Endangered and Threatened Wildlife and Plants; Proposed Endangered Status for Five Freshwater Mussels and Proposed Threatened Status for Two Freshwater Mussels From Eastern Gulf Slope Drainages of Alabama, Florida, and Georgia

DEPARTMENT OF THE INTERIOR

Fish And Wildlife Service

50 CFR Part 17

RIN 1018-AC63

Endangered and Threatened Wildlife and Plants; Proposed

Endangered Status for Five Freshwater Mussels and Proposed Threatened

Status for Two Freshwater Mussels From Eastern Gulf Slope Drainages of

Alabama, Florida, and Georgia

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The Fish and Wildlife Service (Service) proposes to list seven

freshwater mussels: The fat three-ridge (Amblema neislerii), shiny-

rayed pocketbook (Lampsilis subangulata), Gulf moccasinshell

(Medionidus penicillatus), Ochlockonee moccasinshell (Medionidus

simpsonianus), and oval pigtoe (Pleurobema pyriforme) as endangered,

and the Chipola slabshell (Elliptio chipolaensis) and purple

bankclimber (Elliptoideus sloatianus) as threatened under the

Endangered Species Act (Act) of 1973, as amended. These mussels are

endemic to eastern Gulf Slope streams draining the Apalachicolan Region

of southeast Alabama, southwest Georgia, and north Florida. They are

currently known from localized portions of from one to four isolated

marine river systems, mostly in the eastern portion of the

Apalachicolan Region. Impoundments and deteriorating water and benthic

(bottom) habitat quality resulting from channel modification,

siltation, agricultural runoff, silvicultural activities, mining

activities, pollutants, poor land use practices, increased

urbanization, and waste discharges have resulted in the restriction and

fragmentation of these mussels current ranges. In addition, the Service

has little evidence to suggest that populations of these seven species

of mussels are reproductively viable.

DATES: Comments from all interested parties must be received by

November 1, 1994. Public hearing requests must be received by September

19, 1994.

ADDRESSES: Comments and materials concerning this proposal should be

sent to the Field Supervisor, U.S. Fish and Wildlife Service,

Jacksonville Field Office, 6620 Southpoint Drive South, Suite 310,

Jacksonville, Florida 32216 (904/232-2580). 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. Robert S. Butler at the above

address.

SUPPLEMENTARY INFORMATION:

Background

The fat three-ridge, shiny-rayed pocketbook, Gulf moccasinshell,

Ochlockonee moccasinshell, oval pigtoe, Chipola slabshell, and purple

bankclimber are freshwater mussels endemic to eastern Gulf Slope

streams draining the Apalachicolan Region (streams from the Escambia to

the Suwannee river systems in southeast Alabama, southwest Georgia and

north Florida). The Apalachicolan Region primarily drains the Coastal

Plain Physiographic Province. Only the headwaters of the Flint and

Chattahoochee rivers, in the Apalachicola River system, occur above the

Fall Line in the Piedmont Physiographic Province in west-central

Georgia. Streams draining the East Gulf Coastal Plain are generally low

gradient and have substrates of sand, silty sand, mud, and gravel. Some

streams, particularly in the Apalachicola River system, have coarser

substrates of cobble, boulders, and bedrock in addition to areas with

softer bed materials. The seven species of mussels being considered for

listing inhabit medium-sized streams to large rivers with substrates of

silty sand, sand, or gravel, and mixtures of these substrates. All are

generally found in areas with water currents, often in stream channels

swept free of silt. The life histories of these seven species of

mussels are unknown and little biological information is available.

The Apalachicolan Region is known for its high level of endemicity,

harboring nearly 30 species of endemic mussels (Butler 1989), at least

a dozen fishes, over 20 aquatic snails, and nearly two dozen species of

crayfish. In addition, several candidate species from the Service's

animal notice of review published on November 21, 1991 (56 FR 58804)

are also known from the Apalachicolan Region, the majority being

endemic to these drainages. One of these candidates, the Ochlockonee

arc-mussel is thought to be extinct (Turgeon et al. 1988), last

reported in the early 1930's (Williams and Butler, in press). A recent

status survey for candidate species of mussels in the Apalachicola

River system did not locate any populations of the winged spike and

lined pocketbook, species endemic to this system that were last sighted

in 1958 and 1967, respectively. Between 1991 and 1993, the Service's

National Fisheries Research Center, now the National Biological Survey,

Biological Science Center, in Gainesville, Florida, completed field

surveys for mussels in both the Apalachicola (325 collections at 315

sites) and Ochlockonee (77 collections at 72 sites) river systems.

These surveys are summarized by Butler (1993), and the information is

sufficient to support a status recommendation of endangered for the fat

three-ridge, shiny-rayed pocketbook, Gulf moccasinshell, Ochlockonee

moccasinshell, and oval pigtoe, and a status recommendation of

threatened for the Chipola slabshell and purple bankclimber. Common and

scientific nomenclature used in this rule follows that suggested by

Turgeon et al. (1988).

The fat three-ridge (Amblema neislerii) is a medium-sized to large,

subquadrate, inflated, solid, and heavy shelled mussel that reaches a

length of 102 millimeters (4.0 inches). Older individuals are often so

inflated that their width approximates their length. The dark brown to

black shell is strongly sculptured with seven to eight prominent

horizontal parallel ridges. Internally, there are two subequal

pseudocardinal teeth in the left valve and one large and one small

tooth in the right valve. The nacre is bluish white to light purplish

and very iridescent. The Service considers Unio neislerii to be a

synonym of Amblema neislerii.

This taxon was originally assigned to the genera Quadrula and

Crenodonta by Simpson (1914) and Clench and Turner (1956),

respectively. Subsequent investigators have placed the fat three- ridge

in the genus Amblema. The fat three-ridge was described from the Flint

River, Macon County, Georgia, and it historically occurred in the

mainstems of the lower two-thirds of the Flint, the lower one-third of

the Chipola, and in the Apalachicola rivers (Clench and Turner 1956,

Butler 1993). Since 1981, no live specimens have been found in the

Flint River. Its present range is restricted to six localities in

Florida, three each in the Apalachicola River mainstem and the

lowermost Chipola River mainstem (Butler 1993). Only two of these

localities have sizable populations, which number in the dozens of

specimens. However, the viability of these populations of the fat

three-ridge is not known. The fat three-ridge has a very low tolerance

for impoundments.

The shiny-rayed pocketbook (Lampsilis subangulata) is a medium-

sized mussel that reaches approximately 85 mm (3.3 in) in length. The

shell is subelliptical, with broad, somewhat inflated umbos and a

rounded posterior ridge. The fairly thin but solid shell is smooth and

shiny, and light yellowish brown with fairly wide bright emerald green

rays over its entire length. Older individuals appear much darker brown

with obscure raying. Internally, the pseudocardinal teeth are double

and fairly large and erect in the left valve with one large tooth and

one spatulate tooth in the right valve. The nacre is white, with some

individuals exhibiting a salmon tint in the vicinity of the umbonal

cavity. The Service recognizes Unio subangulatus and Unio kirklandianus

as synonyms of Lampsilis subangulata.

The shiny-rayed pocketbook was described from the Chattahoochee

River, Columbus, Georgia. Historically, this mussel occurred at 18

different Flint River system localities including numerous tributaries

and several mainstem sites, 1 Chattahoochee River mainstem site and 6

sites in some of its tributaries, 2 sites in an Apalachicola River

tributary (Mosquito Creek), a couple of Chipola River tributary sites

and several localities in the mainstem above Dead Lake, and several

sites in the Ochlockonee River mainstem from Talquin Reservoir upstream

to Georgia and in a couple of its tributaries (Clench and Turner 1956,

Butler 1993). The 19 populations presently known are restricted to: a

single Uchee Creek system site in the Chattahoochee River system of

Alabama, 11 scattered sites in Flint River tributaries, 2 sites in the

Chipola River system including a mainstem and tributary (Dry Creek)

site, and 5 Ochlockonee River mainstem and tributary sites in the upper

half of the system (Butler 1993). The shiny-rayed pocketbook presently

occupies about two-thirds of its original range. Population sizes

numbered in the dozens of individuals at a few historical sites in both

systems. However, recent collections are generally represented by only

a few individuals, and evidence of any production is scarce. This

riverine species does not tolerate impoundments.

The Gulf moccasinshell (Medionidus penicillatus), a small mussel,

reaches a length of about 55 mm (2.2 in), is elongate-elliptical or

rhomboidal in shape and fairly inflated, and has relatively thin

valves. The ventral margin is nearly straight or slightly rounded. The

posterior ridge is rounded to slightly angled and intersects the end of

the shell at the base line. Females tend to have the posterior point

above the ventral margin and are somewhat more inflated than males.

Sculpturing consists of a series of thin, radially-oriented plications

along the length of the posterior slope. The remainder of the shell

surface is smooth and yellowish to greenish brown with fine, typically

interrupted green rays. The left valve has two stubby pseudocardinal

and two arcuate lateral teeth and the right valve has one

pseudocardinal and one lateral tooth. Nacre color is smokey purple or

greenish and slightly iridescent at the posterior end. The Service

recognizes Unio penicillatus and Unio kingi as synonyms of Medionidus

penicillatus.

Much confusion clouds the taxonomy of Medionidus species in the

Apalachicolan Region. In the Chipola River system, van der Schalie

(1940) recorded two species of Medionidus (M. kingi and M.

penicillatus). Clench and Turner (1956) synonomized M. kingi and two

other nominate species, the Ochlockonee moccasinshell and Suwannee

moccasinshell with the Gulf moccasinshell, an arrangement also followed

by Burch (1975). Johnson (1970) erroneously reported both the Gulf

moccasinshell and Suwannee moccasinshell from the Apalachicola River

system and the Suwannee moccasinshell from the Ochlockonee and Suwannee

rivers as well. In his monograph on Medionidus, Johnson (1977)

recognized the validity of the Gulf moccasinshell, Ochlockonee

moccasinshell, and Suwannee moccasinshell from Apalachicolan Region

streams based on shell characters. Turgeon et al. (1988) also

recognized the validity of these three allopatrically distributed

mussels.

The Gulf moccasinshell was described from three sites in the

Apalachicola River system in Georgia: the Chattahoochee River near

Columbus and Atlanta, and the Flint River near Albany. The historical

distribution of this diminutive species included 18 sites in the

tributaries and mainstems of the Flint and Chattahoochee rivers, one

Apalachicola River site, and 12 sites in the Chipola River system. The

Gulf moccasinshell is known from 38 historical sites and has been

eliminated from about three-quarters of its original range. It persists

at eight tributary sites in the middle Flint River system, and in

Econfina Creek (Butler 1993) but has not been collected in the

Choctawhatchee River system since the early 1930's. Large populations

(60+ individuals) were documented at several of historical sites in the

Chipola River system (van der Schalie 1940); they probably occurred in

similar numbers at other sites as well. However, recent collections of

the Gulf moccasinshell indicate that only small populations persist

today. The Service's recent survey of the Apalachicola River system

located a total of only 10 specimens. Given the small sample sizes, the

population viability of this species is questionable. The Gulf

moccasinshell does not tolerate impoundments.

The Ochlockonee moccasinshell (Medionidus simpsonianus) is a small

species, generally under 55 mm (2.5 in) in length. It is slightly

elongate-elliptical in outline with the posterior end obtusely rounded

at the shells median line and the ventral margin broadly curved. The

posterior ridge is moderately angular and covered in its entire length

with well developed, irregular ridges. Sculpturing may also extend onto

the disk below the ridge and the surface texture is smooth. The color

is light brown to yellowish green, with dark green rays formed by a

series of connecting chevrons or undulating lines across the length of

the shell. Internal characters include thin straight lateral teeth and

compressed pseudocardinal teeth. There are two laterals and two

pseudocardinals in the left valve and one lateral and one

pseudocardinal in the right valve. The nacre is bluish white. The

Service considers Unio simpsonianus to be a synonym of Medionidus

simpsonianus.

The Ochlockonee moccasinshell was described from the Ochlockonee

River, Calvary, Grady County, Georgia. This mussel was known

historically from six sites in the mainstem above Talquin Reservoir,

three each in Georgia and Florida, and single site locations on the

lower mainstem below Talquin Reservoir and in the Little River (Johnson

1977, Butler 1993). However, since 1974, the Ochlockonee moccasinshell

has been represented by only two live individuals (both found as

individuals at a single site in the mainstem above Talquin Reservoir in

Florida in the past 5 years) despite concerted efforts by numerous

investigators to locate additional populations. Four weathered dead

shells were found at other mainstem sites in the past few years,

including two sites in Georgia and one site in Florida. Once a fairly

common species, with some populations numbering in the dozens of

individuals, the Ochlockonee moccasinshell is now one of the rarest

mussels in North America. This narrow endemic does not tolerate

impoundment conditions.

The oval pigtoe (Pleurobema pyriforme) is a small to medium-sized

mussel that attains a length of about 60 mm (2.4 in). The shell is

suboviform compressed, with a shiny smooth epidermis. The periostracum

is yellowish, chestnut, or dark brown, rayless, and with distinct

growth lines. The posterior slope is biangulate and forms a blunt point

on the posterior margin. The umbos are slightly elevated above the

hingeline. As is typical of the genus, no sexual dimorphism is

displayed in shell characters. Internally the pseudocardinal teeth are

fairly large, crenulate and double in both valves. The lateral teeth

are somewhat shortened, arcuate and double in each valve. Nacre color

varies from salmon to bluish white and is iridescent posteriorly.

Variation in this species has led to the description of various nominal

species. The Service recognizes Unio pyriforme, Unio modicus, Unio

bulbosus, Unio amabilis, Unio reclusum, Unio harperi, and Pleurobema

simpsoni as synonyms of Pleurobema pyriforme.

The oval pigtoe was described from the Chattahoochee River, near

Columbus, Georgia. Historically, this species was one of the most

widely distributed mussels endemic to the Apalachicolan Region. It

occurred throughout the mainstems and several tributaries of both the

Flint (16 sites) and Chipola (10 sites) river systems, at 5 sites in

the Chattahoochee River system including one mainstem site, all

associated with the Fall Line in Alabama and Georgia, at 6 sites in the

Ochlockonee River mainstem above Talquin Reservoir in Florida and

Georgia, at a single site on the lower Suwannee River and 15 sites in

the upper Santa Fe River system, its major tributary, in north Florida,

and at a site in Econfina Creek, in northwest Florida (Clench and

Turner 1956, Butler 1993). Fifty-four total historical sites are known.

Existing populations have been verified from 21 sites, including 5

scattered tributaries (7 sites) of the Flint River system and a single

mainstem site, 4 Chipola River sites and 1 in its tributary Dry Creek,

6 upper Ochlockonee River mainstem sites, and single sites in both the

New River in the upper Santa Fe River system, and in Econfina Creek

(Butler 1993).

Recent surveys have documented the extirpation of the oval pigtoe

from approximately two-thirds of its historical range, with no

populations persisting in Alabama. Once a species of localized

abundance (Clench and Turner 1956), oval pigtoe populations sometimes

numbered in the hundreds (van der Schalie 1940). However, recent

collections of the oval pigtoe are generally small, and rarely exceed a

dozen individuals at any one site. The Service in its recent survey

located only a single specimen from the entire Flint River mainstem. It

is not known whether existing populations are sufficient in numbers to

sustain the species. The oval pigtoe does not tolerate impoundments.

The Chipola slabshell (Elliptio chipolaensis) is a medium-sized

species reaching a length of about 85 mm (3.3 in). The shell is ovate

to subelliptical, somewhat inflated and with the posterior ridge

starting out rounded but flattening to form a prominent biangulate

margin. The shell surface is smooth and chestnut in color. Dark brown

coloration may appear in the umbonal region and the remaining surface

may exhibit alternating light and dark bands. The umbos are prominent,

well above the hingeline. Internally, the umbonal cavity is rather

deep. The lateral teeth are long, slender, and slightly curved, with

two in the left and one in the right valve. The pseudocardinal teeth

are compressed and crenulate, with two in the left and one in the right

valve. Nacre color is salmon, becoming more intense dorsally and

somewhat iridescent posteriorly. The Service considers Unio

chipolaensis to be a synonym of Elliptio chipolaensis.

The Chipola slabshell was described from the Chipola River in

Florida. Clench and Turner (1956) restricted the type locality to the

Chipola River, 1 mile north of Marianna, Jackson County, Florida. Until

recently, this species was considered endemic to the Chipola River

system, occurring in the mainstem above Dead Lake and a few of the

larger tributaries, all in Florida (van der Schalie 1940, Clench and

Turner 1956). A single record of this mussel from a tributary of the

Chattahoochee River in extreme southeastern Alabama has been verified

by Butler (1993). These localities bring the total number of historic

sites the Chipola slabshell inhabited to nine. The Chipola slabshell is

known to persist only at four Chipola River mainstem sites and in Dry

Creek, with the populations from Spring Creek (Chipola River system)

and the Chattahoochee River system apparently extirpated. The numbers

of specimens from recent collections indicate that populations are

generally small, except at one site in the lower mainstem where three

dozen specimens were recently observed (W. McCullagh, pers. comm.). The

Chipola slabshell has the most restricted range of the Apalachicolan

Region mussels. This species does not tolerate impoundments, but is

more tolerant of silt than the other species of mussels.

The purple bankclimber (Elliptoideus sloatianus) is a large, heavy

shelled, strongly sculptured mussel reaching a length of about 200 mm

(8.0 in). A well developed posterior ridge extends from the umbos to

the posterior ventral margin of the shell. The posterior slope and the

disk just anterior to the posterior ridge are sculptured by several

irregular ridges that vary greatly in development. Umbos are low,

extending just above the dorsal margin of the shell. Internally, there

is one pseudocardinal tooth in the right valve and two in the left

valve. The lateral teeth are very thick and slightly curved. Nacre

color is whitish near the center of the shell becoming deep purple

towards the margin, and very iridescent posteriorly. The Service

recognizes Unio sloatianus, Unio atromarginatus, Unio aratus, and Unio

plectophorus as synonyms of Elliptoideus sloatianus. The purple

bankclimber was described from the Chattahoochee River and its type

locality is restricted to the Chattahoochee River at Columbus, Georgia

(Clench and Turner 1956).

Historically, the purple bankclimber was found at 14 sites in the

Flint River system; 3 sites on the Chipola River mainstem (Dead Lake

vicinity); 2 sites on the Apalachicola River mainstem; the type

locality on the Chattahoochee River; and at 4 sites along the lower

two-thirds of the Ochlockonee River mainstem in Florida and Georgia

(Clench and Turner 1956, Butler 1993). A total of 24 historic sites are

known for this species.

This large mussel persists at 10 sites in the lower two-thirds of

the Flint River mainstem, at 4 sites in the Apalachicola River, and at

8 sites in the Ochlockonee River mostly above Talquin Reservoir (Butler

1993). Although the purple bankclimber is currently known from only two

fewer total sites than before, the species has nevertheless experienced

a significant reduction in its total range. No specimens in recent

years have been reported from the Chipola River and the species has not

been collected in the Chattahoochee River for several decades. In

addition, Flint River tributary populations appear to have been totally

eliminated. At a few sites in the Florida portion of the Ochlockonee

River, the purple bankclimber may number in the dozens of individuals.

This species of mussel does not tolerate impoundment conditions well.

On November 18, 1993, the Service notified (by mail; 72 letters)

Federal and State agencies, local governments, and interested

individuals that a status review was being conducted for these seven

species. A total of ten comments was received as a result of this

notification. The Florida Division Office of the Federal Highway

Administration replied that no bridge replacement projects were

currently being planned in northwest Florida, and it was anticipated

that any future bridge replacement projects would have no effect on

these species based on the localized and short-term impacts associated

with these activities. The Federal Energy Regulatory Commission

reported that it licenses 12 hydroelectric development projects in the

study area, and that any issues concerning these species could best be

coordinated with the Office of Hydropower Licensing. The Fayette County

(Georgia) Board of Commissioners expressed concern over the Service's

contention that impoundments have played a major role in the decline of

these species, but they did not oppose the listing. The Alachua County

(Florida) Environmental Protection Department, after consultation with

a Florida Museum of Natural History malacologist, indicated that none

of these seven species of mussels are known or were suspected to occur

in Alachua county. The Florida Game and Fresh Water Fish Commission

expressed concern with how its plan to dredge the mouths of several

silted-in streams along the Apalachicola River to improve access to

striped bass might have on these mussels. The Georgia Department of

Natural Resources (GDNR) had some questions concerning the distribution

of these mussels, particularly in Georgia. The Florida Natural Areas

Inventory supported the Service's listing of these species and provided

information on Econfina Creek watershed where the Gulf moccasinshell

and oval pigtoe occur. Three experts on freshwater mussels supported

the potential Federal protection of these species. No objections to the

proposed listing of these species were received.

Previous Federal Action

The purple bankclimber, oval pigtoe, shiny-rayed pocketbook, and

fat three-ridge are included as category 2 species in the Service's

notices of review for animal candidates that were published in the

Federal Register on January 6, 1989 (54 FR 554) and on November 21,

1991 (56 FR 58804). A category 2 species is one that may be in need of

listing as endangered or threatened, but for which conclusive data on

biological vulnerability and threat are not currently available to

support a proposed rule. Based on status surveys that were completed in

1993, the Service has determined that all of the species included in

this proposal now qualify as category 1 species.

Summary of Factors Affecting the Species

Section 4(a)(1) of the Endangered Species Act (16 U.S.C. 1531 et

seq.) 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 fat three-ridge (Amblema neislerii), shiny-rayed pocketbook

(Lampsilis subangulata), Gulf moccasinshell (Medionidus penicillis),

Ochlockonee moccasinshell (Medionidus simpsonianus), oval pigtoe

(Pleurobema pyriforme), Chipola slabshell (Elliptio chipolaensis), and

purple bankclimber (Elliptoideus sloatianus) are as follows:

A. The Present or Threatened Destruction, Modification, or Curtailment

of Its Habitat or Range

These species of mussels are endemic to the eastern Gulf Slope

streams draining the Apalachicolan Region of southeast Alabama,

southwest Georgia and north Florida. They are currently found in

localized portions of from one to four isolated marine river systems,

mostly in the eastern portion of the Apalachicolan Region. These

species have been rendered vulnerable to extinction by the significant

loss of habitat within their restricted ranges in Apalachicolan Region

streams. Factors contributing to this habitat loss are: impoundments

and deteriorating water and benthic habitat quality resulting from

channel modification, siltation, agricultural runoff from crop

monoculture and poultry farms, silvicultural activities, mining

activities, pollutants, poor land use practices, increased

urbanization, and municipal and industrial waste discharges.

A consideration of the effects of these impacts upon fishes is of

critical importance in evaluating the well-being of mussels. Mussels

and fishes are inextricably linked ecologically; most larval mussels

(glochidia) are obligate parasites of specific fishes. Therefore, these

various impacts may have resulted in the elimination of certain fishes

that serve as potential host species for these mussels.

Impoundments have altered a significant portion of the free-flowing

big river habitats of the Apalachicola and Ochlockonee river systems in

which most of these species occur. Stream habitat is destroyed by the

conversion of free-flowing streams to man-made lakes and ponds. In

addition to riverine habitat destruction, dams block the passage of

certain migratory fishes which serve as hosts for one or more of these

seven mussel species. None of these seven mussel species are known to

reproduce in impoundments.

The Apalachicola River system has been especially impacted by the

construction of numerous mainstem dams. This is true for the

Chattahoochee River, which has nine major dams and four locks and dams

along its lower mainstem to facilitate barge traffic. Additional major

dams are located on the Flint River mainstem (e.g., Blackshear

Reservoir) and on the Apalachicola River where it is formed by the

confluence of the Chattahoochee and Flint Rivers (Seminole Reservoir).

Smaller dams are located on major rivers and tributaries throughout the

Apalachicola River system and in other regional streams. Although pre-

impoundment records are generally unknown for the fat three-ridge,

shiny-rayed pocketbook, Gulf moccasinshell, oval pigtoe, and purple

bankclimber in the Apalachicola River system, numerous populations of

these species were possibly destroyed as a result of impoundments. It

has been decades since any live specimens of these five species were

found along the Chattahoochee River mainstem; the type locality for the

shiny-rayed pocketbook, Gulf moccasinshell, oval pigtoe, and purple

bankclimber.

Talquin Reservoir, an impoundment on the Ochlockonee River formed

by the closure of Jackson Bluff Dam, inundated a significant reach of

the middle portion of the river mainstem. Pre-impoundment records for

the shiny-rayed pocketbook, Ochlockonee moccasinshell, oval pigtoe, and

purple bankclimber from a site at the upstream end of Talquin Reservoir

exist in museum collections. Most of these mussel species once had

sizable populations at this site. Undocumented populations of these

four species were probably destroyed by the filling of Talquin

Reservoir.

In addition to riverine habitat being destroyed by Talquin

Reservoir, the river downstream of Jackson Bluff Dam shows noticeable

signs of being impacted by sediment deposition. Riverine mussels such

as the shiny-rayed pocketbook, Ochlockonee moccasinshell, oval pigtoe,

and purple bankclimber, are nearly absent in sizable stretches of this

heavily silted river. One site recently sampled by the Service (with

SCUBA gear) had deposits of detritus and silt sediments. The river

lacked flows adequate to flush the channel of silty sediments.

Potential lower mainstem channel habitat of the shiny-rayed pocketbook,

Ochlockonee moccasinshell, oval pigtoe, and purple bankclimber are

being impacted by this deposition.

Navigation channel maintenance in the Chattahoochee and

Apalachicola Rivers has destroyed long stretches of benthic habitat. In

addition to the damage caused by the mechanical removal of tons of

substrate, these activities increase sedimentation in downstream areas

by resuspending silt fines which smother benthic organisms. Dredging

activities may also resuspend contaminants that are bound to sediments,

thus potentially exposing aquatic organisms to released toxicants.

Potential host fishes for the fat three-ridge and purple bankclimber in

the Apalachicola River may also be disrupted by channel modifications.

Maintenance operations in the Apalachicola River mainstem continue to

disrupt habitat for these two species. A third mussel, the Gulf

moccasinshell, has apparently been extirpated from the Apalachicola

River.

Gravel mining operations have been observed in various portions of

the Apalachicolan Region. Primary stream impacts associated with gravel

mining include stream channel modifications (alterations of habitat,

flow patterns, and sediment transport), water quality modifications,

aquatic invertebrate population changes and changes in fish populations

(alteration and elimination of spawning and nursery habitats, and food

web disruptions) (Kanehl and Lyons 1992). Channel degradation caused by

gravel mining has been implicated in the destruction of mussel

populations (Hartfield 1993, Grace and Buchanan 1981). In a study by

Grace and Buchanan (1981), mussels were still absent from an in-stream

dredged area 15 years after mining took place. Siltation is

particularly increased during the mining of in-stream gravel and/or

during the washing of gravel which rinses silt and debris back into the

stream. Gravel from the Chattahoochee River is used for various

purposes including landscaping throughout the region. Jenkinson (1973)

recorded the shiny-rayed pocketbook, oval pigtoe, Gulf moccasinshell,

and 10 other mussel species in Little Uchee Creek (Chattahoochee River

system) in Alabama. The creek now has active in-stream gravel mines;

only a few shell fragments were found during a recent survey by the

Service.

Municipal and industrial pollutants are widespread in Apalachicolan

Region streams. Many municipal waste water treatment plants provide

only secondary treatment of waste water and three plants discharging

wastes into the New River (Suwannee River system) threaten that

stream's population of the oval pigtoe. From 1955 to 1977, an estimated

950,000,000 gallons of chemical-laden solutions were discharged into

the Flint River from a Department of Defense facility in Albany,

Georgia (P. Laumeyer, Service, pers. comm.). Service biologists

surveyed a stretch of the Flint River where dozens of purple

bankclimbers had been killed by an unknown pollutant. Hundreds of round

washboards (Megalonaias boykiniana) were found dead in the upper Flint

River (C. Coney, Los Angeles County Museum, pers. comm.) and various

beds of dead mussels (species unknown) were observed in the Suwannee

River (L. Parker, Service, pers. comm.). A battery plant operation

threatens water quality in the Chipola River system, which harbors

populations of the fat three-ridge, shiny-rayed pocketbook, oval

pigtoe, and Chipola slabshell.

Various agricultural practices conducted in the Apalachicolan

Region have contributed to stream and habitat degradation. A Soil

Conservation Service (1993) study of a small agricultural watershed

area in the middle Flint River system reported an average of 35.44

metric tons per hectare per year (15.8 tons per acre per year) of

sediment loading into area waters; 97% of the total sedimentation in

the watershed was generated from agricultural runoff. Agricultural

runoff, in the form of organophosphate or carbamate pesticides, has

been implicated in the die-off of populations of freshwater mussels (J.

Fleming, National Biological Survey, unpub. data). The poultry industry

is expanding operations into the Apalachicolan Region, particularly in

the watersheds of the upper Apalachicola River system. Runoff from

chicken farms causes oxygen depletion in streams and has been

implicated in fish and mussel die-offs in Alabama (U.S. Fish and

Wildlife Service 1993). Feedlots are also another source of pollution

in localized portions of the region's streams. Large dairy farms

located in the Suwannee River watershed also contribute to the

pollution of this system's waters.

Erosion from poor land use practices causes extensive loss of

topsoil and the subsequent siltation of stream bottoms. Sources of

siltation include timber clearcutting and other silvicultural

activities, clearing of riparian vegetation for agricultural purposes,

and those construction and mining practices that allow exposed earth to

enter streams. Light to moderate levels of siltation are common in many

of the streams in the Apalachicolan Region that still have populations

of these seven mussel species. Heavily silted streams were observed by

Service biologists in numerous tributaries of the Chattahoochee and

upper Flint Rivers, particularly those draining the Piedmont

Physiographic Province, which is well known for its highly erodible

soils. Stream banks devoid of riparian vegetation commonly slough-off

into stream channels. Several clear-cuts have been observed in

watersheds of the middle Apalachicola River system, some with

inadequate riparian buffer strips (J. Brim-Box, Service, pers. comm.).

A disregard for maintaining riparian buffers during silvicultural

activities threaten streams throughout the Apalachicolan Region.

Continued siltation and sedimentation of these streams may result in a

depauperate fish fauna, reducing populations at many sites to those

dominated by species tolerant of degraded habitats. The negative

effects of silt on benthic fishes were summarized by Burkhead and

Jenkins (1991). Siltation reduces habitat heterogeneity and increases

fish egg and larval mortality, abrades organisms, and alters

macrobenthic communities.

The health of these seven mussel species is directly tied to

benthic habitat quality. The effects of siltation on freshwater mussels

is more devastating than on fishes due to the sedentary nature of

mussels. Ellis (1936) conducted experiments on the effects of silt on

mussels and determined that most mussels tested died from silt deposits

of one quarter to one inch. Silt also transfers organic substances into

streams, adversely affecting stream habitat and water quality by

producing increased and localized enrichment impacts (Ellis 1936).

Artifact and fossil collectors regularly work streams in various

portions of the Apalachicolan Region and have been known to use suction

dredges to scour benthic habitats, thus increasing siltation

downstream. A study on the effects of suction gold dredging on stream

invertebrates (Harvey 1986) concluded that impacts from these

activities are more severe in streams with soft substrates, which are

typical for most Apalachicolan Region streams where these mussels

occur.

Much non-agricultural and non-silvicultural habitat degradation in

the upper Apalachicola River system watershed is attributed to

increased urbanization, particularly in the metropolitan areas of

Atlanta, Columbus, and Albany. This current high rate of development is

resulting in the conversion of farmland in areas relatively remote from

these cities. Associated with increased development and land clearing

is increased siltation from erosion, accelerated runoff and transport

of pollutants in stormwater, and increased discharge of effluents.

The tributaries harboring populations of these seven mussel species

are criss-crossed by numerous road and railroad bridges. These

crossings are potential sites for accidental spills of toxic materials

into streams. The large number of bridge crossings in the Apalachicolan

Region makes it probable that such a spill might occur in the future.

B. Overutilization for Commercial, Recreational, Scientific, or

Educational Purposes.

The fat three-ridge is a potential target species for the cultured

pearl industry. Currently a congener (the three-ridge, Amblema plicata)

is heavily utilized as a source of shell for pearl nuclei in more

northern rivers. Due to a tremendous increase in the price of shell,

the harvesting of shell beds has resulted in the scouting of larger

drainages in the Apalachicolan Region for potential sources of shell.

Although prices have decreased since 1992, future increases in shell

price and competition for harvestable populations can not be ruled out.

Biological supply companies have utilized the Flint and Ochlockonee

rivers as sources for larger mussel specimens, including the purple

bankclimber and possibly the fat three-ridge, to sell to academic

institutions for use in laboratory studies. Supply company

representatives have contacted Service biologists in hopes of obtaining

information on new, unexploited mussel populations in the Apalachicolan

Region. On one recent occasion, approximately 10,000 large mussel

specimens, presumably including the purple bankclimber and possibly the

fat three-ridge, were harvested from the Flint River near Bainbridge

for this purpose (J. Brim-Box, pers. comm.). Some of these species are

a potential source of raw material for the polished chip industry.

Costume jewelry crafted from purple bankclimber shells has been

observed in arts and crafts fairs in the Southeast. Unregulated harvest

of the fat three-ridge and purple bankclimber for these purposes, if

unchecked, could decimate their remaining populations. Small and/or

thin-shelled mussel species, such as the other five mussels considered

here, are not known to be utilized commercially.

There are a large number of shell clubs in Florida and surrounding

States. Both national and international meetings for amateur and

professional malacologists are held in this area, and generally include

organized field collecting trips to a variety of habitats. The

attraction of large numbers of people interested in the study and

collection of mollusks increases the potential for overcollection of

these mussels. These species, particularly the larger ones, are

potential bait species, and are susceptible to harvesting especially

during low-flow periods. Publication of this rule will inform the

general public as to the presence of these seven mussels in

Apalachicolan Region streams. The rarity of these mussels potentially

makes them more appealing to shell collectors. Thus, revealing specific

stream reaches harboring these species could pose a threat from such

collectors. Federal protection would serve to minimize adverse

population impacts from illegal take.

C. Disease or Predation.

Although diseases of freshwater mussels are virtually unknown, the

periodic dieoff of mussel populations in several primarily midwestern

rivers in recent years may be due to unidentified diseases. Juvenile

and adult mussels serve as prey for various animals, and the muskrat

has been implicated in jeopardizing recovery of listed mussels (Neves

and Odum 1989). Muskrats do not occur with regularity on Coastal Plain

streams, where most of these mussels exist. However, Piedmont

populations of the shiny-rayed pocketbook and oval pigtoe in the upper

Flint River system may be subjected to some degree of muskrat

predation.

D. The Inadequacy of Existing Regulatory Mechanisms

A scientific collecting permit is required by the State of Georgia

to collect mussels for scientific purposes. However, dredging,

brailling, or any form of mechanical harvest of mussels is illegal. In

addition, a size limit has been placed on mussels harvested

commercially in Georgia. Handpicking mussels requires only a resident

or non-resident fishing license. In the State of Florida an individual

must purchase a fishing license to collect mussels. Despite these

permit requirements, there are no restrictions on the seasonality or

sites of harvest, quantity, or species of mussels collected in Florida

or Georgia. Alabama has recently imposed a set of guidelines concerning

commercial harvest of mussels, including species-specific size limits,

restricted areas for harvest, and closed seasons. Existing authorities

available to protect aquatic systems, such as the Clean Water Act,

administered by the Environmental Protection Agency (EPA) and the Army

Corps of Engineers, have not been fully utilized and may have led to

the degradation of aquatic environments in the Southeast Region, thus

resulting in a decline of aquatic species. If these seven species are

listed under the Act, it would provide protection under section 9 of

the Act by prohibiting the take of these species except under Federal

permit. Further, listing will require consultation with the EPA in

relationship to water quality criteria, standards, and National

Pollution Discharge Elimination System permits under the Clean Water

Act, and implementation of actions to recover the species.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

The range of these seven mussel species has been fragmented, and

significant portions of the Apalachicola and Ochlockonee river systems

have been permanently altered by various reservoirs. Many of the

streams these species inhabit exhibit moderate to heavy degradation

from poor land use practices. These factors have caused local

extirpation and fragmentation of most of these species' populations. It

is not known how many populations of these seven species are viable,

but few juveniles have been observed in recent years. The restricted

distribution of these seven mussels makes them vulnerable to

extirpation from catastrophic events, such as toxic chemical spills.

The introduced Asian clam (Corbicula fluminea) has invaded nearly

all of the river systems in which these mussels occur, competing with

native mussels for nutrients and space. Densities of Asian clams are

sometimes heavy in Apalachicolan Region streams, with estimates running

from approximately one hundred per square meter (Flint River, Sickel

1973) to thousands per square meter (Santa Fe River, Bass and Hitt

1974). In some streams the substrate has changed from one of a fairly

homogeneous silty sand or sand to one with a gravel-like composition

comprised of huge numbers of live and dead Asian clam shells. In some

of these streams, the Gulf moccasinshell and Ochlockonee moccasinshell

were once common but are now extirpated or severely reduced in numbers.

This exotic species may be particularly competitive with small native

mussels such as the diminutive moccasinshells.

In developing this rule, the Service has assessed the best

scientific and commercial information available regarding the past,

present, and future threats faced by these seven mussels. Based upon

these evaluations, the preferred action is to list the fat three-ridge,

shiny-rayed pocketbook, oval pigtoe, Gulf moccasinshell, and

Ochlockonee moccasinshell as endangered and the Chipola slabshell and

purple bankclimber as threatened. These seven mussel species are

endemic to the Apalachicolan Region in southeast Alabama, southwest

Georgia, and north Florida, where they occur in from one to four

isolated marine river systems. The fat three-ridge, Chipola slabshell,

and Ochlockonee moccasinshell are endemic to single drainages, the

former two species to the Apalachicola and the latter species to the

Ochlockonee river systems. The shiny-rayed pocketbook and purple

bankclimber are restricted to both the Apalachicola and Ochlockonee

river systems, while the oval pigtoe is found in these two rivers in

addition to the Suwannee River and Econfina Creek systems. The Gulf

moccasinshell is now restricted to the Apalachicola River system and

Econfina Creek.

These species have been rendered vulnerable to extinction by

significant loss of habitat and severe range restriction. The

restricted distribution of these seven species also makes localized

populations susceptible to catastrophic events and increased pressures

from take.

Critical Habitat

Section 4(a)(3) of the Act, as amended, and implementing

regulations (50 CFR 424.12) require 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. The Service

finds that designation of critical habitat is not prudent for these

species. 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 human activity, and 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.

Such a determination would result in no known benefit to these species,

and designation of critical habitat could further increase the threat

of collecting or vandalism.

Regulations promulgated for implementing section 7 provide for both

a jeopardy standard, based on listing alone, and for a destruction or

adverse modification standard, in cases where critical habitat has been

designated. The fat three-ridge, shiny-rayed pocketbook, Gulf

moccasinshell, Ochlockonee moccasinshell, oval pigtoe, Chipola

slabshell, and purple bankclimber occupy very restricted stream

reaches. Any significant adverse modification or destruction of their

habitat would likely jeopardize their continued existence. Therefore,

no additional protection for the species would accrue from critical

habitat designation that would not also accrue from listing these

species. If these are listed, the Service believes that protection of

their habitat can be accomplished through the section 7 jeopardy

standard, and through section 9 prohibitions against take.

The publication of critical habitat maps in the Federal Register

and local newspapers and other publicity accompanying critical habitat

designation could increase the harvest or collection threat and also

increase the potential for vandalism during the critical habitat

designation process.

Available Conservation Measures

Conservation measures provided to species listed as endangered or

threatened under the Endangered Species 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 involvement is expected to include the EPA through the

Clean Water Act's provisions for pesticide registration and waste

management actions. The Corps of Engineers will consider these species

in project planning and operation, and during the permit review

process. The Federal Energy Regulatory Commission will consider these

species prior to the relicensing of hydropower dams. The Federal

Highway Administration will consider impacts of federally funded bridge

and road construction projects when known habitat may be impacted.

Continuing development within the Apalachicolan Region may involve the

Farmers Home Administration and their loan programs. The Soil

Conservation Service will consider the species during project planning

and under their farmer's assistance programs. The Forest Service will

consider downstream impacts to habitat of the fat three-ridge and

purple bankclimber when planning or implementing silvicultural,

recreational, or other programs in lands adjacent the lower mainstem of

the Apalachicola River, and to habitat of the purple bankclimber when

planning or implementing these activities in lands adjacent the lower

mainstem of the Ochlockonee River, both drainages are in the

Apalachicola National Forest.

The Act and 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 and threatened wildlife. These prohibitions, in part, make

it illegal for any person subject to jurisdiction of the United States

to take (includes harass, harm, pursue, hunt, shoot, wound, kill, trap,

or collect; or 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 such 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,

17.23, and 17.32. 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 purpose

of the Act.

In some instances, permits may be issued for a specified time to

relieve undue economic hardship that would be suffered if such relief

were not available. However, since none of the species in this proposal

are currently in active trade, no such permits are expected.

Public Comments Solicited

The Service intends that any final action resulting from these

proposals 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 these proposed rules are hereby solicited. Comments

particularly are sought concerning:

(1) Biological, commercial trade, or other relevant data concerning

any threat (or lack thereof) to the species;

(2) The location of any additional populations of the 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 the species; and

(4) Current or planned activities in the subject areas and their

possible impacts on the 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 communication may lead to final regulations

that differ from this proposal.

The Act provides for a public hearing on this proposal, if

requested. Requests must be received within 45 days of the date of

publication of this proposal. Such requests must be made in writing and

should be 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 Endangered

Species Act of 1973, as amended. A notice outlining the Service's

reasons for this determination was published in the Federal Register on

October 25, 1983 (48 FR 49244).

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 Robert S. Butler, U.S.

Fish and Wildlife Service, Jacksonville Field Office, 6620 Southpoint

Drive South, Suite 310, Jacksonville, Florida 32216 (904/232-2580).

List of Subjects in 50 CFR Part 17

Endangered and threatened species, Exports, Imports, Reporting and

recordkeeping requirements, and Transportation.

Proposed Regulation Promulgation

PART 17--[AMENDED]

Accordingly, the Service hereby proposes to amend part 17,

subchapter B, chapter I, title 50 of the Code of Federal Regulations,

as set forth below:

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 ``CLAMS'', to the List of Endangered and

Threatened Wildlife:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *

(h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

Species Vertebrate population

--------------------------------------------------- Historic range where endangered or Status When listed Critical Special

Common name Scientific name threatened habitat rules

--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *

Clams

* * * * * * *

Bankclimber, purple..... Elliptoideus sloatianus. U.S.A. (AL, FL, GA)..... NA..................... T ........... NA NA

* * * * * * *

Moccasinshell, Gulf..... Medionidus pencillatus.. U.S.A. (AL, FL, GA)..... NA..................... E ........... NA NA

Moccasinshell, Medionidus simpsonianus. U.S.A. (FL, GA)......... NA..................... E ........... NA NA

Ochlockonee.

* * * * * * *

Pigtoe, oval............ Pleurobema pyriforme.... U.S.A. (AL, FL, GA)..... NA..................... E ........... NA NA

* * * * * * *

Pocketbook, shiny-rayed. Lampsilis subangulata... U.S.A. (AL, FL, GA)..... NA..................... E ........... NA NA

* * * * * * *

Slabshell, Chipola...... Elliptio chipolaensis... U.S.A. (AL, FL)......... NA..................... T ........... NA NA

* * * * * * *

Three-ridge, fat........ Amblema neislerii....... U.S.A. (FL, GA)......... NA..................... E ........... NA NA

* * * * * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

Dated: July 19, 1994

Mollie H. Beattie

Director, Fish and Wildlife Service.

[FR Doc. 94-18923 Filed 8-2-94; 8:45 am]

BILLING CODE 4310-55-P