Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for Five Freshwater Mussels and Threatened Status for Two Freshwater Mussels From the 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; Determination of

Endangered Status for Five Freshwater Mussels and Threatened Status for

Two Freshwater Mussels From the Eastern Gulf Slope Drainages of

Alabama, Florida, and Georgia

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: The Fish and Wildlife Service (Service) determines five

freshwater mussels, the fat threeridge (Amblema neislerii), shinyrayed

pocketbook (Lampsilis subangulata), Gulf moccasinshell (Medionidus

penicillatus), Ochlockonee moccasinshell (Medionidus simpsonianus), and

oval pigtoe (Pleurobema pyriforme) to be endangered species, and two

freshwater mussels, the Chipola slabshell (Elliptio chipolaensis) and

purple bankclimber (Elliptoideus sloatianus) to be threatened species

under the Endangered Species Act of 1973, as amended (Act). These

mussels are endemic to eastern Gulf Slope streams draining the

Apalachicolan Region of southeast Alabama, southwest Georgia, and north

Florida. Their center of distribution is the Apalachicola-

Chattahoochee-Flint (ACF) River basin of southeast Alabama, southwest

Georgia, and northwest Florida, and the Ochlockonee River system of

southwest Georgia and northwest Florida. They are currently known from

restricted portions of from one to four independent river systems.

These species inhabit stable sandy and gravelly substrates in medium-

sized streams to large rivers, often in areas swept free of silt by the

current. The abundance and distribution of the seven mussel species

decreased historically from habitat loss associated with reservoir

construction, channel construction and maintenance, and

[[Page 12665]]

erosion. These habitat changes have resulted in significant

extirpations (localized loss of populations), restricted and fragmented

distributions, and poor recruitment of young.

DATES: Effective: April 15, 1998.

ADDRESSES: The complete administrative file for this rule is available

for inspection, by appointment, during normal business hours at the

U.S. Fish and Wildlife Service, Jacksonville Field Office, 6620

Southpoint Drive South, Suite 310, Jacksonville, Florida 32216.

FOR FURTHER INFORMATION CONTACT: Dr. Michael M. Bentzien at the above

address, or 904/232-2580, ext. 106.

SUPPLEMENTARY INFORMATION:

Background

Introduction

The fat threeridge, shinyrayed pocketbook, Gulf moccasinshell,

Ochlockonee moccasinshell, oval pigtoe, Chipola slabshell, and purple

bankclimber are freshwater mussels of the family Unionidae found only

in eastern Gulf Slope streams draining the Apalachicolan Region,

defined as streams from the Escambia to the Suwannee river systems, and

occurring in southeast Alabama, southwest Georgia, and north Florida

(Butler 1989). The Apalachicolan Region is known for its high level of

endemicity, harboring approximately 30 species of endemic (found only

in the region) mussels (Butler 1989). The Region drains primarily the

Coastal Plain Physiographic Province. Only the headwaters of the Flint

and Chattahoochee rivers, in the Apalachicola-Chattahoochee-Flint (ACF)

River system, occur above the Fall Line in the Piedmont Physiographic

Province in west-central Georgia.

The decline of some of the species included in this rule was

evident decades ago. The fat threeridge, oval pigtoe, Chipola

slabshell, and purple bankclimber were considered rare, but locally

abundant, in the 1950's (Clench and Turner 1956). The Gulf

moccasinshell, oval pigtoe, and purple bankclimber were recognized in a

list of rare species in 1970 (Athearn 1970), and the fat threeridge was

added to the list of regionally rare mussels a year later (Stansbery

1971a).

General Biology

Freshwater mussel adults are filter-feeders, positioning themselves

in substrates to facilitate siphoning of the water column for oxygen

and food (Kraemer 1979). Their food includes primarily detritus,

plankton, and other microorganisms (Fuller 1974).

As a group, freshwater mussels are extremely long-lived, with life

spans of up to 130 years for certain species (Neves and Moyer 1988,

Bauer 1992). Life spans of these seven species are unknown. Based on

the longevity of a congener of the fat threeridge (the threeridge

[Amblema plicata]; Stansbery 1971b), the longevity of thick-shelled

species (Stansbery 1961), and the large size attained by the fat

threeridge and purple bankclimber (see ``Species Accounts'' in this

section), the latter two species probably have long lifespans.

Freshwater mussels generally have separate sexes. The age of sexual

maturity is variable (Gordon and Layzer 1989), usually requiring from

three (Zale and Neves 1982) to nine (Smith 1979) years, and may be sex

dependent (Smith 1979). Males expel sperm into the water column, while

females draw in the sperm with the in-current water flow (Gordon and

Layzer 1989). Spawning appears to be temperature dependent (Zale and

Neves 1982, Bruenderman and Neves 1993), but may also be influenced by

stream flow (Hove and Neves 1994). Fertilization rates are dependent on

spatial aggregation of reproductive adults (Downing et al. 1993).

Fertilization takes place inside the shell; the fertilized eggs develop

into larvae called glochidia. After an incubation period, mature

glochidia are expelled into the water column and must come into contact

with specific species of fish whose gills and fins they temporarily

parasitize (Gordon and Layzer 1989).

The shinyrayed pocketbook utilizes largemouth bass (Micropterus

salmoides) and spotted bass (M. punctulatus) as primary host fishes.

The latter species appears to have been introduced into the ACF River

system (Lee et al. 1980). The Gulf moccasinshell utilizes the brown

darter (Etheostoma edwini) and blackbanded darter (E. nigrofasciata);

the sailfin shiner (Pteronotropis hypselopterus) serves as the host

fish for the oval pigtoe (O'Brien 1996). Glochidia for the purple

bankclimber transformed on mosquitofish (Gambusia holbrooki) and

blackbanded darter, but these species were not considered by O'Brien

(1996) to be the primary hosts for this mussel.

Host fishes for the fat threeridge, Ochlockonee moccasinshell, and

Chipola slabshell are unknown. The lampsiline Ochlockonee moccasinshell

probably uses darters as host fish, as does its congeners, the Alabama

moccasinshell (Medionidus acutissimus) (W.R. Haag, U.S. Forest Service,

pers. comm.), Cumberland moccasinshell (M. conradicus) (Zale and Neves

1982), and Gulf moccasinshell (O'Brien 1996). Several host fish

families have been identified for the threeridge, a congener of the fat

threeridge, and include eight species of centrarchids (the sunfish

family) (Fuller 1974, Hoggarth 1992). Centrarchids have also been

determined to be fish hosts for species of Elliptio (Fuller 1974,

Hoggarth 1992), and may also serve as host for the Chipola slabshell

and possibly the purple bankclimber, which, genetically, is very

similar to Elliptio spp. (M. Mulvey, Savannah River Ecology Laboratory,

pers. comm.). Minnows (Cyprinidae) may serve as hosts for the fat

threeridge and Chipola slabshell.

The complex life cycle of mussels increases the probability that

weak links in their life history will preclude successful reproduction

and recruitment (Neves 1993). Egg formation and fertilization are

critical phases in the life history; mussels may fail to form eggs

(Downing et al. 1989), or have incomplete fertilization (Matteson

1948). Fertilization success has been shown to be strongly correlated

with spatial aggregation, which either influences the rate of egg

formation, improves fertilization rates of individuals, or both

(Downing et al. 1993).

Status Survey

These seven mussels were considered to be potential candidates for

listing in 1989 (see Previous Federal Actions section). The Service

requested its former National Fisheries Research Center (now the

Florida-Caribbean Science Center of Biological Resources Division of

the U.S. Geological Survey (USGS), subsequently referred to as

``Center'') in Gainesville, Florida, to survey these species in 1991.

The Center surveyed for mussels in both the ACF (324 sites) and

Ochlockonee (77 sites) river systems from 1991 to 1993. Information

gathered during the status survey was summarized by Butler (1993).

Three criteria were used to select status survey sampling sites--(1) to

obtain a thorough and even coverage of the basins, (2) to survey sites

where, based on suitable habitat, there was a maximum chance of finding

one or more of the target species; and (3) to resurvey as many of the

historical sites as possible. The survey was designed to estimate

species distributions and population status, not to determine all

existing populations.

Numerous sites were surveyed in every major river in these

watersheds. Every major tributary was also sampled, and generally at

least one sample was taken on other sizable tributaries in these river

systems. A total of 183

[[Page 12666]]

mainstem, 189 tributary, and 39 reservoir sites were sampled in the ACF

and Ochlockonee River systems. Additional sites were collected in the

Santa Fe River system (Suwannee River system; three sites) and in

Econfina Creek (Bay County, Florida; six sites). Highway bridge

crossings and boat ramps were often used to provide direct access to

sampling sites and to sections of river to be sampled by boat.

The survey technique generally used was hand-picking or grubbing,

which involves a methodical search of the substrate for siphons or

partially exposed specimens, trails, or other signs. Low-visibility

conditions require crawling or lying down on the bottom, and feeling

for shells by running fingers through the substrate. SCUBA and/or

snorkeling were used at about two-thirds of the study sites,

supplemented by hand-picking in shallow water at most sites. Over 95

percent of the collection sites were sampled by four or more people,

spending an average of two hours total effort per sampling site. All

habitat types at each site were sampled for mussels, but efforts

focused on habitats likely to support the target species.

The Center surveyed 150 to 250 meters (m) (492 to 820 feet (ft)) of

a stream reach at most sites. A primary goal was to collect at each

site until there was a high probability that all species occurring

there were found. Small streams were surveyed from bank to bank and

were sampled for longer linear distances than large rivers. Shoals with

high habitat complexity were surveyed more intensively and over longer

distances than slackwater sites with little variation in substrate.

Sites where mussels were uncommon or where only a few common species

were present were sampled for a shorter time and distance. Information

important for establishing baseline mussel population status at each

site was recorded either in the field or during laboratory analyses,

including stream characteristics (e.g., width, depth, water clarity,

substrate), species present, number of live and dead specimens per

species, length of each live mussel, reproductive condition of female

specimens, and condition of dead shells. Most of these specimens were

retained for voucher material, and temporarily stored at the Center in

Gainesville, Florida. After studies unrelated to the status survey are

conducted, the material will be donated to the mollusk collection of an

appropriate museum for curation.

Over 2,300 historical records for mussels in the ACF and

Ochlockonee River systems were also gathered from eight United States

museums with significant mussel holdings. For the purposes of the

survey, a historical collection was any collection made prior to the

status survey (before 1991). Of 300 known historical sites for all

mussel species from the ACF and Ochlockonee River systems, 250 are

identifiable to a specific locality, and 108 harbored one or more of

the seven species. Of the 108 sites with at least one of the species,

100 were in the ACF River system and eight in the Ochlockonee River

system. The ACF River system historical sites include the following--

Flint River system--39 sites, Chipola River system--31 sites,

Chattahoochee River system--20 sites, and Apalachicola River system--10

sites. Additional information on historical mussel populations was

gathered from the scientific literature, unpublished technical reports,

and field records and notes of various collectors.

Previously unknown sites of occurrence for most of the species were

discovered during the status survey in the ACF and Ochlockonee River

systems. The Service believes that historic populations of these

mussels occupied most or all available habitat, and that habitat for

all seven species has declined. The newly discovered sites, therefore,

represent previously unsampled sites. This accounts for the purple

bankclimber being located at more sites during the status survey than

it was known from historically (see ``Species Accounts'' below in this

section). Since mussels are long-lived, these recently discovered

populations have probably existed for at least the past century, as

only a few generations would have elapsed from that time until the

present.

Species Accounts

Fat Threeridge--Amblema Neisleri (Lea, 1858)

The fat threeridge is a medium-sized to large, subquadrate,

inflated, solid, and heavy shelled mussel that reaches a length of 102

millimeters (mm) (4.0 inches (in)). Older, larger individuals are so

inflated that their width approximates their height. The umbos are in

the anterior quarter of the shell. 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 typically 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 Lea, 1858 to be a synonym of

Amblema neislerii. This taxon was incorrectly assigned to the genera

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

respectively. Subsequent investigators (e.g., Turgeon et al. 1988) have

correctly placed the fat threeridge in the genus Amblema.

The fat threeridge was described from the Flint River, Macon

County, Georgia. This species, endemic to the ACF River system,

historically occurred in the mainstems of the Flint, Apalachicola, and

lower Chipola rivers (Clench and Turner 1956, Butler 1993). Clench and

Turner (1956) indicated that this species was generally rare, but

locally abundant. In the Chipola River system, van der Schalie (1940)

reported 17 specimens from two sites (average of 8.5 per site). Clench

and Turner (1956) documented ten to 15 mussels per m (0.9 to 1.4

mussels per ft) square over a 200 m (656 ft) stretch of Dead Lake

(Chipola River) shoreline.

For the status survey, 86 sites were sampled within the historical

range of the fat threeridge, including eight of the 12 (67 percent)

known historical sites. The fat threeridge was found at six of the 86

(7 percent) sampled sites, three each on the Apalachicola and lower

Chipola rivers. Only one of the eight (13 percent) historical sites

still had live individuals. An average of 6.4 live individuals were

found per site.

No live fat threeridge mussels have been found since 1981 in the

Flint River; the species is apparently extirpated from Georgia.

Apparently common in Dead Lake in 1967 (H.G. Lee, amateur malacologist,

pers. comm.), this species was not found live there in 1974 (W.H.

McCullagh, amateur malacologist, pers. comm.), nor during the status

survey.

The smallest live fat threeridge found during the survey was 43 mm

(1.7 in) long. Richardson and Yokley (1996) found evidence of juvenile

fat threeridge at a site in the lower Apalachicola River thought to

have the best extant population of this species (J. Brim Box, USGS,

pers. comm.), where it was the second most common mussel species

encountered. Three fat threeridges under 50 mm (2.0 in) in length were

found employing total substratum removal from six 0.25 m (2.7 ft)

square quadrats. Richardson and Yokley (1996) stated that the smallest

specimens had fewer than the five presumed annual growth rings that

might be indicative of juveniles. A fresh dead individual measured 24

mm (0.9 in) in length and had two to three growth rings. In 1996, three

live specimens ranging from 40 to 50 mm (1.6 to 2.0 in) in length were

located in the same bed (C.A. O'Brien, USGS, pers. comm.). These data

[[Page 12667]]

indicate that the fat threeridge is experiencing limited recruitment at

the site representing its best known population.

Shinyrayed Pocketbook--Lampsilis Subangulata (Lea, 1840)

The shinyrayed pocketbook is a medium-sized species 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

shell is fairly thin but solid. The surface is smooth and shiny, light

yellowish brown with fairly wide, bright emerald green rays over the

entire length of the shell. Older individuals may appear much darker

brown with obscure raying. Female specimens are more inflated

postbasally, whereas males appear to be more pointed posteriorly.

Internally, the pseudocardinal teeth are double and fairly large and

erect in the left valve, and 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 Lea, 1840 and Unio kirklandianus Wright,

1897 as synonyms of Lampsilis subangulata.

The shinyrayed pocketbook was described from the Chattahoochee

River, Columbus, Georgia. Historically, this mussel occurred in

mainstems and tributaries throughout the ACF River system, and in

larger streams of the Ochlockonee River system (Clench and Turner 1956,

Butler 1993). Van der Schalie (1940) found this species to be generally

rare, but locally abundant, documenting 94 specimens at eight Chipola

River system sites (average of 11.8 per site).

During the status survey, 380 sites within the historical range of

the shinyrayed pocketbook were sampled, including 28 of 54 (52 percent)

known historical sites. Live individuals were found at 23 of the sample

sites, including one site in a Chattahoochee River tributary in

Alabama, 13 sites (12 on tributaries) in the Flint River system, one

locality in the Chipola River, and eight sites (seven mainstem) in the

upper half of the Ochlockonee River system. An average of 2.9 live

individuals were found per site. Live individuals were located at six

(21 percent) of the historical sites. This species has apparently been

eliminated from all but one site in the Chattahoochee River system in

Alabama, and from much of the Chipola River system.

During unrelated studies subsequent to the completion of the status

survey, ten additional sites for the shinyrayed pocketbook were located

in the ACF River system. Eight of these new occurrences were from five

Flint River tributaries; one each occurred in tributaries of the

Chattahoochee and Chipola rivers (Butler and Brim Box 1995, J. Brim

Box, USGS, pers. comm.). The latter two records represent streams where

the species had not been previously collected. The Flint River system

records include one stream where the species had never been collected

(a small tributary of a stream where live specimens were found during

the status survey), and another stream where it was found during the

status survey as a single dead shell; the remaining sites are in

tributaries where it was found live during the status survey.

The smallest shinyrayed pocketbook specimen recorded during the

status survey in the Ochlockonee River system, possibly an older

juvenile, measured 41 mm (1.6 in) in length. In the ACF River system,

the three smallest specimens, measuring 55 to 57 mm (2.17 to 2.24 in)

in length, were gravid females. In 1995, four live, apparently

juvenile, specimens from 30 to 40 mm (1.2 to 1.6 in) in length were

located in a Flint River tributary (C.A. O'Brien, USGS, pers. comm.).

O'Brien (1996) sampled the largest known bed of this species for

juveniles. An 18 m (59.1 ft) by 8 m (26.2 ft) area had 37 adult

shinyrayed pocketbooks (average of 2.1 per m square). Whole substratum

removal of 54 0.25 m (2.7 ft) square quadrats within this bed yielded

no juveniles of this species. The density of shinyrayed pocketbooks at

the four other sites, where quantitative work conducted subsequent to

the status survey yielded specimens, never exceeded 0.08 specimens per

meter square (J. Brim Box, USGS, pers. comm.).

Gulf Moccasinshell--Medionidus Penicillatus (Lea, 1857)

The Gulf moccasinshell is a small mussel that reaches a length of

about 55 mm (2.2 in), is elongate-elliptical or rhomboidal 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. Sculpturing consists of a series of thin,

radially-oriented plications along the length of the posterior slope.

The remainder of the 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. 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 Lea, 1857 and Unio kingi Wright,

1900 as synonyms of Medionidus penicillatus.

The recent taxonomic history of Medionidus species in the

Apalachicolan Region is complex. In the Chipola River system, van der

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

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

other nominal species, the Ochlockonee moccasinshell and Suwannee

moccasinshell (M. walkeri [Wright, 1897]) under the Gulf moccasinshell,

an arrangement also followed by Burch (1975). Johnson (1970)

erroneously reported both the Gulf moccasinshell and Suwannee

moccasinshell from the ACF River system and the Suwannee moccasinshell

from the Ochlockonee and Suwannee rivers as well. Johnson (1977)

recognized the validity of the Gulf moccasinshell, Ochlockonee

moccasinshell, and Suwannee moccasinshell from Apalachicolan Region

streams based on shell characters. The validity of the three

allopatrically distributed Apalachicolan Region Medionidus species is

also recognized by Turgeon et al. (1988).

The Gulf moccasinshell was described from three sites in the ACF

River system in Georgia--the Chattahoochee River near Columbus and near

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

system distribution included tributaries and mainstems of the Flint,

Chattahoochee, and Chipola rivers, and the mainstem Apalachicola River.

More western localities in the Apalachicolan Region included Econfina

Creek (Bay County, northwest Florida), the Choctawhatchee River system,

and the Yellow River (Johnson 1977; Butler 1989, 1993). Clench and

Turner (1956) considered this species rare, but locally abundant. Van

der Schalie (1940) reported 166 specimens from 11 sites, including 130

from two sites in the Chipola River system, an average of 15.1 per

site.

During the status survey, 330 sites within the historic range of

the Gulf moccasinshell were sampled, including 13 of 31 (42 percent)

known historical sites. This species was found at eight sites (two

percent), including only one of the historical sites. It was found at

seven sites (including one mainstem site) in the middle Flint River

system, and at one Econfina Creek site. An average of 1.4 live

individuals was

[[Page 12668]]

found per site. All Alabama populations of the Gulf moccasinshell

appear to be extirpated, and no specimens were found in the Chipola

River system during the status survey. The species has not been

collected in the Choctawhatchee River system since the early 1930's and

in the Yellow River since 1963 (Williams and Butler 1994).

Six new sites for the Gulf moccasinshell from tributaries of the

ACF River system were found subsequent to the status survey (Butler and

Brim Box 1995, J. Brim Box, USGS, pers. comm.). Three sites were

streams from which this species had never been found (one tributary

each in the Chattahoochee, Flint, and Chipola rivers), two were streams

(both Flint River system) where this species was found live during the

status survey, and one site was a stream in the Chattahochee River

system where a single dead shell had been located during the status

survey.

Densities of Gulf moccasinshells at two sites where quantitative

work was conducted were under 0.4 specimens per meter square (J. Brim

Box, USGS, pers. comm.). All specimens located during and subsequent to

the status survey were adults; no specimens less than 50 mm (2.2 in)

were located.

Ochlockonee Moccasinshell--Medionidus Simpsonianus Walker, 1905

The Ochlockonee moccasinshell is a small species, generally under

55 mm (2.2 in) in length. It is slightly elongate-elliptical in

outline, the posterior end obtusely rounded at the shell's 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. Sculpture may also extend onto the disk

below the ridge. Surface texture is smooth. The color is light brown to

yellowish green, with dark green rays formed by a series of connected

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. A summary of the taxonomic history of

the genus Medionidus follows the Gulf moccasinshell description above.

The Ochlockonee moccasinshell was described from the Ochlockonee

River, Calvary, Grady County, Georgia. This Ochlockonee River system

endemic was known historically from the mainstem and the Little River

(Johnson 1977, Butler 1993). Museum records for this species sometimes

numbered in the dozens of individuals at sites above Talquin Reservoir.

During the status survey, eight sites were sampled within the

historic range of the Ochlockonee moccasinshell, including three of six

(50 percent) known historical sites. Live individuals were found at two

sites (one specimen at each site); one of these was a historic site.

Another specimen was located in 1995 (J. Brim Box, USGS, pers. comm.)

at a site previously sampled during the status survey. Only three live

individuals are known to have been collected since 1974 despite

concerted efforts by numerous investigators; none were juveniles.

Oval Pigtoe--Pleurobema Pyriforme (Lea, 1857)

The oval pigtoe is a small to medium-sized species 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

currently recognizes Unio pyriformis Lea, 1857, Unio modicus Lea, 1857,

Unio bulbosus Lea, 1857, Unio amabilis Lea, 1865, Unio reclusum Wright,

1898, Unio harperi Wright, 1899, and Pleurobema simpsoni Vanatta, 1915

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 and common mussels endemic to the Apalachicolan

Region. It occurred throughout the mainstems and several tributaries of

both the Flint and Chipola River systems, in the lower Chattahoochee

River mainstem and several of its tributaries, in the Apalachicola

River mainstem, and in the upper portion of the Ochlockonee River

system. The oval pigtoe was also known from a single Suwannee River

mainstem site and the confluent Santa Fe River system, and in Econfina

Creek (Clench and Turner 1956, Butler 1993). Once a species of

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

sometimes numbered in the hundreds (van der Schalie 1940). In the

Chipola River system, van der Schalie (1940) reported 470 specimens

from 9 sites (an average of 52.2 per site).

During the status survey, 410 sites were sampled within the

historic range of this species, including 20 of 50 (40 percent) known

historical sites. The oval pigtoe was found at 24 (6 percent) of the

sample sites, including seven of the historic sites, with an average of

5.2 live individuals per site. The species was found at one mainstem

site and seven tributary sites in the Flint River system, six mainstem

Chipola River sites, six mainstem sites and one tributary site in the

upper Ochlockonee River system, one site in the New River (upper Santa

Fe River system), and two sites in Econfina Creek. The oval pigtoe has

apparently been extirpated from the Chattahoochee River system in

Alabama and much of the Chipola River system.

Subsequently, five new occurrences of the oval pigtoe were located

in three ACF River system tributaries. One occurrence was from a stream

in the Chipola River system not previously known to have harbored this

species. The other four occurrences were in two streams (two sites in

each stream), that are tributaries to the Chattahoochee and Flint

rivers where the species had been recorded during the status survey

(Butler and Brim Box 1995; J. Brim Box, USGS, pers. comm.).

Oval pigtoe density at the five new sites never exceeded 0.4

specimens per meter square (J. Brim Box, USGS, pers. comm.). The

smallest individual collected during or subsequent to the status survey

was 26 mm (1.0 in) in length, indicating that juveniles were not

present in these collections.

Chipola Slabshell--Elliptio Chipolaensis Walker, 1905

The Chipola slabshell 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 surface is smooth

and chestnut colored. 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; two in the left and one in the right valve. The

pseudocardinal teeth are compressed and crenulate; two in the left and

one in the right valve. Nacre color is salmon, becoming more

[[Page 12669]]

intense dorsally and somewhat iridescent posteriorly.

The Chipola slabshell was described from the Chipola River,

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

Chipola River, 1.6 km (1.0 mi) north of Marianna, Jackson County,

Florida. This species was considered to be a Chipola River system

endemic, occurring in the mainstem from the vicinity of Dead Lake

upstream and in a few of its larger tributaries, all in Florida (van

der Schalie 1940, Clench and Turner 1956). However, a historical record

recently brought to light has been verified from a small tributary of

the Chattahoochee River in extreme southeast Alabama (Butler 1993). Van

der Schalie (1940) documented 31 specimens from six sites in the

Chipola River system (an average of 5.2 per site).

During the status survey, 33 sites within the historical range of

this species on the Chipola River were sampled, including 12 of 16 (75

percent) known historical sites. Live individuals were found at five

sites (15 percent), including one historical site. An average of 3.7

live individuals was found per site. Live individuals were located at

one of the 12 historic resurveyed sites. Populations from Spring Creek

(middle Chipola River system) and the Chattahoochee River system

apparently have been extirpated, with the latter loss resulting in the

extirpation of the Chipola slabshell from Alabama.

No live specimens appeared to be juveniles, as the smallest live

individual was 47 mm (1.9 in) in length. The Chipola slabshell has one

of the most restricted ranges of any Apalachicolan Region mussel.

However, it appears to be more tolerant of soft sediments than other

species included in this rule, has potentially more habitat available

than channel-dwelling species, and may co-occur with more silt-tolerant

species in stream bank habitats with slower currents.

Purple Bankclimber--Elliptoideus Sloatianus (Lea, 1840)

The purple bankclimber is a large, heavy-shelled, strongly

sculptured mussel reaching lengths of 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 Lea, 1840, Unio

atromarginatus Lea, 1840, Unio aratus Conrad, 1849, and Unio

plectophorus Conrad, 1950 as synonyms of Elliptoideus sloatianus.

Elliptoideus sloatianus was included in the genus Elliptio until

Frierson (1927) erected the subgenus Elliptoideus based on the presence

of glochidia in all four gills instead of two gills, a characteristic

of the genus Elliptio. Clench and Turner (1956) overlooked the work of

Frierson (1927), placing the species under Elliptio. Subsequent

investigators (e.g., Turgeon et al. 1988) have correctly assigned this

species to the monotypic genus Elliptoideus.

The purple bankclimber was described from the Chattahoochee River

in Georgia. The type locality was restricted to the Chattahoochee River

at Columbus, Georgia, by Clench and Turner (1956). In the ACF River

system, the purple bankclimber was historically found throughout the

mainstem and in a few of the largest tributaries in the Flint River

system, in the vicinity of Dead Lake on the lower Chipola River

mainstem (although not reported by van der Schalie (1940)), and along

the mainstems of the Apalachicola and Chattahoochee rivers. The species

occurred in the lower two-thirds of the mainstem of the Ochlockonee

River, and in the Little River (Clench and Turner 1956, Butler 1993).

During the status survey, 222 sites were sampled within the

historic range of the purple bankclimber, including 14 of 27 (53 per

cent) known historic sites. Live individuals were found at 41 (18

percent) sites, with an average of 54 individuals per site. The purple

bankclimber was found at six of the 14 historical sites. The species

was found at 17 mainstem sites and one tributary site on the lower two-

thirds of the Flint River, at five sites in the Apalachicola River, and

at 18 sites on the Ochlockonee River mainstem, mostly above Talquin

Reservoir. Having been extirpated from the Chipola and Chattahoochee

rivers, no extant populations occur in Alabama. Its range in the Flint

and Ochlockonee River systems also has been reduced.

It is uncertain if purple bankclimber populations are successfully

recruiting young. Two specimens <70 mm (2.8 in) in length were

collected from the Ochlockonee River during the survey; they were 53 mm

(2.1 in) and 59 mm (2.3 in) in length. Based upon the large size

attained by this species, both were possibly juveniles. The smallest

specimen found during the survey in the ACF River system was 76 mm (3.0

in) in length, a size that possibly represents a juvenile. Richardson

and Yokley (1996) took six 0.25 meter (2.7 ft) square total substratum

removal quadrat samples at a site below Jim Woodruff Dam in the

Apalachicola River where the purple bankclimber was abundant, being the

second most commonly encountered species. No specimens smaller than 133

mm (5.2 in) were found, indicating a lack of recruitment at this site.

Previous Federal Action

The fat threeridge, shinyrayed pocketbook, oval pigtoe, and purple

bankclimber first appeared as category 2 species in the Service's

notices of review for animal candidates that were published on January

6, 1989 (54 FR 554) and on November 21, 1991 (56 FR 58804). 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. Designation of category 2 species was discontinued in the

February 28, 1996, Federal Register notice (61 FR 7596) (see also Issue

103 in the ``Summary of Comments and Recommendations'' section). The

Service determined that these four species plus the Gulf moccasinshell,

Ochlockonee moccasinshell, and Chipola slabshell qualified as candidate

species at the time of proposal for listing. A candidate species is a

species for which the Service has sufficient information to propose it

for protection under the Act. All seven species have been recommended

for conservation status by Williams et al. (1992a) and Williams and

Butler (1994).

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

potentially affected Federal and State agencies, local governments, and

interested individuals that a status review was being conducted for

these seven species. Ten comments were received. The Florida Division

Office of the Federal Highway Administration stated that no bridge

replacement projects were currently planned in northwest Florida, and

that any future bridge replacement projects were not anticipated to

affect these species, based on the localized and short-term impacts

associated with these activities. The Federal Energy Regulatory

Commission stated that they license twelve hydroelectric developments

in the study area, and that issues concerning these species should be

coordinated with the Office of Hydropower Licensing. The Fayette

County, Georgia, Board of Commissioners expressed concern with the

Service's belief that impoundments

[[Page 12670]]

had played such a major role in the demise of these species. The

Alachua County, Florida, Environmental Protection Department indicated

that none of the seven species were known or suspected to occur in that

county. The Florida Game and Fresh Water Fish Commission expressed

concern with how their plan to dredge the mouths of several silted in

streams along the Apalachicola River to improve access for striped bass

(Morone saxatilis) might affect these mussels. The Georgia Department

of Natural Resources had questions concerning the distribution of these

mussels, and sent a copy of regulations addressing the commercial

harvest of mussels in Georgia. The Florida Natural Areas Inventory

supported Federal listing of these species, and indicated that a

portion of the Econfina Creek watershed where the Gulf moccasinshell

and oval pigtoe occur is on a list for land purchase by the State of

Florida. Three individuals with knowledge of freshwater mussels

supported Federal listing of these species.

The processing of this final rule conforms with the Service's final

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 rulemakings 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 listing

status of the outstanding proposed listings. This rule falls under Tier

2. Presently, there are no pending Tier 1 actions in Region 4 and this

is the Region's last outstanding Tier 2 action. 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). In a Federal Register notice

published on October 23, 1997 (62 FR 55628), the guidance was extended

beyond FY 1997 until such time as new guidance is published.

In the development of this final rule, the Service has conducted an

internal review of a draft of this rule and other Service-generated

information. Based on this review, the Service has determined that

there is no new information that would substantively affect these

listing decisions and that additional public comment is not warranted.

Summary of Comments and Recommendations

In the August 3, 1994, proposed rule (59 FR 39524), and through

associated notifications, all interested parties were requested to

submit factual reports and information that might contribute to the

development of a final rule. Appropriate Federal and State agencies,

county governments, scientific organizations, and interested parties

were contacted by letter dated August 18, 1994, and were requested to

comment. Legal notices were published in the following newspapers--the

Albany Herald, Albany, Georgia, on August 20, 1994; the Atlanta

Journal-Constitution, Atlanta, Georgia, on August 21, 1994; the

Columbus Ledger-Enquirer, Columbus, Georgia, on August 21, 1994; the

Macon Telegraph, Macon, Georgia, on August 20, 1994; the Thomasville

Times-Enterprise, Thomasville, Georgia, on August 19, 1994; The

Gainesville Sun, Gainesville, Florida, on August 18, 1994; the Jackson

County Floridan, Marianna, Florida, on August 21, 1994; the Tallahassee

Democrat, Tallahassee, Florida, on August 21, 1994; and The News-

Herald, Panama City, Florida, on August 22, 1994.

In response to twelve formal requests during the first public

comment period, the Service scheduled five public hearings in the

three-State area within the historical range of these seven species.

Prior to the hearings, the Service held five public informational

meetings at the same sites as the public hearings. A notice of public

meetings, public hearings, and reopening of the comment period was

published in the Federal Register on December 12, 1994 (59 FR 63987),

and in legal notices in the following newspapers--the Albany Herald,

Albany, Georgia on January 6, 1995; The Atlanta Journal-Constitution,

Atlanta, Georgia on January 8, 1995; the Columbus Ledger-Enquirer,

Columbus, Georgia on January 5, 1995; the Dothan Eagle, Dothan, Alabama

on January 7, 1995; the Montgomery Advertiser, Montgomery, Alabama on

January 5, 1995; the Tallahassee Democrat, Tallahassee, Florida on

January 6, 1995; the Jackson County Floridan, Marianna, Florida on

January 8, 1995; and the Fayette News, Fayetteville, Georgia, on

January 11, 1995. The comment period for the proposal closed on

February 10, 1995.

Public meetings were held at the Fayette County High School in

Fayetteville, Georgia on January 5, 1995; at Chipola Junior College in

Marianna, Florida on January 9, 1995; at the Opera House in Dothan,

Alabama on January 10, 1995; at the Albany Civic Center in Albany,

Georgia on January 11, 1995; and at the Convention and Trade Center in

Columbus, Georgia on January 12, 1995. Public hearings were held at the

same facilities in Fayetteville, Georgia on January 19, 1995; Dothan,

Alabama on January 23, 1995; Marianna, Florida on January 24, 1995;

Albany, Georgia on January 25, 1995; and Columbus, Georgia, on January

26, 1995.

In a Federal Register notice dated April 24, 1995 (60 FR 20072),

the Service reopened the comment period on this proposal until May 5,

1995, to allow for consideration of numerous comments received after

the previous deadline (February 10, 1995) and to provide an opportunity

for further comment. Legal notices were published in the following

newspapers--the Albany Herald, Albany, Georgia on April 21, 1995; The

Atlanta Journal-Constitution, Atlanta, Georgia on April 24, 1995; the

Columbus Ledger-Enquirer, Columbus, Georgia on April 21, 1995; the

Dothan Eagle, Dothan, Alabama on April 26, 1995; the Montgomery

Advertiser, Montgomery, Alabama on April 22, 1995; the Tallahassee

Democrat, Tallahassee, Florida on April 23, 1995; the Jackson County

Floridan, Marianna, Florida on April 26, 1995; and the Fayette News,

Fayetteville, Georgia on April 26, 1995.

During the April 10, 1995, to April 26, 1996, listing moratorium,

studies involving some of these proposed species were conducted in the

ACF River system. To accept this new information, the Service published

a notice in the Federal Register (61 FR 36020) on July 9, 1996,

reopening the comment period until July 26, 1996. Legal notices were

published in the following newspapers--the Albany Herald, Albany,

Georgia on July 14, 1996; The Atlanta Journal-Constitution, Atlanta,

Georgia on July 17, 1996; the Columbus Ledger-Enquirer, Columbus,

Georgia on July 14, 1996; the Dothan Eagle, Dothan, Alabama on July 14,

1996; the Montgomery Advertiser, Montgomery, Alabama on July 14, 1996;

the Tallahassee Democrat, Tallahassee, Florida on July 14, 1996; the

Jackson County Floridan, Marianna, Florida on July 14, 1996; and the

Fayette News, Fayetteville, Georgia on July 14, 1996.

The Service received hundreds of written comments and many oral

statements presented at the public hearings and received during the

comment periods. All pertinent comments have been considered in the

formulation of this final rule. The proposed listings were supported by

the U.S. Forest Service, the Environmental Protection Agency (EPA), and

the States of Alabama (Department of Conservation and Natural

Resources) and Florida (Department of Environmental Protection and Game

and Fresh Water Fish Commission [FGFWFC]). The congressional

delegations of the three States opposed the proposed listings. The

following is

[[Page 12671]]

a summary of the comments, concerns, and questions (referred to as

``Issues'' for the purposes of this summary) and the Service's response

to each. Comments of similar content have been grouped together.

Issue 1: Numerous commenters thought that the status survey was

insufficient to make listing determinations for these seven species.

Issues of concern included sampling methodologies, specimens collected,

sites sampled, interpretation of historical data, whether sampling for

juveniles had been adequate, and evidence of recent reproduction and

recruitment. Other issues raised included the need for quantitative

sampling, the percentage of historical sites sampled, how historical

sites were selected for sampling, the evidence for the decline of these

species, whether newly discovered sites represented new colonization by

these mussels, and the reproductive viability of remaining populations.

Response: Explanations of sampling methodology, specimens

collected, sites sampled, and analysis of historical data have been

included under ``Status Survey'' and ``Species Accounts'' in the

Background section. Other issues associated with the status survey are

discussed below.

Quantitative sampling is not essential to determine the status of

rare riverine mussel species (Miller and Payne 1988). Mussel

populations are often distributed non-randomly (Downing and Downing

1992). Even where habitats appear to be uniform, mussels tend to be

distributed unevenly (Downing 1991). For these reasons, random

transect-type quantitative sampling is less efficient than choosing

sites based on criteria such as available habitat (G.L. Warren, FGFWFC,

in litt. 1995).

The Service compiled 300 historical site records from the ACF and

Ochlockonee River systems; 108 of these sites had records of one or

more of these proposed species. Research into historical mussel

collections since the status survey was completed has yielded

additional historical sites not reported in Butler (1993). The

percentage of historical sites in the ACF and Ochlockonee River systems

resurveyed for the seven species during the status survey ranged from

40 to 75 percent, while the percentages of resurveyed historical sites

in the ACF and Ochlockonee River systems that still supported live

specimens of the seven species ranged from eight to 43 percent.

Detailed analyses of these data are presented under ``Status Survey''

and ``Species Accounts'' in the ``Background'' section. Many historical

sites had been visited more than once by other researchers or

collectors prior to the status survey. If evidence indicated the

species had disappeared from a historical site, and there was little

probability of currently finding it, survey efforts were not expended

there.

The Service believes the newly discovered sites do not represent

newly colonized sites, but sites that have existed historically but

have not been previously sampled by collectors (see ``Status Survey''

under Background).

The fat threeridge, shinyrayed pocketbook, Gulf moccasinshell, and

oval pigtoe were historically considered rare, but widespread and

locally abundant (Clench and Turner 1956). Mussel populations were

decimated in the Chattahoochee River in the vicinity of Columbus,

Georgia, by the early part of this century (Clench and Turner 1956).

The river-dependent mussel species along the entire Chattahoochee River

mainstem now appear to be extirpated (Butler 1993).

Determination of sexual maturity in these species would require

sectioning to locate mature gametes; determining age would require

sectioning the shells (Neves and Moyer 1988); this was not within the

scope or intent of the status survey. The Service considered shells to

represent juveniles if they were less than one-quarter of the maximum

size for each species. Based on the adult sizes typical of these seven

mussel species, very few juvenile specimens were located during the

status survey. While substrate samples were not taken, the survey

biologists located thousands of smaller species of bivalves and snails.

These included the ubiquitous Asian clam (Corbicula fluminea),

pleurocerid (Elimia spp.) and other snails, and the iridescent lilliput

(Toxolasma paulus), a mussel species rarely exceeding 32 mm (1.25 in)

in total length. The Service believes that if significant recruitment

was occurring in the seven species, more juvenile and small shells

would have been located.

Juveniles were also represented in some museum collections.

Specimens of purple bankclimber as small as 26 mm (1.0 in) in length

were represented in museum collections while the smallest specimen

located during the status survey was 53 mm (2.1 in). The occurrence of

juvenile specimens in museum collections substantiated population

viability and indicated recent reproduction at the time the historical

collection was made.

Richardson and Yokley (1996) employed total substratum removal of

six 0.25 m (2.7 ft) quadrats at each of three sites. They found three

juvenile individuals of the fat threeridge in the lower Apalachicola

River, but no evidence of recruitment of the purple bankclimber below

Jim Woodruff Dam on the same river. These two species were both common

and represented the second most abundant species at their respective

sites. The fat threeridge population sampled is the largest known (J.

Brim Box, USGS, pers. comm.). These data indicate that the fat

threeridge is experiencing limited recruitment, but that there is no

evidence of recruitment in the purple bankclimber at these sites.

Brim Box and Dorazio (in press) took 2,867 substrate core samples

(representing a composite 4.23 m (45.5 ft) square) for mussels at 30

sites in the ACF system. No specimens of any of the 7 species in this

rule were located in the 2,867 core samples, although juveniles of a

few common species were found. Brim Box and Dorazio (in press) also

took 2,867 0.25 m (2.7 ft) square quadrat samples, without total

substratum removal, for mussels. No juveniles of the seven species were

found.

Richardson and Yokley (1996) stated that their work demonstrated

that unequivocal evidence of recruitment can be found with minimal

sampling effort. However, most literature on this subject demonstrates

that the collection of juveniles is a low probability event (Kat 1982,

Neves and Widlak 1987, Stansbery 1995). Quadrat sampling has

consistently been determined to be inadequate for rare species (Neves

et al. 1980, Kovalak et al. 1986, Neves and Odum 1989). The extreme

patchiness of mussel distributions makes quantitative surveys

expensive, time consuming, and not the best method to determine the

population status of rare species (Miller and Payne 1988). The large

number of substratum samples necessary to confirm recent recruitment is

also disruptive to the stable benthic habitat essential to these and

other riverine species (A.E. Bogan, North Carolina State Museum, pers.

comm.).

Issue 2: Several commenters said that the author of the proposed

rule stated in a published paper that major portions of the

Apalachicola and Ochlockonee rivers were ``virtually unsurveyed.''

Response: What that statement referred to was that few historical

sampling sites existed on the Apalachicola and lower Ochlockonee rivers

at that time (Butler 1989). Subsequent surveys on the Apalachicola (35

sites) and Ochlockonee River (24 sites) mainstems have provided

adequate information to evaluate the status of the species considered

in this rule.

Issue 3: A few respondents asserted that comparing historical

survey sites

[[Page 12672]]

with status survey sites is difficult because of differing collection

techniques and the dynamic nature of streams (what was suitable habitat

decades ago could now be very unsuitable due to various factors). One

commenter urged the Service to use collection methods employed by early

collectors to thoroughly sample streams.

Response: The Service agrees that there may have been changes in

habitat suitability over time. To compensate for this factor, Center

biologists surveyed upstream and downstream of historical sites. While

streams are dynamic, the proportions of riffle, run, and pool habitats

remain fairly constant. Based on human influences over the past two

centuries, the Service believes that available habitat for these

mussels has diminished significantly (see Factor A in the ``Summary of

Factors Affecting the Species'' section).

Issue 4: One malacologist (mussel expert) asked if it would be

possible to time-code the map symbols in the status survey report so

that the distribution found in this study could be distinguished from

that of earlier collections.

Response: The distributional data could be time-coded; however,

time-coding collections was not essential to determine the status of

the seven mussels.

Issue 5: Two malacologists suggested that some of these species

have always been rare according to the literature, and that population

declines could not be proven. One respondent questioned how many of the

species existed historically compared to now.

Response: Van der Schalie (1940) gathered data on Chipola River

mussels from collections taken between 1915 to 1918 and included actual

numbers of mussels from various sites in the drainage. A comparison of

this historical data with the status survey results indicates a

significant reduction in the numbers of at least two species in the

Chipola River. Historically, 470 oval pigtoe specimens were collected

from nine sites (an average of 52 per site) in the Chipola River versus

35 specimens collected from six sites (an average of six per site)

during the status survey. Historically, 166 specimens of the Gulf

moccasinshell were known taken from eleven sites (an average of 15 per

site) versus no specimens collected in the status survey.

Clench and Turner (1956) indicated that some species (e.g., the fat

threeridge and oval pigtoe) were rare and only locally abundant. They

documented 10 to 15 specimens/meter (0.9 to 1.4 specimens/ft) square of

fat threeridge over a 200 m (656 ft) stretch of Dead Lake (Chipola

River). The fat threeridge apparently disappeared over 20 years ago in

Dead Lake and was not found live there during the status survey. Except

for the purple bankclimber, which is abundant at a few sites, these

species are now rare range-wide and are not abundant at any known sites

(see ``Species Accounts'' in the ``Background'' section).

Issue 6: Two respondents stated that Federal listing of the purple

bankclimber was not warranted because the species was abundant at some

sites in the lower Flint and upper Ochlockonee rivers. One of these

individuals further stated that he was confident that juveniles of this

species were common.

Response: The purple bankclimber is the most abundant of the seven

mussels; however, no additional information on purple bankclimber

abundance or recruitment was provided to the Service by these

commenters. Recent sampling efforts on the Apalachicola River

(Richardson and Yokley 1996) located only large individuals, indicating

a lack of recruitment in this species.

Issue 7: One commenter indicated that the Gulf moccasinshell still

exists at several sites in the Chipola River system.

Response: Van der Schalie (1940) reported 166 Gulf moccasinshells

taken from eleven sites (an average of 15 specimens per site) in the

Chipola River system, but none were located during the status survey.

The Service received information on a recently discovered population in

Baker Creek, in the Chipola River system, after publication of the

proposal (see ``Species Accounts'' in the ``Background'' section), but

the commenter provided no specific location or other information.

Issue 8: Several commenters questioned the Service's statements

regarding impoundments, including status survey efforts in

impoundments, impact of impoundments upon these species, and the purple

bankclimber's tolerance of impoundments.

Response: Much riverine habitat in the ACF system has been

converted to slack-water impoundments, particularly in the

Chattahoochee River; however, verifiable pre-impoundment records of

these species are uncommon (see Factor A in the ``Summary of Factors

Affecting the Species'' section). Museum records confirm that some of

the Ochlockonee River mussel fauna was inundated and lost at the upper

end of Talquin Reservoir. Many historical collections came from the

Chattahoochee River in the vicinity of Columbus, Georgia. Although

exact locality data is generally lacking, several impoundments in this

reach of river permanently reduced available riverine habitat for

mussels.

During the status survey, 39 reservoir sites were surveyed; none of

the seven species were found in permanently impounded river reaches.

None of these species are known to successfully reproduce and recruit

under impoundment conditions. The reference to the purple bankclimber's

tolerance of impounded conditions was based on a mussel relocation

project funded by the U.S. Army Corps of Engineers (Corps). Purple

bankclimbers from the Apalachicola River survived twelve months in

laboratory tanks at the USGS research facility in Gainesville, Florida

(Hamilton et al. 1996). However, the mussels were maintained in flow-

through tanks with currents. The experiment does not indicate that the

purple bankclimber can survive and reproduce under impounded

conditions.

Issue 9: Two commenters questioned the expertise of the Center

biologists who carried out the status survey.

Response: The project leader of the status survey has 20 years

experience with mussel research and surveys. The field leader has an

M.S. degree in aquatic sciences and seven years field experience in

aquatic biology. Field biologists, with one exception, had education in

aquatic biology ranging from the B.S to Ph.D. level. Two scientists

associated with the project have published scientific papers on mussel

surveys and endangered species. The Service believes that all

individuals involved in the survey were well qualified.

Issue 10: One commenter questioned the adequacy of the sampling

done by the status survey biologists, noting that various status survey

field notes (e.g., the water was too cold, too turbid, or too deep)

indicated that sampling was inadequate and that portions of the field

data should be discarded.

Response: The survey biologists employed the most appropriate

sampling techniques based upon the habitat conditions present at each

site. When high water precluded sampling, sites were usually revisited

in lower water conditions to sample. The Service believes that the

information gathered during field work is reliable and supports the

determinations made in this rule.

Issue 11: One commenter assumed that when the survey biologists

checked a mussel for the presence of mature glochidia the mussel was

stressed or even killed. Another respondent questioned the Service's

recording of laboratory data, noting that an entire collection of over

one hundred

[[Page 12673]]

individuals of a common species was comprised of all females.

Response: During the status survey, some voucher mussels were

preserved and brought to the laboratory for analysis, including

inspection for glochidia. Most of the specimens were returned unharmed

to the substrate from which they were collected. The species referred

to by the respondent as consisting of only females were members of the

genus Elliptio. This genus does not exhibit obvious external

differences between the sexes; glochidia must either be present or

gonadal tissues sectioned to determine sex. Laboratory notes on this

collection stated that glochidia were not present (or ``NP'' on the

data sheets) for any individual. The commenter apparently misconstrued

``NP'' as meaning ``female, glochidia not present.'' Although their sex

could not be determined, it is likely that both sexes were represented

in the sample.

Issue 12: Some respondents contended that the Service had not

sampled the Escambia, Yellow, and Choctawhatchee rivers, where there

were historical records of two of these species.

Response: There is one historical record of the Gulf moccasinshell

in the Yellow River (1963) and four records from the Choctawhatchee

River in the 1930's. The Service examined over 30 collections taken

from these watersheds over the past few decades. The Gulf moccasinshell

did not occur in any of these collections. The Service believes this

species is extirpated from the Yellow and Choctawhatchee River systems.

Clench and Turner (1956) confused the shinyrayed pocketbook with

the southern sandshell (Lampsilis australis) and erroneously stated

that the shinyrayed pocketbook's range included the Choctawhatchee

River. Johnson (1970), Heard (1979), and Williams and Butler (1994)

clarified the range of the shinyrayed pocketbook as comprising only the

ACF and Ochlockonee River systems. There are no records of any of the

seven species from the Escambia River system. Collections made by the

Center between 1993 and 1995 in this drainage corroborate this

information.

Issue 13: One respondent commented that the Service's diving

regulations precluded divers from collecting in navigable river

channels, thus making it impossible to assess mussel populations there.

Response: Service diving regulations do not preclude sampling in

navigable channels. Many dives using SCUBA were made in navigable

channels during the status survey, and the Service believes that mussel

populations in such areas were adequately sampled.

Issue 14: One commenter stated that $27,000 was not adequate to

conduct the status survey for the seven proposed mussels.

Response: The Service's Jacksonville, Florida, Field Office

provided $27,000 in initial funding and $12,000 during the survey.

Total expenditures for the status survey were over $110,000. The

Service believes the status survey was adequate to determine the status

of these species.

Issue 15: Various commenters were concerned that the scientific

data associated with the status survey were not subjected to proper

peer review.

Response: The information supporting these determinations was

extensively peer reviewed according to Service policy (see paragraph

following the Service's response to Issue 107 in the ``Summary of

Comments and Recommendations'' section for a discussion of peer

review).

Issue 16: Several respondents stated that any decision to list

these species should be deferred until data is available on habitat

requirements, fish hosts, and threats to the mussels and their host

fish.

Response: Although such data will be important in recovery for

these species, they are not required under the listing factors under

section 4(a) of the Act. To delay these listings until such data become

available might preclude the species from being listed until recovery

becomes less likely or extinction occurs.

Issue 17: As gravid specimens were sometimes documented, some

commenters questioned the Service's use of the term ``lack of

reproductive viability'' in the proposed rule.

Response: In the proposed rule, the Service stated that there was

little evidence to suggest that populations of the seven mussel species

were reproductively viable. This statement was based on the fact that

no known juveniles were collected during the status survey. In this

final rule, the Service has used the phrase ``lack of recruitment'' in

its discussions of mussel reproductive status. This term more

accurately defines the current status of these mussels.

Issue 18: Several commenters thought that the Service had failed to

determine potential host fish status, contending that missing hosts may

be the primary cause of their decline. Two malacologists stated that if

their fish hosts were gone, the mussels were ``functionally extinct'';

a third asked that if this were so, why spend time and effort listing

them?

Response: As discussed under ``Reproductive Biology'' in the

``Background'' section, the fish hosts for some of these species are

not currently known. Without specific host fish information, it would

be premature to spend considerable efforts and funding on fish

sampling. Population and distribution information of potential host

fish is not necessary to justify listing these species.

Loss or depletion of fish host populations may be a primary factor

in declines of some of the seven mussels. A loss of riverine habitat

has probably also affected fish populations (see Factor A in the

``Summary of Factors Affecting the Species'' section).

If some of these seven mussel species are ``functionally extinct,''

recovery may still be possible by restoration of required fish host

populations to the ecosystem. Regardless of the environmental factors

responsible for the decline of these mussels, if one or more of the

listing criteria are met, section 4 of the Act requires that the

species be listed.

Issue 19: One commenter was not convinced that mussels were

important, while numerous malacologists and other commenters stated

that mussels serve as excellent water quality indicators and barometers

of aquatic ecosystem health.

Response: Section 2(a) of the Act recognizes that species have

intrinsic values (i.e., aesthetic, ecological, educational, historical,

recreational, and scientific) to the nation, and the section 4 listing

criteria do not require other justifications. However, mussels are of

demonstrable value to man. Their longevity, relative immobility, and

filter feeding habits make them among the best available indicators of

environmental quality in aquatic systems. Mussels are highly

susceptible to sedimentation and pollutants and provide an early

warning of the deterioration of water and habitat quality. They

accumulate heavy metals and other contaminants in their tissues and

shells, serving as effective test organisms for contaminants studies.

Native Americans and early settlers fed extensively on mussels, as

shown by the large deposits of shell material in middens (Parmalee et

al. 1982). In the first half of this century, mussels supported a large

pearl button industry in the United States (McGregor and Gordon 1992).

The cultured pearl industry harvests thousands of tons of shell from

eastern rivers (Baker 1993), and cultured pearls are a multi-billion

dollar global industry. Mussels are important organisms for biological

studies, particularly because of their diverse methods of attracting

host fish.

[[Page 12674]]

Mussels serve an important ecological function by filtering excess

nutrients from the water, improving water clarity so sunlight may

promote rooted aquatic vegetation growth, thereby increasing habitat

complexity and species diversity. Several vertebrate species, including

mammals, birds, turtles, and fish feed regularly on mussels (Fuller

1974). Their shells provide substrate diversity and a place for many

types of invertebrates to colonize. This function is particularly

important in homogenous sandy coastal plain rivers where hard surfaces

are rare.

Issue 20: Two malacologists questioned the Service's statements

regarding the impacts of various human activities on the mussels,

whereas other malacologists thought that their imperilment was easily

documented given the extensive available literature. Others questioned

the use of personal communications and subjective terms (e.g., maybe,

unknown) in the proposed rule and at public meetings.

Response: Additional references documenting Service conclusions

have been added in this final rule (see ``Background'' and ``Summary of

Factors Affecting the Species'' sections). The Service believes it

appropriate to consider reliable unpublished reports, non-literature

documentation, and personal communications with experts in making

listing determinations.

Issue 21: Several commenters thought that natural factors (e.g.,

floods) and not just the factors of human origin, should be considered

in the species' imperilment.

Response: Natural factors were considered in terms of threats to

these species (see Factors C and E in the ``Summary of Factors

Affecting the Species'' section).

Issue 22: Two commenters questioned the Service's statement

concerning lack of adequate flushing on the Ochlockonee River to rid

the channel of silt and detritus below Talquin Reservoir.

Response: One survey site in the Ochlockonee River below Talquin

Reservoir had silt and detritus deposits extending from bank to bank.

Under normal conditions, these materials are confined to slackwater

areas, where they settle out in low or no-flow conditions. Low flow

releases from Talquin Reservoir may be contributing to this situation.

Issue 23: One commenter stated that these species' lack of

reservoir tolerance may be incorrect, and that it was possible that

mussels had not had enough time to reestablish themselves in the newly

created benthic habitat created by Chattahoochee River impoundments.

Response: There is no evidence that any of these seven mussels can

successfully reproduce and recruit under impoundment conditions. Their

habitat requirements generally consist of stable substrates, usually

gravel, and other rocky materials in stream channels with currents.

Habitat conditions created in impounded rivers consist of softer

sediments (i.e., silt, mud, sand) and minimal currents (except at

reservoir heads). Impoundments also change other physical and chemical

characteristics of rivers (see Factor A in the ``Summary of Factors

Affecting the Species'' section).

Issue 24: Numerous commenters maintained that the results of a

Corps-sponsored study on mussel translocation were relevant to the

proposed listings, and that the comment period should have been

extended until study results were available for public scrutiny.

Response: The Corps investigated the feasibility of translocating

four mussel species, including the purple bankclimber, in the

Apalachicola River below Jim Woodruff Dam (Hamilton et al. 1996). This

study will not provide additional information on the status of these

species and does not justify further extension of the comment period.

Issue 25: Several respondents stated that the Service cannot prove

which, if any, human activities actually affect mussels. Conversely, a

few malacologists stated that determining the direct relationship of

these impacts would be a waste of research time and taxpayer dollars.

Response: Although the precise role of the factors causing the

decline of these species will never be known, there is information

available on how human activities affect these and other species of

mussels (see ``Background'' section and Factor A in the ``Summary of

Factors Affecting the Species'' section).

Issue 26: A few malacologists questioned the rationale for

distinguishing between endangered and threatened; one of them

criticized the lack of criteria for making such distinctions. One

malacologist wondered how the Service determined that the narrowly

distributed Chipola slabshell was threatened and not endangered. They

also wondered at what point information was sufficient to list a

species.

Response: The Act defines an endangered species as a species

threatened with extinction throughout all or a significant portion of

its range, and a threatened species as a species in danger of becoming

endangered throughout all or a significant portion of its range within

the foreseeable future. The decision to propose a species as endangered

or threatened is based solely on the best scientific and commercial

data available after conducting a review of the status of the species.

For the application of these definitions to the seven mussels in

general, and the Chipola slabshell in particular, see ``Summary of

Factors Affecting the Species'' and ``Species Accounts,'' respectively.

Issue 27: One commenter stated that these seven species were

imperiled in 1970, and if the species are still extant, these listings

are long overdue.

Response: The Service believes that the status survey was essential

to determine the current status of these species before proposing them

for listing. The Service carries out status surveys and listing

actions, subject to a priority system published in the Federal Register

on September 21, 1983 (48 FR 43098), and contingent on the availability

of funding, personnel, and supportive information.

Issue 28: Several commenters thought that the Service had

overstated potential commercial utilization and take by biological

supply companies of two species, that Georgia harvest regulations

aiding in conservation had been understated, and that mussel

identification training courses were needed.

Response: Much of the commercial shell harvest in the southeast now

takes place in west Tennessee and north Alabama. Although shells from

the ACF River system are of poor quality, some have been included in

shell shipments (J. Brim Box, USGS, pers. comm.). Demand for shell in

recent years has pushed prices high enough that collectors have

searched widely for unexploited shellbeds. The fat threeridge and

purple bankclimber are so similar to the more common threeridge and

washboard (Megalonaias nervosa) that take is a potential problem.

Training and the development of educational materials will be

considered as tasks when the recovery plan is prepared for these

species.

The Service agrees that the practice of dissecting mussels in

introductory laboratory courses is no longer widespread. However, large

species, such as the fat threeridge and purple bankclimber, may still

be collected for this purpose (see factor B under ``Summary of Factors

Affecting the Species'').

Regulation of commercial harvest in Georgia has changed since the

proposed rule was drafted; this has been

[[Page 12675]]

addressed in the final rule (see Factor D in the ``Summary of Factors

Affecting the Species'' section for discussion of State regulations

affecting these species).

Issue 29: One commenter thought it was inappropriate for Service

staff to recommend that no mussels should be harvested from the ACF and

Ochlockonee River systems when some of the seven species were abundant.

Response: Although some of these species occur in large numbers at

a few sites, the Service believes the current status of the species

does not justify a harvest.

Issue 30: One commenter stated that much field data is gathered by

amateurs, and the Service should recognize the value of this

information. Two malacologists thought that we overestimated the number

of shell clubs and amateurs, and accordingly overstated their threat to

these species from collecting.

Response: The Service acknowledges the significant role amateur

malacologists have played in the development of our current knowledge

of freshwater mussels. Most early mussel collections, including most of

the type material used to describe these seven species, were collected

by amateur naturalists. Amateurs continue to make important

contributions to the knowledge of mussels. The Service agrees that the

potential threat from shell club collectors is minimal (see Factor C in

the ``Summary of Factors Affecting the Species'' section).

Issue 31: Two malacologists commented that the Service may have

taken an alarmist view with the proposal. One malacologist believed the

Service was proposing to list aquatic snails that were abundant and

unthreatened, and doubted the data used to support the listing of the

mussels.

Response: Based on the best available scientific and commercial

data and peer review, the Service believes that listing under the Act

is appropriate for these species (see ``Summary of Factors Affecting

the Species'' section).

Issue 32: A few respondents stated that the taxonomy of these

species deserved further attention as the taxonomy of some species in

the region was unresolved, and speculated that we may have been

confused regarding which species we actually proposed.

Response: Although the genetics of various mussel genera in the

Apalachicolan Region are little known (Butler 1989), the species

included in this final rule have been recognized by the malacological

community for nearly a century. All meet the Act's definition of

``species.''

Issue 33: One commenter wanted to know why one mussel species

addressed in the status survey report was omitted from the proposed

rule.

Response: The status survey included the round washboard

(Megalonaias boykiniana). In December 1993, the Service learned of

molecular genetics studies (Mulvey et al. in press) indicating that the

round washboard might be conspecific with the widespread and common

washboard. Based on this taxonomic uncertainty, this species was not

proposed for listing. The same study, however, confirmed that the fat

threeridge (Amblema neisleri) was a distinct species from the

threeridge (A. plicata).

Issue 34: One commenter suggested that mussel populations in the

relatively pristine, undisturbed Econfina Creek should be thriving

because conditions for mussels are optimal.

Response: Econfina Creek retains high water quality, but has been

altered by Deer Point Reservoir on the lower portion of the creek.

Although Gulf moccasinshell and oval pigtoe populations survive in this

stream, the populations appear to be small. Other factors may explain

why these two species occur in small numbers. Econfina Creek represents

the western-most stream within the historical range of the oval pigtoe,

and the Gulf moccasinshell's western-most extant population. Peripheral

populations in a species' range are often small and scattered.

Issue 53: One malacologist stated that Clench and Turner's (1956)

survey of Apalachicolan Region streams referred to the mussel fauna as

being depauperate, whereas the Service claimed that the region was well

known for its high level of endemicity.

Response: Clench and Turner (1956) stated ``* * * [the mussel]

fauna of [the Apalachicolan Region] has been derived from the west, is

depauperate (not rich in species), and must be fairly old.'' When

compared to adjacent drainages to the west (e.g., Mobile Basin) and

north (e.g., Tennessee River system), the fauna is relatively low in

species diversity. However, the Apalachicolan Region has many endemic

species (see ``Introduction'' in the Background section). About 30 of

the 60 mussel species known from the region are endemic (Butler 1989,

Williams and Butler 1994).

Issue 54: Two malacologists suggested that disease and predators

are not threats to these mussels, and unless information is otherwise

available, references to these factors should be deleted.

Response: Factor C (``Disease or Predation'') in the ``Summary of

Factors Affecting the Species'' section notes that there is no specific

information available on how disease and predation affect these

mussels.

Issue 55: One commenter believed that mussels were more common than

indicated in the proposed rule, because hundreds, if not thousands, of

mussels are eaten by muskrats in the vicinity of his property on the

Chattahoochee River.

Response: No populations of these seven species currently occur in

the Chattahoochee River. The mussels in question may be the Asian clam

(Corbicula fluminea), a well-known food of muskrats, or reservoir-

tolerant native mussels.

Issue 56: One commenter questioned the relationship between mussel

populations and habitat quality.

Response: Many mussels require water free from excessive levels of

sediments and contaminants (Fuller 1974, Havlik and Marking 1987). As

benthic inhabitants, they are readily affected by sedimentation, and as

filter feeders, they are highly susceptible to various contaminants

(see Factor A in the ``Summary of Factors Affecting the Species''

section).

Issue 57: Two malacologists questioned these mussels' decline when

other species in the same habitat had viable populations. Another

commenter thought the Service assumed that all seven mussels had

similar reproductive characteristics.

Response: Species occurring in the same habitat typically have

differences in life histories or ecological requirements (e.g., in the

case of mussels, different host fishes) that permit them to coexist.

These species would not be expected to respond in the same way to

ecological stress. The specific reproductive biologies of the seven

mussels is largely unknown, but would not be expected to be the same.

Issue 58: One commenter thought these mussels were always rare, and

thus served a limited ecosystem function, and further stated that the

Asian clam could fill their niche, thus minimizing a potential chain

reaction from loss of the mussels in the ecosystem.

Response: Historical information indicates that some of these

species were once locally abundant; the purple bankclimber still occurs

abundantly at a few sites. The introduced Asian clam has been common in

Apalachicolan Region rivers since 1960 (Schneider 1967) (see Factor E

in the ``Summary of

[[Page 12676]]

Factors Affecting the Species'' section). Although the Asian clam may

have become an increasingly important food for some predators (e.g.,

the muskrat), the long-term ecological consequences of its colonization

are unknown.

Issue 59: One respondent stated that data were not provided to

substantiate claims that the Asian clam may be responsible for the

imperilment of the Ochlockonee moccasinshell.

Response: Sickel (1973) and Bass and Hitt (1974) indicate that

Asian clam populations are dense in the ACF River system. This final

rule contains additional information on how Asian clams may be

impacting these seven species (see Factor E in the ``Summary of Factors

Affecting the Species'' section).

Issue 60: Several malacologists predicted that the exotic zebra

mussel (Dreissena polymorpha) will inevitably increase the probability

of extinction for the seven species based upon the impacts of this non-

native species in midwestern river systems.

Response: If the zebra mussel invades the ACF system, it may be a

serious threat to these species (see Factor E in the ``Summary of

Factors Affecting the Species'' section).

Issue 61: One commenter stated there is scientific evidence that

certain dredging, navigation, waste water discharges, silvicultural,

and agricultural activities may actually benefit filter feeders through

nutrient enrichment, flow regime modification, and temperature

modulation.

Response: The commenter provided no specific references. The

Service believes significant changes in water quality, including large

increases in sediments, decrease in flow due to impoundments, and

nutrient increases, have been generally detrimental to the native

mussel fauna (Weber 1981, Sheehan et al. 1989, Goudreau et al. 1993).

Issue 62: One commenter stated that, in certain parts of the world,

mussels were used to clean up toxic waste waters, and wondered why

these species seemed to be more susceptible to toxins when all they had

to cope with were agricultural runoff and waste water treatment plant

effluents. The individual wanted to know what chemicals were the most

toxic to mussels.

Response: Mussels are filter feeders that continually pass large

volumes of water through their bodies. Mussels take in heavy metals and

other contaminants and store them in their tissues or incorporate them

into their shells. This allows them to effectively filter pollutants

from water, but only if the species' toxicity threshold is not exceeded

or its reproductive capacity is not impaired.

Cadmium may be the most toxic heavy metal to mussels (Havlik and

Marking 1987). Other heavy metals, ammonia, and chlorine also appear to

be particularly toxic to mussels, especially in the early life stages.

Issue 63: Several respondents questioned the mussel listings if

many of their populations are non-viable. If so, not only was recovery

impossible, but the Service should not have expended funds for mussel

surveys.

Response: These mussel populations have been significantly reduced

in numbers and now exist only as fragmented populations in altered

habitats (see ``Species Accounts'' in the ``Background'' section).

Although some populations may not be viable, this does not preclude

listing. Such populations could be augmented with juveniles produced

through artificial propagation or with reproducing adults from another

population.

Issue 64: Several respondents stated that because the Service's

recovery record was poor, additional species should not be listed.

Another implied that the proposal did not contain data needed to effect

recovery or predict the species' recovery potential.

Response: A species' recovery potential is not a factor in making a

listing determination. Most endangered and threatened species reached

that status over many decades due to habitat loss and other complex

causes. Recovery of these species should not be expected to be rapid or

easy. Recovery planning and implementation occur following a species'

listing, as required by section 4(f) of the Act.

Issue 65: A few malacologists thought that it was the Service's

responsibility to see that life history studies on these species and

research on the well-being of river ecosystems should be conducted.

Response: In preparing the recovery plan for these species, the

Service will consider the need for such research and incorporate it in

the plan as appropriate.

Issue 66: Numerous commenters believed these listings would

significantly impact economies of the three States. One respondent

stated that the Service had ``juggled'' the numbers regarding section 7

consultations to mislead the public.

Response: Based on its experiences with the Act and listed mussels,

the Service does not believe the listing of these species will have a

significant effect on the economy of the three States where they occur.

A 1992 General Accounting Office audit found that 99.9 percent of all

projects (18,211) that were reviewed under the Act between 1988 and

1992 went forward unchanged or with only minor modifications. Only six

projects were halted due to endangered species considerations.

Issue 67: Numerous respondents stated that channel maintenance and

barge navigation in the ACF River system would be shut down or severely

curtailed if these species were listed.

Response: Through the section 7(a)(4) conference requirement of the

Act addressing species proposed for listing, the Service and the Corps

have agreed on measures regarding channel maintenance operations that

will avoid jeopardizing the mussel species present. These measures will

continue to be implemented once the species are listed (see ``Available

Conservation Measures'' section).

Issue 68: One respondent wanted the Service to guarantee that there

would be no financial hardship to industry, or that such costs should

be borne by the Service. Another wanted to know the if Service would

provide assurances regarding minimal potential impacts and restrictions

resulting from these listings. Several respondents requested that the

Service provide an analysis of the potential economic impacts of

listing these species.

Response: Under Section 4(b)(1)(A) of the Act, a listing

determination must be based solely on the best scientific and

commercial data available. The legislative history of this provision

clearly states the intent of Congress to ``ensure'' that listing

decisions are ``* * * based solely on biological criteria and to

prevent nonbiological considerations from affecting such decisions * *

*'' H.R. Rep. No. 97-835, 97th Cong., 2d Sess. 19 (1982). As further

stated in the legislative history, ``* * * economic considerations have

no relevance to determinations regarding the status of species * * *''

Id. at 20. Because the Service is specifically precluded from

considering economic impacts, either positive or negative, in a final

decision on a proposed listing, the Service need not consider the

economic impacts of listing these species.

Issue 69: The Corps disagreed with the statement that

channelization was a primary cause of habitat loss. They stated that

sediment instability in maintained channels made these areas too

unstable to maintain mussel communities.

Response: The impacts of channel modifications are addressed in

Factor A in the ``Summary of Factors Affecting the Species'' section.

[[Page 12677]]

Issue 70: The Corps stated that turbidity from dredging is not as

detrimental to benthic habitats as is runoff from streams along the

Apalachicola River after thunderstorms.

Response: Regardless of origin, impacts from sedimentation,

siltation, and turbidity sources may continue to be a problem in

portions of the ACF River system (see Factor A in the ``Summary of

Factors Affecting the Species'' section).

Issue 71: The Corps stated that the proposal did not provide

evidence for the statement that dredging activities resuspend toxicants

bound to sediments.

Response: While organochlorine insecticides were detected in less

than 10 percent of sediment and tissue samples taken in the ACF River

system during 1992 and 1993, such compounds were formerly widely used

in the basin (Buell and Couch 1995), are persistent in the environment,

toxic to aquatic life, and partitioned into both sediments and the

lipid reservoir of organisms (Day 1990, Burton 1992).

Issue 72: One respondent stated that the proposals did not explain

why impoundments were considered a primary cause of habitat loss.

Another stated that if impoundments are implicated, dams would be

required to be removed.

Response: Reservoir impacts on mussels are well documented, and

there is no evidence that any of the seven species can reproduce and

successfully recruit in impoundments (see Factor A in the ``Summary of

Factors Affecting the Species'' section). Although other factors

contributed to the mussels' decline, the Service believes reservoirs

were a significant factor. Since few if any of these species still

occur in reservoirs, dam removal is not a Service goal, nor would the

Act require such an action.

Issue 73: One commenter feared that the listings would affect ACF

River system water allocations under the Tri-State Water Study (TSW).

The Department of Energy's Southeastern Power Administration was

concerned that the mussel listings would require changes in reservoir

operations that might ultimately affect power generation capabilities.

Another individual thought the species were proposed at this time to

impact the on-going TSW study.

Response: The Service has no flow recommendations for these seven

mussels. The listing proposal was prepared after the completion of the

status survey according to normal listing priorities, and had no

connection with the TSW. However, a review of potential effects from

any proposed water allocation formula will be needed (see ``Available

Conservation Measures'' section).

Issue 74: Two malacologists stated that every human activity

affecting these species and their habitats should not have been

mentioned in the proposed rule; the Service should have focused on

specific factors (i.e., sedimentation, suspended solids, pollution)

with objective, supporting evidence.

Response: The information in the ``Summary of Factors Affecting the

Species'' section has been revised to emphasize the factors believed

most important in the decline of these mussels.

Issue 75: Some commenters disagreed with the Service's assertions

regarding the inadequacy of riparian buffers, particularly for

silvicultural activities. Another commenter stated that the Service

overlooked the fact that the State of Georgia had a law protecting

streamside buffers.

Response: The discussion of riparian buffers has been modified to

incorporate these comments (see Factor A in the ``Summary of Factors

Affecting the Species'' section).

Issue 76: Several commenters questioned the proposed rule's

implication of poor silvicultural practices as contributing to the

mussels' demise. One commenter feared there could be an impact to the

industry, whereas others requested that data be made available to

document habitat reduction as a result of these activities.

Response: Normal silvicultural activities on private lands should

not be affected by these listings (see ``Available Conservation

Measures'' section). The discussion of silvicultural activities has

been clarified in this final rule (see Factor A in the ``Summary of

Factors Affecting the Species'' section).

Issue 77: One commenter stated that timber is a long-term crop and

clear-cutting leaves land generally undisturbed for 25 years or more.

Response: Although clear-cutting may be conducted on a long-term

basis, best management practices for silvicultural activities are

important to protect stream habitats long after such activities have

occurred (see Factor A in the ``Summary of Factors Affecting the

Species'' section).

Issue 78: One respondent stated that if the mussels were listed,

subsequent recovery plans would restrict land use practices and private

property rights. Another stated that if these species are listed,

private individuals and businesses could be subject to sections 7, 9,

and 10 of the Act.

Response: Recovery plans include reasonable actions that the

Service believes necessary to bring species back to the point they no

longer need protection under the Act. They do not restrict land use

practices and private property rights. The recovery planning process is

designed to allow potentially affected segments of the public to

participate in decision making and allows the special local knowledge

of affected communities to be fully considered. Draft plans are made

available for public review and comment, and all affected or interested

individuals and groups are encouraged to participate.

Listing will provide these species the protection of sections 7

(Federal agency actions and consultations) and 9 (prohibitions) of the

Act. Section 9 ``taking'' exemptions are available under both sections

7 and 9. Section 7(b)(4) of the Act provides for incidental take

involving Federal actions if such take is not likely to jeopardize

listed species and if reasonable and prudent measures are implemented

to minimize such take. For further discussion of Federal activities

associated with these listings, see the ``Available Conservation

Measures'' section.

Section 10 of the Act provides for the issuance of permits to

conduct otherwise prohibited activities. Through section 10 habitat

conservation planning (HCP) there is an opportunity to provide species

protection and habitat conservation for non-Federal development and

land use activities that may result in incidental take of a listed

species. For landowners and local governments, it provides long-term

assurances that their activities will be in compliance with the

requirements of the Act. Biologically, it provides the Service with a

tool to offset the incidental take of listed, proposed, candidate, and

other species by reconciling species conservation with economic

development.

Issue 79: One respondent wanted a clarification of the Service's

term ``poor land-use practices.''

Response: Poor land-use practices in the proposed rule referred to

activities that cause excessive erosion and contribute to stream

sedimentation, siltation, and turbidity. These include activities such

as clearing or plowing to the edge of stream banks, or carrying out

upland development without adequate silt screens or erosion control.

Issue 80: Several respondents stated that the species' decline

resulted from historical disturbances, and that present conditions had

improved, making listing unnecessary. Another respondent realized the

role of historical impacts,

[[Page 12678]]

but supported the listings and felt more should be done to protect the

remaining populations.

Response: Historical human activities have contributed to these

species' current status, and some factors may continue to threaten

these mussels (see Factor A in the ``Summary of Factors Affecting the

Species'' section). Although certain factors affecting these species

have improved, continuing threats to these species qualify them for

listing. Listing will provide the Act's protective and recovery

measures.

Issue 81: Several respondents thought the agricultural community

was being directly implicated in poor land use practices. Other

respondents felt better documentation was needed concerning

agricultural impacts, and believed that normal agricultural practices

would be impacted from the listings.

Response: Listing of these mussels should not affect normal

agricultural practices (see ``Available Conservation Measures''

section). Implementation of agricultural best management practices has

reduced erosion in the Apalachicolan Region, and the percentage of

agricultural lands has declined as second-growth forest has replaced

formerly cultivated lands (Couch et al. 1996). If best management

practices are followed, the Service believes that agricultural

activities will be compatible with the continued survival of these

seven mussels.

Issue 82: Several respondents stated that listing the mussels would

adversely impact the gravel-mining industry.

Response: Large-scale mining of stable substrate inhabited by these

mussels would be detrimental to them. The mining of unsuitable habitat

(i.e., unconsolidated substrates, substrates within impoundments) would

not be likely to affect them. Gravel mining in the Chattahoochee River

should be unaffected (see Factor A in the ``Summary of Factors

Affecting the Species'' section).

Issue 83: One commenter feared that these listings could cause

modification, significant construction cost increases, or even

abandonment of existing and planned waste water treatment plants.

Another commenter wanted to know what would happen to municipalities

that discharged effluents into streams inhabited by these species.

Response: The Service has no information showing that current water

quality standards threaten these species. At the time water quality

standards for particular states are reviewed under section 402 of the

Clean Water Act, the EPA will be required to consult with the Service

on any standards that may affect listed species. In the course of the

EPA review of Alabama's water quality standards, the Service's

biological opinion (dated October 8, 1996) resulting from consultation

with EPA determined that there was not sufficient information to

determine whether the standards were likely to jeopardize the continued

existence of some of the listed species found in Alabama. The opinion

anticipated incidental take for a number of listed species, required

modification of water quality standards to protect listed species, and

specified monitoring and research conditions to determine if changes in

the standards were necessary. The Service anticipates that future water

quality standard consultations will follow a similar approach.

Issue 84: The Corps recommended that a statement in the proposed

rule regarding the prolonged release of toxic chemicals from a

Department of Defense facility should be revised, and that the Service

should have considered the long-term dilution factor.

Response: A facility near Albany, Georgia, discharged an estimated

3.6 billion liters (l) (0.95 billion gallons (g)) of rinse, stripping,

cleaning, and plating solutions through a short canal into the Flint

River from 1955 to 1977. The Corps stated that the flow rate in the

Flint River provided an average dilution rate of 1:127,555 l (1:33,700

g) over the 22-year period. Many of these toxicants were heavy metals

used in plating solutions. Regardless of this dilution factor, the

Service believes the long-term release of this effluent likely had, and

may continue to have, a chronic toxic effect on Flint River mussel

populations (see Factor A in the ``Summary of Factors Affecting the

Species'' section) and deserves additional study.

Issue 85: A few commenters questioned the threat of toxic chemical

spills on highway and railway bridges over streams. Some commenters

thought that any listing would hamper efforts to rebuild bridges washed

out during major floods.

Response: Toxic chemical spills can occur at highway, railway, and

pipeline crossings, and industrial sites (see Factor A in the ``Summary

of Factors Affecting the Species'' section). Section 7 consultations

for bridge replacements are performed on a regular basis for aquatic

species throughout the southeast; occasionally, species surveys are

requested prior to construction. Most such projects do not affect, or

have minimal effects on, listed species. These listings are not

expected to affect bridge replacement.

Issue 86: One commenter wanted to know why Federal protection was

necessary if the listings would not affect individual activities.

Response: The Act requires listing based on the five criteria in

section 4(a) and does not allow for consideration of impacts, or a lack

thereof, on individual activities as part of a listing decision.

Issue 87: The Corps stated that the proposal provided minimal

evidence to prioritize human activities that may have affected mussel

habitat.

Response: Additional information on such human activities has been

provided in Factor A in the ``Summary of Factors Affecting the

Species'' section.

Issue 88: One respondent requested information relating to cost/

benefit ratios associated with recovery actions.

Response: Costs associated with implementation of recovery tasks

will be estimated when the recovery plan is developed for these

species. Cost/benefit ratios are not calculated in recovery plans.

Issue 89: One respondent asked what effect the listing would have

on commercial fishermen.

Response: The use of these mussels for bait would be a violation of

section 9 of the Act. No other effects on commercial fishermen are

anticipated.

Issue 90: Several commenters believed the Service had

misrepresented the science in the proposed rule, based upon an internal

Service memorandum. Some individuals felt the Service had changed its

position on the importance of human impacts after the proposed rule was

published.

Response: The Service believes the proposed rule was scientifically

sound, as was confirmed by peer review. Regardless of editing changes

in the draft, the proposed rule signed by the Service Director and

published in the Federal Register on August 3, 1994 (59 FR 39524),

represented the Service's position on the various threats to the seven

mussels. In formulating this final rule, the Service has considered all

substantive comments and re-examined these threats (see the ``Summary

of Factors Affecting the Species'' section).

The perception that the Service changed its position was apparently

based on the description in the proposed rule of human activities (e.g.

agriculture and forestry) that had impacted these species, versus the

Service's explanation at public meetings that the listing would have

little impact on such activities. Most of these activities are not

directly regulated or monitored by the Service or other Federal

agencies, and are, therefore, unlikely to be affected. Secondly, many

human activities result in effects that are non-point in origin (e.g.,

erosion)

[[Page 12679]]

and are not easily attributable to a particular source. The ways in

which these listings are expected to affect human activities are

discussed in the ``Available Conservation Measures'' section below.

Issue 91: EPA requested that the Service clarify the following

statement in the proposal--``Existing authorities available to protect

aquatic systems, such as the Clean Water Act [CWA] administered by EPA

and the [Corps], 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.'' EPA also requested that

the Service identify deficiencies in their implementation of the CWA

regarding State adopted narrative and numeric water quality criteria,

State water use classifications by streams occupied by these species,

aquatic life criteria guidance values; and National Pollutant Discharge

Elimination System (NPDES) permit procedures. Several respondents

questioned the need to improve regional water quality, suggesting that

existing regulations are adequate to protect the species, and that poor

water quality had been corrected since the passage of the CWA.

Response: Through implementation of the CWA, water quality has

improved following the construction of advanced waste water treatment

plants. Water quality criteria, however, were developed without

specific knowledge of the tolerances of these seven mussels and

previously listed mussels, which may be more sensitive than the species

typically used to test waste water (Keller and Zam 1991, Keller 1993).

Some mussel populations continue to decline even in areas that appear

to have suitable physical habitat. Environmental factors including

contaminants may still be adversely affecting the growth, reproduction,

recruitment, and/or survival of these populations (see Factors A and E

in the ``Summary of Factors Affecting the Species'' section). Little is

known about the potential impacts of contaminants on fresh water

mussels. Research is needed to address the lethal and sublethal effects

of acute and chronic exposure to toxins for all life stages of mussels.

This research will entail identifying appropriate surrogate species,

devising test protocols, and conducting studies to evaluate the

effectiveness of these criteria. 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, standards, and NPDES permits within the Service's Southeast

Region. Until the MOA is developed and data are available to fully

evaluate the effectiveness of current national water quality standards,

the Service believes it is premature to attempt, in this final rule, to

address any specific deficiencies and/or inadequacies that may exist in

EPA's implementation of the CWA regarding the protection of water

quality.

Issue 92: One respondent questioned if the Service had complied

with the National Environmental Policy Act in the development of this

rule.

Response: See ``National Environmental Policy Act'' section.

Issue 93: A few respondents stated that current State and Federal

laws, interagency regulations, permit guidelines, and voluntary

programs governing land usage were sufficient to protect the mussels,

and thus, questioned the need to provide additional protection when

private property rights would be compromised.

Response: The Service agrees that current State and Federal laws

and regulations governing land use practices, if fully implemented,

provide significant protection for these species. However, the current

status of these seven species meets the listing criteria of the Act.

Listing will provide the additional protective and recovery provisions

of the Act.

Issue 94: Several respondents stated that listing these species

could be considered an unfunded mandate if State and local governmental

agencies are required to expend funds to satisfy permit requirements

for their protection.

Response: The Act does not mandate State participation in the

recovery of listed species, but the Service recognizes and is sensitive

to the fact that costs of some projects may increase as a result of

these listings. However, the decision to list the species is based on

biological factors regarding status and threats.

Issue 95: One respondent stated that the Service had not considered

the benefits that the erosion control practices required by the U.S.

Food Security Act have had on the aquatic environment.

Response: The Service agrees that these requirements have

benefitted mussels by reducing silt loads in streams.

Issue 96: One respondent stated that if these species are listed,

the public will not know when they are in violation of the Act until

``after the fact.''

Response: See the ``Available Conservation Measures'' section for

activities the Service believes would likely constitute violations of

section 9 of the Act.

Issue 97: One commenter stated that if the Service reintroduced

mussel populations, the public would not know where the reintroductions

occurred, or the regulatory impacts resulting from these efforts.

Response: Section 4(f)(4) of the Act requires the Service to

provide public notice and an opportunity for public review and comment

on all draft recovery plans. Establishment of an experimental

population under section 10(j) of the Act would be done by regulation,

thus, requiring the Service to identify the location of the population

and provide for a public comment period. Any population determined to

be an experimental population is treated as if it were listed as

threatened for purposes of establishing protective regulations under

section 4(d) of the Act. The special rule for the experimental

population would contain the prohibitions and exceptions for that

population.

Issue 98: Numerous commenters stated that the Service had limited

the public's opportunity to comment on the proposal by planning public

hearings outside the affected area, during the Thanksgiving holidays,

and at facilities too small to accommodate the public. They also stated

that comment periods were too short, that the Service might refuse to

pay for public hearing facilities, or had not planned to hold public

meetings.

Response: Section 4(b)(5) of the Act requires that one public

hearing be held on proposed listing regulations, if requested. Meetings

are discretionary and are held dependent on public interest and need.

In conjunction with the proposed rule, the Service held five public

information meetings followed by five public hearings in three States

throughout the range of the mussels (see first part of ``Summary of

Comments and Recommendations'' section). Meetings and hearings were

scheduled to avoid holidays or other conflicts. Meeting and hearing

sites contained seating well beyond the attendance needs at all events.

Comments were accepted at the hearings and by mail; the comment period

was opened four times, over a period of two years (59 FR 39524, 59 FR

63987, 60 FR 20072, 61 FR 36020). The Service, therefore, believes

there was adequate opportunity for public comment.

Issue 99: Several commenters stated that the Service had made the

determination to list these species prior to public consideration,

based on the term ``final rule'' having been used by Service employees

at a public meeting.

Response: The Service recognizes that during the proposal period,

the proper

[[Page 12680]]

terms relating to a regulatory decision are ``final decision'' and

``final decision document.'' This final rule has been prepared after

full consideration of all relevant comments and information received

during the comment period.

Issue 100: One respondent believed the Service had preconceived

ideas and conclusions as to the species' status prior to conducting the

status survey.

Response: The seven species were considered to be category 2

species prior to the status survey (see ``Previous Federal Action''

section), but this did not mean a decision had been made to list them.

Many species for which status surveys are carried out are found not to

meet the listing criteria of the Act.

Issue 101: Several respondents stated that the Service does not use

good science in the listing process; one respondent stated that the

listings would be arbitrary and capricious. Several respondents

believed that the Service had violated the Administrative Procedure

Act, the Act's ``best scientific and commercial data available''

standard, and Constitutional guarantees of equal protection and due

process.

Response: The Service believes that this final rule incorporates

the best available scientific and commercial information and complies

with the Administrative Procedures Act.

Issue 102: One individual stated that he was not provided an

opportunity to comment on the status survey report and the proposed

rule.

Response: The comment periods, public meetings, and public hearings

associated with the proposed rule (see ``Previous Federal Action''

section and the response to issue 98) provided extensive opportunities

for interested parties to comment on or to request copies of Service

documents.

Issue 103: One respondent commented that the Service was under

pressure to list as many as possible of the 3,000 species on the annual

notices of review.

Response: On February 28, 1996, (61 FR 7596) the Service revised

its candidate species list, replacing an old system that listed nearly

4,000 ``candidate'' species under three separate categories (see also

``Previous Federal Action'' section). The old system led many people to

the mistaken conclusion that the addition of thousands of species to

the Federal List of Endangered and Threatened Wildlife and Plants was

imminent. Under the revised list, only those species for which there is

enough information to support a listing proposal are called

``candidates.'' These were formerly known as ``category 1'' species.

The proposal to list these seven mussels followed the Service's normal

priorities and procedures.

Issue 104: Several respondents stated that the Service already

protects too many species and the country does not need any more listed

species.

Response: Section 4(a) of the Act requires species to be listed

based on the five listing factors. The Act sets no limit on the number

of species to be recognized as endangered or threatened.

Issue 105: A few commenters stated that the Service had failed to

designate critical habitat or was planning to designate critical

habitat for these species. One respondent feared that designating

critical habitat would halt navigation channel maintenance, whereas

another thought the Service should determine the critical habitat

necessary for their survival and then conduct an economic impact study.

Response: Section 4(a)(3) of the Act requires the Service to

designate critical habitat to the maximum extent prudent and

determinable at the time a species is listed. The Service has

determined that the designation of critical habitat for these seven

species is not prudent (see ``Critical Habitat'' section).

Issue 106: One commenter believed that any effort to delist a

mussel once it was placed on the Federal list would require volumes of

detailed data and be at the expense of local governments.

Response: The Act provides the same criteria to reclassify or

delist species as to list them. Subsequent to a listing, section 4(f)

of the Act requires the Service to develop and implement recovery plans

for all listed species. Recovery plans include goals for

reclassification and delisting. Section 4(c)(2) of the Act further

requires the Service to review the status of listed species every five

years to determine if reclassification or delisting is appropriate.

There is no obligation for local governments or other parties to

provide information on the status of listed species or to initiate

reclassification or delisting actions.

Issue 107: One respondent claimed the Service missed the

administrative deadline for publishing a final rule for these species.

Based on our Federal Register notice of July 9, 1996, (61 FR 36021) to

reopen the comment period, this commenter was unclear as to whether the

mussels faced ``imminent threat'' on the basis of the Service statement

that the proposals were a ``Tier 2 priority'' for listing.

Response: The congressional moratorium on final decisions on

proposed listings, from April 1995 to April 1996, precluded publication

of a final rule for these species by the Act's administrative deadline

of August 3, 1995 (see ``Previous Federal Action'' section). The

Service published listing priority guidance to address the backlog of

listing activities as a result of the moratorium (March 11, 1996 (61 FR

9651), May 16, 1996 (61 FR 24722), September 17, 1996 (61 FR 48962),

December 5, 1996 (61 FR 64475), and October 23, 1997 (62 FR 55268). The

guidance assigned the processing of a final decision for these seven

mussels to Tier 2 (resolving the listing status of outstanding proposed

rules).

The Service also solicited the expert opinions of 60 scientists

with knowledge of mussels and sampling methodologies, including most

North American malacologists. They were asked to comment on the

adequacy of the status survey in supporting the proposed rule.

Responses were received from 37 individuals and pertinent comments were

incorporated into this final rule.

Generally, the independent reviewers strongly supported the listing

proposal. Many agreed with the Service's concerns about the threats to

these species, including loss of riverine habitat, vulnerability of

specific stages of the life histories, and impaired reproduction. Seven

malacologists stated that the status survey was one of the most

comprehensive studies they were aware of.

Two malacologists suggested that the Service withdraw the proposed

rule and conduct further studies, but provided no specific information

justifying the withdrawal of the listing proposal. However, in a

written statement read at two of the public hearings, one of these

malacologists stated that ``* * * the integrity of the current study is

not questioned * * *'' (P.Yokley, Jr., University of North Alabama, in

litt. 1995).

Summary of Factors Affecting the Species

After a thorough review and consideration of all information

available, the Service has determined that the fat threeridge,

shinyrayed pocketbook, Gulf moccasinshell, Ochlockonee moccasinshell,

and oval pigtoe should be classified as endangered species, and the

Chipola slabshell and purple bankclimber should be classified as

threatened species. Procedures found at Section 4(a)(1) of the Act and

regulations implementing the listing provisions of the Act (50 CFR part

424) were followed. 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

[[Page 12681]]

the fat threeridge (Amblema neislerii), shinyrayed pocketbook

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

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

Historically, mussel faunas in the United States have declined

extensively as an unintended consequence of human development (Havlik

and Marking 1987, Neves 1993). The mussel fauna in much of the

Apalachicolan Region has been negatively impacted by impoundments,

siltation, channelization, and by water pollution. The cumulative

effect of these factors on the aquatic ecosystems of the ACF River

basin has not been systematically evaluated; an ongoing USGS National

Water Quality Assessment is currently addressing this task (Couch et

al. 1996).

Impoundments have permanently altered a significant portion of the

ACF River system, which has 16 mainstem impoundments. Impoundments

affect mussels by altering current, substrate (Sickel 1981, Holland-

Bartels and Waller 1987), and water chemistry (Allan and Flecker 1993,

Stansbery 1995), factors which are important to riverine mussels. Lack

of mussel recruitment in impoundments may be due to loss of glochidia

in the substrate, attacks on glochidia by microorganisms, or the

juveniles' inability to survive in silt (Ellis 1929, Scruggs 1960,

Williams 1969, Fuller 1974).

The Chattahoochee River has 13 dams, including three locks and dams

along its lower half; the lower mainstem is inundated for approximately

400 km (248 mi). An additional 85 km (53 mi) of mainstem habitat are

impounded upstream of Atlanta, making approximately 485 km (301 mi) of

the mainstem's 700 km (434 mi) total length (69 percent) impounded. The

lower portions of many tributaries were permanently flooded because of

these reservoirs, including a known site for the shinyrayed pocketbook

in Walter F. George Reservoir (Clench and Turner 1956).

Impoundments have altered approximately 175 km (109 mi) of 600 km

(372 mi), or 29 percent, of mainstem riverine habitat on the Flint

River. Preimpoundment records from Seminole and Blackshear reservoirs

exist for the fat threeridge and oval pigtoe (one site each), the Gulf

moccasinshell and purple bankclimber (two sites each), and the

shinyrayed pocketbook (three sites) (Clench 1955, Clench and Turner

1956).

Talquin Reservoir inundated approximately 32 km (20 mi) of riverine

habitat (of a total of 278 km [172 mi] of mainstem, or 12 percent

impounded) in the middle portion of the Ochlockonee River and the lower

5 km (3 mi) of the Little River, its largest tributary. Preimpoundment

records exist for four of these species from a site at the upstream end

of Talquin Reservoir (Clench and Turner 1956). This impoundment may

have flooded habitat for the Ochlockonee arcmussel, believed to be

extinct (Williams and Butler 1994), and may block potential host fish

movements for other mussels. The shinyrayed pocketbook, Ochlockonee

moccasinshell, and oval pigtoe were absent downstream of the dam. Only

occasional populations of the purple bankclimber were found in this

portion of the river.

Populations of the shinyrayed pocketbook, Gulf moccasinshell, and

purple bankclimber have been isolated due to major impoundments on the

Apalachicola, Flint, and Ochlockonee rivers. Smaller impoundments on

tributary streams in the region have resulted in further population

isolation of some of the species.

A navigation channel is maintained on the Chattahoochee and

Apalachicola rivers from Columbus, Georgia, to the Gulf Coast, a

distance of approximately 325 km (200 mi), and the lower 50 km (30 mi)

of the Flint River. River habitat and stable benthic substrates have

been altered in significant portions of this system. None of these

seven mussels occur in the navigation channels of the Chattahoochee or

Flint rivers. The fat threeridge and the purple bankclimber occur in

portions of the Apalachicola River that have a navigation channel. The

Corps and the Service have agreed on procedures to minimize impacts to

these species when navigation maintenance is carried out (see

``Available Conservation Measures'' section).

Many regional streams have increased turbidity levels due to

siltation. These seven mussels probably attract host fishes with visual

cues. Such a reproductive strategy depends on clear water. Turbidity is

a limiting factor impeding sight-feeding fishes (Burkhead and Jenkins

1991), and may have contributed to the decline of these seven species.

Light to moderate levels of siltation are common in many

Apalachicolan Region streams with populations of these seven species,

while heavy siltation has occurred in the Piedmont, which is well known

for its highly erodible soils. Most of the topsoil in the Piedmont was

eroded by 1935 (Wharton 1978). Clench (1955) attributed the decline of

the rich mussel fauna of the Chattahoochee River to erosion from

intensive farming before the Civil War. The steep slopes characteristic

of the Fall Line Hills and the Piedmont result in higher erosion rates

than slopes on more level lands (Pimentel et al. 1995).

Couch et al. (1996) indicated that all parts of the ACF Basin have

been subject to alteration of forest cover. They attributed severe

historical erosion and sedimentation in the Blue Ridge Province to

mining and logging. The Service believes that while deforestation

historically represented a threat to these mussels, current

silvicultural activities following best management practices are

compatible with the continued existence of the species (see Available

Conservation Measures' section).

Because of their sedentary characteristics, mussels are extremely

vulnerable to toxic effluents (Sheehan et al. 1989; Goudreau et al.

1993). There are discharges from 137 municipal waste water treatment

facilities in the ACF River basin. Although the quality of effluents

has improved since the 1980's due to improved waste water treatment and

a 1990 phosphate detergent ban in Georgia, two-thirds of the 938 stream

miles in the Georgia portion of the ACF River basin do not meet the

designated water use classifications under the requirements of the

Clean Water Act (Couch et al. 1996).

Agricultural influences include nutrient enrichment from confined

feeding of poultry and livestock (primarily in the Piedmont Province),

and inputs of pesticides and fertilizers from row crop agriculture

(primarily in the Coastal Plain) (Couch et al. 1996).

An estimated 3.6 billion liters (0.95 billion gallons) of chemical-

laden rinse, stripping, cleaning, and plating solutions were discharged

through a short canal into the Flint River from 1955 to 1977 at a

Department of Defense facility in Albany, Georgia (P. Laumeyer, Fish

and Wildlife Service, pers. comm.). The Service believes the long-term

release of this effluent likely had, and may continue to have, a

chronic toxic effect on Flint River mussel populations. The canal and

other portions of the facility are a Superfund site.

Abandoned battery salvage operations affect water quality in the

Chipola River. Concentrations of heavy metals (e.g., chromium and

cadmium) in Asian clams and sediments increased in samples taken

downstream from two

[[Page 12682]]

operations (Winger et al. 1985). Dead Lake, on the lower mainstem, was

considered a contaminant sink. Chromium was found at levels known to be

toxic to mussels (Havlik and Marking 1987) in sediment samples from

Dead Lake downstream (Winger et al. 1985). A large population of the

fat threeridge has been extirpated in Dead Lake, possibly from such

contamination.

Residential development in Georgia is resulting in the conversion

of farmland to subdivisions in areas relatively distant from the cities

of Albany, Atlanta, and Columbus. Development and land clearing

increases siltation from erosion, runoff and transport of pollutants

from stormwater, and municipal waste water facility effluents. Lenat

and Crawford (1994) found that in Piedmont drainages, urban catchments

had higher maximum average concentrations of heavy metals than

agricultural or forested catchments. Urban waterways may harbor human-

produced contaminants in concentrations sufficient to significantly

affect fish health (Ostrander et al. 1995).

Additional water supply impoundments may be planned to satisfy

expanding urban and suburban demand. Any impoundments on streams that

support these species may have impacts on their long-term survival.

Impoundments on streams that do not harbor these species could be

designed in ways to minimize or eliminate potential impacts to these

mussels and their habitat downstream. Future impoundments, particularly

in the metropolitan Atlanta area, could impact stream habitats where

small populations of the shinyrayed pocketbook, Gulf moccasinshell, and

oval pigtoe exist.

In-stream and near-stream gravel mining has occurred in various

portions of the Apalachicolan Region. Jenkinson (1973) recorded the

shinyrayed pocketbook, oval pigtoe, Gulf moccasinshell, and ten other

species in Little Uchee Creek, a tributary of the Chattahoochee River

in Alabama. The creek had supported in-stream gravel mining; only a few

shell fragments were found at Jenkinson's site in the status survey,

although living shiny-rayed pocketbooks were found at another site in

Little Uchee Creek. Gravel mining operations in the Chattahoochee River

do not pose a threat to these mussels since no populations exist there

now. However, where in-stream gravel operations are conducted in the

vicinity of populations of these species, mussels may be displaced,

crushed, or covered by bottom materials.

Some artifact and fossil collectors have used suction dredges to

scour benthic habitats in the ACF system. This can destroy mussel

habitat at the collection site and resuspend silt, impacting downstream

areas. In a study on the effects of suction dredging for gold on stream

invertebrates, Harvey (1986) concluded that impacts from suction

dredges can be expected to be more severe in streams with softer

substrates (e.g., sand, gravel), as is typical for most Apalachicolan

Region streams.

Many of the impacts discussed above occurred in the past as

unintended consequences of human development in the Apalachicolan

Region. Improved understanding of these consequences has led to

regulatory (e.g., the Clean Water Act) and voluntary measures (e.g.,

best management practices for agriculture and silviculture) and

improved land use practices that are generally compatible with the

continued existence of these mussels. Nonetheless, the seven mussel

species currently are highly restricted in numbers and distribution and

show little evidence of recovering from historic habitat losses.

B. Overutilization for Commercial, Recreational, Scientific, or

Educational Purposes

The threeridge (a relative of the fat threeridge) and the washboard

(Megalonaias nervosa), which is superficially similar to both the fat

threeridge and purple bankclimber, are heavily utilized as sources of

shell for nuclei in the cultured pearl industry. The Service has been

informed by commercial shell buyers that shells from the ACF River

system are of poor quality. However, shell material from this area may

be used as ``filler'' for higher quality material from elsewhere (J.

Brim Box, USGS, Gainesville, Florida, pers. comm.). In the 1980's, the

price of shell increased, resulting in increased competition for the

harvesting of shell beds in the Apalachicolan Region.

Biological supply companies have used the Flint River and possibly

the Ochlockonee River as sources for large mussel specimens, including

the purple bankclimber and possibly the fat threeridge, to sell to

academic institutions for use in laboratory studies. The practice of

dissecting mussels in introductory laboratory courses is no longer

widespread, and the threat posed to large species such as the fat

threeridge and purple bankclimber is probably decreasing.

Nonetheless, harvest of the fat threeridge and purple bankclimber

for these purposes could decimate their remaining populations (see

Factor D in this section). The increasing rarity of these mussels

potentially makes them more appealing to shell collectors. Revealing

specific stream reaches harboring these species could pose a threat

from collectors (see ``Critical Habitat'' section below).

State regulations now in effect should deter or prevent the threat

from commercial collecting (see Factor D below).

C. Disease or Predation

Diseases of mussels are virtually unknown; this factor is not

currently known to affect these seven species.

Juvenile and adult mussels may serve as prey for various animals,

mostly fishes, turtles, birds, and mammals (Fuller 1974). The muskrat

has been implicated in potentially jeopardizing recovery of federally

listed mussels (Neves and Odum 1989). Although muskrats are not common

within the range of these species, Piedmont populations of the

shinyrayed pocketbook, Gulf moccasinshell, and oval pigtoe in the upper

Flint River system may be subject to some degree of muskrat predation.

D. The Inadequacy of Existing Regulatory Mechanisms

A scientific collecting permit is required in the State of Georgia

to collect mussels for scientific purposes. Commercial harvest in

Georgia is allowed only for the washboard. Mechanical harvest of

mussels is illegal. Commercially harvested mussels in Georgia must be

large enough to not pass through a 102 mm (4.0 in) ring. The harvest

season is from April 1 to August 31. Hand-picking mussels requires a

resident or non-resident fishing license. Despite permit requirements,

enforcement is difficult and there are no present restrictions on sites

of harvest or quantity taken in Georgia. Although not a target species,

the purple bankclimber is superficially similar to the commercially

exploited washboard to be potentially threatened (see Factor B in this

section). The fat threeridge is probably extirpated from Georgia

(Butler 1993).

Mussel harvest in Florida is deemed non-profitable due to the

absence of large populations of desirable species and poor shell

quality, but there is potential for harvest of the fat threeridge and

purple bankclimber. In July 1996, the State of Florida enacted a

moratorium on commercial mussel harvest (G.L. Warren, FGFWFC, pers.

comm.). Limited collection of mussels under a State permit is allowed

for scientific or other non-commercial purposes. Alabama has commercial

harvest guidelines, including species

[[Page 12683]]

size limits, restricted harvest areas, and closed seasons. Of these

seven mussels, only the shinyrayed pocketbook is found in Alabama, and

it is not a commercially sought species.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

Because of slow growth and relative immobility, mussel

recolonization of impacted river reaches is a lengthy process, achieved

by dispersal of newly metamorphosed juveniles via infected host fish,

passive adult movement downstream (Neves 1993), and active migration or

passive movement downstream of small individuals (Kat 1982).

Establishment of self-sustaining populations requires decades of

immigration and recruitment, even for common species that may occur in

high densities (Neves 1993). A mussel species should be considered

stable only when active population recruitment is demonstrated and a

significant number of viable populations exists (A.E. Bogan, North

Carolina State Museum, in litt. 1995).

The exotic Asian clam (Corbicula fluminea) has invaded all of the

rivers where these seven mussels occur. First reported from the

Apalachicolan Region about 1960 (Schneider 1967), this species may

compete with native mussels for nutrients and space (Clarke 1983,

1986). Densities of Asian clams are sometimes high in Apalachicolan

Region streams, with estimates ranging from approximately 100/m (9/ft)

square (Flint River, Sickel 1973) to over 2,100/m (195/ft) square

(Santa Fe River, Bass and Hitt 1974). In some streams, the substrate

has changed from homogenous silty sand or sand to one with a gravel-

like component comprised of huge numbers of live and dead Asian clams.

Buttner and Heidinger (1981) estimated that an Asian clam could

filter an average of 347 milliliters (12.1 ounces) of water per hour.

Clarke (1983) hypothesized that at a density of 250/m (22/ft) square in

a 1 m (3.3 ft) deep river flowing at 1.6 km (1 mi) per hour, Asian

clams could filter 95 percent of the phytoplankton out of the water

over 38 river km (24 river mi). Clarke (1986) believed the Asian clam

posed a threat to the survival of the endangered Tar spinymussel

(Elliptio steinstansana) in North Carolina. Heard (1977) noted the

disappearance of local ACF River system mussel populations concurrent

with colonization of the Asian clam. Kraemer (1979) stated that the

Asian clam may outcompete native mussels in altered streams.

Another introduced bivalve, the zebra mussel (Dreissena

polymorpha), has caused the extirpation of numerous native mussel

populations and may pose a threat to these mussels in the future.

Introduced into the Great Lakes in the late 1980's, this exotic species

has been rapidly expanding its range in the South, but has not been

reported yet from Apalachicolan Region streams.

The complex life cycle of mussels increases the probability that

weak links in their life history will preclude successful reproduction

and recruitment (Neves 1993). Egg formation and fertilization are

critical phases in the life history, because many mussels fail to form

eggs (Downing et al. 1989) or fertilization is incomplete (Matteson

1948). Fertilization success has been shown to be strongly correlated

with spatial aggregation; excessively dispersed populations may have

poor success (Downing et al. 1993). The need for specific fish hosts

and the difficulty in recolonizing areas where mussels have been

decimated are other life history attributes which make them vulnerable

(see ``General Biology'' in the ``Background'' section).

These seven species have been rendered vulnerable to extinction due

to significant habitat loss, range restriction, and population

fragmentation and size reduction. Most of their populations have been

extirpated from the Piedmont portion of their historical ranges, four

of five species are extirpated from Alabama, and none of the species

remain in the Chattahoochee River. The restricted distribution of these

seven species also makes localized populations susceptible to

catastrophic events and collection.

The Service has carefully assessed the best scientific and

commercial information available regarding the past, present, and

future threats faced by these seven mussels in determining to make this

final rule. Based on this evaluation, the preferred action is to list

the fat threeridge, shinyrayed pocketbook, oval pigtoe, Gulf

moccasinshell, and Ochlockonee moccasinshell as endangered species, and

the Chipola slabshell and purple bankclimber as threatened species.

The fat threeridge, shinyrayed pocketbook, oval pigtoe, Gulf

moccasinshell, and Ochlockonee moccasinshell are in danger of

extinction throughout all or a significant part of their range as

follows:

Fat threeridge: This species historically occurred in the Flint,

Apalachicola, and Chipola rivers, and is currently known from six sites

on the latter two rivers. It has been extirpated from the Flint River,

which included most of its historic range. It has disappeared from most

of the historical sites where it was formerly found, and only seven

percent of sampled sites within the historic range still have live

individuals. Limited recruitment of young appears to be occurring only

at one site on the lower Apalachicola River.

Shinyrayed pocketbook: This species historically occurred in the

ACF, Chipola, and Ochlockonee River systems. It now occurs at only 21

percent of the historical sites sampled, and is extirpated from the

mainstems of the ACF rivers. Populations have declined significantly in

the Chipola River. The species occurs at 29 sites in tributaries of the

ACF rivers and the Chipola and Ochlockonee rivers. Only two sites show

evidence of recruitment; however, the largest known population shows no

signs of recruitment.

Gulf moccasinshell: This species historically occurred in the ACF,

Chipola, Choctawhatchee, and Yellow River systems and in Econfina

Creek. It is no longer present at most of the historical sites sampled,

and is apparently extirpated from the Apalachicola, Choctawhatchee, and

Yellow rivers. There are 13 known sites, none showing evidence of

recruitment.

Ochlockonee moccasinshell: This species occurred historically only

in the Ochlockonee River system. It was formerly known from eight

sites. It is now known only from two sites, where there is no evidence

of recruitment. Only three live individuals have been found since 1974.

Oval pigtoe: This species was historically found throughout the

ACF, Chipola, Ochlockonee, and Suwannee River systems, and in Econfina

Creek. It occurred at one-third of the historical sites sampled. It has

been extirpated from the mainstem of the Chattahoochee River,

representing a significant portion of its historical range; occurrences

in the Flint and Suwannee River systems have decreased from 32 to 12.

The species is currently known to occur at 26 sites, with no evidence

of recruitment.

The Chipola slabshell and purple bankclimber are likely to become

endangered species in the foreseeable future throughout all or a

significant part of their range:

Chipola slabshell: This species occurred historically at eight

sites in the Chipola River and one site in the Chattahoochee River

system. It is currently known from five sites in the Chipola River.

This species appears to have some tolerance of soft sediments and,

therefore, has more habitat potentially available than the other

species in this rule. It was, however, found only at nine percent of

the sites sampled within its historic range, and

[[Page 12684]]

there is no current evidence of recruitment.

Purple bankclimber: This species historically occurred in the ACF,

Chipola, and Ochlockonee River systems. It currently occurs in the

Apalachicola, Flint, and Ochlockonee rivers, with 41 sites known. It

may be extirpated from the Chattahoochee and Chipola rivers. There is

some evidence of recruitment at one site in the Apalachicola River.

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

considerations or protection; and (ii) specific areas outside the

geographic 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. ``Conservation'' means the use of all methods and procedures

needed to bring the species to the point at which listing under the Act

is no longer necessary.

Section 4(a)(3) of the Act, as amended, requires that, to the

maximum extent prudent and determinable, the Secretary designate

critical habitat at the time a species is determined to be endangered

or threatened. The Service's regulations at 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 prudent

for these species. Such a determination would result in no known

benefit to these species, and designation of critical habitat could

further pose a threat to them through publication of their site-

specific localities.

Critical habitat designation, by definition, directly affects only

Federal agency actions. Since these seven mussel 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 fat threeridge, shinyrayed

pocketbook, Gulf moccasinshell, Ochlockonee moccasinshell, oval pigtoe,

Chipola slabshell and purple bankclimber 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. As part of the development of this final rule,

Federal and State agencies were notified of the mussels' general

distributions, and they were requested to provide data on proposed

Federal actions that might adversely affect the species. Should any

future projects be proposed in areas inhabited by these mussels, the

involved Federal agency will already have the general distributional

data needed to determine if the species may be impacted by their

action, and if needed, more specific distributional information would

be provided. Therefore, habitat protection for these seven 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. 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 ACF and

Ochlockonee river systems and the Yellow and Santa Fe rivers. (For the

Apalachicola River, for example, see the discussion under ``Available

Conservation Measures'' below.) 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. 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, any benefit that might be

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 seven mussel 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 and 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.

All known populations of these seven mussel species occur in

streams flowing through private lands. One threat to all surviving

populations of these seven species appears to be pollutants in

stormwater runoff that originate from private land activities (see

Factor A). Therefore, the survival and recovery of these mussels will

be highly dependent on landowner cooperation in reducing land use

impacts. Controversy resulting from critical habitat designation has

been known to reduce private

[[Page 12685]]

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 seven

mussels.

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 seven mussel 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 local agencies, private

organizations, 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) of the Act 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.

The Service notified Federal agencies that may have programs which

could affect these species. Navigation maintenance on the Apalachicola

River has the potential to impact the fat threeridge and purple

bankclimber. These species are concentrated in two short reaches of the

Apalachicola River that have only minimal dredging requirements. The

Service and the Corps have agreed on the following criteria to address

potential navigational impacts--(1) dredging and dredge material

disposal can continue without further coordination with the Service in

all areas where these mussels were not found during the status survey

and in areas where the Corps has dredged or disposed dredge material

since 1991; and (2) in areas that do not meet the first criterion, the

Corps will consult further with the Service to determine if

modifications of their channel maintenance activities are needed to

protect the species. These further consultations may require the Corps

to conduct additional mussel surveys prior to initiating channel

maintenance activities. The Corps and the Service have established an

effective working relationship on this issue, and will make every

effort to continue navigation maintenance while protecting listed

mussels. If conflict arises, potential measures for resolution include

relocation of the channel alignment, disposal areas, or mussels.

A water supply reservoir is under consideration on Line Creek in

the upper Flint River system, in Cowetta and Fayette counties, Georgia.

This project would inundate historical habitat for the shinyrayed

pocketbook and oval pigtoe. The project applicant, Fayette County, will

need to secure a permit pursuant to section 404 of the CWA. In survey

efforts made subsequent to the status survey, however, none of these

seven species were found, and there is very little suitable habitat in

the area to be affected by the proposed dam and reservoir. One live

shinyrayed pocketbook was found several miles downstream of the

proposed dam site, but the Service does not believe the proposed

project will affect this area. Therefore, listing of this species will

not affect the project.

The Corps is responsible for operating the reservoirs and channel

structures in the ACF Basin for a variety of purposes, including

navigation, flood control, water supply, fish and wildlife resources,

recreation, and hydropower. Water allocation formulae are being

developed in conjunction with an Interstate Water Compact involving the

States of Alabama, Florida, and Georgia, to provide for the needs of

these States. Any allocation formula that might affect the seven

mussels will require section 7 consultation between the Corps and the

Service.

No other specific Federal actions were identified that would likely

affect any of the species. Federal activities for which potential

effects to the species would be reviewed include the issuance of

permits for reservoir construction, stream alterations, waste water

facility development, water withdrawal projects, pesticide

registration, agricultural assistance programs, mining, road and bridge

construction, Federal loan programs, water allocation, and hydropower

relicensing. However, it has been the experience of the Service that

nearly all section 7 consultations have been resolved so that the

species has been protected and project objectives met.

The Act and implementing regulations found at 50 CFR 17.21 and

17.31 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 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 is also 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 and threatened wildlife species under certain

circumstances. Regulations governing permits are at 50 CFR 17.22 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,

permits also are available for zoological exhibition, educational

purposes, or special purposes consistent with the purposes of the Act.

It is the policy of the Service (59 FR 34272) to identify at the

time of listing, to the maximum extent practicable, those activities

that would not constitute a violation of section 9 of the Act. The

intent of this policy is to increase public awareness of the effect of

these listings on proposed and ongoing activities within a species'

[[Page 12686]]

range. During the public comment period, comments were received

questioning the effect these listings would have on private landowners

(see response to Issues 69, 76, and 81 in the ``Summary of Comments and

Recommendations'' section), normal agricultural activities (see

response to Issue 84), silvicultural practices (see response to Issue

79), and commercial fishing (see response to Issue 92). The Service

believes, based on the best available information as outlined in the

``Summary of Comments and Recommendations'' section of this rule, that

the aforementioned actions will not result in a violation of section 9

provided the activities are carried out in accordance with any existing

regulations, permit requirements, and best management practices. The

Service also believes that most other human activities will not result

in a section 9 violation. These include use of the river by boaters,

anglers, and other existing recreational uses.

Activities that the Service believes could potentially result in

``take'' of these mussels include, but are not limited to, (1)

unauthorized collection or capture of the species; (2) unauthorized

destruction or alteration of the species' habitat (e.g., in-stream

mining, channelization, discharge of fill material); (3) violation of

any discharge or water withdrawal permit; and (4) illegal discharge or

dumping of toxic chemicals or other pollutants into wat

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