 in (380 mm; 
maximum length was not reported), with most between 13.0 and 15.0 in 
(330 and 380 mm). In 1999, 14 hellbenders were collected over 3 
collection days (approximately 5 hellbenders per search day), also in 
Shannon County, Missouri, and the individuals ranged from 14.8 to 20.3 
in (375 to 515 mm) in length, with most between 17.7 to 19.7 in (450 to 
499 mm) (Wheeler 1999, p. 12). The average size of individuals 
increased by nearly 4 in (100 mm), and the reported increase in length 
suggests that recruitment may be absent in this population. In 2005 and 
2006, researchers found 22 hellbenders throughout the Current River in 
100 hours of searching (equivalent to 5.2 hellbenders per search day). 
In 2006, hellbender experts estimated the current population in the 
Current River to be 80 individuals (Briggler et al. 2007, p. 83).
    Jacks Fork--Jacks Fork, a tributary of the Current River, was 
initially surveyed for Ozark Hellbenders in 1992 (Ziehmer and Johnson 
1992, p. 2). Four hellbenders were collected over 66 person-hours, 
equating to roughly 1.5 hellbenders per search day. The individuals 
were large, ranging from 13.0 to 16.9 in (330 to 430 mm) in length. No 
hellbenders were found during investigations of Jacks Fork in 2003 nor 
were any found in 2006 during 7 person-hours of searching (Phillips 
2010, pers. comm.).

Summary of Comments and Recommendations

    In the proposed rule published on September 8, 2010 (75 FR 54561), 
we requested that all interested parties submit written comments on the 
proposal by November 8, 2010. We also contacted appropriate Federal, 
State, and local agencies; scientific experts; and other interested 
parties and invited them to comment on the proposal. Newspaper notices 
inviting general comments were published in the West Plains Daily Quill 
(West Plains, Missouri), The Times Dispatch (Walnut Ridge, Arkansas), 
and The News-Leader (Springfield, Missouri). We did not receive any 
requests for a public hearing.
    Between October 21, 2010, and October 28, 2010, the Service 
received five requests to extend the public

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comment period for an additional 90 days. The reasons for requesting an 
extension centered on the Service's proposed determination that it was 
not prudent to designate critical habitat for the Ozark Hellbender. 
While the requests cited complexities of the issues involved and 
concerns regarding the water quality in the streams as the basis for an 
extension, no new information was provided that was not already 
outlined in the proposed rule. Therefore, we did not extend the public 
comment period and further delay the listing. We did, however, host a 
conference call with the requesters to provide information and answer 
questions regarding the Service's proposal.
    We received 65 written comments, including comments from 3 peer 
reviewers. Fifty-seven comments supported the proposed listing; while 
six comments expressed neither support for, nor opposition to, the 
proposal. Eight comments supported a ``similarity of appearance'' 
listing for the Eastern Hellbender, with three commenters also 
supporting a separate listing for the Eastern Hellbender.
    We reviewed all comments we received from the public and peer 
reviewers for substantive issues and new information regarding the 
listing of the Ozark Hellbender. All substantive information provided 
during the comment period has either been incorporated into this final 
determination or is addressed below.

Peer Review

    In accordance with our peer review policy published on July 1, 1994 
(59 FR 34270), we solicited expert opinions from three individuals with 
scientific expertise that included familiarity with the species and its 
habitat, the geographic region in which the species occurs, and 
conservation biology principles. We received responses from all three 
peer reviewers from whom we requested comments. The peer reviewers 
generally agreed that the description of the biology and habitat for 
the species was accurate and based on the best available information. 
Peer reviewer comments are addressed in the following summary and 
incorporated into the final rule as appropriate. New and additional 
information on the biology of the species and its threats was provided 
and incorporated into the rulemaking as appropriate. In some cases, it 
has been indicated in the citations by ``personal communication'' 
(pers. comm.); while in other cases, the research citation is provided.

Peer Reviewer Comments

    (1) Comment: In the proposed listing, the Service states that 
Dundee and Dundee (1965) recommended changing the taxonomic status of 
the Ozark Hellbender from species to subspecies due to the small amount 
of genetic variation between Ozark and Eastern Hellbenders. Dundee and 
Dundee (1965) recommended changing the taxonomic status based on 
morphology and ecology, not genetic variation.
    Our Response: We corrected this statement and clarified the 
remaining section on taxonomy to reflect that subsequent genetic 
analyses further supported the subspecies designation by Dundee and 
Dundee (1965).
    (2) Comment: The pathogen Batrachochytrium dendrobatidis has now 
been confirmed in all continents, including Asia (Goka et al. 2009).
    Our Response: We reviewed the reference provided by the peer 
reviewer and have made the correction in this final rule to reflect the 
entire range of this pathogen.
    (3) Comment: Two peer reviewers provided comments regarding the 
reference in the proposed rule to Pfingsten's (1990) caution that the 
failure to detect larvae could be interpreted to mean that larvae could 
occur in areas not surveyed. One peer reviewer relayed that two Eastern 
Hellbender larvae had been captured in Ohio in habitat similar to that 
occupied by adults. The peer reviewer also commented that a 
``retrospective'' analysis of the data collected by Pfingsten for 
Eastern Hellbender populations in Ohio provides strong evidence that 
the lack of detection of a younger size class (i.e. larvae) was due to 
the lack of recruitment in most Ohio populations rather than 
Pfingsten's failure to survey sites occupied by larvae (Lipps 2010, 
pers. comm.). The peer reviewer suggested that a similar situation or 
phenomenon was likely responsible for the lack of recruitment in Ozark 
Hellbender populations (Lipps 2010, pers. comm.). A second peer 
reviewer provided two arguments supporting the explanation that lack of 
larvae detection in surveys is due to an actual lack of recruitment and 
not survey technique. He noted that researchers have searched in 
several microhabitats (for example, gravel beds, smaller tributaries) 
in excess of 100 person-hours without detecting the presence of larvae, 
and that others have found larvae and juveniles of the Eastern 
Hellbender in the same microhabitats as adults.
    Our Response: We concur that the inability to detect larval and 
juvenile hellbenders is not solely a function of survey technique but 
most likely reflects an actual reduction or lack of recruitment in the 
populations. Information provided by the peer reviewers and other 
supporting references have been incorporated into this final rule.
    (4) Comment: The Service should consider listing pesticides as a 
potential direct threat to the Ozark Hellbender. The peer reviewer 
supports this recommendation with several references, including 
statements in the proposed rule indicating that hellbenders would be 
vulnerable to multiple chemicals. The peer reviewer also states that 
pesticide registration and usage is listed as a potential Federal 
agency action that may require conference or consultation under 
Available Conservation Measures.
    Our Response: In testing water samples collected from the North 
Fork, White, and Eleven Point rivers from 2003-2004, Solis et al. 
(2007; pp. 430,432) detected only two pesticides: metolachlor and 
tebuthiuron. Median concentrations of both chemicals were lower than 
median concentrations detected from 1992-1995 at various sites 
throughout the Ozark Plateau (Petersen et al. 1998; p. 24). Metolachlor 
and tebuthiuron concentrations in 2003-2004 were also lower than the 
Environmental Protection Agency (EPA) aquatic life benchmarks for the 
protection of aquatic species (U.S. EPA 2011). Atrazine, which can 
interfere with normal gonadal development and adversely affect 
fertility (PARC 2007), was not detected in water samples collected 
during 2003 and 2004 (Solis et al. 2007; pp. 430, 432). While it is 
possible that atrazine may be present at concentrations below 
detectable limits and thus potentially affect hellbenders, available 
data do not support the recommendation that pesticides are a direct 
threat.
    (5) Comment: The Service states in the proposed rule that predation 
by introduced trout cannot be ruled out as a factor affecting the Ozark 
Hellbender and that it possibly contributes to the observed population 
declines. However, nonnative fish stocking is not included in the 
actions that would be reviewable under section 7(a)(2) of the Act or 
under actions that may require consultation with the Service. The 
Service should clarify if they lack the authority to review fish 
stocking in Ozark Hellbender habitat or explain why this action is not 
included.
    Our Response: Section 7(a)(2) of the Act requires that each Federal 
agency insure that any action they authorize, fund, or carry out is not 
likely to

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jeopardize the continued existence of any endangered or threatened 
species or result in the destruction or adverse modification of 
critical habitat of such species. If an agency receives Federal funding 
for stocking nonnative fish (such as from the Service's Wildlife and 
Sport Fish Restoration Program), or if this action is authorized by a 
Federal agency, the Service would work closely with our partners during 
the section 7(a)(2) consultation process to assess impacts to Ozark 
Hellbenders and avoid or minimize these impacts. In the proposed rule 
we provided a limited list of agency actions that may require 
conference or consultation for the Ozark Hellbender (see Available 
Conservation Measures). We have modified the list to also include 
federally funded activities. Because federally funded or authorized 
activities can include numerous actions, we did not provide a 
comprehensive list of all actions that may require section 7 
consultation.
    (6) Comment: One reviewer interpreted the Service's ``not prudent'' 
finding to indicate that the Service has determined that sections 
7(a)(1) and 7(a)(2) of the Act can sufficiently contribute to the 
conservation and recovery of the Ozark Hellbender without protecting 
areas outside the geographical area occupied at the time of listing 
(through designation of critical habitat). The reviewer requested that 
the Service explain how we will protect areas outside the currently 
occupied locations if those areas are considered essential to the 
recovery of the species and critical habitat is not designated.
    Our Response: As detailed under Benefits to the Species from 
Critical Habitat Designation, the Service recognizes that in some 
instances the designation of critical habitat can provide additional 
protection beyond that which is already provided through the section 
7(a)(2) consultation process (see response to Comment 13a for 
additional information). One of these benefits is the protection of 
unoccupied habitat considered essential to the recovery of the species. 
It is necessary, however, to weigh this benefit against the increased 
threat of illegal collection to the taxa by designating critical 
habitat. In doing so, the Service believes that the conservation and 
recovery of Ozark Hellbenders can best be achieved by preventing the 
illegal removal of animals from the populations, a threat directly 
resulting from the publication of critical habitat maps and disclosure 
of specific locations of occupied sites.
    (7) Comment: The Service includes ``flipping large rocks within 
streams'' as an action likely to result in violation of section 9 of 
the Act. Moving shelter rocks used by hellbenders, even when returned 
to their original side down, may make the space beneath the rock 
unsuitable for hellbenders (personal observation by peer reviewer). 
Despite taking great effort to return rocks to their original 
positions, disturbing the ``seal'' of sedimentation around hellbender 
shelter rocks may result in the space being abandoned by hellbenders 
and becoming occupied by rock bass and other fish, thereby reducing the 
amount of suitable habitat available for hellbenders (Horchler 2010, p. 
20). The Service should replace the word ``flipping'' with 
``disturbing.'' Furthermore, under 50 CFR 17.21 and 17.31, it is 
illegal to pursue or attempt to pursue an endangered species and this 
language should be included in the list of likely violations of section 
9.
    Our Response: Manipulation of shelter rocks to locate or capture 
hellbenders would in most cases be in the form of flipping 
(overturning) rocks. However, within the context of unauthorized 
destruction or alteration of hellbender habitat (for reasons other than 
to locate hellbenders), the microhabitat under or around the rock may 
be altered by disturbances other than just flipping. Therefore, we have 
replaced the word ``flipping'' with ``disturbing.'' In response to the 
second part of the peer reviewer's comment, in this final rule, we have 
specifically identified ``pursuing, or attempting to pursue'' within 
those actions likely to result in a violation of section 9.
    (8) Comment: One reviewer noted that many of the factors 
potentially contributing to hellbender declines may be operating 
synergistically to reduce survival. The reviewer provides the following 
examples: (1) Higher water temperatures due to siltation may lead to an 
environment favorable for pathogens; (2) poor water quality could 
contribute to lowered immune capabilities of hellbenders and make them 
more susceptible to infection from pathogens; and (3) reduced body 
condition due to water quality issues or pathogen infection could 
result in individuals becoming more vulnerable to predation (similar 
linkages with pesticides have been shown in other aquatic amphibians).
    Our Response: Although we lack definitive data to support this 
assertion, it is likely that effects of some factors may enhance the 
effects of other impacts. Because this interaction could further 
contribute to the Ozark Hellbender's decline, we have referenced 
synergistic effects and cumulative effects under Factor E (Other 
Natural or Manmade Factors Affecting Its Continued Existence).

Public Comments

    (9) Comment: Several commenters provided supporting data and 
information regarding the biology, ecology, life history, population 
estimates, threat factors affecting the Ozark Hellbender, and current 
conservation efforts.
    Our Response: We thank all of the commenters for their interest in 
the conservation of this species and thank those commenters who 
provided information for our consideration in making this listing 
determination. Much of the information submitted was duplicative of 
information contained in the proposed rule; however, some comments 
contained information that provided additional clarity or support to, 
but did not substantially change, information already contained in the 
proposed rule. This information has been incorporated into this final 
rule, where appropriate.
    (10) Comment: There was no mention in the proposed rule of other 
emerging bacterial and viral infections which may cause significant 
mortality and contribute rangewide to the decline of Ozark Hellbenders. 
To support this concern, the commenter noted that a flesh-eating 
bacterium (Citrobacter sp.) had been identified on an Ozark Hellbender 
in Missouri, and that symptoms present on the Missouri specimen are 
present on the majority of hellbenders captured in Arkansas. The 
commenter also stated that animals infected with Batrachochytrium 
dendrobatidis (the pathogen which causes amphibian chytrid fungus) may 
become immunosuppressed and thus more susceptible to these secondary 
infections.
    Our Response: During the development of the proposed rule, factors 
causing the severe abnormalities observed in Ozark Hellbenders were 
unknown. Since that time, personnel from the Saint Louis Zoo and other 
hellbender experts have postulated that the abnormalities are likely 
caused by secondary bacterial and fungal infections (Briggler 2011a, 
pers. comm.). Therefore, we have incorporated this information into 
this final rule under Factor C (Disease or Predation). Although 
evidence is lacking to conclude that Batrachochytrium dendrobatidis 
(Bd) suppresses the immune response of animals (and thereby increases 
their vulnerability to secondary infections), we believe that Bd may be 
contributing to some of the abnormalities exhibited by hellbenders. Not 
all hellbenders with abnormalities, such as lesions and appendage loss, 
however, test positive for infection with

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Bd (Briggler 2011a, pers. comm.). Therefore, we believe there are 
factors other than amphibian chytrid fungus that cause increased 
vulnerability of hellbenders to secondary infections and result in 
abnormalities.
    (11) Comment: The Service needs to further investigate the threat 
of trout to larval hellbenders.
    Our Response: Concern regarding the potential effect of nonnative 
trout was expressed by multiple commenters. Because nonnative trout are 
stocked in all rivers that historically and currently contain 
hellbenders, and because data from Gall (2008, pp. 48-49) indicate that 
larval Ozark Hellbenders do not recognize trout as predators, we agree 
that this topic warrants further investigation. Future conservation and 
recovery efforts for the Ozark Hellbender will include identifying and 
implementing research projects that will address the role of nonnative 
trout as a potential factor contributing to the decline of this 
subspecies. Should results from research studies indicate that 
nonnative trout are a threat to Ozark Hellbender populations, the 
Service will work with the States to avoid or minimize these effects.
    (12) Comment: Several commenters concurred with the Service's 
decision not to designate critical habitat, citing the threat posed by 
illegal collection and the pet trade. However, 12 commenters expressed 
opposition to the Service's proposed determination not to designate 
critical habitat for the Ozark Hellbender. These comments generally 
centered on five main topics and are addressed individually below.
    (12a) Comment: The Service cannot protect the Ozark Hellbender 
without designating critical habitat.
    Our Response: Listed species and their habitat are protected by the 
Endangered Species Act whether or not they are in an area designated as 
critical habitat. To understand the additional protection that critical 
habitat may provide to an area, it is necessary to understand the 
protection afforded to any endangered or threatened species, even if 
critical habitat is not designated. Section 7(a)(2) of the Act requires 
Federal agencies to consult with the Service to ensure that any action 
they authorize, fund, or carry out is not likely to jeopardize the 
continued existence of any listed species or result in the destruction 
or adverse modification of critical habitat (referred to as the 
consultation process). In consultations for species with critical 
habitat, Federal agencies are required to ensure that their activities 
do not destroy or adversely modify critical habitat. In most instances, 
particularly in occupied habitat, the species protection benefits 
provided by the designation of critical habitat largely duplicate those 
already provided to the species without the designation of critical 
habitat by the ``jeopardy standard.'' This is because when the Service 
evaluates the impacts of activities, we also look at impacts to the 
species habitat. Despite this overlap, the Service recognizes that, in 
some instances, designation of critical habitat could provide some 
benefits to the Ozark Hellbender (as described under Benefits to the 
Species from Critical Habitat Designation). These benefits, however, do 
not outweigh the increased illegal collection that will likely occur if 
critical habitat maps are published and the specific locations of 
currently occupied sites are disclosed (see discussion under Increased 
Threat to the Species Outweighs the Benefits of Critical Habitat 
Designation).
    (12b) Comment: Multiple commenters questioned the degree of threat 
posed by illegal collection and believed that the publication of 
critical habitat maps would not increase the risk of unauthorized 
collection.
    Our Response: Although the black market for smuggling and illegally 
selling protected reptiles and amphibians is widely recognized by 
herpetofauna experts and law enforcement officials, we realize that it 
may be necessary to provide additional information to support our 
concern. Therefore, we provided instances in this final rule under 
Factor B (Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes) to further evidence the threat of illegal 
collection, including: (1) A testimonial from an individual who 
collected more than 100 Ozark Hellbenders from the North Fork of the 
White River in the 1980s to sell for the pet trade; (2) the citation of 
two individuals in 1985 by Missouri Department of Conservation Agents 
for illegally collecting Ozark Hellbenders; (3) information referencing 
the unauthorized removal of more than 100 Ozark Hellbenders from the 
Spring River in the 1980s, and (4) recent information demonstrating 
that a demand for hellbenders still exists.
    Because Ozark Hellbenders are not uniformly distributed throughout 
streams in which they occur, collecting is often focused on a known 
source or site, thereby threatening extirpation of subpopulations at 
the site. Publication of critical habitat maps would disclose these 
sites and facilitate removal by collectors.
    (12c) Comment: Because only adult hellbenders are subject to 
illegal collection and larval hellbenders occupy separate habitats from 
adults, designating critical habitat for all life stages will not 
increase the threat of illegal collection.
    Our Response: The Service is unaware of any reasons for which 
nonadult Ozark Hellbenders would not be subject to illegal collection 
or of any information supporting this assertion. The contention that 
hellbender larvae drift downstream with the current and occupy 
different habitats than adults was expressed by several commenters who 
opposed the Service's proposed determination that designating critical 
habitat for this species is not prudent. We are not aware of 
information indicating that larval hellbenders drift downstream or that 
they occupy separate habitats from adults. On the contrary, the best 
available information indicates that, while larval hellbenders may 
occupy different microhabitats than adults (interstices of gravel 
rather than large cover rocks), larvae occupy the same stream reach 
segments as adults (Bishop 1941, pp. 48, 52; Nickerson and Mays 1973a, 
p. 12; Nickerson et al. 2003, pp. 624-625, 627; Briggler 2010c, pers. 
comm.; Horchler 2010, pers. comm.; Lipps 2010, pers. comm.; Phillips 
2010, pers. comm.). Therefore, designating critical habitat for all 
hellbender life stages would not prevent unauthorized collecting.
    (12d) Comment: The locations of hellbender sites are already 
available to the public; therefore, publishing critical habitat maps 
would not increase the threat of illegal collection.
    Our Response: Information currently available to the public is 
limited and reveals only a small proportion of the total number of 
sites occupied by Ozark Hellbenders. The designation of critical 
habitat would result in publishing in the Federal Register precise 
information about the species and its habitat requirements, where it is 
found, and maps with geographic coordinates for all occupied locations. 
The Service is already aware of instances in which the publication of 
locality information for occupied sites resulted in the removal of 
almost all individuals from the location. Thus, publishing locations of 
the remaining occupied sites would only further facilitate illegal 
collection.
    (12e) Comment: The habitat of the Ozark Hellbender does not 
comprise discrete points along the streams, but rather its habitat 
comprises stream reaches. Therefore, the Service can avoid disclosing 
exact locations to the public by designating large segments as critical 
habitat in streams occupied by Ozark Hellbenders. One commenter further 
noted that the Service has

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designated large stream reaches for the Niangua darter and the Topeka 
shiner.
    Our Response: When designating critical habitat, the Service must 
determine--based on the best available scientific information--the 
physical and biological features that are essential to the conservation 
of a species and which may require special management considerations or 
protection. Essential physical and biological features are specific 
habitat components that enable a species to fulfill its life cycle 
needs. Appropriate cover rocks or other crevices are necessary features 
to fulfill the life cycle needs of the Ozark Hellbender because they 
provide protection and nesting habitat. However, unlike the habitat for 
Niangua darters and the Topeka shiner, stream reaches containing 
suitable habitat for the Ozark Hellbender are not continuous. Areas 
with suitable habitat typically range from 100 to 400 yards (91 to 366 
meters (m)) in length, and subpopulations within each river system are 
often separated by miles (kilometers) of unsuitable habitat (data from 
mark-recapture studies indicate that hellbenders rarely move between 
sites (Irwin 2009, pers. comm., Briggler 2010b, pers. comm.)). 
Therefore, by mapping the critical habitat and describing the physical 
and biological features essential to the conservation of the species, 
the Service would disclose the specific location of occupied sites and 
subject the hellbenders to collection.
    (13) Comment: It is our understanding that the Saint Louis Zoo is 
currently engaged in propagation efforts and that the Missouri 
Department of Conservation plans to release captive-reared hellbenders 
into the Eleven Point River. This effort only addresses the Eleven 
Point River and not the Current River or the North Fork of the White 
River. In addition, we are concerned that these augmentation efforts 
will not be successful.
    Our Response: Results from genetic studies (Crowhurst et al. 2011; 
pp. 640-643; Sabatino and Routman 2009; pp. 1239-1240, 1244) indicate 
that mixing Ozark Hellbenders among rivers could cause an outbreeding 
depression, or the reduction in fitness of offspring because of the 
genetic differences between parents. For this reason, it is unlikely 
that captive-reared individuals will be released into rivers other than 
those from which the eggs were collected. To date, the Missouri 
Department of Conservation has collected Ozark Hellbender eggs from the 
North Fork White River and the Eleven Point River, but has been unable 
to locate eggs from the Current River. Therefore, releases of captive-
reared individuals are planned only for those rivers from which eggs 
have been collected (North Fork White River and Eleven Point River). 
Specific areas where augmentation or reintroductions will occur, 
however, have yet to be identified. Such propagation efforts will be 
identified in the development of a future approved Federal recovery 
plan for the species that will be developed through cooperative 
partnerships with the Ozark Hellbender Work Group and other potentially 
affected Federal, State, and private entities.
    Regarding the predicted success of propagation efforts, the Service 
believes that captive propagation efforts will likely be necessary to 
conserve and recover the Ozark Hellbender, until causes for the lack of 
recruitment in the wild can be definitively identified and addressed. 
When eggs are collected in the wild, larvae can be hatched and reared 
at significantly higher survivorship rates than those estimated from 
the wild. When individuals are reared to larger sizes and then 
released, substantially more hellbenders can survive to maturity and 
contribute to the population.

Summary of Changes From Proposed Rule

    We fully considered comments from the public and peer reviewers on 
the proposed rule to develop this final listing of the Ozark 
Hellbender. This final rule incorporates changes to our proposed 
listing based on comments received that are discussed above and on 
newly available scientific and commercial information. Reviewers 
generally commented that the proposed rule was thorough and 
comprehensive. We made some technical corrections based on new, 
although limited, information. Based on comments we received during the 
public comment period, we also included additional information to 
provide further evidence of the threat of illegal collection. 
Information received supports the Service's decision to list the Ozark 
Hellbender as endangered.

Summary of Factors Affecting the Species

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

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

    One of the most likely causes of the decline of the Ozark 
Hellbender in the White River system in Missouri and Arkansas is 
habitat degradation resulting from impoundments, ore and gravel mining, 
sedimentation, nutrient runoff, and nest site disturbance from 
recreational uses of the rivers (Williams et al. 1981, p. 99; LaClaire 
1993, pp. 4-5). Both hellbender subspecies are habitat specialists that 
depend on consistent levels of dissolved oxygen, temperature, and flow 
(Williams et al. 1981, p. 97). Therefore, even minor alterations to 
stream habitat are likely to be detrimental to hellbender populations.
Impoundments
    Impoundments impact stream habitat in many ways. When a dam is 
built on a free-flowing stream, riffle and run habitats are converted 
to lentic (still), deep-water habitat. As a result, surface water 
temperatures tend to increase, and dissolved oxygen levels tend to 
decrease (Allan and Castillo 2007, pp. 97-98, 323-324). Hellbenders 
depend upon highly vascularized lateral skin folds for respiration. 
Therefore, lakes and reservoirs are unsuitable habitat for Ozark 
Hellbenders, because these areas have lower oxygen levels and higher 
water temperatures (Williams et al. 1981, p. 97; LaClaire 1993, p. 5) 
than do fast-flowing, cool-water stream habitats. Impoundments also 
fragment hellbender habitat, blocking the flow of immigration and 
emigration between populations (Dodd 1997, p. 178). The resulting 
small, isolated populations are more susceptible to environmental 
perturbation and demographic stochasticity, both of which can lead to 
local extinction (Wyman 1990, p. 351).
    In the upper White River, construction of Beaver, Table Rock, Bull 
Shoals, and Norfork dams in the 1940s and 1950s destroyed the potential 
hellbender habitat downstream of the impoundments and effectively 
isolated Ozark Hellbender populations. Norfork Dam was constructed on 
the North Fork in 1944 and has isolated Ozark

[[Page 61965]]

Hellbender populations in Bryant Creek from those in the North Fork. 
Furthermore, populations downstream of Beaver, Table Rock, Bull Shoals, 
and Norfork dams were likely extirpated due to hypolimnetic releases 
from the reservoir. Hypolimnetic releases are cooler than normal stream 
temperatures because they are from a layer of water that is below the 
thermocline, and the water from this layer typically has reduced oxygen 
levels because it is noncirculating or does not ``turn over'' to the 
surface. The tailwater zones below dams also experience extreme water 
level fluctuations and scouring for several miles downstream. This can 
impact hellbender populations by washing out the pebbles and cobbles 
used as cover by juveniles and by creating unpredictable habitat 
conditions outside the Ozark Hellbender's normal range of tolerance.
    Impoundments can also affect hellbender habitat upstream by 
increasing sedimentation during periods of heavy rain because the flow 
of water is impeded by the presence of the reservoir. In 2008 and 2011, 
heavy rains and flooding resulted in an increase in water levels in 
excess of 10 to 15 feet (ft) (3 to 5 meters (m)) and significantly 
reduced flow velocity (Briggler 2011d, pers. comm.; Crabill 2011b, 
pers. obs.). Deposition of gravel from the 2008 flood event removed an 
estimated 30 percent of the available cover rocks and habitat at one of 
the most abundant Ozark Hellbender sites; while flooding in 2011 
removed an additional 50 percent of the habitat at this site (Briggler 
2011d, pers. comm.). During high water levels, Ozark Hellbenders at 
sites upstream of the reservoirs are also exposed to increased 
predation pressure by large predatory fishes. The increased water 
levels allow fish to expand upstream of the reservoir and have been 
observed in large numbers at upstream Ozark Hellbender sites (Roberts 
2011, pers. comm.). The increased abundance of large predatory fish, 
such as brown trout and striped bass, at sites upstream of Norfork 
Reservoir has even been noted by private landowners near these sites 
(Anon. 2010, pers. comm.).
Mining
    Gravel mining, which continues to occur in a number of streams 
within the range of the Ozark Hellbender, has directly contributed to 
Ozark Hellbender habitat alteration and loss. Gravel mining, also 
referred to as dredging, results in stream instability, both up and 
downstream of the dredged portion (Box and Mossa 1999, pp. 103-104). 
Head cutting, in which the increase in transport capacity of a dredged 
stream causes severe erosion and degradation upstream, results in 
extensive bank erosion and increased turbidity (Allan and Castillo 
2007, p. 331). Reaches downstream of the dredged stream reach often 
experience aggradation (raised stream bed from sediment build u