[Federal Register Volume 63, Number 50 (Monday, March 16, 1998)]
[Rules and Regulations]
[Pages 12664-12687]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-6493]
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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="" waters="" supporting="" these="" species.="" activities="" not="" identified="" in="" the="" above="" two="" paragraphs="" will="" be="" reviewed="" on="" a="" case-by-case="" basis="" to="" determine="" if="" a="" violation="" of="" section="" 9="" of="" the="" act="" may="" have="" occurred.="" the="" service="" does="" not="" consider="" these="" lists="" to="" be="" exhaustive="" and="" provides="" them="" as="" information="" to="" the="" public.="" questions="" regarding="" whether="" specific="" activities="" will="" constitute="" a="" violation="" of="" section="" 9="" should="" be="" directed="" to="" the="" field="" supervisor="" of="" the="" service's="" jacksonville,="" florida="" field="" office="" (see="" addresses="" section)="" or="" the="" field="" supervisor="" of="" the="" service's="" panama="" city,="" florida="" field="" office="" (u.s.="" fish="" and="" wildlife="" service,="" 1612="" june="" avenue,="" panama="" city,="" florida="" 32405,="" telephone="" 904/769-0552).="" requests="" for="" copies="" of="" the="" regulations="" on="" listed="" species="" and="" inquiries="" regarding="" prohibitions="" and="" permits="" should="" be="" addressed="" to="" the="" u.s="" fish="" and="" wildlife="" service,="" ecological="" services,="" 1875="" century="" boulevard,="" suite="" 200,="" atlanta,="" georgia="" 30345-3301="" (404/679-7313).="" national="" environmental="" policy="" act="" the="" fish="" and="" wildlife="" service="" has="" determined="" that="" an="" environmental="" assessment,="" as="" defined="" under="" the="" authority="" of="" the="" nepa="" of="" 1969,="" need="" not="" be="" prepared="" in="" connection="" with="" regulations="" adopted="" pursuant="" to="" section="" 4(a)="" of="" the="" act.="" a="" notice="" outlining="" the="" service's="" reasons="" for="" this="" determination="" was="" published="" in="" the="" federal="" register="" on="" october="" 25,="" 1983="" (48="" fr="" 49244).="" required="" determinations="" this="" rule="" does="" not="" contain="" collections="" of="" information="" that="" require="" approval="" by="" the="" omb="" under="" 44="" u.s.c.="" 3501="" et="" seq.="" references="" cited="" a="" complete="" list="" of="" all="" references="" cited="" herein,="" as="" well="" as="" others,="" is="" available="" upon="" request="" from="" the="" field="" supervisor="" (see="" addresses="" section).="" author="" the="" primary="" author="" of="" this="" final="" rule="" is="" mr.="" robert="" s.="" butler,="" u.s.="" fish="" and="" wildlife="" service,="" asheville="" field="" office,="" 160="" zillicoa="" street,="" asheville,="" north="" carolina="" 28801="" (704/258-3939).="" list="" of="" subjects="" in="" 50="" cfr="" part="" 17="" endangered="" and="" threatened="" species,="" exports,="" imports,="" reporting="" and="" recordkeeping="" requirements,="" transportation.="" regulation="" promulgation="" accordingly,="" the="" service="" amends="" part="" 17,="" subchapter="" b="" of="" chapter="" i,="" title="" 50="" of="" the="" code="" of="" federal="" regulations,="" as="" follows:="" part="" 17--[amended]="" 1.="" the="" authority="" citation="" for="" part="" 17="" continues="" to="" read="" as="" follows:="" authority:="" 16="" u.s.c.="" 1361-1407;="" 16="" u.s.c.="" 1531-1544;="" 16="" u.s.c.="" 4201-4245;="" pub.="" l.="" 99-625,="" 100="" stat.="" 3500;="" unless="" otherwise="" noted.="" 2.="" amend="" section="" 17.11(h)="" by="" adding="" the="" following,="" in="" alphabetical="" order="" under="" clams,="" to="" the="" list="" of="" endangered="" and="" threatened="" wildlife:="" sec.="" 17.11="" endangered="" and="" threatened="" wildlife.="" *="" *="" *="" *="" *="" (h)="" *="" *="" *="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" species="" vertebrate="" --------------------------------------------------------="" population="" where="" critical="" special="" historic="" range="" endangered="" or="" status="" when="" listed="" habitat="" rules="" common="" name="" scientific="" name="" threatened="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" *="" *="" *="" *="" *="" *="" *="" clams="" *="" *="" *="" *="" *="" *="" *="" bankclimber,="" purple..............="" elliptoideus="" u.s.a.="" (al,="" fl,="" and="" na.................="" t="" 633="" na="" na="" sloatianus.="" ga).="" *="" *="" *="" *="" *="" *="" *="" moccasinshell,="" gulf..............="" medionidus="" u.s.a.="" (al,="" fl,="" and="" na.................="" e="" 633="" na="" na="" penicillatus.="" ga).="" moccasinshell,="" ochlockonee.......="" medionidus="" u.s.a.="" (fl="" and="" ga).="" na.................="" e="" 633="" na="" na="" simpsonianus.="" *="" *="" *="" *="" *="" *="" *="" pigtoe,="" oval.....................="" pleurobema="" pyriforme="" u.s.a.="" (al,="" fl,="" and="" na.................="" e="" 633="" na="" na="" ga).="" *="" *="" *="" *="" *="" *="" *="" pocketbook,="" shinyrayed...........="" lampsilis="" u.s.a.="" (al,="" fl,="" and="" na.................="" e="" 633="" na="" na="" subangulata.="" ga).="" *="" *="" *="" *="" *="" *="" *="" slabshell,="" chipola...............="" elliptio="" u.s.a.="" (al="" and="" fl).="" na.................="" t="" 633="" na="" na="" chipolaensis.="" [[page="" 12687]]="" *="" *="" *="" *="" *="" *="" *="" threeridge,="" fat..................="" amblema="" neislerii...="" u.s.a.="" (fl="" and="" ga).="" na.................="" e="" 633="" na="" na="" *="" *="" *="" *="" *="" *="" *="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" dated:="" january="" 23,="" 1998.="" jamie="" rappaport="" clark,="" director,="" fish="" and="" wildlife="" service.="" [fr="" doc.="" 98-6493="" filed="" 3-13-98;="" 8:45="" am]="" billing="" code="" 4310-55-p="">