[Federal Register Volume 62, Number 201 (Friday, October 17, 1997)]
[Proposed Rules]
[Pages 54020-54028]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-27548]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018-AE36
Endangered and Threatened Wildlife and Plants; Proposed Rule to
List Three Aquatic Snails as Endangered, and Three Aquatic Snails as
Threatened in the Mobile River Basin of Alabama
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule and notice of petition findings.
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SUMMARY: The Fish and Wildlife Service (Service) proposes to list the
cylindrical lioplax (Lioplax cyclostomaformis), flat pebblesnail
(Lepyrium showalteri), and plicate rocksnail (Leptoxis plicata) as
endangered; and the painted rocksnail (Leptoxis taeniata), round
rocksnail (Leptoxis ampla), and lacy elimia (Elimia crenatella) as
threatened species under the authority of the Endangered Species Act of
1973, as amended (Act). These aquatic snails are found in localized
portions of the Black Warrior, Cahaba, Alabama, and Coosa rivers or
their tributaries in Alabama. Impoundment and water quality degradation
have eliminated the six snails from 90 percent or more of their
historic habitat. Surviving populations are currently threatened by
pollutants such as sediments and nutrients that wash into streams from
the land surface. This proposed rule, if made final, would extend the
Act's protection to these six snail species.
DATES: Comments from all interested parties must be received by
December 16, 1997. Public hearing requests must be received by December
1, 1997.
ADDRESSES: Comments and materials concerning this proposal should be
sent to the Field Supervisor, U.S. Fish and Wildlife Service, 6578
Dogwood View Parkway, Jackson, Mississippi 39213. Comments and
materials received will be available for public inspection, by
appointment, during normal business hours at the above address.
FOR FURTHER INFORMATION CONTACT: Mr. Paul Hartfield at the above
address, or telephone 601/965-4900, Ext. 25.
SUPPLEMENTARY INFORMATION:
Background
The Mobile River Basin (Basin) historically supported the greatest
diversity of freshwater snail species in the world (Bogan et al. 1995),
including six genera and over 100 species that were endemic to the
Basin. During the past few decades, publications in the scientific
literature have primarily dealt with the apparent decimation of this
fauna following the construction of dams within the Basin and the
inundation of extensive shoal habitats by impounded waters (Goodrich
1944, Athearn 1970, Heard 1970, Stein 1976, Palmer 1986, Garner 1990).
In 1990, the Service initiated a status review of the endemic
freshwater snails of the Basin. An extensive literature survey
identified sources of information on taxonomy, distribution, ecology,
and status of the fauna and was used to assemble a checklist of the
Basin's snails and their distributions (Bogan 1992). Field surveys and
collections were made for snails and other freshwater mollusks
throughout the Basin (Bogan and Pierson, 1993a,b; McGregor et al. 1996;
Service Field Records, Jackson, Mississippi 1989-1996; Bogan in litt.
1995; M. Pierson Field Records, Calera, Alabama, in litt. 1993-1994; J.
Garner, Alabama Department of Conservation, pers. comm. 1996; J.
Johnson, Auburn University, in litt. 1996).
Bogan et al. (1995) summarized the results of their efforts noting
the apparent extinction of numerous snail species in the Coosa and
Cahaba River drainages, and the imperiled state of many other aquatic
snails in the Basin.
The taxonomy used in this proposal follows Burch (1989), which
relies almost exclusively on shell morphology. Many of the Basin's
freshwater snail species, particularly in the family Pleuroceridae, are
known to exhibit marked clinal variation (gradual change in characters
of a species that manifests itself along a geographic gradient) in
shell form, some of which has been described as environmentally induced
(e.g., Goodrich 1934, 1937). Four of the six species considered in this
proposal belong to the family Pleuroceridae and their relationships to
each other, as well as to other Pleuroceridae, are poorly understood.
In order to better document taxonomic relationships among these snails,
a genetic study was conducted during the status review of a select
group of the Basin's Pleuroceridae (Lydeard et al. 1997). The four
snails within this family considered herein (lacy elimia, round
rocksnail, plicate rocksnail, and painted rocksnail) were included in
the genetic study. This study supported their current taxonomic status
(Lydeard et al. 1997).
The cylindrical lioplax (Lioplax cyclostomaformis (Lea 1841)) is a
gill-breathing snail in the family Viviparidae. The shell is elongate,
reaching about 28 millimeters (mm) (1.1 inches (in)) in length. Shell
color is light to dark olivaceous-green externally, and bluish inside
of the aperture (shell opening). The cylindrical lioplax is
distinguished from other viviparid snails in the Basin by the number of
whorls, and differences in size, sculpture, microsculpture, and spire
angle. No other species of lioplax snails are known to occur in the
Mobile Basin (see Clench and Turner 1955 for a more detailed
description).
Habitat for the cylindrical lioplax is unusual for the genus, as
well as for other genera of viviparid snails. It lives in mud under
large rocks in rapid currents over stream and river shoals.
Other lioplax species are usually found in exposed situations or in
mud or muddy sand along the margins of rivers. Little is known of the
biology or life history of the cylindrical lioplax. It is believed to
brood its young and filter-feed, as do other members of the
Viviparidae. Life spans have been reported from 3 to 11 years in
various species of Viviparidae (Heller 1990).
Collection records for the cylindrical lioplax exist from the
Alabama River (Dallas County, Alabama), Black Warrior River (Jefferson
County, Alabama) and tributaries (Prairie Creek, Marengo County,
Alabama; Valley Creek, Jefferson County, Alabama), Coosa River
[[Page 54021]]
(Shelby, Elmore counties, Alabama) and tributaries (Oothcalooga Creek,
Bartow County, Georgia; Coahulla Creek, Whitfield County, Georgia;
Armuchee Creek, Floyd County, Georgia; Little Wills Creek, Etowah
County, Alabama; Choccolocco Creek, Talladega County, Alabama;
Yellowleaf Creek, Shelby County, Alabama), and the Cahaba River (Bibb,
Shelby counties, Alabama) and its tributary, Little Cahaba River
(Jefferson County, Alabama) (Clench and Turner 1955). A single
collection of this species has also been reported from the Tensas
River, Madison Parish, Louisiana (Clench 1962), however, there are no
previous or subsequent records outside of the Alabama-Coosa system, and
searches of the Tensas River in Louisiana by Service biologists (1995)
and others (Vidrine 1996) have found no evidence of the species or its
typical habitat.
The cylindrical lioplax is currently known only from approximately
24 kilometers (km) (15 miles (mi)) of the Cahaba River above the Fall
Line in Shelby and Bibb counties, Alabama (Bogan and Pierson 1993b).
Survey efforts by Davis (1974) failed to locate this snail in the Coosa
or Alabama rivers, and more recent survey efforts have also failed to
relocate the species at historic localities in the Alabama, Black
Warrior, Little Cahaba, and Coosa rivers and their tributaries (Bogan
and Pierson 1993a, 1993b; M. Pierson in litt. 1993, 1994; Service Field
Records 1991, 1992, 1993).
The flat pebblesnail (Lepyrium showalteri (Lea 1861)) is a small
snail in the family Hydrobiidae; however, the species has a large and
distinct shell, relative to other hydrobiid species. This snail's shell
is also distinguished by its depressed spire and expanded, flattened
body whorl. The shells are ovate in outline, flattened, and grow to 3.5
to 4.4 mm (0.1-0.2 in) high and 4 to 5 mm (0.2 in) wide. The umbilical
area is imperforate (no opening), and there are 2 to 3 whorls which
rapidly expand. The anatomy of this species has been described in
detail by Thompson (1984). The flat pebblesnail is found attached to
clean, smooth stones in rapid currents of river shoals. Eggs are laid
singly in capsules on hard surfaces (Thompson 1984). Little else is
known of the natural history of this species.
The flat pebblesnail was historically known from the mainstem Coosa
River in Shelby and Talladega counties, the Cahaba River in Bibb and
Dallas counties, and Little Cahaba River in Bibb County, Alabama
(Thompson 1984). The flat pebblesnail has not been found in the Coosa
River portion of its range since the construction of Lay and Logan
Martin Dams, and recent survey efforts have failed to locate any
surviving populations outside of the Cahaba River drainage (Bogan and
Pierson, 1993a,b; McGregor et al. 1996; Service Field Records, Jackson,
Mississippi 1989-1996; Bogan in litt. 1995; M. Pierson Field Records,
Calera, Alabama, in litt. 1993-1994; J. Garner pers. comm. 1996; J.
Johnson in litt. 1996). The flat pebblesnail is currently known from
one site on the Little Cahaba River, Bibb County, and from a single
shoal series on the Cahaba River above the Fall Line, Shelby County,
Alabama (Bogan and Pierson 1993b).
The lacy elimia (Elimia crenatella (Lea 1860)) is a small species
in the family Pleuroceridae. Growing to about 1.1 centimeters (cm) (0.4
in.) in length, the shell is conic in shape, strongly striate, and
often folded in the upper whorls. Shell color is dark brown to black,
often purple in the aperture, and without banding. The aperture is
small and ovate. The lacy elimia is easily distinguished from other
elimia species by a combination of characters (i.e., size,
ornamentation, color).
In a recent genetic sequence study of the 16S rRNA gene, the lacy
elimia was found to be very similar to the compact elimia (Elimia
showalteri) (Lydeard et al. 1997). Despite their apparent close genetic
relationship, the authors made no suggestion that the two species
represented a single species. Upon review of Lydeard et al. (1997),
Dillon (College of Charleston, Charleston, South Carolina, in litt.
1997) suggested that additional genetic studies were needed to
demonstrate the genetic uniqueness of the lacy elimia. However, the
Lydeard et al. (1997) genetic study addressed only one small genetic
character of the genome of these species, and other characters strongly
support the taxonomic status of the lacy elimia. The two species are
allopatric (the compact elimia occurs in the Cahaba River, whereas the
lacy elimia was found in the Coosa River and tributaries), and are
strikingly different in size, appearance, and behavior. The compact
elimia has a large, robust, smooth shell boldly colored brown and/or
green, whereas the lacy elimia has a small, delicate, darkly colored,
and ornamented shell. The lacy elimia is one of the few elimia snails
in the Basin that does not exhibit clinal variation (Goodrich 1936). In
addition, compact elimia are found grazing individually throughout
shoal habitats, whereas the lacy elimia is usually found in tight
clusters or colonies on larger rocks within a shoal (P. Hartfield,
Jackson, MS, pers. obsv.). Allopatry, morphology, and behavior are
strong characters supporting species specific status of the lacy
elimia.
Elimia snails are gill breathing snails that typically inhabit
highly oxygenated waters on rock shoals and gravel bars. Most species
graze on periphyton growing on benthic substrates. Individual snails
are either male or female. Eggs are laid in early spring and hatch in
about 2 weeks. Snails apparently become sexually mature in their first
year, but, in some species, females may not lay until their second
year. Some elimia may live as long as 5 years (Dillon 1988).
The lacy elimia was historically abundant in the Coosa River main
stem from St. Clair to Chilton County, Alabama, and was also known in
several Coosa River tributaries--Big Will's Creek, DeKalb County;
Kelley's Creek, St. Clair County; and Choccolocco and Tallaseehatchee
creeks, Talladega County, Alabama (Goodrich 1936). The lacy elimia has
not been recently located at any historic collection site. However, as
a result of the recent survey efforts previously unreported populations
were discovered in three Coosa River tributaries--Cheaha, Emauhee, and
Weewoka creeks, Talladega County, Alabama (Bogan and Pierson 1993a).
The species is locally abundant in the lower reaches of Cheaha Creek.
This stream originates within the Talladega National Forest; however,
no specimens of the lacy elimia have been collected on Forest Service
lands. The species has also been found at single sites in Emauhee and
Weewoka creeks, where specimens are rare, and difficult to locate.
The painted rocksnail (Leptoxis taeniata (Conrad 1834)) is a small
to medium snail about 19 mm (0.8 in.) in length, and subglobose to oval
in shape. The aperture is broadly ovate, and rounded anteriorly.
Coloration varies from yellowish to olive-brown, and usually with four
dark bands. Some shells may not have bands and some have the bands
broken into squares or oblongs (see Goodrich 1922 for a detailed
description). All of the rocksnails that historically inhabited the
Basin had broadly rounded apertures, oval shaped shells, and variable
coloration. Although the various species were distinguished by relative
sizes, coloration patterns, and ornamentation, identification could be
confusing. However, the painted rocksnail is the only known survivor of
the 15 rocksnail species that were historically known from the Coosa
River drainage.
Rocksnails are gill breathing snails found attached to cobble,
gravel, or other hard substrates in the strong currents of riffles and
shoals. Adult
[[Page 54022]]
rocksnails move very little, and females probably glue their eggs to
stones in the same habitat (Goodrich 1922). Heller (1990) reported a
short life span (less than 2 years) in a Tennessee River rocksnail.
Longevity in the painted and the Basin's other rocksnails is unknown.
The painted rocksnail had the largest range of any rocksnail in the
Mobile River Basin (Goodrich 1922). It was historically known from the
Coosa River and tributaries from the northeastern corner of St. Clair
County, Alabama, downstream into the mainstem of the Alabama River to
Claiborne, Monroe County, Alabama, and the Cahaba River below the Fall
Line in Perry and Dallas counties, Alabama (Goodrich 1922, Burch 1989).
Surveys by Service biologists and others (Bogan and Pierson 1993a,
1993b; M. Pierson, in litt. 1993) in the Cahaba River, unimpounded
portions of the Alabama River, and a number of free-flowing Coosa River
tributaries have located only three localized Coosa River drainage
populations.
The painted rocksnail is currently known from the lower reaches of
three Coosa River tributaries--Choccolocco Creek, Talladega County;
Buxahatchee Creek, Shelby County (Bogan and Pierson 1993a); and
Ohatchee Creek, Calhoun County, Alabama (Pierson in litt. 1993).
The round rocksnail (Leptoxis ampla (Anthony 1855)) grows to about
20 mm (0.8 in) in length. The shell is subglobose, with an ovately
rounded aperture. The body whorl is shouldered at the suture, and may
be ornamented with folds or plicae. Color may be yellow, dark brown, or
olive green, usually with four entire or broken bands (Goodrich 1922).
Round rocksnails inhabit riffles and shoals over gravel, cobble, or
other rocky substrates.
Lydeard et al. (1997) found slight differences in DNA sequencing
between the painted rocksnail and the round rocksnail, and considered
them to be sister species. Following analysis by allozyme
electrophoresis on these same species, Dillon (in litt. 1997)
speculated that the two species represented isolated populations
belonging to a single species. The two species are geographically
separated, with the painted rocksnail inhabiting Coosa River
tributaries, while the round rocksnail is the only surviving rocksnail
species in the Cahaba River drainage. Both species are currently
recognized by the malacological community (e.g., Burch 1989; Turgeon et
al. 1988, revision in review), and are treated as distinct in this
proposed rule.
The round rocksnail was historically found in the Cahaba River, and
its tributary, Little Cahaba River, Bibb County, Alabama; and the Coosa
River, Elmore County, and tributaries--Canoe Creek and Kelly's Creek,
St. Clair County; Ohatchee Creek, Calhoun County; Yellowleaf Creek,
Shelby County; and Waxahatchee Creek, Shelby/Chilton counties, Alabama
(Goodrich 1922).
The round rocksnail is currently known from a shoal series in the
Cahaba River, Bibb and Shelby counties, Alabama, and from the lower
reach of the Little Cahaba River, and the lower reaches of Shade and
Six-mile creeks in Bibb County, Alabama (Bogan and Pierson 1993b).
The plicate rocksnail (Leptoxis plicata (Conrad, 1834)) grows to
about 20 mm (0.8 in) in length. Shells are subglobose with broadly
rounded apertures. The body whorl may be ornamented with strong folds
or plicae. Shell color is usually brown, occasionally green, and often
with four equidistant color bands. The columella (central column or
axis) is smooth, rounded, and typically pigmented in the upper half.
The aperture is usually bluish-white, occasionally pink or white. The
operculum (plate that closes the shell when the snail is retracted) is
dark red, and moderately thick (Goodrich 1922). Although
morphologically similar to the Basin's other three surviving rocksnail
species, the plicate rocksnail is genetically distinct (Lydeard et al.
1997, Dillon in litt. 1997).
The plicate rocksnail historically occurred in the Black Warrior
River and its tributary, the Little Warrior River, and the Tombigbee
River (Goodrich 1922). Status survey efforts found populations of
plicate rocksnails only in an approximately 88km (55 mi) reach of the
Locust Fork of the Black Warrior River, Jefferson and Blount counties,
Alabama (Service Field Records, Jackson, Mississippi 1991, 1992;
Malcolm Pierson, Calera, Alabama, Field Notes 1993). Surveys during
1996 (Garner in progress) indicate that the snail has recently
disappeared from the upstream \4/5\ portion of that habitat and now
appears restricted to an approximately 17.6 km (11 mi) reach in
Jefferson County.
Previous Federal Action
The six aquatic snails were identified as Category 2 species in
notices of review published in the Federal Register on November 21,
1991 (56 FR 58804), and November 15, 1994 (59 FR 58982). At that time,
a Category 2 species was one that was being considered for possible
addition to the Federal List of Endangered and Threatened Wildlife, but
for which conclusive data on biological vulnerability and threat were
not available to support a proposed rule. Designation of Category 2
species was discontinued in the February 28, 1996, Notice of Review (61
FR 7956). The six snails considered in this proposal were approved as
Candidate species by the Service on November 9, 1995, and identified as
Candidates in the 1996 Notice of Review. A Candidate species is defined
as a species for which the Service has on file sufficient information
on biological vulnerability and threats to support issuance of a
proposed rule.
A status review summary, that included these six snails, was mailed
on August 23, 1994 (62 letters), to appropriate species authorities,
State and Federal agencies, private organizations, and interested
individuals. A cover letter provided notification that a status review
was in progress by the Service, stated that the species appeared to
qualify for listing under the Act, and requested a review of the status
review summary for accuracy regarding taxonomy, distribution, threats,
and status. Three species authorities responded by telephone concurring
with the status reviews. No other comments were received as a result of
this notification.
An updated status report, along with a review request, was mailed
on March 11, 1997 (157 letters), following elevation of the snails to
Candidate status. One snail authority concurred with the status review
analysis; however, he recommended additional genetic studies on the
lacy elimia (see Background section above). Two other snail authorities
responded concurring with the analysis, as well as the taxonomic
treatment of the six species.
On September 5, 1995, the Service received two petitions, dated
August 31, 1995, from a coalition of environmental organizations
(Coosa-Tallapoosa Project, Biodiversity Legal Foundation, and Alabama
Wilderness Alliance) represented by Mr. Ray Vaughan. The petitioners
requested the Service to list the plicate rocksnail as endangered and
to designate critical habitat for this species. The second petition
requested the Service to list the lacy elimia as a threatened species
and to designate critical habitat.
Section 4 (b)(3)(A) of the Act and implementing regulations at 50
CFR part 424.14 require that, to the extent practicable, the Service
make a finding of substantiality on any petition within 90 days of its
receipt, and publish a notice of its finding in the Federal Register.
If a substantial 90-day finding is made, the Service is required, to
the
[[Page 54023]]
extent practicable, within 12 months of receipt of the petition, to
make a finding as to whether the action requested in the petition is
(a) not warranted, (b) warranted, or (c) warranted but precluded.
Because of budgetary constraints and the lasting effects of a
congressionally imposed listing moratorium, the Service is processing
petitions and other listing actions according to the listing priority
guidance published in the Federal Register on December 5, 1996 (61 FR
64475). The guidance clarifies the order in which the Service will
process listing actions during fiscal year 1997. The guidance calls for
giving highest priority to handling emergency situations (Tier 1) and
second highest priority (Tier 2) to resolving the status of outstanding
proposed listings. Third priority (Tier 3) is given to resolving the
conservation status of Candidate species and processing administrative
findings on petitions to add species to the lists or reclassify
threatened species to endangered status. The processing of these two
petitions and the proposed rule falls under Tier 3. At this time, the
Southeast Region has no pending Tier 1 actions and is near completion
of its pending Tier 2 actions. Additionally, the guidance states that
``effective April 1, 1997, the Service will concurrently undertake all
of the activities presently included in Tiers 1, 2, and 3'' (61 FR
64480). This proposal constitutes the 90-day and 12-month finding on
the petitioned actions.
Summary of Factors Affecting the Species
Section 4 of the Act and regulations (50 CFR part 424) promulgated
to implement the listing provisions of the Act set forth the procedures
for adding species to the Federal lists. 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). These factors and their
application to the cylindrical lioplax (Lioplax cyclostomaformis), flat
pebblesnail (Lepyrium showalteri), plicate rocksnail (Leptoxis
plicata), painted rocksnail (Leptoxis taeniata), round rocksnail
(Leptoxis ampla), and lacy elimia (Elimia crenatella) are as follows:
A. The present or threatened destruction, modification, or
curtailment of its habitat or range. The cylindrical lioplax, flat
pebblesnail, lacy elimia, round rocksnail, painted rocksnail, and
plicate rocksnail have all disappeared from more than 90 percent of
their historic ranges. All of these snails were historically, and
continue to be, strongly associated with river or stream habitats
characterized by flowing currents, and hard, clean bottoms (e.g.,
bedrock, boulder, gravel) (Goodrich 1922, 1936; Clench and Turner
1955). The curtailment of habitat and range for these six species in
the Basin's larger rivers (Coosa, Alabama, Tombigbee and Black Warrior)
is primarily due to extensive construction of dams and the inundation
of the snail's shoal habitats by impounded waters. Thirty dams have
changed this system from a continuum of free-flowing riverine habitats
into a series of impoundments connected by short, free-flowing reaches.
On the Alabama River there are 3 dams (built between 1968-1971); the
Black Warrior has 5 (1915-1959); the Coosa 10 (1914-1966), and the
Tombigbee 12 (1954-1979). Dams impound approximately 1,650 km (1,022
mi) of river channel in the Basin.
These six snail species have disappeared from all portions of their
historic habitats that have been impounded by dams. As noted earlier,
they are all associated with fast currents over clean, hard bottom
materials. Dams change such areas by eliminating or reducing currents,
and allowing sediments to accumulate on inundated channel habitats.
Impounded waters also experience changes in water chemistry which could
affect survival or reproduction of riverine snails. For example, many
reservoirs in the Basin currently experience eutrophic conditions,
including chronically low dissolved oxygen levels (Alabama Department
of Environmental Management (ADEM) 1994, 1996). Such physical and
chemical changes can affect feeding, respiration, and reproduction of
these riffle and shoal snail species.
A site on the Locust Fork River is currently considered for the
construction of a water supply impoundment (C. Waldrep, Gorham &
Waldrep, P.C., Montgomery, Alabama, in litt. 1995). If constructed,
this impoundment would bisect and threaten the only single surviving
population of the plicate rocksnail. Plicate rocksnails occurred in
riffle and shoal habitats above and below the reservoir site in 1994.
In 1996, plicate rocksnails could not be relocated in the portion of
the river to be flooded by the reservoir; however, they were confirmed
to continue to survive in an approximately 17.6 km (11 mi) reach of
river below the proposed dam site, which would be subject to impacts
from construction activities and post-construction changes in water
quality (Garner pers. comm. 1996).
In addition to directly altering snail habitats, dams and their
impounded waters also formed barriers to the movement of snails that
continued to live below dams or in unimpounded tributaries. It is
suspected that many such isolated colonies gradually disappear as a
result of local water and habitat quality changes. Unable to emigrate,
the isolated snail populations are vulnerable to local discharges as
well as any detrimental land surface runoff within their watersheds.
Although many watershed impacts have been temporary, eventually
improving or even disappearing with the advent of new technology,
practices, or laws, dams and their impounded waters prevent natural
recolonization by snail populations surviving elsewhere.
Prior to the passage of the Clean Water Act and the adoption of
State water quality criteria, water pollution may have been a
significant factor in the disappearance of snail populations from
unimpounded tributaries of the Basin's impounded mainstem rivers. For
example, Hurd (1974) noted the extirpation of freshwater mussel
communities from several Coosa River tributaries, including the
Conasauga River below Dalton, Georgia, the Chatooga River, and
Tallaseehatchee Creek, apparently as a result of textile and carpet
mill waste discharges. He also attributed the disappearance of the
mussel fauna from the Etowah River, Talladega and Swamp creeks, and
from many of the lower tributaries of the Coosa River, to organic
pollution and siltation.
Short-term and long-term impacts of point and nonpoint source water
and habitat degradation continue to be a primary concern for the
survival of all these snails, compounded by their isolation and
localization. Point source discharges and land surface runoff (nonpoint
pollution) can cause nutrification, decreased dissolved oxygen
concentration, increased acidity and conductivity, and other changes in
water chemistry that are likely to seriously impact aquatic snails.
Point sources of water quality degradation include municipal and
industrial effluents.
Nonpoint source pollution from land surface runoff can originate
from virtually all land use activities, and may include sediments,
fertilizers, herbicides, pesticides, animal wastes, septic tank and
gray water leakage, and oils and greases (ADEM 1996). During many
recent surveys for these snails, sediment deposition and nutrient
enrichment of stream reaches was noted as being associated with the
absence of snails from historic collection localities (Bogan and
Pierson 1993a, 1993b; Hartfield 1991; Service Field
[[Page 54024]]
Observations 1992-1994, Jackson Field Office, MS).
Excessive sediments are believed to impact riverine snails
requiring clean, hard shoal stream and river bottoms, by making the
habitat unsuitable for feeding or reproduction. Similar impacts
resulting from sediments have been noted for many other components of
aquatic communities. For example, sediments have been shown to abrade
and/or suffocate periphyton (organisms attached to underwater surfaces,
upon which snails may feed); affect respiration, growth, reproductive
success, and behavior of aquatic insects and mussels; and affect fish
growth, survival, and reproduction (Watters 1995).
Sediment is the most abundant pollutant produced in the Basin (ADEM
1989). Potential sediment sources within a watershed include virtually
all activities that disturb the land surface, and all localities
currently occupied by these snails are affected to varying degrees by
sedimentation. The amount and impact of sedimentation on snail habitats
may be locally correlated with the land use practice. For example, the
use of agriculture, forestry, and construction Best Management
Practices can reduce sediment amounts and impacts.
Land surface runoff contributes the majority of human-induced
nutrients to water bodies throughout the country (Louisiana Department
of Environmental Quality 1995). Excessive nutrient input (from
fertilizers, sewage waste, animal manure, etc.) can result in periodic
low dissolved oxygen levels that are detrimental to aquatic species
(Hynes 1970). Nutrients also promote heavy algal growth that may cover
and eliminate clean rock or gravel habitats of shoal dwelling snails.
Nutrient and sediment pollution may have synergistic effects on
freshwater snails and their habitats, as has been suggested for aquatic
insects (Watters 1995).
The cylindrical lioplax, flat pebblesnail, and the round rocksnail
currently survive in localized reaches of the Cahaba River drainage.
Water quality studies in the upper Cahaba River drainage by the
Geological Survey of Alabama (Shepard et al. 1996) found that
discharges from 34 waste water treatment plants (WWTPs) in the upper
drainage have contributed to water quality impairment. This was
reflected by low levels of dissolved oxygen downstream of Birmingham;
ammonia and chlorination by-products in excess of recommended water
quality criteria; and eutrophication due to excessive levels of
phosphorus and nitrogen. The study noted that these problems are
chronic and have been a factor in a loss of mollusk and fish diversity
throughout the drainage. Their results indicate that the upper Cahaba
River drainage is primarily impacted by nonpoint runoff and WWTPs
through physical habitat destruction by sedimentation, and chronic
stress from exposure to toxics and low dissolved oxygen. The middle
Cahaba River is primarily impacted by eutrophication and associated
affects.
The lacy elimia is now restricted to three small stream channels in
Talladega County, Alabama--Cheaha, Emauhee, and Weewoka creeks (Coosa
River drainage). The painted rocksnail currently survives in localized
reaches of three other Coosa River tributaries, Choccolocco,
Buxahatchee, and Ohatchee creeks. The plicate rocksnail inhabits a
single short reach of the Locust Fork River in Jefferson County,
Alabama (Black Warrior River drainage). All of these streams are
variously impacted by sediments and nutrients from a variety of
upstream rural, suburban, and/or urban sources. The streams are all
small to moderate in size and volumes of flow, and their water and
habitat quality can be rapidly affected by local and offsite pollution
sources.
Habitat fragmentation and population isolation are a significant
threat to the continued survival of the lacy elimia and painted
rocksnail. The known populations of these two species are isolated by
extensive areas of impoundment, and there is little, if any,
possibility of genetic exchange between them. Over time, this isolation
may result in genetic drift, with each population becoming unique and
vulnerable to environmental disturbance.
B. Overutilization for commercial, recreational, scientific, or
educational purposes. The six aquatic snail species addressed in this
proposed rule are currently not of commercial value, and
overutilization has not been a problem. However, as their rarity
becomes known, they may become more attractive to collectors.
Unregulated collecting by private and institutional collectors poses a
threat. The cylindrical lioplax, flat pebblesnail, plicate rocksnail,
painted rocksnail, round rocksnail, and lacy elimia inhabit shallow,
fast-flowing waters of shoals and riffles. Because of their occurrence
and exposure in such areas, they are readily vulnerable to
overcollecting and/or vandalism. In these areas, the snails are also
exposed to crushing by recreational activities such as canoeing,
wading, swimming, or fishing; however, normal recreational activities
are not believed to be a factor in their decline.
C. Disease or predation. Aquatic snails are consumed by various
vertebrate predators, including fishes, mammals, and possibly birds.
Predation by naturally occurring predators is a normal aspect of the
population dynamics of a species and is not considered a threat to
these species. However, the potential now exists for black carp
(Mylopharyngodon piceus), a nonselective molluskivore recently
introduced into waters of the United States, to eventually enter the
Mobile River Basin. Exotic black carp recently escaped to the Osage
River in Missouri when hatchery ponds were flooded during a 1994 spring
flood of the river (LMRCC newsletter, 1994). The extent of stocking
black carp for snail control in aquaculture ponds within the Basin is
unknown; however, black carp are currently cultured and sold within the
State of Mississippi (D. Reike, Mississippi Department of Wildlife,
Fisheries, and Parks, 1997).
D. The inadequacy of existing regulatory mechanisms. Although the
negative effects of point source discharges on aquatic communities have
probably been reduced over time by compliance with State and Federal
regulations pertaining to water quality, there is currently no
information on the sensitivity of the Mobile River Basin snail fauna to
common industrial and municipal pollutants. Current State and Federal
regulations regarding such discharges are assumed to be protective;
however, these snails may be more susceptible to some pollutants than
test organisms currently used in bioassays. A lack of adequate research
and data currently prevents existing authorities, such as the Clean
Water Act (CWA), administered by the Environmental Protection Agency
(EPA) and the Army Corps of Engineers, from being fully utilized. The
Service is currently working with EPA to develop a memorandum of
agreement (MOA) that will address how EPA and the Service will interact
relative to CWA water quality criteria and standards within the
Service's Southeast Region.
Lacking State or Federal recognition, these snails are not given
any special consideration under other environmental laws when project
impacts are reviewed.
E. Other natural or manmade factors affecting its continued
existence. The narrow distribution of extant populations of all six
snail species and the nature of their habitats (i.e., small to moderate
sized streams) renders them vulnerable to a natural catastrophic event
(e.g., flood, drought).
The Service has carefully assessed the best scientific and
commercial
[[Page 54025]]
information available regarding the past, present, and future threats
faced by these species in determining to propose this rule. Based on
these evaluations, the preferred action is to list the cylindrical
lioplax, flat pebblesnail, and plicate rocksnail as endangered; and the
painted rocksnail, round rocksnail, and lacy elimia as threatened. All
of these species have been rendered vulnerable due to significant loss
of habitat and severe range restriction.
The cylindrical lioplax is confined in distribution to a short
reach of the Cahaba River. The flat pebblesnail currently survives in
localized portions of the Cahaba River and the Little Cahaba River.
Both species are vulnerable to extinction by their confined ranges, and
current impacts from water quality degradation in the Cahaba River
drainage. The single known population of the plicate rocksnail is
threatened by the proposed construction of an impoundment within its
remaining habitat in the Locust Fork, and water quality degradation.
The plicate rocksnail has also experienced a significant reduction in
range within the Locust Fork within the past 2 years, apparently due to
pollution of its habitat from nonpoint sources. Endangered status is
appropriate for these three species due to their single populations,
restricted numbers within these populations, existing threats to their
occupied habitats, and in the case of the plicate rocksnail, an ongoing
decline in range.
The lacy elimia, painted rocksnail, and round rocksnail are each
currently known from three distinct drainage localities. Extant
populations and colonies of these three species are localized,
isolated, and are vulnerable to water quality degradation, future human
activities that would degrade their habitats, and random catastrophic
events. Threatened status is considered more appropriate for these
species due to the larger number of populations or colonies, and the
less immediate nature of these threats.
Critical Habitat
Critical habitat is defined in section 3 of the Act as: (i) the
specific areas within the geographical area occupied by a species, at
the time it is listed in accordance with the Act, on which are found
those physical or biological features (I) essential to the conservation
of the species and (II) that may require special management
consideration or protection and; (ii) specific areas outside the
geographical area occupied by a species at the time it is listed, upon
a determination that such areas are essential for the conservation of
the species.
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 424.12) requires that, to the maximum extent
prudent and determinable, the Secretary designate critical habitat at
the time the species is determined to be endangered or threatened.
Service regulations (50 CFR 424.12(a)(1)) state that designation of
critical habitat is not prudent when one or both of the following
situations exist (1) The species is threatened by taking or other
activity and the identification of critical habitat can be expected to
increase the degree of threat to the species or (2) such designation of
critical habitat would not be beneficial to the species. The Service
finds that designation of critical habitat is not presently prudent for
any of these six aquatic snails.
Critical habitat designation, by definition, directly affects only
Federal agency actions. Since these snail species are aquatic
throughout their life cycles, Federal actions that might affect these
species and their habitats include those with impacts on stream channel
geometry, bottom substrate composition, water quantity and quality, and
stormwater runoff. Such activities would be subject to review under
section 7(a)(2) of the Act, whether or not critical habitat was
designated. Section 7(a)(2) requires Federal agencies to ensure that
activities they authorize, fund, or carry out are not likely to
jeopardize the continued existence of a listed species or to destroy or
adversely modify its critical habitat. The cylindrical lioplax, flat
pebblesnail, plicate rocksnail, round rocksnail, painted rocksnail, and
lacy elimia have become so restricted in distribution that any
significant adverse modification or destruction of their occupied
habitats would likely jeopardize their continued existence. This would
also hold true as the species recovers and its numbers increase.
Therefore, habitat protection for these six species can be accomplished
through the section 7 jeopardy standard and there is no benefit in
designating currently occupied habitat of these species as critical
habitat.
Recovery of these species will require the identification of
unoccupied stream and river reaches appropriate for reintroduction.
Critical habitat designation of unoccupied stream and river reaches may
benefit these species by alerting permitting agencies to potential
sites for reintroduction and allow them the opportunity to evaluate
projects which may affect these areas. The Service is currently working
with the State and other Federal agencies to periodically survey and
assess habitat potential of stream and river reaches for listed and
candidate aquatic species within the Mobile River basin. This process
provides up to date information on instream habitat conditions in
response to land use changes within watersheds. Information generated
from surveys and assessments is disseminated through Service
coordination with other agencies. Should this rule become final, the
Service will work with State and Federal agencies, as well as private
property owners and other affected parties, through the recovery
process to identify stream reaches and potential sites for
reintroduction of these species. Thus, the benefit provided by
designation of unoccupied habitat as critical will be accomplished more
effectively with the current coordination process and is preferable for
aquatic habitats which change rapidly in response to watershed land use
practices. In addition, the Service believes that any potential
benefits to critical habitat designation are outweighed by additional
threats to the species that would result from such designation, as
discussed below.
Though critical habitat designation directly affects only Federal
agency actions, this process can arouse concern and resentment on the
part of private landowners and other interested parties. The
publication of critical habitat maps in the Federal Register and local
newspapers, and other publicity or controversy accompanying critical
habitat designation may increase the potential for vandalism as well as
other collection threats (See Factor B under ``Summary of Factors
Affecting the Species''). For example, in 1993 the Alabama sturgeon was
proposed for endangered status with critical habitat (59 FR 33148).
Critical habitat included the lower portions of the Alabama, Cahaba,
and Tombigbee rivers in south Alabama. The proposal generated thousands
of comments with the primary concern that the actions would devastate
the economy of the State of Alabama and severely impact adjoining
States. There were reports from State conservation agents and other
knowledgeable sources of rumors inciting the capture and destruction of
Alabama sturgeon. A primary contributing factor to this controversy was
the proposed designation of critical habitat for the sturgeon.
The six snail species addressed in this proposal are especially
vulnerable to vandalism. They all are found in shallow shoals or
riffles in restricted stream and river segments. The flat
[[Page 54026]]
pebblesnail, plicate rocksnail, round rocksnail, painted rocksnail, and
lacy elimia attach to the surfaces of bedrock, cobble, or gravel, while
the cylindrical lioplax is found under large boulders. The six species
are relatively immobile and unable to escape collectors or vandals.
They inhabit remote but easily accessed areas, and they are sensitive
to a variety of easily obtained commercial chemicals and products.
Because of these factors, vandalism or collecting could be undetectable
and uncontrolled. For example, the plicate rocksnail recently
disappeared from approximately 80 percent of its known occupied
habitat. While the Service has been unable to determine the cause of
this decline, the disappearance illustrates the vulnerability of this
and the other snail species.
All known populations of these six snail species occur in streams
flowing through private lands. The primary threat to all surviving
populations appears to be pollutants in stormwater runoff that
originate from private land activities (see Factor A). Therefore, the
survival and recovery of these snails will be highly dependent on
landowner cooperation in reducing land use impacts.
Controversy resulting from critical habitat designation has been
known to reduce private landowner cooperation in the management of
species listed under the Act (e.g., spotted owl, golden cheeked
warbler). The Alabama sturgeon experience suggests that critical
habitat designation could affect landowner cooperation within
watersheds occupied by these six snails.
Based on the above analysis, the Service has concluded critical
habitat designation would provide little additional benefit for these
species beyond those that would accrue from listing under the Act. The
Service also concludes that any potential benefit from such a
designation would be offset by an increased level of vulnerability to
vandalism or collecting, and by a possible reduction in landowner
cooperation to manage and recover these species. The designation of
critical habitat for these six snail species is not prudent.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing encourages and results in
conservation actions by Federal, State, and private agencies, groups,
and individuals. The Act provides for possible land acquisition and
cooperation with the States and requires that recovery actions be
carried out for all listed species. The protection required of Federal
agencies and the prohibitions against taking and harm are discussed, in
part, below.
Section 7(a) of the Act, as amended, requires Federal agencies to
evaluate their actions with respect to any species that is proposed or
listed as endangered or threatened and with respect to its critical
habitat, if any is being designated. Regulations implementing this
interagency cooperation provision of the Act are codified at 50 CFR
part 402. Section 7(a)(4) requires Federal agencies to confer
informally with the Service on any action that is likely to jeopardize
the continued existence of a proposed species or result in destruction
or adverse modification of proposed critical habitat. If a species is
listed subsequently, section 7(a)(2) requires Federal agencies to
ensure that activities they authorize, fund, or carry out are not
likely to jeopardize the continued existence of such a species or to
destroy or adversely modify its critical habitat. If a Federal action
may affect a listed species or its critical habitat, the responsible
Federal agency must enter into formal consultation with the Service.
Federal activities that could occur and impact these species
include, but are not limited to, the carrying out or the issuance of
permits for reservoir construction, stream alterations, discharges,
wastewater facility development, water withdrawal projects, pesticide
registration, mining, and road and bridge construction. It has been the
experience of the Service, however, that nearly all section 7
consultations have been resolved so that the species have been
protected and the project objectives have been met. Other than a
potential dam on the Locust Fork River, Jefferson and Blount counties,
Alabama, no other Federal activities that may affect these species are
currently known to be under consideration.
The Act and its implementing regulations found at 50 CFR 17.21 for
endangered species, and 17.21 and 17.31 for threatened species set
forth a series of general prohibitions and exceptions that apply to all
endangered or threatened wildlife. These prohibitions, in part, make it
illegal for any person subject to the jurisdiction of the United States
to take (includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
or collect, or to attempt any of these), import or export, ship in
interstate commerce in the course of commercial activity, or sell or
offer for sale in interstate or foreign commerce any listed species. It
also is illegal to possess, sell, deliver, carry, transport, or ship
any wildlife that has been taken illegally. Certain exceptions apply to
agents of the Service and State conservation agencies.
Permits may be issued to carry out otherwise prohibited activities
involving endangered or threatened wildlife species under certain
circumstances. Regulations governing permits are at 50 CFR 17.22 and
17.23 for endangered species and 17.32 for threatened species. Such
permits are available for scientific purposes, to enhance the
propagation or survival of the species, and/or for incidental take in
connection with otherwise lawful activities. For threatened species,
there are also permits for zoological exhibition, educational purposes,
or special purposes consistent with the purposes of the Act.
It is the policy of the Service published in the Federal Register
on July 1, 1994 (59 FR 34272), to identify, to the maximum extent
practicable, those activities that would or would not constitute a
violation of section 9 of the Act if these species are listed. The
intent of this policy is to increase public awareness as to the effects
of these proposed listings on future and ongoing activities within a
species' range.
Activities which the Service believes are unlikely to result in a
violation of section 9 for these six snails are:
(1) Existing discharges into waters supporting these species,
provided these activities are carried out in accordance with existing
regulations and permit requirements (e.g., activities subject to
sections 402, 404, and 405 of the Clean Water Act and discharges
regulated under the National Pollutant Discharge Elimination System
(NPDES)).
(2) Typical agriculture and silviculture practices.
(3) Development and construction activities designed and
implemented pursuant to State and local water quality regulations.
(4) Existing recreational activities such as swimming, wading,
canoeing, and fishing.
Activities that the Service believes could potentially result in
``take'' of these snails, if they should be listed, include:
(1) The unauthorized collection or capture of the species;
(2) Unauthorized destruction or alteration of the species habitat
(e.g., instream dredging, channelization, discharge of fill material);
(3) Violation of any discharge or water withdrawal permit;
[[Page 54027]]
(4) Illegal discharge or dumping of toxic chemicals or other
pollutants into waters supporting the species.
Other activities not identified above will be reviewed on a case-
by-case basis to determine if a violation of section 9 of the Act may
be likely to result from such activity should these snails become
listed. The Service does not consider these lists to be exhaustive and
provides them as information to the public.
Questions regarding whether specific activities may constitute a
future violation of section 9 should these snails be listed should be
directed to the Field Supervisor of the Service's Jackson Field Office
(see ADDRESSES section). Requests for copies of regulations regarding
listed species and inquiries about prohibitions and permits should be
addressed to the U.S. Fish and Wildlife Service, Ecological Services
Division, 1875 Century Boulevard, Atlanta, Georgia 30345 (Phone 404/
679-7313; Fax 404/679-7081).
Public Comments Solicited
The Service intends that any final action resulting from this
proposal will be as accurate and as effective as possible. Therefore,
comments or suggestions from the public, other concerned governmental
agencies, the scientific community, industry, or any other interested
party concerning this proposed rule are hereby solicited. Comments
particularly are sought concerning:
(1) biological, commercial trade, or other relevant data concerning
any threat (or lack thereof) to this species;
(2) the location of any additional populations of this species and
the reasons why any habitat should or should not be determined to be
critical habitat as provided by Section 4 of the Act;
(3) additional information concerning the range, distribution, and
population size of this species; and
(4) current or planned activities in the subject area and their
possible impacts on this species.
Final promulgation of the regulations on these species will take
into consideration the comments and any additional information received
by the Service, and such communications may lead to final regulations
that differ from this proposal.
The Act provides for one or more public hearings on this proposal,
if requested. Requests must be received within 45 days of the date of
publication of the proposal in the Federal Register. Such requests must
be made in writing and addressed to the Field Supervisor (see ADDRESSES
section).
National Environmental Policy Act
The Fish and Wildlife Service has determined that an Environmental
Assessment, as defined under the authority of the National
Environmental Policy Act of 1969, need not be prepared in connection
with regulations adopted pursuant to Section 4(a) of the Act. A notice
outlining the Service's reasons for this determination was published in
the Federal Register on October 25, 1983 (48 FR 49244).
Required Determinations
The Service has examined this regulation under the Paperwork
Reduction Act of 1995 and found it to contain no information collection
requirements.
References Cited
A complete list of all references cited herein, as well as others,
is available upon request from the Field Supervisor (see ADDRESSES
section).
Author: The primary author of this proposed rule is Paul Hartfield
(see ADDRESSES section)(601/965-4900, Ext. 25).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, the Service hereby proposes to amend part 17,
subchapter B of chapter I, title 50 of the Code of Federal Regulations,
as set forth below:
PART 17--[AMENDED]
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.
2. Section 17.11(h) is amended by adding the following, in
alphabetical order under SNAILS, to the List of Endangered and
Threatened Wildlife to read as follows:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
-------------------------------------------------------- population where Critical Special
Historic range endangered or Status When listed habitat rules
Common name Scientific name threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Snails
* * * * * * *
Elimia, lacy..................... Elimia crenatella... U.S.A. (AL)........ NA................. T NA NA
* * * * * * *
Lioplax, cylindrical............. Lioplax U.S.A. (AL)........ NA................. E NA NA
cyclostomaformis.
* * * * * * *
Pebblesnail, flat................ Lepyrium showalteri. U.S.A. (AL)........ NA................. E NA NA
* * * * * * *
Rocksnail, painted............... Leptoxis taeniata... U.S.A. (AL)........ NA................. T NA NA
* * * * * * *
Rocksnail, plicate............... Leptoxis plicata.... U.S.A. (AL)........ NA................. E NA NA
* * * * * * *
Rocksnail, round................. Leptoxis ampla...... U.S.A. (AL)........ NA................. T NA NA
[[Page 54028]]
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dated: September 12, 1997.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 97-27548 Filed 10-16-97; 8:45 am]
BILLING CODE 4310-55-P
