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

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