[Federal Register Volume 59, Number 148 (Wednesday, August 3, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-18923]
[[Page Unknown]]
[Federal Register: August 3, 1994]
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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; Proposed
Endangered Status for Five Freshwater Mussels and Proposed Threatened
Status for Two Freshwater Mussels From Eastern Gulf Slope Drainages of
Alabama, Florida, and Georgia
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule.
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SUMMARY: The Fish and Wildlife Service (Service) proposes to list seven
freshwater mussels: The fat three-ridge (Amblema neislerii), shiny-
rayed pocketbook (Lampsilis subangulata), Gulf moccasinshell
(Medionidus penicillatus), Ochlockonee moccasinshell (Medionidus
simpsonianus), and oval pigtoe (Pleurobema pyriforme) as endangered,
and the Chipola slabshell (Elliptio chipolaensis) and purple
bankclimber (Elliptoideus sloatianus) as threatened under the
Endangered Species Act (Act) of 1973, as amended. These mussels are
endemic to eastern Gulf Slope streams draining the Apalachicolan Region
of southeast Alabama, southwest Georgia, and north Florida. They are
currently known from localized portions of from one to four isolated
marine river systems, mostly in the eastern portion of the
Apalachicolan Region. Impoundments and deteriorating water and benthic
(bottom) habitat quality resulting from channel modification,
siltation, agricultural runoff, silvicultural activities, mining
activities, pollutants, poor land use practices, increased
urbanization, and waste discharges have resulted in the restriction and
fragmentation of these mussels current ranges. In addition, the Service
has little evidence to suggest that populations of these seven species
of mussels are reproductively viable.
DATES: Comments from all interested parties must be received by
November 1, 1994. Public hearing requests must be received by September
19, 1994.
ADDRESSES: Comments and materials concerning this proposal should be
sent to the Field Supervisor, U.S. Fish and Wildlife Service,
Jacksonville Field Office, 6620 Southpoint Drive South, Suite 310,
Jacksonville, Florida 32216 (904/232-2580). Comments and materials
received will be available for public inspection, by appointment,
during normal business hours at the above address.
FOR FURTHER INFORMATION CONTACT: Mr. Robert S. Butler at the above
address.
SUPPLEMENTARY INFORMATION:
Background
The fat three-ridge, shiny-rayed pocketbook, Gulf moccasinshell,
Ochlockonee moccasinshell, oval pigtoe, Chipola slabshell, and purple
bankclimber are freshwater mussels endemic to eastern Gulf Slope
streams draining the Apalachicolan Region (streams from the Escambia to
the Suwannee river systems in southeast Alabama, southwest Georgia and
north Florida). The Apalachicolan Region primarily drains the Coastal
Plain Physiographic Province. Only the headwaters of the Flint and
Chattahoochee rivers, in the Apalachicola River system, occur above the
Fall Line in the Piedmont Physiographic Province in west-central
Georgia. Streams draining the East Gulf Coastal Plain are generally low
gradient and have substrates of sand, silty sand, mud, and gravel. Some
streams, particularly in the Apalachicola River system, have coarser
substrates of cobble, boulders, and bedrock in addition to areas with
softer bed materials. The seven species of mussels being considered for
listing inhabit medium-sized streams to large rivers with substrates of
silty sand, sand, or gravel, and mixtures of these substrates. All are
generally found in areas with water currents, often in stream channels
swept free of silt. The life histories of these seven species of
mussels are unknown and little biological information is available.
The Apalachicolan Region is known for its high level of endemicity,
harboring nearly 30 species of endemic mussels (Butler 1989), at least
a dozen fishes, over 20 aquatic snails, and nearly two dozen species of
crayfish. In addition, several candidate species from the Service's
animal notice of review published on November 21, 1991 (56 FR 58804)
are also known from the Apalachicolan Region, the majority being
endemic to these drainages. One of these candidates, the Ochlockonee
arc-mussel is thought to be extinct (Turgeon et al. 1988), last
reported in the early 1930's (Williams and Butler, in press). A recent
status survey for candidate species of mussels in the Apalachicola
River system did not locate any populations of the winged spike and
lined pocketbook, species endemic to this system that were last sighted
in 1958 and 1967, respectively. Between 1991 and 1993, the Service's
National Fisheries Research Center, now the National Biological Survey,
Biological Science Center, in Gainesville, Florida, completed field
surveys for mussels in both the Apalachicola (325 collections at 315
sites) and Ochlockonee (77 collections at 72 sites) river systems.
These surveys are summarized by Butler (1993), and the information is
sufficient to support a status recommendation of endangered for the fat
three-ridge, shiny-rayed pocketbook, Gulf moccasinshell, Ochlockonee
moccasinshell, and oval pigtoe, and a status recommendation of
threatened for the Chipola slabshell and purple bankclimber. Common and
scientific nomenclature used in this rule follows that suggested by
Turgeon et al. (1988).
The fat three-ridge (Amblema neislerii) is a medium-sized to large,
subquadrate, inflated, solid, and heavy shelled mussel that reaches a
length of 102 millimeters (4.0 inches). Older individuals are often so
inflated that their width approximates their length. The dark brown to
black shell is strongly sculptured with seven to eight prominent
horizontal parallel ridges. Internally, there are two subequal
pseudocardinal teeth in the left valve and one large and one small
tooth in the right valve. The nacre is bluish white to light purplish
and very iridescent. The Service considers Unio neislerii to be a
synonym of Amblema neislerii.
This taxon was originally assigned to the genera Quadrula and
Crenodonta by Simpson (1914) and Clench and Turner (1956),
respectively. Subsequent investigators have placed the fat three- ridge
in the genus Amblema. The fat three-ridge was described from the Flint
River, Macon County, Georgia, and it historically occurred in the
mainstems of the lower two-thirds of the Flint, the lower one-third of
the Chipola, and in the Apalachicola rivers (Clench and Turner 1956,
Butler 1993). Since 1981, no live specimens have been found in the
Flint River. Its present range is restricted to six localities in
Florida, three each in the Apalachicola River mainstem and the
lowermost Chipola River mainstem (Butler 1993). Only two of these
localities have sizable populations, which number in the dozens of
specimens. However, the viability of these populations of the fat
three-ridge is not known. The fat three-ridge has a very low tolerance
for impoundments.
The shiny-rayed pocketbook (Lampsilis subangulata) is a medium-
sized mussel that reaches approximately 85 mm (3.3 in) in length. The
shell is subelliptical, with broad, somewhat inflated umbos and a
rounded posterior ridge. The fairly thin but solid shell is smooth and
shiny, and light yellowish brown with fairly wide bright emerald green
rays over its entire length. Older individuals appear much darker brown
with obscure raying. Internally, the pseudocardinal teeth are double
and fairly large and erect in the left valve with one large tooth and
one spatulate tooth in the right valve. The nacre is white, with some
individuals exhibiting a salmon tint in the vicinity of the umbonal
cavity. The Service recognizes Unio subangulatus and Unio kirklandianus
as synonyms of Lampsilis subangulata.
The shiny-rayed pocketbook was described from the Chattahoochee
River, Columbus, Georgia. Historically, this mussel occurred at 18
different Flint River system localities including numerous tributaries
and several mainstem sites, 1 Chattahoochee River mainstem site and 6
sites in some of its tributaries, 2 sites in an Apalachicola River
tributary (Mosquito Creek), a couple of Chipola River tributary sites
and several localities in the mainstem above Dead Lake, and several
sites in the Ochlockonee River mainstem from Talquin Reservoir upstream
to Georgia and in a couple of its tributaries (Clench and Turner 1956,
Butler 1993). The 19 populations presently known are restricted to: a
single Uchee Creek system site in the Chattahoochee River system of
Alabama, 11 scattered sites in Flint River tributaries, 2 sites in the
Chipola River system including a mainstem and tributary (Dry Creek)
site, and 5 Ochlockonee River mainstem and tributary sites in the upper
half of the system (Butler 1993). The shiny-rayed pocketbook presently
occupies about two-thirds of its original range. Population sizes
numbered in the dozens of individuals at a few historical sites in both
systems. However, recent collections are generally represented by only
a few individuals, and evidence of any production is scarce. This
riverine species does not tolerate impoundments.
The Gulf moccasinshell (Medionidus penicillatus), a small mussel,
reaches a length of about 55 mm (2.2 in), is elongate-elliptical or
rhomboidal in shape and fairly inflated, and has relatively thin
valves. The ventral margin is nearly straight or slightly rounded. The
posterior ridge is rounded to slightly angled and intersects the end of
the shell at the base line. Females tend to have the posterior point
above the ventral margin and are somewhat more inflated than males.
Sculpturing consists of a series of thin, radially-oriented plications
along the length of the posterior slope. The remainder of the shell
surface is smooth and yellowish to greenish brown with fine, typically
interrupted green rays. The left valve has two stubby pseudocardinal
and two arcuate lateral teeth and the right valve has one
pseudocardinal and one lateral tooth. Nacre color is smokey purple or
greenish and slightly iridescent at the posterior end. The Service
recognizes Unio penicillatus and Unio kingi as synonyms of Medionidus
penicillatus.
Much confusion clouds the taxonomy of Medionidus species in the
Apalachicolan Region. In the Chipola River system, van der Schalie
(1940) recorded two species of Medionidus (M. kingi and M.
penicillatus). Clench and Turner (1956) synonomized M. kingi and two
other nominate species, the Ochlockonee moccasinshell and Suwannee
moccasinshell with the Gulf moccasinshell, an arrangement also followed
by Burch (1975). Johnson (1970) erroneously reported both the Gulf
moccasinshell and Suwannee moccasinshell from the Apalachicola River
system and the Suwannee moccasinshell from the Ochlockonee and Suwannee
rivers as well. In his monograph on Medionidus, Johnson (1977)
recognized the validity of the Gulf moccasinshell, Ochlockonee
moccasinshell, and Suwannee moccasinshell from Apalachicolan Region
streams based on shell characters. Turgeon et al. (1988) also
recognized the validity of these three allopatrically distributed
mussels.
The Gulf moccasinshell was described from three sites in the
Apalachicola River system in Georgia: the Chattahoochee River near
Columbus and Atlanta, and the Flint River near Albany. The historical
distribution of this diminutive species included 18 sites in the
tributaries and mainstems of the Flint and Chattahoochee rivers, one
Apalachicola River site, and 12 sites in the Chipola River system. The
Gulf moccasinshell is known from 38 historical sites and has been
eliminated from about three-quarters of its original range. It persists
at eight tributary sites in the middle Flint River system, and in
Econfina Creek (Butler 1993) but has not been collected in the
Choctawhatchee River system since the early 1930's. Large populations
(60+ individuals) were documented at several of historical sites in the
Chipola River system (van der Schalie 1940); they probably occurred in
similar numbers at other sites as well. However, recent collections of
the Gulf moccasinshell indicate that only small populations persist
today. The Service's recent survey of the Apalachicola River system
located a total of only 10 specimens. Given the small sample sizes, the
population viability of this species is questionable. The Gulf
moccasinshell does not tolerate impoundments.
The Ochlockonee moccasinshell (Medionidus simpsonianus) is a small
species, generally under 55 mm (2.5 in) in length. It is slightly
elongate-elliptical in outline with the posterior end obtusely rounded
at the shells median line and the ventral margin broadly curved. The
posterior ridge is moderately angular and covered in its entire length
with well developed, irregular ridges. Sculpturing may also extend onto
the disk below the ridge and the surface texture is smooth. The color
is light brown to yellowish green, with dark green rays formed by a
series of connecting chevrons or undulating lines across the length of
the shell. Internal characters include thin straight lateral teeth and
compressed pseudocardinal teeth. There are two laterals and two
pseudocardinals in the left valve and one lateral and one
pseudocardinal in the right valve. The nacre is bluish white. The
Service considers Unio simpsonianus to be a synonym of Medionidus
simpsonianus.
The Ochlockonee moccasinshell was described from the Ochlockonee
River, Calvary, Grady County, Georgia. This mussel was known
historically from six sites in the mainstem above Talquin Reservoir,
three each in Georgia and Florida, and single site locations on the
lower mainstem below Talquin Reservoir and in the Little River (Johnson
1977, Butler 1993). However, since 1974, the Ochlockonee moccasinshell
has been represented by only two live individuals (both found as
individuals at a single site in the mainstem above Talquin Reservoir in
Florida in the past 5 years) despite concerted efforts by numerous
investigators to locate additional populations. Four weathered dead
shells were found at other mainstem sites in the past few years,
including two sites in Georgia and one site in Florida. Once a fairly
common species, with some populations numbering in the dozens of
individuals, the Ochlockonee moccasinshell is now one of the rarest
mussels in North America. This narrow endemic does not tolerate
impoundment conditions.
The oval pigtoe (Pleurobema pyriforme) is a small to medium-sized
mussel that attains a length of about 60 mm (2.4 in). The shell is
suboviform compressed, with a shiny smooth epidermis. The periostracum
is yellowish, chestnut, or dark brown, rayless, and with distinct
growth lines. The posterior slope is biangulate and forms a blunt point
on the posterior margin. The umbos are slightly elevated above the
hingeline. As is typical of the genus, no sexual dimorphism is
displayed in shell characters. Internally the pseudocardinal teeth are
fairly large, crenulate and double in both valves. The lateral teeth
are somewhat shortened, arcuate and double in each valve. Nacre color
varies from salmon to bluish white and is iridescent posteriorly.
Variation in this species has led to the description of various nominal
species. The Service recognizes Unio pyriforme, Unio modicus, Unio
bulbosus, Unio amabilis, Unio reclusum, Unio harperi, and Pleurobema
simpsoni as synonyms of Pleurobema pyriforme.
The oval pigtoe was described from the Chattahoochee River, near
Columbus, Georgia. Historically, this species was one of the most
widely distributed mussels endemic to the Apalachicolan Region. It
occurred throughout the mainstems and several tributaries of both the
Flint (16 sites) and Chipola (10 sites) river systems, at 5 sites in
the Chattahoochee River system including one mainstem site, all
associated with the Fall Line in Alabama and Georgia, at 6 sites in the
Ochlockonee River mainstem above Talquin Reservoir in Florida and
Georgia, at a single site on the lower Suwannee River and 15 sites in
the upper Santa Fe River system, its major tributary, in north Florida,
and at a site in Econfina Creek, in northwest Florida (Clench and
Turner 1956, Butler 1993). Fifty-four total historical sites are known.
Existing populations have been verified from 21 sites, including 5
scattered tributaries (7 sites) of the Flint River system and a single
mainstem site, 4 Chipola River sites and 1 in its tributary Dry Creek,
6 upper Ochlockonee River mainstem sites, and single sites in both the
New River in the upper Santa Fe River system, and in Econfina Creek
(Butler 1993).
Recent surveys have documented the extirpation of the oval pigtoe
from approximately two-thirds of its historical range, with no
populations persisting in Alabama. Once a species of localized
abundance (Clench and Turner 1956), oval pigtoe populations sometimes
numbered in the hundreds (van der Schalie 1940). However, recent
collections of the oval pigtoe are generally small, and rarely exceed a
dozen individuals at any one site. The Service in its recent survey
located only a single specimen from the entire Flint River mainstem. It
is not known whether existing populations are sufficient in numbers to
sustain the species. The oval pigtoe does not tolerate impoundments.
The Chipola slabshell (Elliptio chipolaensis) is a medium-sized
species reaching a length of about 85 mm (3.3 in). The shell is ovate
to subelliptical, somewhat inflated and with the posterior ridge
starting out rounded but flattening to form a prominent biangulate
margin. The shell surface is smooth and chestnut in color. Dark brown
coloration may appear in the umbonal region and the remaining surface
may exhibit alternating light and dark bands. The umbos are prominent,
well above the hingeline. Internally, the umbonal cavity is rather
deep. The lateral teeth are long, slender, and slightly curved, with
two in the left and one in the right valve. The pseudocardinal teeth
are compressed and crenulate, with two in the left and one in the right
valve. Nacre color is salmon, becoming more intense dorsally and
somewhat iridescent posteriorly. The Service considers Unio
chipolaensis to be a synonym of Elliptio chipolaensis.
The Chipola slabshell was described from the Chipola River in
Florida. Clench and Turner (1956) restricted the type locality to the
Chipola River, 1 mile north of Marianna, Jackson County, Florida. Until
recently, this species was considered endemic to the Chipola River
system, occurring in the mainstem above Dead Lake and a few of the
larger tributaries, all in Florida (van der Schalie 1940, Clench and
Turner 1956). A single record of this mussel from a tributary of the
Chattahoochee River in extreme southeastern Alabama has been verified
by Butler (1993). These localities bring the total number of historic
sites the Chipola slabshell inhabited to nine. The Chipola slabshell is
known to persist only at four Chipola River mainstem sites and in Dry
Creek, with the populations from Spring Creek (Chipola River system)
and the Chattahoochee River system apparently extirpated. The numbers
of specimens from recent collections indicate that populations are
generally small, except at one site in the lower mainstem where three
dozen specimens were recently observed (W. McCullagh, pers. comm.). The
Chipola slabshell has the most restricted range of the Apalachicolan
Region mussels. This species does not tolerate impoundments, but is
more tolerant of silt than the other species of mussels.
The purple bankclimber (Elliptoideus sloatianus) is a large, heavy
shelled, strongly sculptured mussel reaching a length of about 200 mm
(8.0 in). A well developed posterior ridge extends from the umbos to
the posterior ventral margin of the shell. The posterior slope and the
disk just anterior to the posterior ridge are sculptured by several
irregular ridges that vary greatly in development. Umbos are low,
extending just above the dorsal margin of the shell. Internally, there
is one pseudocardinal tooth in the right valve and two in the left
valve. The lateral teeth are very thick and slightly curved. Nacre
color is whitish near the center of the shell becoming deep purple
towards the margin, and very iridescent posteriorly. The Service
recognizes Unio sloatianus, Unio atromarginatus, Unio aratus, and Unio
plectophorus as synonyms of Elliptoideus sloatianus. The purple
bankclimber was described from the Chattahoochee River and its type
locality is restricted to the Chattahoochee River at Columbus, Georgia
(Clench and Turner 1956).
Historically, the purple bankclimber was found at 14 sites in the
Flint River system; 3 sites on the Chipola River mainstem (Dead Lake
vicinity); 2 sites on the Apalachicola River mainstem; the type
locality on the Chattahoochee River; and at 4 sites along the lower
two-thirds of the Ochlockonee River mainstem in Florida and Georgia
(Clench and Turner 1956, Butler 1993). A total of 24 historic sites are
known for this species.
This large mussel persists at 10 sites in the lower two-thirds of
the Flint River mainstem, at 4 sites in the Apalachicola River, and at
8 sites in the Ochlockonee River mostly above Talquin Reservoir (Butler
1993). Although the purple bankclimber is currently known from only two
fewer total sites than before, the species has nevertheless experienced
a significant reduction in its total range. No specimens in recent
years have been reported from the Chipola River and the species has not
been collected in the Chattahoochee River for several decades. In
addition, Flint River tributary populations appear to have been totally
eliminated. At a few sites in the Florida portion of the Ochlockonee
River, the purple bankclimber may number in the dozens of individuals.
This species of mussel does not tolerate impoundment conditions well.
On November 18, 1993, the Service notified (by mail; 72 letters)
Federal and State agencies, local governments, and interested
individuals that a status review was being conducted for these seven
species. A total of ten comments was received as a result of this
notification. The Florida Division Office of the Federal Highway
Administration replied that no bridge replacement projects were
currently being planned in northwest Florida, and it was anticipated
that any future bridge replacement projects would have no effect on
these species based on the localized and short-term impacts associated
with these activities. The Federal Energy Regulatory Commission
reported that it licenses 12 hydroelectric development projects in the
study area, and that any issues concerning these species could best be
coordinated with the Office of Hydropower Licensing. The Fayette County
(Georgia) Board of Commissioners expressed concern over the Service's
contention that impoundments have played a major role in the decline of
these species, but they did not oppose the listing. The Alachua County
(Florida) Environmental Protection Department, after consultation with
a Florida Museum of Natural History malacologist, indicated that none
of these seven species of mussels are known or were suspected to occur
in Alachua county. The Florida Game and Fresh Water Fish Commission
expressed concern with how its plan to dredge the mouths of several
silted-in streams along the Apalachicola River to improve access to
striped bass might have on these mussels. The Georgia Department of
Natural Resources (GDNR) had some questions concerning the distribution
of these mussels, particularly in Georgia. The Florida Natural Areas
Inventory supported the Service's listing of these species and provided
information on Econfina Creek watershed where the Gulf moccasinshell
and oval pigtoe occur. Three experts on freshwater mussels supported
the potential Federal protection of these species. No objections to the
proposed listing of these species were received.
Previous Federal Action
The purple bankclimber, oval pigtoe, shiny-rayed pocketbook, and
fat three-ridge are included as category 2 species in the Service's
notices of review for animal candidates that were published in the
Federal Register on January 6, 1989 (54 FR 554) and on November 21,
1991 (56 FR 58804). A category 2 species is one that may be in need of
listing as endangered or threatened, but for which conclusive data on
biological vulnerability and threat are not currently available to
support a proposed rule. Based on status surveys that were completed in
1993, the Service has determined that all of the species included in
this proposal now qualify as category 1 species.
Summary of Factors Affecting the Species
Section 4(a)(1) of the Endangered Species Act (16 U.S.C. 1531 et
seq.) and regulations (50 CFR part 424) promulgated to implement the
listing provisions of the Act set forth the procedures for adding
species to the Federal lists. A species may be determined to be an
endangered or threatened species due to one or more of the five factors
described in section 4(a)(1). These factors and their application to
the fat three-ridge (Amblema neislerii), shiny-rayed pocketbook
(Lampsilis subangulata), Gulf moccasinshell (Medionidus penicillis),
Ochlockonee moccasinshell (Medionidus simpsonianus), oval pigtoe
(Pleurobema pyriforme), Chipola slabshell (Elliptio chipolaensis), and
purple bankclimber (Elliptoideus sloatianus) are as follows:
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
These species of mussels are endemic to the eastern Gulf Slope
streams draining the Apalachicolan Region of southeast Alabama,
southwest Georgia and north Florida. They are currently found in
localized portions of from one to four isolated marine river systems,
mostly in the eastern portion of the Apalachicolan Region. These
species have been rendered vulnerable to extinction by the significant
loss of habitat within their restricted ranges in Apalachicolan Region
streams. Factors contributing to this habitat loss are: impoundments
and deteriorating water and benthic habitat quality resulting from
channel modification, siltation, agricultural runoff from crop
monoculture and poultry farms, silvicultural activities, mining
activities, pollutants, poor land use practices, increased
urbanization, and municipal and industrial waste discharges.
A consideration of the effects of these impacts upon fishes is of
critical importance in evaluating the well-being of mussels. Mussels
and fishes are inextricably linked ecologically; most larval mussels
(glochidia) are obligate parasites of specific fishes. Therefore, these
various impacts may have resulted in the elimination of certain fishes
that serve as potential host species for these mussels.
Impoundments have altered a significant portion of the free-flowing
big river habitats of the Apalachicola and Ochlockonee river systems in
which most of these species occur. Stream habitat is destroyed by the
conversion of free-flowing streams to man-made lakes and ponds. In
addition to riverine habitat destruction, dams block the passage of
certain migratory fishes which serve as hosts for one or more of these
seven mussel species. None of these seven mussel species are known to
reproduce in impoundments.
The Apalachicola River system has been especially impacted by the
construction of numerous mainstem dams. This is true for the
Chattahoochee River, which has nine major dams and four locks and dams
along its lower mainstem to facilitate barge traffic. Additional major
dams are located on the Flint River mainstem (e.g., Blackshear
Reservoir) and on the Apalachicola River where it is formed by the
confluence of the Chattahoochee and Flint Rivers (Seminole Reservoir).
Smaller dams are located on major rivers and tributaries throughout the
Apalachicola River system and in other regional streams. Although pre-
impoundment records are generally unknown for the fat three-ridge,
shiny-rayed pocketbook, Gulf moccasinshell, oval pigtoe, and purple
bankclimber in the Apalachicola River system, numerous populations of
these species were possibly destroyed as a result of impoundments. It
has been decades since any live specimens of these five species were
found along the Chattahoochee River mainstem; the type locality for the
shiny-rayed pocketbook, Gulf moccasinshell, oval pigtoe, and purple
bankclimber.
Talquin Reservoir, an impoundment on the Ochlockonee River formed
by the closure of Jackson Bluff Dam, inundated a significant reach of
the middle portion of the river mainstem. Pre-impoundment records for
the shiny-rayed pocketbook, Ochlockonee moccasinshell, oval pigtoe, and
purple bankclimber from a site at the upstream end of Talquin Reservoir
exist in museum collections. Most of these mussel species once had
sizable populations at this site. Undocumented populations of these
four species were probably destroyed by the filling of Talquin
Reservoir.
In addition to riverine habitat being destroyed by Talquin
Reservoir, the river downstream of Jackson Bluff Dam shows noticeable
signs of being impacted by sediment deposition. Riverine mussels such
as the shiny-rayed pocketbook, Ochlockonee moccasinshell, oval pigtoe,
and purple bankclimber, are nearly absent in sizable stretches of this
heavily silted river. One site recently sampled by the Service (with
SCUBA gear) had deposits of detritus and silt sediments. The river
lacked flows adequate to flush the channel of silty sediments.
Potential lower mainstem channel habitat of the shiny-rayed pocketbook,
Ochlockonee moccasinshell, oval pigtoe, and purple bankclimber are
being impacted by this deposition.
Navigation channel maintenance in the Chattahoochee and
Apalachicola Rivers has destroyed long stretches of benthic habitat. In
addition to the damage caused by the mechanical removal of tons of
substrate, these activities increase sedimentation in downstream areas
by resuspending silt fines which smother benthic organisms. Dredging
activities may also resuspend contaminants that are bound to sediments,
thus potentially exposing aquatic organisms to released toxicants.
Potential host fishes for the fat three-ridge and purple bankclimber in
the Apalachicola River may also be disrupted by channel modifications.
Maintenance operations in the Apalachicola River mainstem continue to
disrupt habitat for these two species. A third mussel, the Gulf
moccasinshell, has apparently been extirpated from the Apalachicola
River.
Gravel mining operations have been observed in various portions of
the Apalachicolan Region. Primary stream impacts associated with gravel
mining include stream channel modifications (alterations of habitat,
flow patterns, and sediment transport), water quality modifications,
aquatic invertebrate population changes and changes in fish populations
(alteration and elimination of spawning and nursery habitats, and food
web disruptions) (Kanehl and Lyons 1992). Channel degradation caused by
gravel mining has been implicated in the destruction of mussel
populations (Hartfield 1993, Grace and Buchanan 1981). In a study by
Grace and Buchanan (1981), mussels were still absent from an in-stream
dredged area 15 years after mining took place. Siltation is
particularly increased during the mining of in-stream gravel and/or
during the washing of gravel which rinses silt and debris back into the
stream. Gravel from the Chattahoochee River is used for various
purposes including landscaping throughout the region. Jenkinson (1973)
recorded the shiny-rayed pocketbook, oval pigtoe, Gulf moccasinshell,
and 10 other mussel species in Little Uchee Creek (Chattahoochee River
system) in Alabama. The creek now has active in-stream gravel mines;
only a few shell fragments were found during a recent survey by the
Service.
Municipal and industrial pollutants are widespread in Apalachicolan
Region streams. Many municipal waste water treatment plants provide
only secondary treatment of waste water and three plants discharging
wastes into the New River (Suwannee River system) threaten that
stream's population of the oval pigtoe. From 1955 to 1977, an estimated
950,000,000 gallons of chemical-laden solutions were discharged into
the Flint River from a Department of Defense facility in Albany,
Georgia (P. Laumeyer, Service, pers. comm.). Service biologists
surveyed a stretch of the Flint River where dozens of purple
bankclimbers had been killed by an unknown pollutant. Hundreds of round
washboards (Megalonaias boykiniana) were found dead in the upper Flint
River (C. Coney, Los Angeles County Museum, pers. comm.) and various
beds of dead mussels (species unknown) were observed in the Suwannee
River (L. Parker, Service, pers. comm.). A battery plant operation
threatens water quality in the Chipola River system, which harbors
populations of the fat three-ridge, shiny-rayed pocketbook, oval
pigtoe, and Chipola slabshell.
Various agricultural practices conducted in the Apalachicolan
Region have contributed to stream and habitat degradation. A Soil
Conservation Service (1993) study of a small agricultural watershed
area in the middle Flint River system reported an average of 35.44
metric tons per hectare per year (15.8 tons per acre per year) of
sediment loading into area waters; 97% of the total sedimentation in
the watershed was generated from agricultural runoff. Agricultural
runoff, in the form of organophosphate or carbamate pesticides, has
been implicated in the die-off of populations of freshwater mussels (J.
Fleming, National Biological Survey, unpub. data). The poultry industry
is expanding operations into the Apalachicolan Region, particularly in
the watersheds of the upper Apalachicola River system. Runoff from
chicken farms causes oxygen depletion in streams and has been
implicated in fish and mussel die-offs in Alabama (U.S. Fish and
Wildlife Service 1993). Feedlots are also another source of pollution
in localized portions of the region's streams. Large dairy farms
located in the Suwannee River watershed also contribute to the
pollution of this system's waters.
Erosion from poor land use practices causes extensive loss of
topsoil and the subsequent siltation of stream bottoms. Sources of
siltation include timber clearcutting and other silvicultural
activities, clearing of riparian vegetation for agricultural purposes,
and those construction and mining practices that allow exposed earth to
enter streams. Light to moderate levels of siltation are common in many
of the streams in the Apalachicolan Region that still have populations
of these seven mussel species. Heavily silted streams were observed by
Service biologists in numerous tributaries of the Chattahoochee and
upper Flint Rivers, particularly those draining the Piedmont
Physiographic Province, which is well known for its highly erodible
soils. Stream banks devoid of riparian vegetation commonly slough-off
into stream channels. Several clear-cuts have been observed in
watersheds of the middle Apalachicola River system, some with
inadequate riparian buffer strips (J. Brim-Box, Service, pers. comm.).
A disregard for maintaining riparian buffers during silvicultural
activities threaten streams throughout the Apalachicolan Region.
Continued siltation and sedimentation of these streams may result in a
depauperate fish fauna, reducing populations at many sites to those
dominated by species tolerant of degraded habitats. The negative
effects of silt on benthic fishes were summarized by Burkhead and
Jenkins (1991). Siltation reduces habitat heterogeneity and increases
fish egg and larval mortality, abrades organisms, and alters
macrobenthic communities.
The health of these seven mussel species is directly tied to
benthic habitat quality. The effects of siltation on freshwater mussels
is more devastating than on fishes due to the sedentary nature of
mussels. Ellis (1936) conducted experiments on the effects of silt on
mussels and determined that most mussels tested died from silt deposits
of one quarter to one inch. Silt also transfers organic substances into
streams, adversely affecting stream habitat and water quality by
producing increased and localized enrichment impacts (Ellis 1936).
Artifact and fossil collectors regularly work streams in various
portions of the Apalachicolan Region and have been known to use suction
dredges to scour benthic habitats, thus increasing siltation
downstream. A study on the effects of suction gold dredging on stream
invertebrates (Harvey 1986) concluded that impacts from these
activities are more severe in streams with soft substrates, which are
typical for most Apalachicolan Region streams where these mussels
occur.
Much non-agricultural and non-silvicultural habitat degradation in
the upper Apalachicola River system watershed is attributed to
increased urbanization, particularly in the metropolitan areas of
Atlanta, Columbus, and Albany. This current high rate of development is
resulting in the conversion of farmland in areas relatively remote from
these cities. Associated with increased development and land clearing
is increased siltation from erosion, accelerated runoff and transport
of pollutants in stormwater, and increased discharge of effluents.
The tributaries harboring populations of these seven mussel species
are criss-crossed by numerous road and railroad bridges. These
crossings are potential sites for accidental spills of toxic materials
into streams. The large number of bridge crossings in the Apalachicolan
Region makes it probable that such a spill might occur in the future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes.
The fat three-ridge is a potential target species for the cultured
pearl industry. Currently a congener (the three-ridge, Amblema plicata)
is heavily utilized as a source of shell for pearl nuclei in more
northern rivers. Due to a tremendous increase in the price of shell,
the harvesting of shell beds has resulted in the scouting of larger
drainages in the Apalachicolan Region for potential sources of shell.
Although prices have decreased since 1992, future increases in shell
price and competition for harvestable populations can not be ruled out.
Biological supply companies have utilized the Flint and Ochlockonee
rivers as sources for larger mussel specimens, including the purple
bankclimber and possibly the fat three-ridge, to sell to academic
institutions for use in laboratory studies. Supply company
representatives have contacted Service biologists in hopes of obtaining
information on new, unexploited mussel populations in the Apalachicolan
Region. On one recent occasion, approximately 10,000 large mussel
specimens, presumably including the purple bankclimber and possibly the
fat three-ridge, were harvested from the Flint River near Bainbridge
for this purpose (J. Brim-Box, pers. comm.). Some of these species are
a potential source of raw material for the polished chip industry.
Costume jewelry crafted from purple bankclimber shells has been
observed in arts and crafts fairs in the Southeast. Unregulated harvest
of the fat three-ridge and purple bankclimber for these purposes, if
unchecked, could decimate their remaining populations. Small and/or
thin-shelled mussel species, such as the other five mussels considered
here, are not known to be utilized commercially.
There are a large number of shell clubs in Florida and surrounding
States. Both national and international meetings for amateur and
professional malacologists are held in this area, and generally include
organized field collecting trips to a variety of habitats. The
attraction of large numbers of people interested in the study and
collection of mollusks increases the potential for overcollection of
these mussels. These species, particularly the larger ones, are
potential bait species, and are susceptible to harvesting especially
during low-flow periods. Publication of this rule will inform the
general public as to the presence of these seven mussels in
Apalachicolan Region streams. The rarity of these mussels potentially
makes them more appealing to shell collectors. Thus, revealing specific
stream reaches harboring these species could pose a threat from such
collectors. Federal protection would serve to minimize adverse
population impacts from illegal take.
C. Disease or Predation.
Although diseases of freshwater mussels are virtually unknown, the
periodic dieoff of mussel populations in several primarily midwestern
rivers in recent years may be due to unidentified diseases. Juvenile
and adult mussels serve as prey for various animals, and the muskrat
has been implicated in jeopardizing recovery of listed mussels (Neves
and Odum 1989). Muskrats do not occur with regularity on Coastal Plain
streams, where most of these mussels exist. However, Piedmont
populations of the shiny-rayed pocketbook and oval pigtoe in the upper
Flint River system may be subjected to some degree of muskrat
predation.
D. The Inadequacy of Existing Regulatory Mechanisms
A scientific collecting permit is required by the State of Georgia
to collect mussels for scientific purposes. However, dredging,
brailling, or any form of mechanical harvest of mussels is illegal. In
addition, a size limit has been placed on mussels harvested
commercially in Georgia. Handpicking mussels requires only a resident
or non-resident fishing license. In the State of Florida an individual
must purchase a fishing license to collect mussels. Despite these
permit requirements, there are no restrictions on the seasonality or
sites of harvest, quantity, or species of mussels collected in Florida
or Georgia. Alabama has recently imposed a set of guidelines concerning
commercial harvest of mussels, including species-specific size limits,
restricted areas for harvest, and closed seasons. Existing authorities
available to protect aquatic systems, such as the Clean Water Act,
administered by the Environmental Protection Agency (EPA) and the Army
Corps of Engineers, have not been fully utilized and may have led to
the degradation of aquatic environments in the Southeast Region, thus
resulting in a decline of aquatic species. If these seven species are
listed under the Act, it would provide protection under section 9 of
the Act by prohibiting the take of these species except under Federal
permit. Further, listing will require consultation with the EPA in
relationship to water quality criteria, standards, and National
Pollution Discharge Elimination System permits under the Clean Water
Act, and implementation of actions to recover the species.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
The range of these seven mussel species has been fragmented, and
significant portions of the Apalachicola and Ochlockonee river systems
have been permanently altered by various reservoirs. Many of the
streams these species inhabit exhibit moderate to heavy degradation
from poor land use practices. These factors have caused local
extirpation and fragmentation of most of these species' populations. It
is not known how many populations of these seven species are viable,
but few juveniles have been observed in recent years. The restricted
distribution of these seven mussels makes them vulnerable to
extirpation from catastrophic events, such as toxic chemical spills.
The introduced Asian clam (Corbicula fluminea) has invaded nearly
all of the river systems in which these mussels occur, competing with
native mussels for nutrients and space. Densities of Asian clams are
sometimes heavy in Apalachicolan Region streams, with estimates running
from approximately one hundred per square meter (Flint River, Sickel
1973) to thousands per square meter (Santa Fe River, Bass and Hitt
1974). In some streams the substrate has changed from one of a fairly
homogeneous silty sand or sand to one with a gravel-like composition
comprised of huge numbers of live and dead Asian clam shells. In some
of these streams, the Gulf moccasinshell and Ochlockonee moccasinshell
were once common but are now extirpated or severely reduced in numbers.
This exotic species may be particularly competitive with small native
mussels such as the diminutive moccasinshells.
In developing this rule, the Service has assessed the best
scientific and commercial information available regarding the past,
present, and future threats faced by these seven mussels. Based upon
these evaluations, the preferred action is to list the fat three-ridge,
shiny-rayed pocketbook, oval pigtoe, Gulf moccasinshell, and
Ochlockonee moccasinshell as endangered and the Chipola slabshell and
purple bankclimber as threatened. These seven mussel species are
endemic to the Apalachicolan Region in southeast Alabama, southwest
Georgia, and north Florida, where they occur in from one to four
isolated marine river systems. The fat three-ridge, Chipola slabshell,
and Ochlockonee moccasinshell are endemic to single drainages, the
former two species to the Apalachicola and the latter species to the
Ochlockonee river systems. The shiny-rayed pocketbook and purple
bankclimber are restricted to both the Apalachicola and Ochlockonee
river systems, while the oval pigtoe is found in these two rivers in
addition to the Suwannee River and Econfina Creek systems. The Gulf
moccasinshell is now restricted to the Apalachicola River system and
Econfina Creek.
These species have been rendered vulnerable to extinction by
significant loss of habitat and severe range restriction. The
restricted distribution of these seven species also makes localized
populations susceptible to catastrophic events and increased pressures
from take.
Critical Habitat
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 424.12) require that, to the maximum extent prudent
and determinable, the Secretary designate critical habitat at the time
the species is determined to be endangered or threatened. The Service
finds that designation of critical habitat is not prudent for these
species. Service regulations (50 CFR 424.12(a)(1)) state that
designation of critical habitat is not prudent when one or both of the
following situations exist--(1) The species is threatened by taking or
other human activity, and identification of critical habitat can be
expected to increase the degree of threat to the species, or (2) such
designation of critical habitat would not be beneficial to the species.
Such a determination would result in no known benefit to these species,
and designation of critical habitat could further increase the threat
of collecting or vandalism.
Regulations promulgated for implementing section 7 provide for both
a jeopardy standard, based on listing alone, and for a destruction or
adverse modification standard, in cases where critical habitat has been
designated. The fat three-ridge, shiny-rayed pocketbook, Gulf
moccasinshell, Ochlockonee moccasinshell, oval pigtoe, Chipola
slabshell, and purple bankclimber occupy very restricted stream
reaches. Any significant adverse modification or destruction of their
habitat would likely jeopardize their continued existence. Therefore,
no additional protection for the species would accrue from critical
habitat designation that would not also accrue from listing these
species. If these are listed, the Service believes that protection of
their habitat can be accomplished through the section 7 jeopardy
standard, and through section 9 prohibitions against take.
The publication of critical habitat maps in the Federal Register
and local newspapers and other publicity accompanying critical habitat
designation could increase the harvest or collection threat and also
increase the potential for vandalism during the critical habitat
designation process.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Endangered Species Act include recognition,
recovery actions, requirements for Federal protection, and prohibitions
against certain practices. Recognition through listing encourages and
results in conservation actions by Federal, State, and private
agencies, groups, and individuals. The Act provides for possible land
acquisition and cooperation with the States and requires that recovery
actions be carried out for all listed species. The protection required
of Federal agencies and the prohibitions against taking and harm are
discussed, in part, below.
Section 7(a) of the Act, as amended, requires Federal agencies to
evaluate their actions with respect to any species that is proposed or
listed as endangered or threatened and with respect to its critical
habitat, if any is being designated. Regulations implementing this
interagency cooperation provision of the Act are codified at 50 CFR
part 402. Section 7(a)(4) requires Federal agencies to confer
informally with the Service on any action that is likely to jeopardize
the continued existence of a proposed species or result in destruction
or adverse modification of proposed critical habitat. If a species is
listed subsequently, section 7(a)(2) requires Federal agencies to
ensure that activities they authorize, fund, or carry out are not
likely to jeopardize the continued existence of such a species or to
destroy or adversely modify its critical habitat. If a Federal action
may affect a listed species or its critical habitat, the responsible
Federal agency must enter into formal consultation with the Service.
Federal involvement is expected to include the EPA through the
Clean Water Act's provisions for pesticide registration and waste
management actions. The Corps of Engineers will consider these species
in project planning and operation, and during the permit review
process. The Federal Energy Regulatory Commission will consider these
species prior to the relicensing of hydropower dams. The Federal
Highway Administration will consider impacts of federally funded bridge
and road construction projects when known habitat may be impacted.
Continuing development within the Apalachicolan Region may involve the
Farmers Home Administration and their loan programs. The Soil
Conservation Service will consider the species during project planning
and under their farmer's assistance programs. The Forest Service will
consider downstream impacts to habitat of the fat three-ridge and
purple bankclimber when planning or implementing silvicultural,
recreational, or other programs in lands adjacent the lower mainstem of
the Apalachicola River, and to habitat of the purple bankclimber when
planning or implementing these activities in lands adjacent the lower
mainstem of the Ochlockonee River, both drainages are in the
Apalachicola National Forest.
The Act and implementing regulations found at 50 CFR 17.21 for
endangered species, and 17.21 and 17.31 for threatened species set
forth a series of general prohibitions and exceptions that apply to all
endangered and threatened wildlife. These prohibitions, in part, make
it illegal for any person subject to jurisdiction of the United States
to take (includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
or collect; or attempt any of these), import or export, ship in
interstate commerce in the course of commercial activity, or sell or
offer for sale in interstate or foreign commerce any listed species. It
also is illegal to possess, sell, deliver, carry, transport, or ship
any such wildlife that has been taken illegally. Certain exceptions
apply to agents of the Service and State conservation agencies.
Permits may be issued to carry out otherwise prohibited activities
involving endangered or threatened wildlife species under certain
circumstances. Regulations governing permits are at 50 CFR 17.22,
17.23, and 17.32. Such permits are available for scientific purposes,
to enhance the propagation or survival of the species, and/or for
incidental take in connection with otherwise lawful activities. For
threatened species, there are also permits for zoological exhibition,
educational purposes, or special purposes consistent with the purpose
of the Act.
In some instances, permits may be issued for a specified time to
relieve undue economic hardship that would be suffered if such relief
were not available. However, since none of the species in this proposal
are currently in active trade, no such permits are expected.
Public Comments Solicited
The Service intends that any final action resulting from these
proposals will be as accurate and as effective as possible. Therefore,
comments or suggestions from the public, other concerned governmental
agencies, the scientific community, industry, or any other interested
party concerning these proposed rules are hereby solicited. Comments
particularly are sought concerning:
(1) Biological, commercial trade, or other relevant data concerning
any threat (or lack thereof) to the species;
(2) The location of any additional populations of the species and
the reasons why any habitat should or should not be determined to be
critical habitat as provided by section 4 of the Act;
(3) Additional information concerning the range, distribution, and
population size of the species; and
(4) Current or planned activities in the subject areas and their
possible impacts on the species.
Final promulgation of the regulations on these species will take
into consideration the comments and any additional information received
by the Service, and such communication may lead to final regulations
that differ from this proposal.
The Act provides for a public hearing on this proposal, if
requested. Requests must be received within 45 days of the date of
publication of this proposal. Such requests must be made in writing and
should be addressed to the Field Supervisor (see ADDRESSES section).
National Environmental Policy Act
The Fish and Wildlife Service has determined that an Environmental
Assessment, as defined under the authority of the National
Environmental Policy Act of 1969, need not be prepared in connection
with regulations adopted pursuant to section 4(a) of the Endangered
Species Act of 1973, as amended. A notice outlining the Service's
reasons for this determination was published in the Federal Register on
October 25, 1983 (48 FR 49244).
References Cited
A complete list of all references cited herein, as well as others,
is available upon request from the Field Supervisor (see ADDRESSES
section).
Author
The primary author of this proposed rule is Robert S. Butler, U.S.
Fish and Wildlife Service, Jacksonville Field Office, 6620 Southpoint
Drive South, Suite 310, Jacksonville, Florida 32216 (904/232-2580).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, and Transportation.
Proposed Regulation Promulgation
PART 17--[AMENDED]
Accordingly, the Service hereby proposes to amend part 17,
subchapter B, chapter I, title 50 of the Code of Federal Regulations,
as set forth below:
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.
2. Section 17.11(h) is amended by adding the following, in
alphabetical order under ``CLAMS'', to the List of Endangered and
Threatened Wildlife:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate population
--------------------------------------------------- Historic range where endangered or Status When listed Critical Special
Common name Scientific name threatened habitat rules
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Clams
* * * * * * *
Bankclimber, purple..... Elliptoideus sloatianus. U.S.A. (AL, FL, GA)..... NA..................... T ........... NA NA
* * * * * * *
Moccasinshell, Gulf..... Medionidus pencillatus.. U.S.A. (AL, FL, GA)..... NA..................... E ........... NA NA
Moccasinshell, Medionidus simpsonianus. U.S.A. (FL, GA)......... NA..................... E ........... NA NA
Ochlockonee.
* * * * * * *
Pigtoe, oval............ Pleurobema pyriforme.... U.S.A. (AL, FL, GA)..... NA..................... E ........... NA NA
* * * * * * *
Pocketbook, shiny-rayed. Lampsilis subangulata... U.S.A. (AL, FL, GA)..... NA..................... E ........... NA NA
* * * * * * *
Slabshell, Chipola...... Elliptio chipolaensis... U.S.A. (AL, FL)......... NA..................... T ........... NA NA
* * * * * * *
Three-ridge, fat........ Amblema neislerii....... U.S.A. (FL, GA)......... NA..................... E ........... NA NA
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dated: July 19, 1994
Mollie H. Beattie
Director, Fish and Wildlife Service.
[FR Doc. 94-18923 Filed 8-2-94; 8:45 am]
BILLING CODE 4310-55-P
