[Federal Register Volume 75, Number 211 (Tuesday, November 2, 2010)]
[Proposed Rules]
[Pages 67552-67583]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-27413]



[[Page 67551]]

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Part IV





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Listing the Rayed Bean 
and Snuffbox as Endangered; Proposed Rule

Federal Register / Vol. 75 , No. 211 / Tuesday, November 2, 2010 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R3-ES-2010-0019; MO 92210-0-0008-B2]
RIN 1018-AV96


Endangered and Threatened Wildlife and Plants; Listing the Rayed 
Bean and Snuffbox as Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the rayed bean (Villosa fabalis) and snuffbox (Epioblasma 
triquetra) as endangered throughout their ranges, under Endangered 
Species Act of 1973, as amended (Act). This proposed rule, if made 
final, would extend the Act's protection to the rayed bean and the 
snuffbox. We have determined that designating critical habitat for 
these species is prudent, but not determinable at this time. The 
Service seeks data and comments from the public on this proposed 
listing rule.

DATES: We will consider comments we receive on or before January 3, 
2011. We must receive requests for public hearings, in writing, at the 
address shown in the FOR FURTHER INFORMATION CONTACT section on or 
before December 17, 2010.

ADDRESSES: You may submit comments by one of the following methods:
    <bullet> Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the instructions for submitting comments on Docket No. FWS-R3-
2010-0019.
    <bullet> U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R3-2010-0019; Division of Policy and Directives Management; 
U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; 
Arlington, VA 22203.
    We will post all comments on http://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT: Angela Boyer at the U.S. Fish and 
Wildlife Service, Ohio Ecological Services Field Office, 4625 Morse 
Road, Suite 104, Columbus, OH 43230; telephone 614-416-8993, ext. 22.

SUPPLEMENTARY INFORMATION:

Public Comments

    Our intent is to use the best available commercial and scientific 
data as the foundation for all endangered and threatened species 
listing determinations. We therefore request comments or suggestions 
from other concerned governmental agencies, the scientific community, 
industry, or any other interested party concerning this proposed rule 
to list the rayed bean and snuffbox as endangered. We particularly seek 
comments concerning:
    (1) Survey results for the rayed bean or snuffbox, as well as any 
studies that may show distribution, status, population size, or 
population trends, including indications of recruitment;
    (2) Pertinent aspects of life history, ecology, and habitat use of 
the rayed bean or snuffbox;
    (3) Current and foreseeable threats faced by the rayed bean or 
snuffbox, or both species, in relation to the five factors (as defined 
in section 4(a)(1) of the Act (16 U.S.C. 1531 et seq.));
    (4) The specific physical and biological features to consider, and 
specific areas that may meet the definition of critical habitat and 
that should or should not be considered for a proposed critical habitat 
designation as provided by section 4 of the Act; and
    (5) The data and studies to which this proposal refers.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section. We will not 
accept comments sent by e-mail or fax or to an address not listed in 
the ADDRESSES section. Comments must be submitted to http://www.regulations.gov before midnight (Eastern Time) on the date 
specified in the DATES section. Finally, we will not consider hand-
delivered comments that we do not receive, or mailed comments that are 
not postmarked, by the date specified in the DATES section.
    We will post your entire comment --including your personal 
identifying information--on http://www.regulations.gov. If you provide 
us personal identifying information such as your street address, phone 
number, or e-mail address, you may request at the top of your document 
that we withhold this information from public review. However, we 
cannot guarantee that we will be able to do so.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on http://www.regulations.gov, or by 
appointment, during normal business hours at the Ohio Ecological 
Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Public Hearing

    The Act provides for one or more public hearings on this proposal, 
if requested. We must receive requests by the date listed in the DATES 
section above. Such requests must be made in writing and addressed to 
the Field Supervisor of the Ohio Ecological Services Field Office (see 
FOR FURTHER INFORMATION CONTACT).

Background

Species Descriptions

    The rayed bean is a small mussel usually less than 1.5 inches (in) 
(3.8 centimeters (cm)) in length (Cummings and Mayer 1992, p. 142; 
Parmalee and Bogan 1998, p. 244; West et al. 2000, p. 248). The shell 
outline is elongate or ovate in males and elliptical in females, and 
moderately inflated in both sexes, but more so in females (Parmalee and 
Bogan 1998, p. 244). The valves are thick and solid. The anterior end 
is rounded in females and bluntly pointed in males (Cummings and Mayer 
1992, p. 142). Females are generally smaller than males (Parmalee and 
Bogan 1998, p. 244). Dorsally, the shell margin is straight, while the 
ventral margin is straight to slightly curved (Cummings and Mayer 1992, 
p. 142). The beaks are slightly elevated above the hingeline (West et 
al. 2000, p. 248), with sculpture consisting of double loops with some 
nodules (Parmalee and Bogan 1998, p. 244). No posterior ridge is 
evident. Surface texture is smooth and sub-shiny, and green, yellowish-
green, or brown in color, with numerous wavy, dark-green rays of 
various widths (sometimes obscure in older, blackened specimens) 
(Cummings and Mayer 1992, p. 142; West et al. 2000, p. 248). 
Internally, the left valve has two pseudocardinal teeth (tooth-like 
structures along the hinge line of the internal portion of the shell) 
that are triangular, relatively heavy, and large, and two short, heavy 
lateral teeth (Cummings and Mayer 1992, p. 142). The right valve has a 
low, triangular pseudocardinal tooth, with possibly smaller secondary 
teeth anteriorly and posteriorly, and a short, heavy, and somewhat 
elevated lateral tooth (Parmalee and Bogan 1998, p. 244). The color of 
the nacre (mother-of-pearl) is silvery white or bluish and iridescent 
posteriorly. Key characters useful for distinguishing the rayed bean 
from other mussels is its small size, thick valves, unusually heavy 
teeth for a small mussel, and color pattern (Cummings and Mayer 1992, 
p. 142).
    The snuffbox is a small- to medium-sized mussel with males reaching 
up to 2.8 in. (7.0 cm) in length (Cummings

[[Page 67553]]

and Mayer 1992, p. 162; Parmalee and Bogan 1998, p. 108). The maximum 
length of females is about 1.8 in (4.5 cm) (Parmalee and Bogan 1998, p. 
108). The shape of the shell is somewhat triangular (females), oblong, 
or ovate (males) with the valves solid, thick, and very inflated. The 
beaks are located somewhat anterior of the middle, swollen, turned 
forward and inward, and extended above the hingeline (Cummings and 
Mayer 1992, p. 162). Beak sculpture consists of three or four faint, 
double-looped bars (Cummings and Mayer 1992, p. 162; Parmalee and Bogan 
1998, p. 108). The anterior end of the shell is rounded, and the 
posterior end is truncated, highly so in females. The posterior ridge 
is prominent, being high and rounded, while the posterior slope is 
widely flattened. The posterior ridge and slope in females is covered 
with fine ridges and grooves, and the posterioventral shell edge is 
finely toothed (Cummings and Mayer 1992, p. 162). When females are 
viewed from a dorsal or ventral perspective, the convergence of the two 
valves on the posterior slope is nearly straight due to being highly 
inflated. This gives the female snuffbox a unique broadly lanceolate or 
cordate perspective when viewed at the substrate and water column 
interface (Ortmann 1919, p. 329; van der Schalie 1932, p. 104). The 
ventral margin is slightly rounded in males and nearly straight in 
females. Females have recurved denticles on the posterior shell margin 
that aid in holding host fish (Barnhart 2008, p. 1). The periostracum 
(external shell surface) is generally smooth and yellowish or 
yellowish-green in young individuals, becoming darker with age. Green 
squarish, triangular, or chevron-shaped marks cover the umbone (the 
inflated area of the shell along the dorsal margin) but become poorly 
delineated stripes with age. Internally, the left valve has two high, 
thin, triangular, emarginate pseudocardinal teeth (the front tooth 
being thinner than the back tooth) and two short, strong, slightly 
curved, and finely striated lateral teeth. The right valve has a high, 
triangular pseudocardinal tooth with a single short, erect, and heavy 
lateral tooth. The interdentum (a flattened area between the 
pseudocardinal and lateral teeth) is absent, and the beak cavity is 
wide and deep. The color of the nacre is white, often with a silvery 
luster, and a gray-blue or gray-green tinge in the beak cavity. The 
soft anatomy was described by Oesch (1984, pp. 233-234), and Williams 
et al. (2008, p. 282). Key characters useful for distinguishing the 
snuffbox from other species include its unique color pattern, shape 
(especially in females), and high degree of inflation.

Taxonomy

    The rayed bean is a member of the freshwater mussel family 
Unionidae and was originally described as Unio fabalis by Lea in 1831. 
The type locality is the Ohio River (Parmalee and Bogan 1998, p. 244), 
probably in the vicinity of Cincinnati, Ohio. Over the years, the rayed 
bean has been placed in the genera Unio, Margarita, Margaron, Eurynia, 
Micromya, and Lemiox. It was ultimately placed in the genus Villosa by 
Stein (1963, p. 19), where it remains today (Turgeon et al. 1998, p. 
33). We recognize Unio capillus, U. lapillus, and U. donacopsis as 
synonyms of Villosa fabalis.
    The snuffbox is a member of the freshwater mussel family Unionidae 
and was described as Truncilla triqueter (Rafinesque 1820, p. 300). The 
species name was later changed to triquetra (Simpson 1900, p. 517), 
from the Latin triquetrous meaning ``having three acute angles,'' a 
reference to the general shape of the female. The type locality is the 
Falls of the Ohio (Ohio River, Louisville, Kentucky) (Parmalee and 
Bogan 1998, p. 108). The synonymy of the snuffbox was summarized by 
Johnson (1978, pp. 248-249), Parmalee and Bogan (1998, p. 108), and Roe 
(no date, p. 3). This species has also been considered a member of the 
genera Unio, Dysnomia, Plagiola, Mya, Margarita, Margaron, and 
Epioblasma at various times since its description. The monotypic 
subgenus Truncillopsis was created for this species (Ortmann and Walker 
1922, p. 65). The genus Epioblasma was not in common usage until the 
1970s (Stansbery 1973, p. 22; Stansbery 1976, p. 48; contra Johnson 
1978, p. 248), where it currently remains (Turgeon et al. 1998, p. 34). 
Unio triqueter, U. triangularis, U. triangularis longisculus, U. 
triangularis pergibosus, U. cuneatus, and U. formosus are recognized as 
synonyms of E. triquetra. Tricorn pearly mussel is another common name 
for this species (Clarke 1981a, p. 354).

Life History

    The general biology of the rayed bean and the snuffbox are similar 
to other bivalved mollusks belonging to the family Unionidae. Adults 
are suspension-feeders, spending their entire lives partially or 
completely buried within the substrate (Murray and Leonard 1962, p. 
27). Adults feed on algae, bacteria, detritus, microscopic animals, and 
dissolved organic material (Silverman et al. 1997, p. 1859; Nichols and 
Garling 2000, p. 873; Christian et al. 2004, pp. 108-109; Strayer et 
al. 2004, pp. 430-431). Recent evidence suggests that adult mussels may 
also deposit-feed on particles in the sediment (Raikow and Hamilton 
2001, p. 520). For their first several months, juvenile mussels employ 
foot (pedal) feeding, consuming settled algae and detritus (Yeager et 
al. 1994, p. 221). Unionids have an unusual mode of reproduction. Their 
life cycle includes a brief, obligatory parasitic stage on fish. Eggs 
develop into microscopic larvae called glochidia within special gill 
chambers of the female. The female expels the mature glochidia, which 
must attach to the gills or the fins of an appropriate fish host to 
complete development. Host fish specificity varies among unionids. Some 
species appear to use a single host, while others can transform on 
several host species. Following successful infestation, glochidia 
encyst (enclose in a cyst-like structure) and drop off as newly 
transformed juveniles. For further information on freshwater mussels, 
see Gordon and Layzer (1989, pp. 1-17).
    Mussel biologists know relatively little about the specific life-
history requirements of the rayed bean and the snuffbox. Most mussels, 
including the rayed bean and snuffbox, have separate sexes. The age at 
sexual maturity, which is unknown for the rayed bean and snuffbox, is 
highly variable among and within species (0-9 years) (Haag and Staton 
2003, pp. 2122-2123), and may be sex dependent (Smith 1979, p. 382). 
Both species are thought to be long-term brooders; rayed bean females 
brood glochidia from May through October (Parmalee and Bogan 1998, p. 
108; Ecological Specialists, Inc. (ESI) 2000, p. 5; Woolnough 2002, p. 
23), and snuffbox brood glochidia from September to May (Ortmann 1912, 
p. 355; 1919, p. 327). The only published research identifies the 
Tippecanoe darter (Etheostoma tippecanoe) as a host fish for the rayed 
bean (White et al. 1996, p. 191). Other rayed bean hosts are thought to 
include the greenside darter (E. blennioides), rainbow darter (E. 
caeruleum), mottled sculpin (Cottus bairdi), and largemouth bass 
(Micropterus salmoides) (Woolnough 2002, p. 51). Based on inference of 
closely related species, additional hosts may be suitable, including 
other darter and sculpin species (Jones 2002, pers. comm.). Juvenile 
snuffbox have successfully transformed on logperch (Percina caprodes), 
blackside darter (P. maculata), rainbow darter, Iowa darter (E. exile), 
blackspotted topminnow (Fundulus olivaceous), mottled sculpin, banded 
sculpin (C. carolinae), Ozark sculpin (C. hypselurus), largemouth

[[Page 67554]]

bass, and brook stickleback (Culaea inconstans) in laboratory tests 
(Sherman 1994, p. 17; Yeager and Saylor 1995, p. 3; Hillegass and Hove 
1997, p. 25; Barnhart et al. 1998, p. 34; Hove et al. 2000, p. 30; 
Sherman Mulcrone 2004, pp. 100-103).

Habitat Characteristics

    The rayed bean is generally known from smaller, headwater creeks, 
but occurrence records exist from larger rivers (Cummings and Mayer 
1992, p. 142; Parmalee and Bogan 1998, pp. 244). They are usually found 
in or near shoal or riffle areas, and in the shallow, wave-washed areas 
of glacial lakes, including Lake Erie (West et al. 2000, p. 253). In 
Lake Erie, the species is generally associated with islands in the 
western portion of the lake. Preferred substrates typically include 
gravel and sand. The rayed bean is oftentimes found among vegetation 
(water willow (Justicia americana) and water milfoil (Myriophyllum 
sp.)) in and adjacent to riffles and shoals (Watters 1988b, p. 15; West 
et al. 2000, p. 253). Specimens are typically buried among the roots of 
the vegetation (Parmalee and Bogan 1998, pp. 245). Adults and juveniles 
appear to produce byssal threads (thin, protein-based fibers) 
(Woolnough 2002, pp. 99-100), apparently to attach themselves to 
substrate particles.
    The snuffbox is found in small to medium-sized creeks to larger 
rivers and in lakes (Cummings and Mayer 1992, p. 162; Parmalee and 
Bogan 1998, p. 108). The species occurs in swift currents of riffles 
and shoals and wave-washed shores of lakes over gravel and sand with 
occasional cobble and boulders. Individuals generally burrow deep into 
the substrate except when spawning or attempting to attract a host 
(Parmalee and Bogan 1998, p. 108).
    Strayer (1999a, pp. 471-472) demonstrated in field trials that 
mussels in streams occur chiefly in flow refuges, or relatively stable 
areas that displayed little movement of particles during flood events. 
Flow refuges conceivably allow relatively immobile mussels to remain in 
the same general location throughout their entire lives. He thought 
that features commonly used in the past to explain the spatial 
patchiness of mussels (water depth, current speed, sediment grain size) 
were poor predictors of where mussels actually occur in streams.

Rayed Bean Historical Distribution

    The rayed bean historically occurred in 112 streams, lakes, and 
some human-made canals in 10 States: Illinois, Indiana, Kentucky, 
Michigan, New York, Ohio, Pennsylvania, Tennessee, Virginia, and West 
Virginia; and Ontario, Canada. The mussel occurred in parts of the 
upper (Lake Michigan drainage) and lower Great Lakes systems, and 
throughout most of the Ohio and Tennessee River systems. During 
historical times, the rayed bean was fairly widespread and locally 
common in many Ohio River system streams based on collections made over 
a several-decade period. The species was once fairly common in the 
Belle, South Branch Thames, Detroit, Scioto, Wabash, and Duck Rivers; 
several tributaries in the Scioto system (Olentangy River, and Big 
Darby and Alum Creeks); and Tippecanoe Lake based on literature and 
museum records (Call 1900; Watters 1994, p. 105; West et al. 2000, p. 
251; Badra 2002, pers. comm.). The rayed bean was last reported from 
some streams several decades ago (North Branch Clinton, Auglaize, Ohio, 
West Fork, Beaver, Shenango, Mahoning, Mohican, Scioto, Green, Barren, 
Salamonie, White, Big Blue, Tennessee, Holston, South Fork Holston, 
Nolichucky, Clinch, North Fork Clinch, and Powell Rivers; Wolf, 
Conewango, Oil, Crooked, Pymatuning, Mill, Alum, Whetstone, Deer, Lick, 
and Richland Creeks; and Buckeye, Tippecanoe, Winona, and Pike Lakes). 
The rayed bean population in Lake Erie was once considerable (Ohio 
State University Museum of Biological Diversity (OSUM) collections), 
but has been eliminated by the zebra mussel.

Rayed Bean Current Distribution

    Extant populations of the rayed bean are known from 28 streams and 
1 lake in six States and one Canadian province: Indiana (St. Joseph 
River (stream) (Fish Creek (tributary)), Tippecanoe River (Lake 
Maxinkuckee, Sugar Creek)), Michigan (Black River (Mill Creek), Pine 
River, Belle River, Clinton River), New York (Allegheny River (Olean 
Creek, Cassadaga Creek, French Creek)), Ohio (Swan Creek, Fish Creek, 
Blanchard River, Tymochtee Creek, Walhonding River, Mill Creek, Big 
Darby Creek, Scioto Brush Creek), (Great Miami River, Little Miami 
River (East Fork Little Miami River), Stillwater River), Pennsylvania 
(Allegheny River (French Creek (Cussewago Creek))), and West Virginia 
(Elk River); and Ontario, Canada (Sydenham River, Thames River).

Rayed Bean Population Estimates and Status

    Based on historical and current data, the rayed bean has declined 
significantly rangewide and is now known from only 28 streams and 1 
lake (down from 112), a 74 percent decline (Table 1). This species has 
also been eliminated from long reaches of former habitat in hundreds of 
miles of the Maumee, Ohio, Wabash, and Tennessee Rivers and from 
numerous stream reaches and their tributaries. In addition, this 
species is no longer known from the States of Illinois, Kentucky, 
Tennessee, and Virginia. The rayed bean was also extirpated in West 
Virginia until the 2006 reintroduction into the Elk River (Clayton 
2007, pers. comm.).
    In this proposed rule, mussel shell collection records have been 
classified according to the condition of shell material. Fresh dead 
(FD) shells still have flesh attached to the valves, they may or may 
not retain a luster to their nacre, and their periostracum is non-
peeling, all indicating relatively recent death (generally less than 1 
year) (Buchanan 1980, p. 4). Relic (R) shells have lost the luster to 
their nacre, have peeling or absent periostracum, may be brittle or 
worn, and likely have been dead more than a year (Buchanan 1980, pp. 4-
5; Zanatta et al. 2002, p. 482). Generally, FD shells indicate the 
continued presence of the species at a site (Metcalf 1980, p. 4). The 
presence of R shells only, along with repeated failure to find live (L) 
animals or FD shells, likely signifies that a population is extirpated 
(Watters and Dunn 1993-94, pp. 253-254). Shells labeled R may 
originally have been reported by collectors as either weathered dead 
(or weathered dry) or subfossil. If no details on shell condition were 
provided for a record, the shell is simply referred to as dead. In this 
document, a population is considered viable if it is reproducing and 
has enough individuals to sustain the population at its current level 
for the foreseeable future.

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                               Table 1--Rayed Bean Status at Historical Locations
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                                                     Last observed  (R =
          River basin                  Stream               relic)          Current status         Comments
----------------------------------------------------------------------------------------------------------------
Upper Great Lakes Sub-basin....  Pigeon River......  1996 (R)             Extirpated........  ..................
Lower Great Lakes Sub-basin....  Black River.......  2001                 Unknown...........  Small and of
                                                                                               questionable
                                                                                               viability.
                                 Mill Creek........  2002                 Unknown...........  Unknown.
                                 Pine River........  2002                 Declining.........  Recruiting.
                                 Belle River.......  2003                 Unknown...........  ..................
                                 Clinton River.....  1992                 Unknown...........  Recruiting.
                                 North Fork Clinton  1933                 Extirpated........  ..................
                                  River.
                                 Sydenham River      2003                 Stable............  Recruiting.
                                  (Canada).
                                 Thames River......  2008                 Unknown...........  Unknown.
                                 Detroit River.....  1983                 Extirpated........  ..................
                                 Rouge River.......  <1914                Extirpated........
                                 Huron River.......  1931-32              Extirpated........
                                 Raisin River......  1941                 Extirpated........
                                 Macon Creek.......  1976-78 (R)          Extirpated........
                                 Maumee River......  1913                 Extirpated........
                                 Swan Creek........  2009                 Stable............  Recruiting.
                                 St. Joseph River..  1998                 Declining.........  Probably not
                                                                                               recruiting.
                                 West Branch St.     1997 (R)             Extirpated........
                                  Joseph River.
                                 Fish Creek........  2009                 Declining.........  Unknown.
                                 Cedar Creek.......  1985                 Extirpated........
                                 Feeder Canal to     1988 (R)             Extirpated........
                                  St. Joseph River.
                                 Auglaize River....  1964                 Extirpated........
                                 Ottawa River......  1998 (R)             Extirpated........
                                 Blanchard River...  2009                 Unknown...........  Recruiting.
                                 Sandusky River....  1978                 Extirpated........
                                 Tymochtee Creek...  1996                 Unknown...........  Unknown.
                                 Wolf Creek........  1971 (R)             Extirpated........
                                 Lake Erie.........  1977-87              Extirpated........
Ohio River system..............  Ohio River          <1960                Extirpated........
                                  mainstem.
                                 Allegheny River...  2007                 Stable............  Recruiting.
                                 Chautauqua Lake     <1919                Extirpated........
                                  outlet.
                                 Chautauqua Lake...  <1919                Extirpated........
                                 Olean Creek.......  2000                 Unknown...........  Recruiting.
                                 Cassadaga Creek...  1994                 Unknown...........  Recruiting.
                                 Conewango Creek...  ~1908                Extirpated........
                                 Oil Creek.........  <1970                Extirpated........
                                 French Creek......  2005                 Stable............  Recruiting.
                                 Cussewago Creek...  1991                 Unknown...........
                                 Crooked Creek.....  ~1908                Extirpated........
                                 West Fork River...  <1913                Extirpated........
                                 Beaver River......  ~1910                Extirpated........
                                 Shenango River....  ~1908                Extirpated........
                                 Pymatuning Creek..  ~1908                Extirpated........
                                 Mahoning River....  <1921                Extirpated........
                                 Middle Island       1980 (R)             Extirpated........
                                  Creek.
                                 Muskingum River...  1980 (R)             Extirpated........
                                 Tuscarawas River..  ?                    Extirpated........
                                 Walhonding River..  1991-95              Declining.........  Probably not
                                                                                               recruiting.
                                 Mohican River.....  1969                 Extirpated........
                                 Elk River.........  2008                 Reintroduced in
                                                                           2006.
                                 Scioto River......  1964                 Extirpated........
                                 Mill Creek........  2007                 Unknown...........
                                 Alum Creek........  1970                 Extirpated........
                                 Blacklick Creek...  ?                    Extirpated........
                                 Olentangy River...  1962                 Extirpated........
                                 Whetstone Creek...  1961                 Extirpated........
                                 Big Walnut Creek..  1961                 Extirpated........
                                 Walnut Creek......  1994 (R)             Extirpated........
                                 Big Darby Creek...  2008                 Declining.........  Unknown.
                                 Little Darby Creek  1990 (R) or 1986     Extirpated........
                                                      (R)
                                 Deer Creek........  1981                 Extirpated........
                                 Sugar Creek.......  <1900                Extirpated........
                                 Scioto Brush Creek  1987                 Unknown...........  Probably not
                                                                                               recruiting.
                                 Cedar Creek.......  ?                    Extirpated........
                                 Buckeye Lake......  ?                    Extirpated........
                                 Ohio and Erie       ?                    Extirpated........  ..................
                                  Canal.
                                 Great Miami River.  2009                 Unknown...........  Unknown.
                                 Little Miami River  1990-91              Unknown...........  Probably not
                                                                                               recruiting.
                                 East Fork Little    1990-91              Unknown...........
                                  Miami River.

[[Page 67556]]

 
                                 Stillwater River..  1987                 Unknown...........  Probably not
                                                                                               recruiting.
                                 South Fork Licking  1982 (R)             Extirpated........
                                  River.
                                 North Fork Elkhorn  1982 (R)             Extirpated........
                                  Creek.
                                 Eagle Creek.......  1981 (R)             Extirpated........
                                 Brashears Creek...  1983 (R)             Extirpated........
                                 Green River.......  1964                 Extirpated........
                                 Nolin River.......  1983 (R)             Extirpated........
                                 Barren River......  <1900, ?             Extirpated........
                                 Wabash River......  1962 (R)             Extirpated........
                                 Salamonie River...  1971                 Extirpated........
                                 Mississinewa River  1994 (R)             Extirpated........
                                 Tippecanoe River..  1995                 Declining.........  Possibly
                                                                                               recruiting.
                                 Tippecanoe Lake...  <1920                Extirpated........
                                 Winona Lake.......  1934                 Extirpated........
                                 Pike Lake.........  1906                 Extirpated........
                                 Lake Maxinkuckee..  1997                 Declining.........  Unknown.
                                 Vermilion River...  1999 (R)             Extirpated........
                                 Salt Fork           1956-57              Extirpated........
                                  Vermilion River.
                                 Middle Fork         1991                 Extirpated........
                                  Vermilion River.
                                 North Fork          1995 (R)             Extirpated........
                                  Vermilion River.
                                 Embarras River....  1956                 Extirpated........
                                 Sugar Creek.......  1998                 Unknown...........  Unknown.
                                 White River.......  <1903                Extirpated........
                                 West Fork White     1989-91 (R)          Extirpated........
                                  River.
                                 East Fork White     ?                    Extirpated........
                                  River.
                                 Big Blue River....  1944                 Extirpated........
                                 Walnut Creek......  1992 (R)             Extirpated........
                                 Mill Creek........  1992 (R)             Extirpated........
                                 Fall Creek........  ?                    Extirpated........
                                 Sugar Creek.......  1950                 Extirpated........
Tennessee River system.........  Tennessee River     <1939                Extirpated........
                                  mainstem.
                                 Holston River.....  1914-15              Extirpated........
                                 North Fork Holston  1913                 Extirpated........
                                  River.
                                 South Fork Holston  1914                 Extirpated........
                                  River.
                                 Nolichucky River..  1968                 Extirpated........
                                 Lick Creek........  1967 (R)             Extirpated........
                                 First Creek.......  ?                    Extirpated........
                                 Clinch River......  1965                 Extirpated........
                                 North Fork Clinch   <1921                Extirpated........
                                  River.
                                 Powell River......  1913-15              Extirpated........
                                 Elk River.........  1965                 Extirpated........
                                 Richland Creek....  1892                 Extirpated........
                                 Duck River........  1982                 Extirpated........
----------------------------------------------------------------------------------------------------------------

Upper Great Lakes Sub-Basin

    The rayed bean was not known from the upper Great Lakes sub-basin 
until 1996, when relic specimens were documented from a tributary to 
the St. Joseph River, a tributary to Lake Michigan. No extant 
populations of the rayed bean are currently known from this system.

Lower Great Lakes Sub-Basin

    Of the 112 water bodies from which the rayed bean was historically 
recorded, 27 are in the lower Great Lakes system. The species is 
thought to be extant in 12 streams, which are discussed below, but 
historically significant populations have been eliminated from Lake 
Erie and the Detroit River.
    Black River--A tributary of the St. Clair River, linking Lakes 
Huron and St. Clair, the Black River is located in southeastern 
Michigan. Hoeh and Trdan (1985, p. 115) surveyed 17 sites in the Black 
River system, including 12 mainstem sites, but failed to find the rayed 
bean. The rayed bean was not discovered there until the summer of 2001 
when a single live (L) individual was found in the lower river in the 
Port Huron State Game Area (PHSGA) (Badra 2002, pers. comm.). A survey 
in 2003 failed to find any rayed bean, and two surveys in 2005 found 
only two valves (Badra 2008, pers. comm.). An additional survey was 
performed in 2005 at six sites, but no rayed bean were found (Badra 
2008, pers. comm.). The status of this population cannot be accurately 
assessed at this time, but would appear to be small and of questionable 
viability (Butler 2002, p. 8).
    Mill Creek--Mill Creek is a tributary of the Black River, St. Clair 
County, in southeastern Michigan. The rayed bean was discovered in Mill 
Creek in August 2002. Five dead specimens were found approximately 0.5 
miles (mi) (0.8 kilometers (km)) above its confluence with the Black 
River in the PHSGA (Badra 2002, pers. comm.). A Mill Creek site 0.25 mi 
(0.4 km) from the confluence of the Black River was surveyed in 2003 
and 2004 with one rayed bean shell found during each survey (Badra 
2008, pers. comm.). Similar to the population in the Black River, the 
status of this newly discovered population cannot be accurately 
assessed at this time.

[[Page 67557]]

    Pine River--Another tributary of the St. Clair River, the Pine 
River is located in southeastern Michigan. The rayed bean was 
apparently not collected in the Pine River until 1982 when specimens 
were found at three sites (Hoeh and Trdan 1985, p. 116). These 
collections included 5 L individuals and 23 FD specimens (Badra 2002, 
pers. comm.). Hoeh and Trdan (1985, p. 116) considered it to be 
``rare,'' semi-quantitatively defined as occurring at a rate of less 
than one specimen per person-hour sampling effort. In 1997, two L 
individuals were found. The last survey in the Pine River occurred in 
2002 (Badra 2008, pers. comm.), and one L rayed bean was documented 
(Badra and Goforth 2003, p. 6). The species may have declined 
significantly since the 1980s, but is probably still viable in the Pine 
River.
    Belle River--The Belle River is a third tributary of the St. Clair 
River harboring an extant population of the rayed bean. This species 
was first collected from the Belle River in 1965, when 17 FD specimens 
were collected (OSUM 1965:0106). The same site was revisited in 1978, 
but only one FD shell is represented in OSUM 1978:0013. Since that 
time, L individuals or FD specimens have been found in 1983 and 1992, 
while only R shells were found in 1994 (Badra 2008, pers. comm.). 
During summer 2002 sampling, single L specimens were found at two new 
sites, with an additional four and two FD specimens, respectively, also 
found from these sites (Badra 2008, pers. comm.). The status of the 
population is still not well known, but appears to be small.
    Clinton River--The rayed bean was first recorded from the Clinton 
River in 1933 (Badra 2008, pers. comm.). The mussel fauna in the entire 
mainstem of the Clinton River downstream of Pontiac, Michigan, was 
apparently wiped out by pollution between 1933 and 1977 (Strayer 1980, 
p. 147). In 1992, Trdan and Hoeh (1993, p. 102) found 26 L individuals 
using a suction dredge from a bridge site slated for widening where 
Strayer (1980, p. 146) found only R shells. The rayed bean represented 
1.2 percent relative abundance of the 10 species collected at the site. 
The population is probably viable but currently restricted to about 3 
mi (4.8 km) of stream in the western suburbs of Pontiac. Its long-term 
status appears to be highly precarious.
    Sydenham River--The rayed bean in the Sydenham River represents one 
of the largest rayed bean populations remaining. West et al. (2000, pp. 
252-253) presented a highly detailed collection history of the rayed 
bean in the Sydenham River. The rayed bean is currently thought to 
exist in an approximately 75-mi (120-km) reach of the middle Sydenham, 
from the general vicinity of Napier, Ontario, downstream to Dawn Mills. 
The species appears to be most abundant in the lower half of this river 
reach. Although the range has remained relatively consistent over time, 
abundance data at repeatedly sampled sites from the 1960s to the late 
1990s indicate a general decline of the rayed bean. Based on the range 
of sizes and roughly equal number of specimens in various size classes 
of the L and FD material they gathered, West et al. (2000, p. 256) 
considered the population to be ``healthy'' and ``reproducing'' 
(recruiting). Data from sampling in 2001 shows evidence of recruitment 
and variable size classes for both sexes from most of the sites 
(Woolnough 2002, p. 50). Based on this data, the rayed bean population 
in the Sydenham River is doing considerably better than West et al. 
(2000, pp. 252-253) suggested. Woolnough and Morris (2009, p. 19) 
estimates that there are 1.5 million mature rayed bean in the Sydenham 
River living in the 38-mile (61-km) stretch between Napier Road near 
Alvinston, Ontario, and Dawn Mills, Ontario.
    Thames River--The Thames River flows west through southwestern 
Ontario. The rayed bean was historically known from only the south 
branch until 2008, when it was discovered in the north branch. In July 
2008, six gravid (full of eggs) females were collected at two north 
branch sites (Woolnough 2008, pers. comm.). In September 2008, four L 
females and two L males were collected at two different north branch 
sites (Woolnough 2008, pers. comm.). All of these individuals were 
collected within a 4.5-mi (7.2-km) reach of the river (Woolnough 2008, 
pers. comm.). Woolnough and Morris (2009, p. 19) estimates that there 
are 4,300 mature rayed bean in the Thames River.
    Maumee River System--The Maumee River system, which flows into the 
western end of Lake Erie, was once a major center of distribution of 
the rayed bean. The species was historically known from eight streams 
in the system in addition to the mainstem Maumee. Further, an 
additional population was discovered in the system in 2005 in Swan 
Creek.
    Swan Creek--Swan Creek is a tributary of the lower Maumee River in 
northwestern Ohio. This population was discovered in 2005. Surveys 
conducted in 2006 and 2007 found that the Swan Creek population is 
limited to about 3 river mi (5 river km) between river mile (RM) 18.3 
and 15.3 (Grabarkiewicz 2008, p. 11). The rayed bean was the fourth 
most abundant unionid present within the 2006-2008 sample area, 
reaching densities of eight individuals per square meter in some areas 
and comprising about 14.1 percent of the total mussel community 
(Grabarkiewicz 2008, p. 10). The rayed bean population in Swan Creek is 
viable and, although limited to a short reach, may be one of the most 
robust remaining populations.
    St. Joseph River--The St. Joseph River is one of the two major 
headwater tributaries to the Maumee, with a drainage area in 
southeastern Michigan, northwestern Ohio, and northeastern Indiana. The 
mainstem flows in a southwesterly direction to its confluence with the 
St. Mary's River to form the Maumee in Ft. Wayne, Indiana. The rayed 
bean was historically known from numerous sites on the river, but now 
apparently persists only at a couple of sites in the lower St. Joseph 
River in Allen and DeKalb Counties, Indiana (Watters 1988b, p. 15; 
1998, Appendix C); a few FD specimens were found in both studies, but 
no live individuals were found. Grabarkiewicz and Crail (2008, p. 13) 
surveyed six sites on the West Branch St. Joseph River in 2007, but did 
not encounter any rayed bean.
    Fish Creek--A tributary of the St. Joseph River that begins in 
Ohio, Fish Creek flows west then south through Indiana, then eventually 
east into Ohio before joining the St. Joseph River at Edgerton. The 
rayed bean persists in Williams County, Ohio, and possibly DeKalb 
County, Indiana. Based on the appearance of 2 L individuals and FD 
shells, it inhabits the lower 10 mi (16.1 km) or less of the stream 
(Watters 1988b, p. 18; Grabarkiewicz 2009, pers. comm.). Watters 
(1988b, p. ii) considered Fish Creek to be ``the most pristine 
tributary of the St. Joseph system.'' A major diesel fuel spill from a 
ruptured pipeline in DeKalb County in 1993 resulted in a mussel kill in 
the lower portion of the stream (Sparks et al. 1999, p. 12). It is not 
known if the rayed bean was affected by the spill. Surveys in 2004 (at 
64 qualitative sites) and 2005 (at 11 quantitative sites) failed to 
detect the species (Brady et al. 2004, p. 2; 2005, p. 3). However, 
Grabarkiewicz (2009, pers. comm.) reported finding two L and three FD 
rayed bean in 2005 at the County Road 3 bridge in Ohio. In 2009, two FD 
rayed bean were found in lower Fish Creek in Ohio (personal 
observation). The viability and status of this population is uncertain 
(Fisher 2008, pers. comm.).
    Blanchard River--The Blanchard River is a tributary of the Auglaize 
River in the Maumee River system, in northwestern Ohio. First 
discovered in

[[Page 67558]]

1946, this population is one of the largest of the rayed bean 
rangewide. The rayed bean in the Blanchard River is restricted to 25-30 
river mi (40-48 river km) in the upper portion of the stream in Hardin 
and Hancock Counties upstream of Findley (Hoggarth et al. 2000, p. 22). 
Hoggarth et al. (2000, p. 23) reported the rayed bean to be the fourth 
most common species in the drainage. The population is considered to be 
viable.
    Tymochtee Creek--Tymochtee Creek is a tributary to the upper 
Sandusky River in north-central Ohio, which flows into the southwestern 
portion of Lake Erie. The rayed bean is known from three sites in a 
reach of stream in Wyandot County and was first collected in 1970. All 
collections of the rayed bean have been small, with not more than five 
FD shells found in any one collection effort. The last record is for 
1996, when a pair and three unpaired valves were collected. The 
condition of at least one of the valves indicated that the rayed bean 
is probably still extant in the stream, although no L individuals were 
observed (Athearn 2002, pers. comm.). The rayed bean status in 
Tymochtee Creek is therefore currently unknown.

Ohio River System

    The rayed bean was historically known from the Ohio River in the 
vicinity of Cincinnati, Ohio, downstream to the Illinois portion of the 
river. It undoubtedly occurred elsewhere in the upper mainstem. Few 
historical records are known (mostly circa 1900), and no recent 
collections have been made, indicating that it became extirpated there 
decades ago. It was historically known from 71 streams, canals, and 
lakes in the system, representing roughly two-thirds of its total 
range. Ortmann (1925, p. 354) considered the rayed bean to be 
``abundant in small streams'' in the Ohio River system. Currently, only 
16 streams and a lake are thought to have extant rayed bean populations 
in the system.
    Allegheny River System--Nine streams and Chautauqua Lake 
historically harbored rayed bean populations in the Allegheny River 
system. Currently, the rayed bean is found in half of these water 
bodies, but in good numbers in two streams (Allegheny River and French 
Creek) in this drainage.
    Allegheny River--The Allegheny River drains northwestern 
Pennsylvania and western New York joining the Monongahela River at 
Pittsburgh, Pennsylvania, to form the Ohio River. Ortmann (1909a, p. 
179; 1919, p. 262) was the first to report the rayed bean from the 
Allegheny. The population once stretched from Cataraugus County, New 
York, to Armstrong County, Pennsylvania. Based on historical 
collections, it appears that the rayed bean is more abundant now than 
it was historically in the Allegheny River. This may indicate that the 
rayed bean population in the Allegheny has expanded in the past 100 
years. Many streams in western Pennsylvania have improved water quality 
since Ortmann's time, when he reported on the wholesale destruction of 
mussels in several streams (Ortmann 1909b, pp. 11-12). It currently 
occurs in Pennsylvania downstream of Allegheny (Kinzua) Reservoir in 
Warren County to the pool of Lock and Dam 8 in northern Armstrong 
County, a distance of over 100 river mi (161 river km) (Villella 
Bumgardner 2008, pers. comm.). The Allegheny population is viable and 
one of the most important remaining rangewide today.
    Olean Creek--Olean Creek is a tributary of the Allegheny River in 
western New York. A small population of the rayed bean is known from 
the lower portions of the stream. Strayer et al. (1991, p. 67) reported 
the rayed bean from three sites during 1987-90 sampling, although just 
one L individual was located with R shells from the other two sites. 
Only R shells were found in Olean Creek in 1994, but three L 
individuals were found in 2000, at the proposed construction site of 
the City of Olean Water Treatment Plant (ESI 2000, p. 8). Collected 
only during their quantitative sampling effort, the rayed bean 
represented a relative abundance of 11.5 percent of the seven L species 
sampled. The rayed bean age distribution of these specimens also 
indicates recent recruitment into the population (ESI 2000, p. 9). 
Relic specimens are now known from an 8-mi (13-km) reach of stream, 
with L individuals known from less than 1.5 mi (2.4 km) of the lower 
creek. The Olean Creek population appears viable, but is small and 
tenuous (Butler 2008, pers. comm.)
    Cassadaga Creek--Cassadaga Creek is a tributary of Conewango Creek 
in the Allegheny River system, in western New York. A small population 
of the rayed bean is known from a single riffle (Ross Mills) in the 
lower creek north of Jamestown. Four L specimens were found in 1994 
(Strayer 1995). Muskrat middens collected during the winter of 2002 
produced 38 FD specimens with a size range of 0.8-1.7 in (2.0-4.3 cm) 
(Clapsadl 2002, pers. comm.). Although the rayed bean is not known from 
other sites in the stream, it appears to be viable at this site. The 
highly restricted extent of the population combined with its proximity 
to roads and retail development, including a gas station close to the 
flood zone upstream, makes it extremely susceptible to a stochastic 
event (such as a toxic chemical spill).
    French Creek--French Creek is a major tributary of the middle 
Allegheny River, in western New York and northwestern Pennsylvania. One 
of the largest rayed bean populations known is found in much of the 
lower portions of the stream in four Pennsylvania counties (the species 
is not known from the New York portion of stream). Ortmann (1909a, p. 
188; 1919, p. 264) reported the species from two counties, Crawford and 
Vanango. Not until circa 1970 did the population become more thoroughly 
known, with museum lot sizes indicating sizable populations at several 
sites, particularly in the lower reaches of the stream. Recent 
collections indicate that population levels remain high with the rayed 
bean occurring throughout the mainstem (Villella Bumgardner 2002, pers. 
comm.; Smith and Crabtree 2005, pp. 15-17; Enviroscience 2006, p. 5).
    Cussewago Creek--Cussewago Creek is a tributary of lower French 
Creek, with its confluence at Meadville, Crawford County, Pennsylvania. 
A small population was reported in 1991 from Cussewago Creek (Proch 
2001, pers. comm.). The rayed bean is thought to persist in the stream, 
but its current status is unknown.
    Walhonding River--The Walhonding River is a tributary of the upper 
Muskingum River system, in central Ohio, forming the latter River at 
its confluence with the Tuscarawas River at Coschocton. Small numbers 
of rayed bean shells are represented in OSUM collections from the 1960s 
and 1970s. During 1991-93, Hoggarth (1995-96, p. 161) discovered one L 
individual and one FD specimen at one site, while four R specimens were 
found at three other sites. A small rayed bean population is thought to 
remain in the Walhonding River; its status is unknown, but is deemed 
highly tenuous given the small population size. The population is 
probably nearing extirpation (Hoggarth 2008a, pers. comm.).
    Elk River--The Elk River is a major 181-river-mi (291-river-km) 
tributary in the lower Kanawha River system draining central West 
Virginia and flowing west to the Kanawaha River at Charleston. The 
rayed bean was extirpated in the Elk River sometime in the 1990s. In 
2006 and 2007, approximately 600 adults were reintroduced into the Elk 
River above Clendenin. In 2008, an effort was made to monitor the 
reintroduction. A 30-

[[Page 67559]]

minute search yielded two L individuals, but efforts were discontinued 
due to high water and excessive habitat disturbance caused by the 
search effort (Clayton 2008, pers. comm.). The translocated adults are 
thought to persist in the stream, but it is unknown if this new 
population is reproducing.
    Scioto River system--The Scioto River system, in central and south-
central Ohio, is a major northern tributary of the Ohio River. A 
historically large meta-population of the rayed bean occupied at least 
11 streams, the Ohio and Erie Canal, and Buckeye Lake. Sizable 
populations were noted in at least the Olentangy River, and Alum and 
Big Darby Creeks, based on OSUM collections primarily from the 1960s. A 
series of system reservoirs mostly north of Columbus reduced habitat 
and contributed to the elimination of some populations in several 
streams (Alum, Big Walnut, and Deer Creeks; Olentangy and Scioto 
Rivers). The location of the Columbus Metropolitan Area in the heart of 
the watershed has also taken a major toll on the species. The 
historical Scioto rayed bean meta-population has since been decimated 
by anthropogenic factors. Currently, remnant populations are known only 
from Mill Creek, Big Darby Creek, and Scioto Brush Creek.
    Mill Creek--Mill Creek is a tributary of the Scioto River in 
central Ohio that joins the Scioto River at the O'Shaughnessy Reservoir 
northwest of the City of Columbus. In 2004, seven FD specimens were 
found during a survey in the City of Marysville (Hoggarth 2005, p. 7). 
In 2007, Hoggarth (2007a, pp. 5-6) found two L rayed bean at the same 
site and one L individual at an additional site. No other information 
is available on the status of this population.
    Big Darby Creek--Big Darby Creek is one of the major tributaries 
draining the northwestern portion of the Scioto River system in central 
Ohio. A sizable rayed bean population was noted in Big Darby Creek from 
OSUM collections primarily from the 1960s. Watters (1994, p. 105) 
reported finding a few FD specimens in 1986, but none in 1990, and 
indicated that the rayed bean was probably extirpated from Big Darby 
Creek. In 2006, one L individual was found at the U.S. Highway 42 
bridge replacement project site (Hoggarth 2006, p. 6). This individual 
was relocated to a site upstream out of the impact zone of the bridge 
project, and nine additional L individuals were subsequently found at 
the relocation site (Hoggarth 2006, p. 6). In 2007, three L rayed bean 
were found at the relocation site (Hoggarth 2007b, p. 9). Hoggarth 
(2008b, pers. comm.) visited the same relocation site in 2008, and 
reported finding ``numerous living specimens'' of the rayed bean. The 
status of this population cannot be accurately assessed at this time, 
but would appear to be small and of questionable viability.
    Scioto Brush Creek-- Scioto Brush Creek is a small western 
tributary of the lower Scioto River in Scioto County, south-central 
Ohio. Watters (1988a, p. 45) discovered the rayed bean in this stream 
in 1987, reporting two FD and two R specimens from a site, and a R 
specimen from a second site among the 20 sites he collected. This 
population's current status is uncertain.
    Great Miami River--The Great Miami River is a major northern 
tributary of the Ohio River in southwestern Ohio that originates from 
Indian Lake in west-central Ohio and flows into the Ohio River west of 
Cincinnati. The occurrence of the rayed bean in the Great Miami River 
was discovered in August 2009, during a mussel survey for a bridge 
project in Logan County, Ohio. Only one individual was documented, a 
male approximately 7 to 8 years of age (Hoggarth 2009, pers. comm.). 
The status of this newly discovered population is not known.
    Little Miami River--The Little Miami River is a northern tributary 
of the Ohio River in southwestern Ohio, flowing into the latter at the 
eastern fringe of the Cincinnati metropolitan area. Hoggarth (1992, p. 
248) surveyed over 100 sites in the entire system. He found one L 
individual at a site in Warren County and possibly a subfossil shell at 
another site, although there is contradictory data in his paper (Butler 
2002, p. 17). The latter site may have been the same as that reported 
for a pre-1863 record (Hoggarth 1992, p. 265). The rayed bean appears 
to be very rare in the Little Miami, having been found extant at only 1 
of 46 mainstem sites. Hoggarth (1992, p. 267) highlighted the ``fragile 
nature'' of the extant mussel community in the system, while noting 
that localized reaches of the Little Miami were ``severely impacted.'' 
The species status in the river is uncertain, but apparently very 
tenuous and probably headed toward extirpation (Butler 2002, p. 17).
    East Fork Little Miami River--The East Fork Little Miami River is 
an eastern tributary of the lower Little Miami River, with its 
confluence at the eastern fringe of the Cincinnati metropolitan area. 
According to OSUM records, eight FD specimens were reported from a site 
in eastern Clermont County in 1973. Hoggarth (1992, p. 265) reported 
one L, three FD, and one R rayed bean from three sites in a 7-river-mi 
(11-river-km) stretch of the stream in western Clermont and adjacent 
Brown County (including the 1973 site). Harsha Reservoir on the East 
Fork destroyed several miles of potential stream habitat for the rayed 
bean a few miles downstream of the extant population. The status of the 
rayed bean in the river is uncertain but probably of doubtful 
persistence (Butler 2002, p. 17).
    Stillwater River--The Stillwater River is a western tributary of 
the middle Great Miami River in southwestern Ohio. The rayed bean is 
known from two specimens, one FD and one R, collected in 1987 at two 
sites spanning the Miami-Montgomery County line (OSUM records). Both 
sites occur in the footprint of Englewood Reservoir (constructed circa 
1920), which serves as a retarding basin (a constructed empty lake used 
to absorb and contain flooding in periods of high rain) that is 
normally a free-flowing river except in times of flood, therefore 
continuing to provide riverine habitat that is normally destroyed by 
permanently impounded reservoirs. The rayed bean in the Stillwater 
River may be extant, but its status is currently unknown and considered 
highly imperiled.
    Tippecanoe River--The Tippecanoe River is a large northern 
tributary of the middle Wabash River in north-central Indiana. The 
first records for the rayed bean date to circa 1900 (Daniels 1903, p. 
646). Historically, this species was known from numerous sites in six 
counties in the Tippecanoe River. A total of 12 FD specimens from 5 of 
30 sites were found when sampled in 1992. The rayed bean ``is 
apparently on the decline'' in the river (ESI 1993, p. 87). The 
Tippecanoe rayed bean population was thought to be recruiting by Fisher 
(2008, pers. comm.), but appears tenuous and its long-term viability is 
questionable.
    Lake Maxinkuckee--Lake Maxinkuckee is a glacial lake in the 
headwaters of the Tippecanoe River in north-central Indiana. The rayed 
bean has been known from the lake for more than a century (Blatchley 
1901). A 1997 OSUM record included seven FD specimens collected at its 
outlet to the Tippecanoe River. Fisher (2002, pers. comm.), who made 
the 1997 OSUM collection, noted that many native mussels had zebra 
mussels attached to their valves and were apparently contributing to 
their mortality. The status of the rayed bean in Lake Maxinkuckee is 
therefore highly tenuous, and its long-term persistence questionable.
    Sugar Creek--Sugar Creek is a tributary of the East Fork White 
River, in the lower Wabash River system in south-central Indiana. A 
rayed bean population was first reported there in

[[Page 67560]]

1930. Harmon (1992, p. 33) sampled 27 mainstem and 16 tributary sites 
finding FD specimens at 3 mainstem sites and R specimens from 2 other 
sites. The sites with FD material were found in the lowermost 6 mi (9.7 
km) of stream. The status and viability of this tenuous population is 
uncertain (Fisher 2008, pers. comm.).

Tennessee River System

    Historically, the rayed bean was known from the Tennessee River and 
12 of its tributary streams. Ortmann (1924, p. 55) reported that the 
rayed bean had a ``rather irregular distribution''; however, museum 
lots show that it was fairly common in some streams (North Fork Clinch, 
Duck Rivers). The last L rayed bean records from the system, with the 
exception of the Duck River, were from the 1960s or earlier. The 
species held on in the Duck until the early 1980s. Recent intensive 
sampling in the Duck watershed has failed to locate even a R shell of 
the rayed bean (Ahlstedt et al. 2004, p. 29). Tributaries in this 
system have been extensively sampled over the past 25 years. It is 
highly probable that this species is extirpated from the entire 
Tennessee River system.
    A project was initiated in 2008 to reintroduce rayed bean into the 
Duck River by translocating over 1,000 adults from the Allegheny River 
system. Although the rayed bean was extirpated from the Duck River 
about 25 years ago, major improvements in water quality and physical 
habitat conditions have occurred in the past 15 years. In response to 
these improvements, recruitment of nearly all extant mussel species has 
been documented and suggests that reintroduction of the rayed bean 
might be successful (Anderson 2008, pers. comm.). The reintroduction 
has not yet occurred.
    The information presented in this document indicates that the rayed 
bean has experienced a significant reduction in range and most of its 
populations are disjunct, isolated, and with few exceptions, appear to 
be declining (West et al. 2000, p. 251). The extirpation of this 
species from over 80 streams and other water bodies within its 
historical range indicates that substantial population losses have 
occurred. Relatively few streams are thought to harbor sizable viable 
populations (Sydenham, Swan, Blanchard, and Allegheny Rivers, and 
French Creek). Small population size and restricted stream reaches of 
current occurrence are a real threat to the rayed bean due to the 
negative genetic aspects associated with small, geographically isolated 
populations. This can be especially true for a species, like rayed 
bean, that was historically widespread and had population connectivity 
among mainstem rivers and multiple tributaries. The current 
distribution, abundance, and trend information illustrates that the 
rayed bean is imperiled.

Snuffbox Historical Distribution

    The snuffbox historically occurred in 208 streams and lakes in 18 
States and 1 Canadian province: Alabama, Arkansas, Illinois, Indiana, 
Iowa, Kansas, Kentucky, Michigan, Minnesota, Mississippi, Missouri, New 
York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and 
Wisconsin; and Ontario. The major watersheds of historical streams and 
lakes of occurrence include the upper Great Lakes sub-basin (Lake 
Michigan drainage), lower Great Lakes sub-basin (Lakes Huron, Erie, and 
Ontario drainages), upper Mississippi River sub-basin, lower Missouri 
River system, Ohio River system, Cumberland River system, Tennessee 
River system, lower Mississippi River sub-basin, and White River 
system.

Snuffbox Current Distribution

    Extant populations of the snuffbox are known from 74 streams in 14 
States and 1 Canadian province: Alabama (Tennessee River, Paint Rock 
River, and Elk River), Arkansas (Buffalo River, Spring River, and 
Strawberry River), Illinois (Kankakee River and Embarras River), 
Indiana (Pigeon River, Salamonie River, Tippecanoe River, Sugar Creek, 
Buck Creek, Muscatatuck River, and Graham Creek), Kentucky (Tygarts 
Creek, Kinniconick Creek, Licking River, Slate Creek, Middle Fork 
Kentucky River, Red Bird River, Red River, Rolling Fork Salt River, 
Green River, and Buck Creek), Michigan (Grand River, Maple River, Pine 
River, Belle River, Clinton River, Huron River, Davis Creek, South Ore 
Creek, and Portage River), Minnesota (St. Croix River), Missouri 
(Meramec River, Bourbeuse River, St. Francis River, and Black River), 
Ohio (Grand River, Ohio River, Muskingum River, Walhonding River, 
Killbuck Creek, Olentangy River, Big Darby Creek, Little Darby Creek, 
Salt Creek, Scioto Brush Creek, South Fork Scioto Brush Creek, Little 
Miami River, and Stillwater River), Pennsylvania (Allegheny River, 
French Creek, West Branch French Creek, Le Boeuf Creek, Muddy Creek, 
Conneaut Outlet, Little Mahoning Creek, Dunkard Creek, Shenango River, 
and Little Shenango River), Tennessee (Clinch River, Powell River, Elk 
River, and Duck River), Virginia (Clinch River and Powell River), West 
Virginia (Ohio River, Dunkard Creek, Middle Island Creek, North Fork 
Hughes River, and Elk River), Wisconsin (St. Croix River, Wolf River, 
Embarrass River, Little Wolf River, and Willow Creek), and Ontario 
(Ausable River and Sydenham River). It is probable that the species 
persists in some of the 134 streams or lakes where it is now considered 
extirpated (Butler 2007, p. 16); however, if extant, these populations 
are likely to be small and not viable.

Snuffbox Population Estimates and Status

    Based on historical and current data, the snuffbox has declined 
significantly rangewide and is now known from only 74 streams (down 
from 208 historically), representing a 65 percent decline in occupied 
streams (Table 2). Since multiple streams may comprise a single 
snuffbox population (French Creek system), the actual number of extant 
populations is less than 74. Extant populations, with few exceptions, 
are highly fragmented and restricted to short reaches. Available 
records indicate that 24 of 74, or 33 percent, of streams considered to 
harbor extant populations of the snuffbox are represented by only one 
or two recent L or FD individuals (Embarrass, Little Wolf, Maple, 
Pigeon, Kankakee, Meramec, Ohio, Muskingum, Olentangy, Stillwater, 
Green, Powell, Duck, and Black Rivers; and Little Mahoning, Middle 
Island, Big Darby, Little Darby, Salt, South Fork Scioto Brush, Slate, 
and Buck (Indiana), Graham, Buck (Kentucky) Creeks.
    Butler (2007, pp. 70-71) categorized the extant populations into 
three groups based on population size, general distribution, evidence 
of recent recruitment, and assessment of current viability. Stronghold 
populations were described as having sizable populations generally 
distributed over a significant and more or less contiguous length of 
stream (30 or more river mi (48 or more river km)), with ample evidence 
of recent recruitment, and currently considered viable. Significant 
populations were defined as small, generally restricted populations 
with limited recent recruitment and viability. Many significant 
populations are susceptible to extirpation, but this category has a 
broad range of quality. The third category, marginal populations, are 
defined as those which are very small and highly restricted with no 
evidence of recent recruitment, of questionable viability, and that may 
be on the verge of extirpation in the immediate future. Following this 
criteria, there are 6 stronghold populations, 23 significant 
populations,

[[Page 67561]]

and 45 marginal populations of snuffbox.
    A population is considered extant if L individuals or FD specimens 
have been located since approximately 1985. A population is considered 
to be recruiting if there was recent (within approximately 10 years) 
evidence of subadults (generally, individuals less than or equal to 1.5 
in (3.8 cm) long or less than or equal to 4 years).

                                       Table 2--Snuffbox Extant Stream Population Summary by Stream of Occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                    Last                             Potential
         Stream (state)           observed      Recruiting           viability        Population size    Population trend          Status category
--------------------------------------------------------------------------------------------------------------------------------------------------------
Wolf River (WI)................       2006  Yes...............  High..............  Large.............  Declining.........  Stronghold.
Embarrass River (WI)...........       1995  ?.................  ?.................  Small.............  ?.................  Marginal.
Little Wolf River (WI).........       1999  ?.................  ?.................  Small.............  ?.................  Marginal.
Willow Creek (WI)..............       2001  ?.................  ?.................  Small.............  ?.................  Marginal.
Grand River (MI)...............       2002  Yes...............  High..............  Medium............  ?.................  Significant.
Maple River (MI)...............       2001  ?.................  ?.................  Small.............  ?.................  Marginal.
Pine River (MI)................       2002  ?.................  Low...............  Small.............  Stable............  Marginal.
Belle River (MI)...............       2002  Yes...............  High..............  Small.............  ?.................  Significant.
Clinton River (MI).............       2003  Yes...............  High..............  Large.............  Declining.........  Significant.
Huron River (MI)...............       2001  ?.................  Low...............  Medium............  ?.................  Significant.
Davis Creek (MI)...............       2005  Yes...............  High..............  Medium............  ?.................  Significant.
South Ore Creek (MI)...........       1999  Yes...............  High..............  Small.............  ?.................  Significant.
Portage River (MI).............       1998  Yes...............  High..............  Medium............  ?.................  Significant.
Grand River (OH)...............       2006  Yes...............  High..............  Medium............  ?.................  Significant.
St. Croix River (MN and WI)....       2004  Yes...............  High..............  Large.............  Declining.........  Significant.
Kankakee River (IL)............       1991  ?.................  ?.................  Small.............  ?.................  Marginal.
Meramec River (MO).............       1997  ?.................  ?.................  Small.............  Declining.........  Marginal.
Bourbeuse River (MO)...........       2006  Yes...............  High..............  Large.............  Improving.........  Stronghold.
Ohio River (OH)................       2001  ?.................  Low...............  Small.............  ?.................  Marginal.
Muskingum River (OH)...........       2005  ?.................  ?.................  Small.............  ?.................  Marginal.
Walhonding River (OH)..........       1991  ?.................  ?.................  Small.............  Declining.........  Significant.
Killbuck Creek (OH)............       2009  ?.................  ?.................  Small.............  Declining.........  Marginal.
Olentangy River (OH)...........       1989  ?.................  ?.................  Small.............  Declining.........  Marginal.
Big Darby Creek (OH)...........       2008  ?.................  ?.................  Small.............  Declining.........  Marginal.
Little Darby Creek (OH)........       1999  ?.................  ?.................  Small.............  Declining.........  Marginal.
Salt Creek (OH)................       1987  ?.................  ?.................  Small.............  ?.................  Marginal.
Scioto Brush Creek (OH)........       1987  ?.................  ?.................  Small.............  ?.................  Marginal.
South Fork Scioto Brush Creek         1987  ?.................  ?.................  Small.............  ?.................  Marginal.
 (OH).
Little Miami River (OH)........       1991  ?.................  ?.................  Small.............  ?.................  Marginal.
Stillwater River (OH)..........       1987  ?.................  ?.................  Small.............  ?.................  Marginal.
Pigeon River (IN)..............       1998  ?.................  ?.................  Small.............  ?.................  Marginal.
Salamonie River (IN)...........       2004  Yes...............  Low...............  Small.............  ?.................  Significant.
Tippecanoe River (IN)..........       2003  ?.................  ?.................  Small.............  Declining.........  Marginal.
Embarras River (IL)............       2008  Yes...............  Low...............  Small.............  Declining.........  Significant.
Sugar Creek (IN)...............       1990  ?.................  ?.................  Small.............  Declining.........  Marginal.
Buck Creek (IN)................       1990  ?.................  ?.................  Small.............  ?.................  Marginal.
Muscatatuck River (IN).........       1988  ?.................  ?.................  Small.............  ?.................  Marginal.
Graham Creek (IN)..............       1990  ?.................  ?.................  Small.............  Declining.........  Marginal.
St. Francis River (MO).........       2006  Yes...............  High..............  Medium............  Stable............  Significant.
Black River (MO)...............       2002  Yes...............  Low...............  Small.............  ?.................  Significant.
Tygarts Creek (KY).............       1995  ?.................  ?.................  Small.............  Declining.........  Marginal.
Kinniconick Creek (KY).........       2005  ?.................  Low...............  Small.............  Declining.........  Marginal.
Licking River (KY).............       2006  ?.................  Low...............  Small.............  ?.................  Marginal.
Slate Creek (KY)...............       1992  ?.................  ?.................  Small.............  Declining.........  Marginal.
Middle Fork Kentucky River (KY)       1997  ?.................  ?.................  Small.............  ?.................  Marginal.

[[Page 67562]]

 
Red Bird River (KY)............       1995  ?.................  ?.................  Small.............  ?.................  Marginal.
Red River (KY).................      ~2002  ?.................  ?.................  Small.............  ?.................  Significant.
Rolling Fork Salt River (KY)...      ~2005  ?.................  ?.................  Small.............  ?.................  Marginal.
Green River (KY)...............       1989  ?.................  ?.................  Small.............  Declining.........  Marginal.
Buck Creek (KY)................    1987-90  ?.................  ?.................  Small.............  Declining.........  Marginal.
Clinch River (TN and VA).......       2006  Yes...............  High..............  Large.............  Stable or           Stronghold.
                                                                                                         Declining.
Powell River (TN and VA).......       2008  ?.................  ?.................  Small.............  Declining.........  Marginal.
Tennessee River (AL)...........       2006  ?.................  ?.................  Small.............  ?.................  Marginal.
Paint Rock River (AL)..........       2008  Yes...............  High..............  Large.............  Improving.........  Stronghold.
Elk River (TN and AL)..........       2007  Yes...............  Low...............  Small.............  Stable............  Significant.
Duck River (TN)................       2001  ?.................  ?.................  Small.............  ?.................  Marginal.
Buffalo River (AR).............       2006  ?.................  ?.................  Small.............  ?.................  Marginal.
Spring River (AR)..............       2005  ?.................  Low...............  Medium............  ?.................  Significant.
Strawberry River (AR)..........       1997  ?.................  ?.................  Small.............  ?.................  Marginal.
Allegheny River (PA)...........       2001  ?.................  ?.................  Small.............  ?.................  Marginal.
French Creek (PA)..............       2008  Yes...............  High..............  Large.............  Stable............  Stronghold.
West Branch French Creek (PA)..       2008  ?.................  ?.................  Small.............  ?.................  Marginal.
Le Boeuf Creek (PA)............       2006  Yes...............  Low...............  Small.............  ?.................  Marginal.
Muddy Creek (PA)...............       2008  Yes...............  Low...............  Medium............  ?.................  Significant.
Conneaut Outlet (PA)...........       1997  ?.................  ?.................  Small.............  ?.................  Marginal.
Little Mahoning Creek (PA).....       1991  ?.................  ?.................  Small.............  ?.................  Marginal.
Dunkard Creek (PA and WV)......       2009  ?.................  ?.................  Small.............  Declining.........  Significant.
Shenango River (PA)............       2002  ?.................  ?.................  Small.............  ?.................  Marginal.
Little Shenango River (PA).....       2002  ?.................  ?.................  Small.............  ?.................  Significant.
Middle Island Creek (WV).......       2001  ?.................  ?.................  Small.............  Declining.........  Marginal.
North Fork Hughes River (WV)...       2001  ?.................  Low...............  Small.............  Declining.........  Significant.
Elk River (WV).................       2004  ?.................  Low...............  Medium............  Improving.........  Significant.
Ausable River (ON).............       2006  Yes...............  High..............  Medium............  Declining.........  Significant.
Sydenham River (ON)............       2002  Yes...............  High..............  Large.............  ?.................  Stronghold.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Upper Great Lakes Sub-Basin

    The snuffbox was formerly known from 15 streams and lakes in the 
upper Great Lakes sub-basin. The Fox River system in Wisconsin, 
particularly its major tributary the Wolf River (and its tributaries), 
had a widespread and locally abundant population. The species is 
thought to be extant in seven sub-basin streams; however, all but the 
Wolf and Grand Rivers have populations that are considered marginal.
    Wolf River--The Wolf River is the major tributary of the Fox River 
draining a large portion of northeastern Wisconsin and flowing 
southward to join the Fox River at Lake Butte Des Morts, near Oshkosh. 
Snuffbox records are known from Shawano, Waupaca, and Outagamie 
Counties. The snuffbox is known from a 30-river-mi (48-river-km) reach 
of the Wolf River (Butler 2007, p. 21). It is one of the few stronghold 
populations, but appears to exhibit a low level of recruitment. Only 4 
of 257 individuals collected in the mid-1990s were less than 6 years 
old (Butler 2007, p. 21). A bridge replacement project on the south 
side of Shawano, scheduled to begin in 2010, may adversely impact the 
large snuffbox bed located just downstream (ESI 2006, p. 10). The zebra 
mussel occurs in this river, with a 0.7 percent infestation rate on 
unionids sampled in 2006 (ESI 2006, p. 6). This large population 
continues to be viable but appears to be in decline (Butler 2008, pers. 
comm.).
    Embarrass River--A western tributary of the lower Wolf River, the 
Embarrass River parallels the western bank of the Wolf River before 
joining it at New London, Wisconsin. A population of the snuffbox is 
located in the headwaters below a small dam at Pella, Wisconsin. 
Records exist for three L individuals and two dead specimens during 
1987-1988 and a single D specimen in 1995 (Butler 2007, p. 22). Its 
current status is unknown.
    Little Wolf River--The Little Wolf River is a western tributary of 
the lower

[[Page 67563]]

Wolf River in Waupaca County, Wisconsin. The snuffbox is known from a 
single L individual collected in 1988 at RM 14 below the Mill Pond dam 
at Manawa (Butler 2007, p. 22). Five D specimens were found during 1999 
at RM 2, where shells were abundant in a muskrat midden (Butler 2007, 
p. 22). Nothing else is known regarding this population.
    Willow Creek--Willow Creek flows eastward into Lake Poygan, a large 
flow-through lake of the Wolf River system, in Waushara County, 
Wisconsin. The snuffbox is known from a single observation of two L 
females in 2001 (Butler 2007, p. 22). No other information is available 
on the status of this population.
    Grand River--The Grand River, a major Lake Michigan tributary, 
represents the largest lotic (moving water) watershed in Michigan and 
is located in the southwestern portion of the State. The snuffbox is 
sporadically distributed in approximately 25 river mi (40 river km) of 
the middle Grand River, approximately between the confluences of the 
Flat and Maple Rivers. The medium-sized population appears to have a 
low level of viability, with recruitment noted in 1999 (Badra 2008, 
pers. comm.).
    Maple River--The Maple River is a northeastern tributary of the 
Grand River draining south-central Michigan. A single snuffbox record 
(one L individual) is known from 2001 in southern Gratiot County, 
approximately 20 river mi (32 river km) upstream of the Grand River 
(Badra 2008, pers. comm.). Portions of the Maple River and several 
tributaries have been channelized, but the suitability of these 
channelized areas for the snuffbox is unknown (Badra 2010, pers. 
comm.). The current status of this small population is unknown.
    Pigeon River--The Pigeon River is a headwater tributary of the St. 
Joseph River system of Lake Michigan, flowing westward across northern-
most Indiana, crossing the State border to its confluence in 
southwestern Michigan. One very large FD specimen was found in 1998, 
among thousands of shells in LaGrange County, Indiana (Butler 2007, p. 
24). The same site was sampled in 1996 without evidence of this 
species, and R shells were found at three of nine sites sampled in 2004 
(Butler 2007, p. 24). The snuffbox occupied reach historically covered 
more than 10 river mi (16.1 river km) in north-central LaGrange County. 
The species is very rare in this river, and its viability is unknown.

Lower Great Lakes Sub-Basin

    Of all the water bodies from which the snuffbox was historically 
recorded, 32 are in the lower Great Lakes sub-basin, including several 
chains-of-lakes, springs, and channels in some systems (Clinton, Huron 
Rivers). Historically sizable populations occurred in some streams 
(Lake Erie; Belle, Clinton, Huron, Portage, and Niagara Rivers), but 
the species had become ``characteristically uncommon'' by the 1970s 
(Strayer 1980, p. 147). A pre-zebra mussel decline of unionids in Lake 
Erie was noted (Mackie et al. 1980, p. 101), and the snuffbox appeared 
extirpated there by the late 1960s. The Lake St. Clair population of 
snuffbox persisted until around 1983 (Nalepa and Gauvin 1988, p. 414; 
Nalepa 1994, p. 2231; Nalepa et al. 1996, p. 361), which was the year 
the zebra mussel is thought to have invaded (Schloesser et al. 1998, p. 
70). Observations of L and FD snuffbox from the Detroit River were made 
until 1994, but the mussel fauna has since been devastated by zebra 
mussels, and the snuffbox is now considered to be extirpated 
(Schloesser et al. 1998 p. 69; Butler 2007, p. 25). Other snuffbox 
populations in the sub-basin may also have suffered from zebra mussel 
invasions, but not those in the Ausable and Sydenham Rivers in Ontario. 
The lack of impounded area on these streams has likely prevented the 
introduction or the establishment of zebra mussels (Ausable River 
Recovery Team 2005, p. 12; Dextrase et al. 2000, p. 10). The snuffbox 
is considered extant in 10 streams of the lower Great Lakes sub-basin, 
including a stronghold population in the Sydenham River and sizable but 
reach-limited populations in the Clinton River and Davis Creek. A 
single FD valve was reported in 1998 from among 24 sites sampled in the 
Thames River, but no evidence of the snuffbox was found at 16 Thames 
sites in 2004 (McGoldrick 2005, pers. comm.). Currently, the species is 
considered extant in Canada only in the Ausable and Sydenham Rivers 
(Morris and Burridge 2006, p. 9). Both of these populations are viable.
    Ausable River--The Ausable River is a southeastern tributary of 
Lake Huron, draining southwestern Ontario, Canada. A survey conducted 
in 2006 found that a sizable population of snuffbox occurs in the lower 
portion of the stream in over 23 river mi (37 river km) (McGoldrick 
2007, pers. comm.). The size range of individuals found in the 2006 
survey indicates recent recruitment in the viable population 
(McGoldrick 2007, pers. comm.; Staton 2007, pers. comm.).
    Pine River--A tributary of the St. Clair River, the Pine River 
flows south and is located in St. Clair County, in southeastern 
Michigan. Although apparently stable, the snuffbox population is small, 
very restricted in range, and has a low potential for viability (Badra 
2002, pers. comm.; Badra and Goforth 2003, p. 23).
    Belle River--The Belle River is another tributary of the St. Clair 
River in St. Clair County, flowing in a southeasterly direction. 
Records for the snuffbox date to the early 1960s, but all L and FD 
records over the past 40 years have been from the same lower mainstem 
site. Historically, a sizable population was found in the Belle (65 
specimens, 1965). The Belle is located in a primarily agricultural 
watershed (Hoeh and Trdan 1985, p. 115), and is impacted by 
sedimentation and runoff. The population has declined to the point of 
being small, but shows evidence of recruitment and viability (Badra 
2002, pers. comm.; Badra and Goforth 2003, p. 24; Sherman 2005, pers. 
comm.).
    Clinton River--The Clinton River is an eastward flowing chain-of-
lakes tributary of Lake St. Clair in southeastern Michigan. The 
snuffbox population in the Clinton River is limited to around 10 river 
mi (16.2 river km) and lakeshore in the western suburbs of Pontiac 
primarily between Cass and Loon Lakes. This population appears to be 
recruiting (Sherman Mulcrone 2004, p. 64) and viable, although 
apparently in decline since the early 1990s (Badra 2002, pers. comm.; 
Butler 2007, p. 27).
    Sydenham River--The Sydenham River is a large, southeasterly 
flowing, eastern tributary of Lake St. Clair in extreme southwestern 
Ontario. The snuffbox was reported in the mid-1960s and early 1970s but 
was overlooked during surveys in 1985 (except D shells) and 1991 
(Butler 2007, p. 28). During the 1997-99 sampling, a total of 10 L and 
FD individuals were found from 4 of 12 sites, including the 3 1960s 
sites (Metcalfe-Smith et al. 2003, p. 41). The snuffbox was recorded at 
a rate of 0.22 per hour of effort during 1997-98 (Metcalfe-Smith et al. 
2000, p. 728). More recent sampling found 57 L and FD individuals from 
21 collection events (some individuals may have been counted multiple 
times) at six sites during 2000-02. The increase in numbers relative to 
historical collections may be attributed to more intensive sampling 
methods rather than to improving population size (Metcalfe-Smith et al. 
2003, p. 46), thus making population trend assessments difficult 
(Morris and Burridge 2006, p. 12). This

[[Page 67564]]

stronghold population is recruiting (Butler 2007, p. 28), viable, and 
is currently known from approximately 30 river miles (48 km) of the 
middle Sydenham.
    Huron River--The Huron River is a major tributary of western Lake 
Erie draining a significant portion of southeastern Michigan. It is a 
complex system of flow-through chains-of-lakes and tributaries. The 
snuffbox is considered extant in two disjunct upper mainstem reaches. 
Individuals in the middle Huron River reach and in Davis Creek are 
considered a single population segment (Marangelo 2005a, pers. comm.).
    Zebra mussels invaded the Huron River system in the early 1990s. 
Zebra mussel densities on individual mussels increased from less than 1 
in spring 1995 to 245 in winter 1998 (Nichols et al. 2000, p. 72). 
Despite the increasing presence of zebra mussels, the Huron population 
is probably recruiting and viable (Butler 2007, p. 29).
    Davis Creek--Davis Creek is a chain-of-lakes in the upper Huron 
River system, primarily in southeastern Livingston County, Michigan. 
The snuffbox appears to be limited to the lower 3 river mi (4.8 river 
km), comprising a single population with one of the extant Huron River 
population segments in this area. This viable population appears to be 
sizable and is experiencing recent recruitment (Marangelo 2005a, pers. 
comm.; Zanatta 2005, pers. comm.).
    South Ore Creek--South Ore Creek is a northern tributary of the 
Huron River, forming a southward flowing chain-of-lakes draining 
southeastern Livingston County, Michigan. The snuffbox was discovered 
in 1999, just upstream of Ore Lake, which is near the Huron River 
confluence (Butler 2007, p. 31). Three subadult snuffbox (two age 2, 
one age 3-4) were recorded. Despite the lack of additional information, 
the small population appears to be viable based on recent recruitment.
    Portage River--The Portage River is a chain-of-lakes in the 
northwestern portion of the Huron River system. Two University of 
Michigan Museum of Zoology (UMMZ) records suggest historical abundance 
(Badra 2002, pers. comm.). The species was reported as ``rare'' in the 
lower river during 1976-78 (Strayer 1979, p. 94). At least 22 L, young 
(age 4 and younger) individuals were identified in 1998 at one of three 
sites upstream of Little Portage Lake and Portage Lake (Butler 2007, p. 
31). The localized population appears to be medium-sized and viable.
    Grand River--The Grand River is a 99-river-mi (159-river-km) 
tributary of Lake Erie, flowing north then west to its confluence 
northeast of Cleveland, Ohio. Several museum snuffbox records date back 
to the 1800s. Dozens of FD snuffbox were found washed up on the banks 
in the vicinity of the Interstate 90 crossing in Lake County, Ohio, 
following a major flood in 2006 (Butler 2007, p. 32). The species is 
known from approximately 12 river mi (19.3 river km) downstream of 
Harpersfield Dam (Huehner et al. 2005, p. 59; Zimmerman 2008a, pers. 
comm.). The sizable population was considered recruiting based on the 
1995 Huehner et al. (2005, p. 59) survey.

Upper Mississippi River Sub-basin

    The snuffbox was historically known from 17 streams in the upper 
Mississippi River sub-basin. Records exist for Mississippi River Pools 
(MRPs) 3-4, 5a-6, and 14-16 (Kelner no date, p. 6), with early surveys 
summarized by van der Schalie and van der Schalie (1950, p. 456). The 
species was reported L in the upper river in the 1920s (Grier 1922, p. 
15; Grier 1926, p. 119) but not from subsequent surveys (254 sites 
upstream of the Ohio River during 1930-1931 (UMMZ, Ellis 1931, pp. 1-
10), MRPs 5-7 and 9 in 1965 (Finke 1966, Table 2; Thiel 1981, p. 16), 
MRPs 3-11 during 1977-79 (Thiel 1981, p. 16)) and is now extirpated 
from the mainstem of the Mississippi River (Havlik and Sauer 2000, p. 
4). Only 4 of 17 historical populations remain, but they include two of 
the largest rangewide (St. Croix and Bourbeuse Rivers). Three 
populations, including the St. Croix, appear to be declining.
    St. Croix River--The St. Croix River is a major south-flowing 
tributary of the upper Mississippi River and forms the border between 
southeastern Minnesota and northwestern Wisconsin. Densities of 
juvenile snuffbox declined at eight sites between 1992 and 2002 
(Hornbach et al. 2003, p. 344). Snuffbox density at Interstate Park 
declined significantly between 1988 and 2004 (WIDNR 2004). A flood in 
2001 may have contributed to these declines in mussel density, but 
post-flood recruitment was also surprisingly low (WIDNR 2004). The St. 
Croix snuffbox population occurs from the Northern States Power Dam 
(NSPD) at RM 54.2 to RM 36.8 (Heath 2005, pers. comm.), represents the 
species' northernmost occurrence, and despite recent observed declines, 
remains one of the six stronghold populations rangewide.
    Kankakee River--The Kankakee River is a major, westward-flowing, 
upper Illinois River tributary with its headwaters in northwest Indiana 
and northeast Illinois. The snuffbox was reported over a century ago 
(Baker 1906, p. 63), but surveys in 1911 (43 sites; Wilson and Clark 
1913, pp. 41-50), 1978 (13 sites; Suloway 1981, p. 236), 1975-2000 (18 
samples from an unknown number of Will County, Illinois, sites; Sietman 
et al. 2001, p. 279), and 1999 (4 sites, Stinson et al. 2000, Appendix 
C) failed to find it. It was considered extirpated from the Kankakee by 
Cummings et al. (1988, p. 16), but single FD specimens in Illinois 
(Will County in 1988, Kankakee County in 1991) were subsequently found. 
Only R shells have been found since 1991. The Kankakee River 
population, if extant, appears small, localized, and of doubtful 
viability.
    Meramec River--The Meramec River is a 236-mi (380-km) tributary 
that flows northeasterly into the Mississippi River downstream of St. 
Louis and drains the northeastern slope of the Ozark Plateaus in east-
central Missouri. Early species lists failed to report the snuffbox 
(Grier 1916, p. 518; Utterback 1917, p. 28). Buchanan (1980, p. 63) 
found FD specimens at three sites and R shells at two other sites 
sampled in 1977-78. Roberts and Bruenderman (2000, p. 85) sampled 42 
sites in 1997, including 26 of Buchanan's (1980, p. 5) sites, and found 
FD specimens at RM 33.5, 48.8, and 59.8; and one L individual at RM 
39.8. The L individual (2.4 in (6.1 cm), approximately 6 years old) was 
reported from a reach where a die-off, perhaps attributable to disease, 
was reported in 1978 (Buchanan 1986, p. 44). There was an obvious 
decline of mussels in the system based on catch-per-unit-effort data 
over the 20-year period (Roberts and Bruenderman 2000, p. 8). The 
Meramec snuffbox population is rare, sporadically distributed over 
approximately 26 river mi (41.8 river km), and of unknown viability.
    Bourbeuse River--The Bourbeuse River is a 149-mi (240-km), 
northeasterly flowing, northern tributary of the Meramec River, joining 
it at RM 68. The snuffbox is currently distributed over about 60 river 
mi (96.6 river km) upstream of RM 16, plus a disjunct site at the mouth 
of the river. Although it was considered to have ``greatly declined'' 
by the late 1990s (Roberts and Bruenderman 2000, p. 15), post-2000 
sampling indicates that the population is recruiting, viable, and 
improving (McMurray 2006, pers. comm.). The Bourbeuse, one of the few 
stronghold snuffbox populations rangewide, has been augmented with 
laboratory propagated juveniles since 2002 (McMurray 2006, pers. 
comm.).

[[Page 67565]]

Lower Missouri River System

    The snuffbox was historically known from four streams in this 
system. The highly disjunct occurrences suggest that it was more 
widespread historically. All populations in the system are considered 
extirpated (Butler 2007, p. 36).

Ohio River System

    Half of the water body occurrences for the snuffbox rangewide are 
known from the Ohio River system, which collectively represented the 
largest block of available habitat for this species. Sizable 
populations historically occurred in at least a dozen streams in the 
system. Today, only French Creek is considered to have a stronghold 
population, although nine others are also significant. Currently, the 
species is known from 40 of the 107 streams of historical occurrence.
    Ohio River--The Ohio River is the largest eastern tributary of the 
Mississippi, with its confluence marking the divide between the upper 
and lower portions of the latter system. Numerous historical records 
are known from throughout the River. Recently, single FD and L 
specimens have been reported from just below Belleville Lock and Dam, 
Ohio and West Virginia, in 1995 and 2001, respectively (ESI 2002, p. 
27). Having persisted in this highly modified river may indicate that 
the small population exhibits a low level of viability.
    Allegheny River--The 325-mi (523-km) Allegheny River drains 
northwestern Pennsylvania and a small portion of adjacent New York 
flowing south before joining the Monongahela River at Pittsburgh to 
form the Ohio River. Snuffbox collections are sporadically known since 
around 1900 in Pennsylvania from Forest County downstream to Armstrong 
County. The snuffbox is currently known from three disjunct sites over 
a 42-river-mi (67.6-river-km) reach centered in Venango County (Butler 
2007, p. 37). Its occurrence in the lower Allegheny River and lower 
French Creek could be considered a single population segment. The 
viability status of the small population is unknown.
    French Creek--French Creek is a major tributary of the middle 
Allegheny River with its headwaters in western New York and flowing 
south into northwestern Pennsylvania. The snuffbox is known from the 
length of the stream in Pennsylvania in Erie, Crawford, Mercer, and 
Venango Counties. Most records date since approximately 1970 (Dennis 
1971, p. 97). Snuffbox collections made during 2002-2004 were 
summarized by Smith (2005, pp. 3-9). Live and FD specimens were found 
at 19 sites throughout the stream. The size of the L individuals 
indicated that multiple year classes were represented, including 
subadults. The species stretches for approximately 80 river mi (128.7 
river km) from around RM 10, upstream. The population encompasses 
several of its tributary population segments as well, making it 
relatively more secure when compared to most of the other stronghold 
populations that are linearly distributed and, thus, more susceptible 
to stochastic events (Sydenham, Bourbeuse, and Clinch Rivers). The 
French Creek snuffbox population is considered large and viable (Evans 
2003a, pers. comm.; Zimmerman 2008c, pers. comm.), appears stable, and 
may represent the best stronghold population rangewide.
    West Branch French Creek--West Branch of French Creek follows a 
southerly course to its parent stream in Erie County, Pennsylvania. The 
only record for the snuffbox dates from 1993, but the number of 
specimens and shell condition are unknown (Evans 2003b, pers. comm.). 
Union City Lake isolates the upper French Creek and West Branch French 
Creek population segment from the main French Creek population. The 
snuffbox was not found at three sites sampled in 2006 (Smith 2006, 
pers. comm.). Zimmerman (2008c, pers. comm.) documented 38 L 
individuals at a site near Wattsburg, Pennsylvania. This population 
appears to be small and of unknown viability.
    Le Boeuf Creek--Le Boeuf Creek is a small western tributary of 
upper French Creek flowing in a southerly direction just west of West 
Branch French Creek in Erie County. The first snuffbox collections in 
this creek were made 100 years ago (Ortmann 1909a, p. 188). Two FD and 
6 R shells were reported in 1988 (Evans 2003b, pers. comm.), and 1 L, 
16 FD, and 8 R specimens were found in 1991 (Butler 2007, p. 40). Three 
L individuals were found at a site in 2006 (Smith 2006, pers. comm.). 
The snuffbox population has recently recruited and exhibits some level 
of viability, but appears to be very limited in extent.
    Muddy Creek--Muddy Creek is an eastern tributary of upper French 
Creek in Crawford County, Pennsylvania. The snuffbox was not discovered 
until the summer of 2003. Forty-two L individuals were reported from 11 
of 20 lower river sites (Morrison 2005, pers. comm.). Low numbers were 
found at most sites, but 18 L individuals were collected from a site 
near the mouth. This occurrence is considered to be part of the more 
extensive French Creek snuffbox population. Zimmerman (2008c, pers. 
comm.) documented one L female in 2008. The population is medium-sized, 
occurs along 8 river mi (12.9 river km) of the lower mainstem, and is 
recruiting, as recent juveniles were recorded (Morrison 2005, pers. 
comm.).
    Conneaut Outlet--This stream forms the outlet to Conneaut Lake, 
flowing in a southeasterly direction until its confluence with middle 
French Creek, Crawford County. The snuffbox was first reported by 
Ortmann (1909a, p. 188), and was rediscovered L in 1997, but without 
collection details (Butler 2007, p. 40). No specimens were found at a 
site sampled in 2006 (Smith 2006, pers. comm.). The snuffbox is 
considered rare in this stream and its viability is unknown.
    Little Mahoning Creek--Little Mahoning Creek is a tributary of 
Mahoning Creek, a lower eastern tributary of the Allegheny River 
northeast of Pittsburgh. The snuffbox was discovered in 1991, when 
sampling produced two FD and one R specimen at 1 of 12 sites in the 
system (Butler 2007, p. 41). The lower 10 miles of Little Mahoning 
Creek is subject to periodic inundation by a reservoir on Mahoning 
Creek (Butler 2010, pers. comm.). However, the impact of this periodic 
flooding on the snuffbox is not known. Viability is unknown.
    Dunkard Creek--Dunkard Creek is an easterly flowing, western 
tributary of the middle Monongahela River, straddling the Pennsylvania 
and West Virginia State lines. Snuffbox records occur in both States 
from several museum collections from 1969-74. Small numbers of 
specimens, of undocumented condition, were found at four sites during 
1993-94 sampling in Pennsylvania (Bogan 1993, p. 8; Evans 2003b, pers. 
comm.). Eight specimens, of undocumented condition, were collected at a 
West Virginia site in 1997. On September 1, 2009, a fish kill was 
reported in Dunkard Creek due to an unknown cause (Clayton 2009, pers. 
comm.). The Upper Monongahela River Association (2009) reported that 
161 aquatic species including fish, mussels, and plants died along 
Dunkard Creek due to this toxic event. According to Clayton (2009, 
pers. comm.), the event may have killed 100 percent of the mussel fauna 
in the entire stream. The status of this population is not known at 
this time, but the snuffbox may now be extirpated from Dunkard Creek.
    Shenango River--The Shenango River is a large tributary in the 
Beaver River system, a northern tributary of the upper Ohio River in 
west-central Pennsylvania. The snuffbox was

[[Page 67566]]

reported from four sites on the Shenango in 1908 (Ortmann 1919, p. 
328). Six L individuals were collected from three sites sampled in 
2001-02 between Jamestown and New Hamburg (about 25 river mi (40.2 
river km)). The upper reach is considered the best habitat in the 
Shenango River. The population is small and has declined, although some 
recent reproduction is evident (Zimmerman 2008b, pers. comm.).
    Little Shenango River--The Little Shenango River is a small 
tributary of the upper Shenango River, Mercer County, Pennsylvania. 
This population was not located during limited surveys (Dennis 1971, p. 
97; Bursey 1987, p. 42), but a single FD museum record from 1991 
exists. The species was reported to be relatively abundant and 
reproducing in the lower portion in 2002 (Zimmerman 2008b, pers. 
comm.). Viability of the small population is unknown.
    Middle Island Creek--Middle Island Creek is a small tributary of 
the Ohio River in northwestern West Virginia. The first snuffbox 
records were made at six sites in 1969, when the species was locally 
common in Doddridge, Tyler, and Pleasants Counties (Taylor and Spurlock 
1981, p. 157). The snuffbox was later found at two sites in Tyler 
County in 1980, and the overall mussel population was considered to be 
``thriving'' (Taylor and Spurlock 1981, p. 157). The most recent record 
was for a single L individual collected in Tyler County in 2001 
(Zimmerman 2008b, pers. comm.). This snuffbox population has declined, 
is currently rare, and its viability is questionable (Zimmerman 2008b, 
pers. comm.).
    Muskingum River--The Muskingum River is a large, southerly flowing, 
northern tributary of the upper Ohio River draining a significant 
portion of east-central Ohio. The snuffbox, which has a long collection 
history dating to the early 1800s, occurred along the entire mainstem 
and was locally abundant. Two L individuals and two FD shells were 
found in 1979, but no L or FD snuffbox were found in surveys conducted 
in 1979-81 (Stansbery and King 1983) and in 1992-93 (Watters and Dunn 
1993-94, p. 241). A single L specimen was located during sampling for a 
construction project in 2005 near Dresden (Taylor 2006, pers. comm.). 
Viability of this population is unknown.
    Walhonding River--The Walhonding River is a short (23.3 river mi 
(37.5 river km)), east flowing tributary of the Muskingum River in 
central Ohio, forming the latter river at its confluence with the 
Tuscarawas River, and formed by the confluence of the Mohican and 
Kokosing Rivers. The snuffbox historically occurred throughout the 
river. The extant snuffbox reach (RM 1.8-6.8) is downstream from 
Killbuck Creek. The population had apparently declined in range and 
size by the early 1990s and possibly further since. A once productive 
site about 0.25 mi (0.40 km) downstream of the Killbuck Creek 
confluence yielded only a few mussels of very common species in 2006, 
but no snuffbox (Butler 2007, p. 44). The Walhonding River population 
is considered small and of unknown viability.
    Killbuck Creek--Killbuck Creek is a large tributary of the lower 
Walhonding River, flowing south from southern Medina County to 
Coshocton County and entering the latter at approximately RM 7. Live 
and FD snuffbox were found by Hoggarth (1997, p. 33) at eight sites 
from RM 15 to the mouth. Its occurrence has become more sporadic in the 
last 10 years. In spring 2006, 4 L adults were found at 2 sites 
approximately 3 river mi (4.8 river km) apart, while 9 large L 
individuals and a single FD specimen were collected near RM 13 during 
fall 2006 (Ahlstedt 2007, pers. comm.; Butler 2007, p. 45). A shrinking 
distribution, declining population size, and lack of evidence of recent 
recruitment suggest that the population may be losing viability and 
trending towards extirpation.
    North Fork Hughes River--The North Fork Hughes River is a westerly 
flowing tributary of the Hughes River in the lower Little Kanawha River 
system in northwestern West Virginia. The snuffbox was found at one of 
six North Fork sites sampled during a 1981-82 survey of the Little 
Kanawha River system (Schmidt et al. 1983). A total of 41 L adult 
individuals (23 reported as gravid) were reported at 5 sites located 
over a 1.5-mi (2.4-km) reach in North Fork State Park, Richie County, 
in 1993 (Butler 2007, p. 46). At least 10 L individuals were found at a 
site in the park in 1997 (Butler 2007, p. 46), and a single FD specimen 
was collected at an additional site downstream in 2001 (Butler 2007, p. 
46). This small snuffbox population is declining and currently 
restricted to less than 4 river mi (6.4 river km), but may be viable.
    Elk River--The Elk River is a major, 181-mi (291-km) tributary in 
the lower Kanawha River system draining central West Virginia flowing 
west to the Kanawha at Charleston. The snuffbox went undetected in a 
1920s survey (Butler 2007, p. 46). Ten L individuals were collected 
during 1991-1995, the smallest being about 5 years old (Butler 2007, 
pp. 46-47). Collectively, 16 L individuals were identified at 8 sites 
in a 13-river-mi (20.9-river-km) reach in Kanawha County in 2002, and 4 
L individuals were found at 4 sites in 2004 over a 16.8-river-mi (27-
river-km) reach further upstream (Douglas 2005, pers. comm.). This 
medium-sized population extends over 30 river mi (48.3 river km), is 
viable, and may have improved since the 1970s.
    Tygarts Creek--Tygarts Creek is a small, north-flowing, southern 
tributary of the Ohio River in northeastern Kentucky. Thirteen snuffbox 
were reported from one of five sites sampled in 1977 (Taylor 1980, p. 
90). FD specimens are also known from 1981 and 1987 (Cicerello 2003, 
pers. comm.). Nine L (Butler 2007, p. 47) and 36 FD specimens were 
found at 2 sites, respectively, in 1988, while 1 L and 2 FD were 
reported from at least 2 sites in 1995 (Cicerello 2003, pers. comm.). 
The overall mussel population appeared ``healthy'' in 1977 (Taylor 
1980), but the small snuffbox population has recently declined, and its 
viability is unknown.
    Scioto River System--The Scioto River system in central and south-
central Ohio is a major northern tributary of the upper Ohio River. The 
system was one of the most routinely sampled watersheds for mussels 
(mostly OSUM records), and historically harbored a large and thoroughly 
dispersed snuffbox population in the mainstem and 16 tributaries. The 
system was either exceptional for its snuffbox population, or it 
provided a general historical perspective of what researchers may have 
found if other systems had been as thoroughly sampled. Sizable 
populations were noted in at least the Olentangy River, Big Darby 
Creek, and Big Walnut Creek. Development associated with the Columbus 
metropolitan area has taken a major toll on the aquatic fauna. 
Pollutants from the 1800s included wastes from sawmills, breweries, and 
slaughterhouses (Butler 2007, p. 48). Only a few fish species were 
found in the Scioto River 100 years ago (Trautman 1981, p. 33). 
Currently, 90 to 95 percent of the normal summer-fall flow in the river 
consists of wastewater treatment plant (WWTP) discharges (Yoder et al. 
2005, p. 410). Museum records indicate that the snuffbox had completely 
disappeared from the mainstem by the 1970s. A series of reservoirs 
around Columbus fragmented habitat and eliminated or reduced 
populations (Olentangy and Scioto Rivers; Alum, Big Walnut and Deer 
Creeks). Currently, remnant populations remain in six streams, making 
the snuffbox precariously close to extirpation throughout this once 
rich system.

[[Page 67567]]

    Olentangy River--The Olentangy River is a major headwater tributary 
of the Scioto River, draining central Ohio and flowing south to its 
confluence in Franklin County. OSUM snuffbox records date to the 1870s, 
although most are from the 1950s and 1960s. The snuffbox was reported 
from 15 of 31 mainstem sites collected during a 1960-61 survey, when it 
appeared ``fairly common'' in the lower river (Stein 1963, p. 138). A 
single L individual in southern Delaware County and two FD specimens in 
eastern Marion County were found among 30 sites in 1989, with R shells 
at 7 other sites (Hoggarth 1990, pp. 20-27). The small population has 
declined (Hoggarth 1990, p. 14), and viability is unknown.
    Big Darby Creek--Big Darby Creek is one of the major tributaries 
draining the northwestern portion of the Scioto River system in central 
Ohio. Dozens of large OSUM lots of snuffbox date to the late 1950s; six 
Pickaway County collections in 1962 alone had 250 L and FD specimens. 
Watters (1990, p. 4; 1994, p. 100) surveyed 42 mainstem sites in 1986 
and 49 sites in 1990. Combining the data from both years, 80 L and FD 
snuffbox were collected at 22 sites (Watters 1994, p. 101). The 
population in 1990 occurred in a reach from approximately RM 11.5 to RM 
42.5. The snuffbox was recruiting (Watters 1994, p. 101); four 
individuals during both 1986 and 1990 were 2 to 5 years of age. The 
overall population trend over the past 40 years has been downward. 
Between 1986 and 1990, the number of L and FD specimens was reduced 
from 54 to 16 and its distribution declined from 17 to 8 sites. Two FD 
specimens were found at sites in Franklin (1996) and Pickaway (2000) 
Counties, and three other sites produced only R specimens (OSUM 
records). This historically large snuffbox population has declined to 
marginal status and its viability is questionable.
    Little Darby Creek--Little Darby Creek is the major tributary in 
the Big Darby Creek system, flowing in a southeasterly direction to its 
confluence in southwestern Franklin County, Ohio. The 25 OSUM lots for 
this species are small (fewer than five specimens per lot), date to the 
early 1960s, and represent lower mainstem sites in Madison County. 
Single FD and R specimens were collected in 1999 from a Union County 
site (OSUM 66740), where L individuals were collected in 1964 (Stein 
1966, p. 23). This site yielded only R specimens in 1990 (Watters 1990, 
Appendix A.11; 1994, p. 102). Overall, the snuffbox was historically 
known from 35 river mi (56 river km). The well documented OSUM 
collection history illustrates the steady decline of a snuffbox 
population nearing extirpation.
    Salt Creek--Salt Creek is an eastern tributary in the Scioto River 
system, south-central Ohio. All records (OSUM) were collected in the 
lower mainstem (Ross County) beginning in 1958. A single L individual 
from 1987 represents the last known record. The mussels in this system 
``have been heavily impacted, apparently by the towns of Adelphi and 
Laurelville'' (Watters 1992, p. 78). The current status of this 
snuffbox population is unknown.
    Scioto Brush Creek--Scioto Bush Creek is a small, western tributary 
of the lower Scioto River in Scioto County, south-central Ohio. The 
snuffbox was discovered here in the 1960s (Watters 1988a, p. 45). Three 
L and FD specimens from 2 sites and R shells from 2 other sites were 
collected during a 1987 survey covering 11 sites (Watters 1988a, pp. 
210-220). The snuffbox population, collectively known from five 
fragmented sites along the lower two-thirds of stream, is small, and 
its viability is unknown.
    South Fork Scioto Brush Creek--South Fork Scioto Brush Creek is a 
small tributary of Scioto Brush Creek, in the lower Scioto River 
system. A single snuffbox was found during a survey of five sites in 
1987 (Watters 1988a, pp. 210-220). The South Fork and Scioto Brush 
Creek populations can be considered a single population unit, the 
viability of this unit is uncertain.
    Kinniconick Creek--Kinniconick Creek is a small, southern tributary 
of the Ohio River in northeastern Kentucky. Snuffbox was reported L 
from 4 of 15 sites sampled in 1982 with R shells from an additional 2 
sites (Warren et al. 1984, pp. 48-49). Single FD and L snuffbox were 
collected in 2001 and 2004, respectively, from sampling efforts at 
several sites (Butler 2007, p. 51), and a single FD specimen was found 
while resurveying four sites in 2005 (Butler 2007, p. 51). The snuffbox 
declined in the past few decades, is considered rare, and its viability 
is uncertain.
    Little Miami River--The Little Miami River is a northern tributary 
of the Ohio River in southwestern Ohio, flowing south into the latter 
at the eastern fringe of the Cincinnati metropolitan area. Snuffbox 
records from the Little Miami date to the mid-1800s, but most 
collections are from the past several decades. Seven FD specimens were 
found at 4 of 46 mainstem sites surveyed during 1990-91, with 10 R 
shells at 6 other sites (Hoggarth 1992, p. 265). The FD specimens were 
found in approximately 20 river mi (32.2 river km), mostly in Warren 
County. Current viability of this small population is unknown.
    Licking River--The Licking River is a southern tributary of the 
Ohio River in northeastern Kentucky, flowing in a northwesterly 
direction to its confluence across from Cincinnati. The snuffbox 
occurred at 13 of 60 historical mainstem sites below Cave Run Reservoir 
(Laudermilk 1993, p. 45) and a preimpoundment site in the reservoir 
footprint (Clinger 1974, p. 52). The population extended approximately 
50 river mi (80.5 river km). All collections of snuffbox are small in 
number (Butler 2007, p. 52). A single L individual and a FD specimen 
were found at 2 sites and R shells were reported from 7 other sites 
among 49 sites sampled in 1991 (Laudermilk 1993, p. 45). Single L and 
FD snuffbox were collected in 1999 (Cicerello 2003, pers. comm.), and a 
single L individual was found in 2006 (Butler 2007, p. 53). The 
snuffbox has become very rare, sporadic in occurrence, and its 
viability is questionable.
    Slate Creek--Slate Creek is a southern tributary of the Licking 
River below Cave Run Dam in east-central Kentucky. Historically, the 
snuffbox was considered ``extremely abundant throughout the stream'' 
(Taylor and Spurlock 1983) and collectively known from six sites 
(Laudermilk 1993, p. 45). Seventeen D specimens were recorded from a 
site in 1987 (Cicerello 2003, pers. comm.). A single FD and seven R 
specimens were found at three sites sampled in 1991 (Butler 2007, p. 
53), when it was considered ``occasional'' in distribution (Laudermilk 
1993, p. 45). Twelve L individuals were found in 1992 (Cicerello 2003, 
pers. comm.). Subsequent sampling has produced no additional snuffbox; 
two sites and four sites yielded only R specimens in 2001 and 2002, 
respectively (Cicerello 2005, pers. comm.). If extant, the population 
is marginal at best, with unlikely viability.
    Stillwater River--The Stillwater River is a 67-mi (108-km), western 
tributary of the Great Miami River draining southwestern Ohio. The 
species was collectively known from eight sites throughout the River 
(Watters 1988a, pp. 59-71; OSUM records). One FD specimen below 
Englewood Dam in Montgomery County was found among 18 sites surveyed in 
1987, with R shells from 5 other sites (Watters 1988a, pp. 59-71). No 
other information on the small population is available, and its 
viability is unknown.
    Middle Fork Kentucky River--The Middle Fork is one of three 
headwater

[[Page 67568]]

tributaries (with the North and South Forks) forming the Kentucky 
River, flowing in a northerly then westerly direction and draining a 
portion of southeastern Kentucky. The snuffbox was first reported in 
1966. Three L individuals and a R shell were found at three sites in 
1996, and a single L individual was collected from another site in 1997 
(Cicerello 2003, pers. comm.). All sites occur within a 10-river-mi 
(16-river-km) reach above Buckhorn Reservoir in Leslie County. This 
small population has unknown viability.
    Red Bird River--The Red Bird River is a north-flowing headwater 
tributary of the South Fork Kentucky River in Clay County, southeastern 
Kentucky, forming the latter at its confluence with Goose Creek. Ten FD 
specimens were recorded from two sites in 1988, and three L and one FD 
snuffbox were collected from four sites in 1995 (Cicerello 2003, pers. 
comm.). This small population occurs sporadically in the lower 20 river 
mi (32 river km), and viability is unknown (Cicerello 2003, pers. 
comm.; 2006, pers. comm.).
    Red River--The Red (or North Fork Red) River is a westerly flowing 
tributary of the upper Kentucky River in eastern Kentucky. No L 
snuffbox were found in surveys of the 9-river-mi (15-river-km) reach of 
the Wild River section during surveys of 1980, 1986, and 1991 (Houp 
1980, p. 56; 1993, p. 96), but two FD and one L snuffbox were found at 
three sites in 1988, while five L individuals were found in 1996 
(Cicerello 2006, pers. comm.). Mostly males have been found since 2002, 
and they are being held in captivity for future culture efforts (Butler 
2007, p. 55). A small population persists over a 10-river-mi (16-river-
km) reach in the lower section of the Red River Gorge Geological Area 
of the Daniel Boone National Forest in Menifee, Wolfe, and Powell 
Counties (Cicerello 2006, pers. comm.). Viability of this population is 
unknown.
    Rolling Fork Salt River--The Rolling Fork is a major southern 
tributary of the Salt River in central Kentucky, flowing in a 
northwesterly direction to join the Salt near its mouth. The snuffbox 
was first reported in 1958 (Rosewater 1959, p. 62). Seven FD specimens 
and a single L subadult were collected in 1988 from four sites in 
Larue, Marion, and Nelson Counties (Cicerello 2003, pers. comm.; Haag 
2006, pers. comm.). A survey of 12 mainstem and 30 tributary sites in 
the Rolling Fork system in 1998-99 yielded no evidence of the snuffbox, 
prompting an investigator to consider it extirpated (Akers 2000, p. 
13), but occasional specimens may still be found (Butler 2007, p. 55). 
The species is sporadically distributed over 40 river miles of the 
upper river (Cicerello 2006, pers. comm.). If it is still extant, the 
viability of this small population is unknown.
    Green River--A major southern tributary of the lower Ohio River, 
the Green River flows in a westerly direction and drains west-central 
Kentucky. Ortmann (1926, p. 182) considered the snuffbox to be well 
distributed over the system, but not abundant. Large museum collections 
of snuffbox were taken from Munfordville during 1961-66, but only six R 
shells were reported there in 1967. The snuffbox has been rare since. 
Five L and FD snuffbox were collected at 4 of 42 sites during 1987-89 
sampling in Mammoth Cave National Park (Cicerello and Hannan 1990, pp. 
16-17). Three L and six FD snuffbox were reported in the upper Green 
River from 1984-90 (Cicerello 2003, pers. comm.). A single L individual 
was collected in Taylor County in 1989 (Layzer 2009, pers. comm.), but 
no evidence of the snuffbox was reported at numerous other sites in 
1999, 2000, 2001, and 2003 (Cicerello 2006, pers. comm.). Once abundant 
and occurring over 200 river mi (322 river km), the species has become 
exceedingly rare since the 1960s. Current snuffbox viability is 
unknown, and it may be nearing extirpation from the entire Green River 
system, where it was formerly known from eight tributaries.
    Wabash River System--The Wabash River is the second largest sub-
basin within the Ohio River system, the watershed of the 350-mi (563-
km) river encompassing much of Indiana, west-central Ohio, and 
southeastern Illinois. The mainstem and at least 27 streams had one of 
the largest snuffbox population clusters. The species persists today as 
seven small populations in the system; the viability of these 
populations is unknown (Butler 2007, p. 57).
    Salamonie River--The Salamonie River is a southern tributary of the 
upper Wabash River, flowing in a northwesterly direction and draining 
east-central Indiana. Two historical museum records were found. Nine 
sites were surveyed during 1993-94 without finding any evidence of the 
snuffbox (ESI 1995, p. 19). The snuffbox was rediscovered in 2004 above 
Salamonie Reservoir, where two L individuals at one site and FD shells, 
including a very small juvenile, were found at another site 2 mi (3 km) 
away (Fisher 2005, pers. comm.). The small population is considered to 
be recruiting and viable at some level.
    Tippecanoe River--The largest tributary of the upper Wabash River 
system, the Tippecanoe River drains north-central Indiana and flows 
westerly then southerly before joining the Wabash near Lafayette. 
Nearly all records of the snuffbox were made in the past 20 years. Two 
weathered shells were found in the lower mainstem among 16 sites 
sampled in 1987 (Cummings et al. 1987, p. 25; Cummings and Berlocher 
1990, p. 93) and 30 sites in 1991-92 (ESI 1993, p. 68). One L 
individual and over 32 FD specimens were found at a site at the upper 
end of Freeman Reservoir during a 1993 drawdown that may have 
contributed to their demise (Fisher 2003, pers. comm.). A single FD 
specimen was found below Shafer Reservoir among 13 sites sampled in 
2003 (ESI 2003, p. 9). The viability of this declining population is 
unknown, but it appears close to extirpation (Fisher 2003, pers. 
comm.).
    Embarras River--The Embarras River is a southerly flowing, western 
tributary of the lower Wabash River in southeastern Illinois. Museum 
lots represent collections dating to 1956 and contain snuffbox from 
nine mainstem and two tributary sites. A total of 9 L and 15 FD 
specimens were collected at four sites in 1986 in Coles and Douglas 
Counties (Cummings et al. 1988, p. 8). Although overall mussel 
abundance at the 21 sites sampled in both 1956 and 1986 dropped 86 
percent, the snuffbox was one of only five species that showed 
relatively stable population size over the 30-year period (Cummings et 
al. 1988, p. 9). Additional L and FD snuffbox from museum collections 
were recorded from single sites in 1988. Three L and eight FD snuffbox 
were found at two sites in 1992, and one L and three FD were found at 
three of six sites surveyed during 2001-2002. Since 1986, the small 
snuffbox population has occurred sporadically at six sites over 50 
river mi (80 river km) of the upper river. The species was reported as 
significant and viable by Butler (2007 pers. comm.), but has declined 
to some extent. Recent surveys, however, documented only one L 
individual in 2005 and one L and one FD in 2008, indicating that the 
Embarras River population may be closer to a marginal population than a 
significant one (Tiemann 2009, pers. comm.).
    Sugar Creek--Sugar Creek is a tributary in the upper East Fork 
White River system, draining central Indiana east and south of 
Indianapolis. A single L individual from one site, FD specimens from 
seven sites, and R shells from an additional eight sites were reported 
in 1990 (Harmon 1992, pp. 40-41 1998). The snuffbox population

[[Page 67569]]

occurred sporadically over 35 river mi (56 km) to near the mouth. Only 
R shells were found while resampling some historical sites in 1995, 
1998, and 2001 (Butler 2007, p.59). It is questionable whether the 
population remains extant.
    Buck Creek--Buck Creek is a southerly flowing, western tributary of 
Sugar Creek in the upper East Fork White River system east of 
Indianapolis. A FD snuffbox was found near the mouth and R specimens at 
an upstream site in 1990 (Harmon 1992, p. 41. Similar to the parent 
stream population in Sugar Creek, the snuffbox may already be 
extirpated in Buck Creek (Fisher 2003, pers. comm.).
    Muscatatuck River--The Muscatatuck River is a large, westerly 
flowing tributary of the upper East Fork White River in southeastern 
Indiana. The snuffbox was first reported from the stream by Daniels 
(1903, p. 646). FD specimens (unknown number) were recorded at a site 
downstream from Graham Creek that was sampled in 1988 (Harmon 1989, p. 
118). Status and viability of snuffbox in the Muscatatuck River are 
unknown.
    Graham Creek--Graham Creek flows southwesterly to join Big Creek in 
forming the Muscatatuck River in the East Fork White River system in 
southeastern Indiana. The species was found FD (numbers unknown) at six 
sites over 10 river mi (16 river km) of the lower stream in Jennings 
County in 1988 (Harmon 1989, p. 117), and a single FD specimen was 
found in 1990 (Harmon 1998). Viability of these small population is 
unknown.
    Cumberland River System--Snuffbox populations are known from the 
mainstem Cumberland River and 6 of its tributaries. With few 
exceptions, most mainstem records were made prior to the 1920s when the 
species was locally common (Wilson and Clark 1914, p. 45). The snuffbox 
is considered extirpated from the mainstem. Currently, a single 
tributary population may be extant, but is considered not viable. The 
species is likely to become extirpated from the entire river system in 
the foreseeable future.
    Buck Creek--Buck Creek is a southerly flowing, northern tributary 
of the upper Cumberland River below Cumberland Falls in southeastern 
Kentucky. One D valve was found at a site in 1981 (Clarke 1981b, 
Appendix), and two L and one FD snuffbox were reported from three sites 
during 1983-84 (Schuster et al. 1989, p. 82). The species was also 
reported L from a lower mainstem site among seven sites sampled from 
1987-90 (Layzer and Anderson 1992, p. 16). A recent survey found only R 
shells at 3 of 23 sites (Hagman 2000, p. 21). If extant, the declining 
snuffbox population in Buck Creek is likely to become extirpated in the 
foreseeable future.

Tennessee River System

    The Tennessee River is the largest tributary of the Ohio River, 
draining seven southeastern States and joining the Ohio near its mouth 
in western Kentucky. The snuffbox originally was known from throughout 
all but the lower section of river and 17 of its tributaries. Hundreds 
of miles of large river habitat on the mainstem have been lost under 
nine reservoirs, with additional dams on several tributaries (Clinch, 
Holston, and Elk Rivers) (Tennessee Valley Authority (TVA) 1971, p. 4). 
The loss of mussel resources has been substantial (Watters 2000, p. 
262). Muscle Shoals, the 53-river-mi (85-river-km) reach in 
northwestern Alabama, historically harbored 69 mussel species, the most 
diverse mussel fauna ever known (Garner and McGregor 2001, p. 155). The 
construction of three dams (Wilson in 1925, Wheeler in 1930, and 
Pickwick Landing in 1940) inundated most of the mussel beds. No L 
snuffbox have been reported at Muscle Shoals for around 100 years 
(Garner and McGregor 2001, p. 162). The snuffbox may persist in the 
mainstem at a very low density and in only five tributaries. The Clinch 
River maintains a stronghold population, but highly restricted 
populations persist in the other streams.
    Clinch River--The 350-mi (563-km) Clinch River is a major tributary 
of the upper Tennessee River originating in southwestern Virginia, and 
flowing in a southwesterly direction to its confluence near Knoxville 
in northeastern Tennessee. No other river in North America has extant 
populations of more federally endangered (15) and candidate (4) species 
of mussels than does the upper Clinch River above Norris Reservoir. The 
snuffbox was reported from nine sites by Ortmann (1918, pp. 601-606). 
Museum records from Hancock County, Tennessee, during 1965-71 
documented a very large population of snuffbox. The snuffbox is 
generally distributed from RM 170 to RM 195 in Hancock County, but is 
sporadic in Virginia (RM 213-235), where it has recently declined 
(Butler 2007, p. 62). The snuffbox population is recruiting, viable, 
and currently stable, although decreased in size and range from 40 
years ago. The Clinch River ranks among the six stronghold snuffbox 
populations rangewide.
    Powell River--The Powell River is the major tributary of the upper 
Clinch River flowing in a southwesterly direction parallel to and 
northwest of the Clinch River in southwestern Virginia and northeastern 
Tennessee. The snuffbox was reported at three sites by Ortmann (1918, 
pp. 597-598), five sites during 1973-78 by Dennis (1981, p. 3), four 
sites from 1975-78 by Ahlstedt and Brown (1979, p. 42), and four 
Virginia sites in 1988-89 by Wolcott and Neves (1994, p. 7). Large 
collections attest to its former abundance. The species was found L and 
FD in the Powell River, Tennessee, during 1989-90 (Hubbs et al. 1991, 
Appendix A). Johnson (2008) collected two L individuals at RM 95. The 
population has declined, viability is questionable, and its extirpation 
may be imminent (Butler 2007, p. 63).
    Tennessee River--The snuffbox originally was known from all but the 
lower section of the river. Butler (2007, p. 61) reported the snuffbox 
as ``believed to be extirpated from the entire Tennesssee River.'' 
However, Yokley (2002, p. 1) collected a single FD male in 2002 at the 
U.S. 231 Bridge, Madison and Morgan Counties. In 2006, one L female was 
found at the same location, though it was the only snuffbox out of 
8,978 mussels collected at the site (Yokley 2006, p. 1). Nothing 
further is known about the status of the snuffbox in the Tennessee 
River mainstem.
    Paint Rock River--The Paint Rock River is a southerly flowing, 
northern tributary of the southern bend of the Tennessee River in 
northeastern Alabama and adjacent Tennessee. The snuffbox was first 
reported from one of six mainstem sites by Ortmann (1925, p. 359). No 
evidence of snuffbox was found in two surveys during 1965-67 (Isom and 
Yokley 1973, p. 444) and a 1980 survey (Butler 2007, p. 64). Twelve L 
and FD snuffbox were found at four sites between RMs 13 and 21 
(Ahlstedt 1995-96, p. 70). The species was again absent from 10 upper 
mainstem sites surveyed in 2002 (Godwin 2002, p. 9). Four FD specimens 
of varying sizes were found at lower river sites in 2002 (Fraley 2003, 
pers. comm.; Smith 2005, pers. comm.) and 2003-2006 (Freeman 2006, 
pers. comm.). One L and 11 FD specimens were found at RM 21 in 2005, 
and 2 L and 16 FD were collected at RM 31 in 2007 (Gangloff 2007, pers. 
comm.). In July 2008, Freeman (2008, pers. comm.) observed multiple age 
classes (sizes) of FD snuffbox in middens between RM 34.7 and 32.5. 
Fobian et al. (2008, p. 14) collected 21 L snuffbox at 7 sites and FD 
specimens at 8 sites between RM 46.7 and 13.1. The stronghold snuffbox 
population exists between RMs 13 and 44, and is

[[Page 67570]]

recruiting, viable, and has clearly improved since 1980.
    Elk River--The Elk River is a large, northern tributary flowing 200 
river mi (322 river km) in a southwesterly direction in the southern 
bend of the Tennessee River in south-central Tennessee and north-
central Alabama. Snuffbox collections have been sporadic. The species 
was found at 2 sites in the mid-1960s (Isom et al. 1973, p. 440), and a 
single L individual was found among 108 sites sampled in 1980 (Ahlstedt 
1983, p. 47). Single specimens were also reported from 4 sites sampled 
in the lower river in 1997 (Madison and Layzer 1998, Table 6) and 16 
sites sampled in 1999 (Service 1999, p. 3). A very large FD specimen 
was found at RM 51 among 4 sites sampled in 2001 (Hubbs 2002, p. 5; 
Butler 2007, p. 65). A single L and a FD snuffbox were found at a site 
in Giles County during qualitative sampling events at five sites in 
2005 (Ahlstedt et al. 2006). Ford (2008, pers. comm.) reported 
collecting FD specimens at Stairstep Shoals in Giles County, Tennessee, 
in July 2007. The small snuffbox population has recently recruited, 
exhibits some level of viability, and its numbers appear relatively 
stable in recent history.
    Duck River--The Duck River is the downstream-most large tributary 
of the Tennessee River draining south-central Tennessee and flowing 285 
river miles (459 river km) west to its confluence near the head of 
Kentucky Reservoir. The snuffbox historically occurred throughout the 
Duck River and, based on museum records, was locally common 40 to 50 
years ago, but was absent in surveys from RM 180 downstream in the mid-
1970s (Ahlstedt 1981, p. 62; Dennis 1984, p. 38). Two L individuals 
were collected from 2 of 99 sites surveyed in 1979 (Butler 2007, p. 
66). A single L individual was discovered in Maury County among 72 
sites sampled during 2000-03 (Ahlstedt et al. 2004, p. 119), but none 
were found at 11 lower sites surveyed in 2000 (Schilling and Williams 
2002, p. 409). The snuffbox is very rare, and its viability is 
uncertain.

Lower Mississippi River Sub-Basin

    The Lower Mississippi River Sub-basin includes 954 miles of the 
Mississippi River from its confluence with the Ohio River at Cairo, 
Illinois, to its mouth in the Gulf of Mexico. The snuffbox is known 
from a single stream in this sub-basin, outside of the White River 
system.
    St. Francis River--The St. Francis River is a major tributary of 
the lower Mississippi with its headwaters in southeastern Missouri, and 
flowing south into northeastern Arkansas. The only Arkansas records 
available for this 450-mi (724-km) river are from 1964, located 
approximately 1 mi southwest of Parkin in Cross County (Bates and 
Dennis 1983, p. 63; Harris et al. 2007, p. 10). Snuffbox records exist 
for Butler, Wayne, and Stoddard Counties, Missouri, where it was 
considered ``locally abundant'' (Oesch 1984, p. 235). The species is 
known from above Wappapello Reservoir, but was absent from Missouri 
surveys conducted below Wappapello Dam in 1983 (Bates and Dennis 1983, 
p. 63) and 1986 (Ahlstedt and Jenkinson 1991, p. 240). Twelve L 
snuffbox were sampled at sites in 2002 (Hutson and Barnhart 2004, pp. 
84-85). Live individuals were found during collections at RM 172.1 in 
2005 and 2006 (Butler 2007, p. 67). The snuffbox is restricted to a 10-
mi (16-km) reach (RM 172.1-182.0) on the northeastern edge of the Ozark 
Plateaus in the vicinity of Sam A. Baker State Park, Wayne County 
(Hutson and Barnhart 2004, p. 85). This medium-sized snuffbox 
population appears to be stable and viable, but restricted in 
distribution.
    White River System--The 690-mi (1,110-km) White River is a large 
tributary system of the western bank of the Mississippi River. A 
snuffbox population once occurred in the mainstem and six of its larger 
tributaries. The last record from the mainstem in Arkansas is pre-1921 
(Harris et al. 2007, p. 10). Highly restricted populations persist in 
four streams.
    Buffalo River--The Buffalo River is a large, eastward-flowing 
tributary of the middle White River in north-central Arkansas. The 
snuffbox was not found during surveys in 1910 (26 sites; Meek and Clark 
1912, p. 13) and 1995 (40 sites; Harris 1996, p. 9), but two L 
individuals were found at a single site among 60 sites surveyed in 2006 
(Matthews 2007, pers. comm.). The small population occurs in the lower 
river in Marion County, and its viability is unknown.
    Black River--The Black River is the largest tributary in the White 
River system, draining much of southeastern Missouri and northeastern 
Arkansas before flowing in a southerly direction into the White River 
near Newport, Arkansas. A long but sporadic collection history for the 
snuffbox appears in the 300-mi (483-km) Black River. A single, 
approximately 4-year-old L male was collected at RM 65.5, Wayne County, 
among 51 Missouri sites sampled in 2002 (Hutson and Barnhart 2004, p. 
154). The species has become extirpated from the lower river on the 
Mississippi Embayment, including Arkansas. The snuffbox appears rare 
but viable at some level.
    Spring River--The Spring River is a large tributary of the Black 
River that drains the eastern Ozark Plateaus in south-central Missouri 
and northeastern Arkansas. Based on pre-1986 records, the snuffbox was 
known in low numbers from at least four sites in approximately 20 river 
mi (34 river km) of the lowermost mainstem in Arkansas (Harris and 
Gordon 1987, p. 53). A single L adult male was found in Lawrence County 
in 2005, and represents the first L specimen found in Arkansas in more 
than 20 years (Butler 2007, p. 69). Further, 53 FD snuffbox were 
collected in four large muskrat middens (Harris et al. 2007, p. 15). 
The extent of the population is not known, but it is probably limited 
to relatively few miles in the lower mainstem in Lawrence and Randolph 
Counties. This population appears small, and its status and viability 
are unknown.
    Strawberry River--The Strawberry River is a western tributary of 
the Black River draining a portion of the southeastern Ozark Plateaus 
in northeastern Arkansas. The only snuffbox records were from around 
1983 and 1997 in the middle mainstem in Sharp County (Butler 2007, p. 
69). No other details on these collections or the status of the 
population are known. Considering the dearth of records, the snuffbox 
appears to be very rare in the Strawberry River, and of unknown 
viability.

Summary of Snuffbox Population Estimates and Status

    The snuffbox has declined rangewide and appears to be extant in 74 
of 208 streams and lakes of historical occurrence, a 65 percent decline 
in occupied streams. Realistically, much more than 65 percent of the 
habitat historically available for this species no longer supports its 
populations. Habitat losses measured in the thousands of miles have 
occurred rangewide. Since multiple streams may comprise single snuffbox 
population segments (for example, the French Creek system), the actual 
number of extant populations is somewhat less. Extant populations, with 
few exceptions, are highly fragmented and restricted to short reaches. 
The elimination of this species from scores of streams and thousands of 
miles of stream reaches indicates catastrophic population losses and a 
precipitous decline in overall abundance. It is reasonable to estimate 
that total range reduction and overall population losses for the 
snuffbox each approximate, if not exceed, 90 percent.

[[Page 67571]]

Previous Federal Action

    We identified the rayed bean as a Category 2 species in a notice of 
review published in the Federal Register on May 22, 1984 (49 FR 21664). 
The rayed bean remained a Category 2 species in subsequent notices 
including January 6, 1989 (54 FR 554), November 21, 1991 (56 FR 58804), 
and November 15, 1994 (59 FR 58982). Prior to 1996, a Category 2 
species was one that we were considering for possible addition to the 
Federal List of Endangered and Threatened Wildlife but for which 
conclusive data on biological vulnerability and threats were not 
available to support a proposed rule. We stopped designating Category 2 
species in the February 28, 1996, Notice of Review (61 FR 7596). We now 
define a candidate species as a species for which we have on file 
sufficient information to propose it for protection under the Act. We 
designated the rayed bean as a candidate species on May 4, 2004 (69 FR 
24876).
    We identified the snuffbox as a Category 2 species in the notice of 
review published in the Federal Register on November 21, 1991 (56 FR 
58804). The snuffbox remained a Category 2 in the subsequent notice on 
November 15, 1994 (59 FR 58982) but was dropped from the list in the 
February 28, 1996, Notice of Review (61 FR 7596), when we stopped 
designating Category 2 species. The snuffbox is not currently listed as 
a candidate species for listing.

Summary of Information Pertaining to the Five Factors

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations at 50 CFR part 424, set forth the procedures for adding 
species to the Federal lists of Endangered and Threatened Wildlife and 
Plants. Under section 4(a)(1) of the Act, we may determine a species to 
be endangered or threatened due to one or more of the following five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. Listing actions may be warranted based on any of 
the above threat factors, singly or in combination. Each of these 
factors is discussed below.

A. The Present or Threatened Destruction, Modification, or Curtailment 
of Their Habitat or Range.

    Both species have experienced significant curtailment of their 
occupied habitats (see Background, above). The rayed bean has been 
eliminated from about 74 percent of the streams it historically 
occurred in. This species has also been eliminated from long reaches of 
former habitat in hundreds of miles of the Maumee, Ohio, Wabash, and 
Tennessee Rivers and from numerous stream reaches in their tributaries. 
The snuffbox has been eliminated from about 65 percent of the streams 
in which it historically occurred. Furthermore, extant populations, 
with few exceptions, are highly fragmented and restricted to short 
reaches. Available records indicate that 33 percent of streams 
considered to harbor extant populations of the snuffbox are represented 
by only one or two recent L or FD individuals. The primary cause of 
range curtailment for both species has been modification and 
destruction of river and stream habitats, primarily by the construction 
of impoundments.
    Impoundment--Impoundments result in the dramatic modification of 
riffle and shoal habitats and a resulting loss of mussel resources, 
especially in larger rivers. Neves et al. (1997, pp. 63-64) and Watters 
(2000, pp. 261-262) reviewed the specific effects of impoundments on 
freshwater mollusks. Dams interrupt a river's ecological processes by 
modifying flood pulses; controlling impounded water elevations; 
altering water flow, sediments, nutrients, and energy inputs and 
outputs; increasing depth; decreasing habitat heterogeneity; decreasing 
stability due to subsequent sedimentation; blocking host fish passage; 
and isolating mussel populations from fish hosts. Even small, low-head 
dams can have some of these effects on mussels.
    The reproductive process of riverine mussels is generally disrupted 
by impoundments, making the rayed bean and snuffbox unable to 
successfully reproduce and recruit under reservoir conditions. 
Population losses due to impoundments have likely contributed more to 
the decline and imperilment of the rayed bean and snuffbox than has any 
other single factor. Neither species occurs in reservoirs lacking 
riverine characteristics, and only the snuffbox persists in large 
rivers with dams (Ohio River), and then only in sections retaining 
riverine characteristics (generally tailwaters). Both species, however, 
historically occurred in the wave-washed shallows of several glacial 
lakes, an environment very different from that found in impoundments.
    Stream habitat throughout major portions of the range of both 
species has been impounded. The majority of the Tennessee and 
Cumberland River mainstems and many of their largest tributaries are 
now impounded. There are 36 major dams located in the Tennessee River 
system, and about 90 percent of the Cumberland River downstream of 
Cumberland Falls is either directly impounded by U.S. Army Corps of 
Engineers (Corps) structures or otherwise impacted by cold tailwater 
released from dams. Watters (2000, pp. 262-263) summarizes the 
tremendous loss of mussel species from various portions of the 
Tennessee and Cumberland River systems. The rayed bean has been 
eliminated from the Tennessee River system and the snuffbox, once 
widespread throughout both systems, now persists in only five Tennessee 
River tributaries and one Cumberland River tributary.
    This impoundment scenario is similar in many other parts of the 
range of the rayed bean and snuffbox, and includes numerous 
navigational locks and dams (Ohio, Allegheny, Muskingum and Green 
Rivers), major dams (Shenango, Elk, Walhonding, Scioto, Little Miami, 
Green, Nolin, Barren, Tippecanoe, Wabash, Mississinewa, Salamonie, and 
Duck Rivers), and low-head dams (Pine, Belle, Clinton, Huron, Maumee, 
Auglaize, Sandusky, Mahoning, Tuscarawas, Walhonding, Scioto, 
Olentangy, Wabash, Mississinewa, East Fork White, West Fork White, and 
Duck Rivers; and Middle Island, Big Walnut, Alum, Big Darby, Little 
Darby, Sugar, and Richland Creeks) that have contributed to the loss of 
the species' habitat. Sediment accumulations behind dams of all sizes 
generally preclude the occurrence of the rayed bean and snuffbox.
    Dredging and Channelization--Dredging and channelization activities 
have profoundly altered riverine habitats nationwide. Hartfield (1993, 
pp. 131-141), Neves et al. (1997, pp. 71-72), and Watters (2000, pp. 
268-269) reviewed the specific effects of channelization on freshwater 
mollusks. Channelization impacts a stream's physical (accelerated 
erosion, reduced depth, decreased habitat diversity, geomorphic 
instability, and riparian canopy loss) and biological (decreased fish 
and mussel diversity, changed species composition and abundance, 
decreased biomass, and reduced growth rates) characteristics (Hartfield 
1993, p. 131; Hubbard et al. 1993, pp. 136-145). Channel construction 
for navigation has

[[Page 67572]]

been shown to increase flood heights (Belt 1975, p. 189). This is 
partially attributed to a decrease in stream length and increase in 
gradient (Hubbard et al. 1993, p. 137). Flood events may thus be 
exacerbated, conveying into streams large quantities of sediment, 
potentially with adsorbed contaminants. Channel maintenance may result 
in profound impacts downstream (Stansbery 1970, p. 10), such as 
increases in turbidity and sedimentation, which may smother benthic 
(bottom-dwelling) organisms such as the rayed bean and snuffbox.
    The only known rayed bean populations that remain in navigation 
channels are in the upper two navigation pools of the Allegheny River. 
Activities associated with navigation channels may have contributed to 
the elimination of the rayed bean from the Ohio, lower Allegheny, and 
Muskingum Rivers, and potentially others. Channel maintenance 
operations for barge navigation have impacted habitat for the snuffbox 
in several large rivers. Impacts associated with barge traffic, which 
include construction of fleeting areas, mooring cells, docking 
facilities, and propeller wash, also disrupt habitat. Navigation 
maintenance activities may continue to adversely affect this species in 
the upper Ohio River. Hundreds of miles of rayed bean (Olentangy, 
Salamonie, Mississinewa, Vermilion, North Fork Vermilion, Embarras 
Rivers) and snuffbox (Grand, Kankakee, Sangamon, Kaskaskia, Olentangy, 
Salamonie, Mississinewa, Eel, Vermilion, and North Fork Vermilion, 
Embarras, Paint Rock, and St. Francis Rivers; and Tonawanda, Killbuck, 
Chickamauga, and Bear Creeks) streams were dredged and channelized 
decades ago, and some populations have been eliminated from these 
streams. The entire length of the Kankakee River in Indiana was 
channelized by 1917. In addition, hundreds of drains (formed from 
ditching low-gradient creeks and swales) were created around 100 years 
ago in Illinois, Michigan, and other midwestern States. Stream 
channelizations were attempts to reduce flooding, drain low-lying 
areas, and ``improve'' storm flow runoff.
    Chemical Contaminants--Chemical contaminants are ubiquitous 
throughout the environment and are considered a major threat in the 
decline of freshwater mussel species (Cope et al. 2008, p. 451; Richter 
et al. 1997, p. 1081; Strayer et al. 2004, p. 436; Wang et al. 2007, p. 
2029). Chemicals enter the environment through both point and nonpoint 
discharges, including spills, industrial sources, municipal effluents, 
and agricultural runoff. These sources contribute organic compounds, 
heavy metals, pesticides, and a wide variety of newly emerging 
contaminants to the aquatic environment. As a result, water and 
sediment quality can be degraded to the extent that mussel populations 
are adversely impacted.
    Chemical spills can be especially devastating to mussels because 
they may result in exposure of a relatively immobile species to 
extremely elevated concentrations that far exceed toxic levels and any 
water quality standards that might be in effect. Some notable spills 
that released large quantities of highly concentrated chemicals 
resulting in mortality to mussels include: massive mussel kills on the 
Clinch River at Carbo, Virginia, occurred from a power plant alkaline 
fly ash pond spill in 1967 and a sulfuric acid spill in 1970 (Crossman 
et al. 1973, p. 6); approximately 18,000 mussels of several species 
including 750 individuals from three endangered mussel species were 
eliminated from the upper Clinch River near Cedar Bluff, Virginia, in 
1998, when an overturned tanker truck released 1,600 gallons (6,056 
liters) of a chemical used in rubber manufacturing (Jones et al. 2001, 
p. 20; Schmerfeld 2006, p. 12); and an ongoing release of sodium 
dimethyl dithiocarbamate, a chemical used to reduce and precipitate 
hexachrome, starting in 1999 impacted approximately 10 river miles (16 
km) of the Ohio River and resulted in an estimated loss of one million 
mussels, including individuals from two federally listed species 
(DeVault 2009, pers. comm.; Clayton 2008, pers. comm.). These are not 
the only instances where chemical spills have resulted in the loss of 
high numbers of mussels (Brown et al. 2005, p. 1457; Neves 1991, p. 
252; Jones et al. 2001, p. 20; Schmerfeld 2006, pp. 12-13), but are 
provided as examples of the serious threat chemical spills pose to 
mussel species. The rayed bean and snuffbox are especially threatened 
by chemical spills because these spills can occur anywhere there are 
highways with tanker trucks, industries, or mines and where these 
overlap with rayed bean and snuffbox distribution.
    Exposure of mussels to lower concentrations of contaminants more 
likely to be found in aquatic environments can also adversely affect 
mussels and result in the decline of freshwater mussel species. Such 
concentrations may not be immediately lethal, but over time, can result 
in mortality, reduced filtration efficiency, reduced growth, decreased 
reproduction, changes in enzyme activity, and behavioral changes to all 
mussel life stages. Frequently, procedures which evaluate the ``safe'' 
concentration of an environmental contaminant (for example, national 
water quality criteria) do not have data for freshwater mussel species 
or exclude data that is available for freshwater mussels (March et al. 
2007, pp. 2066-2067, 2073).
    Current research is now starting to focus on the contaminant 
sensitivity of freshwater mussel glochidia and newly-released juvenile 
mussels (Goudreau et al. 1993, pp. 219-222; Jacobson et al. 1997, p. 
2390; Wang, 2007a, pp. 2041-2046; Valenti 2005, pp. 1244-1245; Valenti 
2006, pp. 2514-2517; March 2007, pp. 2068-2073) and juveniles (Bartsch 
et al. 2003, p. 2561; Augspurger et al. 2003, p. 2569; Mummert et al. 
2003, p. 2549, Wang, 2007b, pp. 2053-2055, Wang, 2007a, pp. 2041-2046, 
Valenti 2005, pp. 1244-1245; Valenti 2006, pp. 2514-2517; March 2007, 
pp. 2068-2073) to such contaminants as ammonia, metals, chlorine, and 
pesticides. The toxicity information presented in this section focuses 
on recent water-only laboratory acute (sudden and severe exposure) and 
chronic (prolonged or repeated exposure) toxicity tests with early life 
stages of freshwater mussels using the standard testing methodology 
published by the American Society for Testing and Materials (ASTM) 
(American Society for Testing and Materials 2008, pp. 1442-1493). Use 
of this standard testing method generates consistent, reliable toxicity 
data with acceptable precision and accuracy (Wang et al. 2007a, p. 
2035) and was used for toxicity tests on ammonia, copper, chlorine, and 
select pesticides (Augspurger et al. 2007, p. 2025; Bringolf et al. 
2007a, p. 2087; Bringolf et al. 2007c, p. 2101; Wang et al. 2007a, p. 
2029; Wang et al. 2007b, p. 2036; Wang et al. 2007c, p. 2048). Use of 
these tests has documented that while mussels are sensitive to some 
contaminants, they are not universally sensitive to all contaminants 
(Augspurger et al. 2007, pp. 2025-2026).
    One chemical that is particularly toxic to early life stages of 
mussels is ammonia. Sources of ammonia include agricultural sources 
(animal feedlots and nitrogenous fertilizers), municipal wastewater 
treatment plants, and industrial waste (Augspurger et al. 2007, p. 
2026), as well as precipitation and natural processes (decomposition of 
organic nitrogen) (Goudreau et al. 1993, p. 212; Hickey and Martin 
1999, p. 44; Augspurger et al. 2003, p. 2569; Newton 2003, p. 1243). 
Therefore, ammonia is considered a limiting factor for survival and 
recovery of some mussel species due to its ubiquity in aquatic 
environments, high level of toxicity, and because the highest 
concentrations

[[Page 67573]]

typically occur in mussel microhabitats (Augspurger et al. 2003, p. 
2574). In addition, studies have shown that ammonia concentrations 
increase with increasing temperature and low-flow conditions (Cherry et 
al. 2005, p. 378; Cooper et al. 2005, p. 381), which may be exacerbated 
by the effects of climate change, and may cause ammonia to become more 
problematic for juvenile mussels. The Environmental Protection Agency's 
established ammonia water quality criteria (EPA 1985, p. 94-99) may not 
be protective of mussels (Augspurger et al. 2003, p. 2572; Sharpe 2005, 
p. 28) under current and future climate conditions.
    Mussels are also affected by metals (Keller and Zam 1991, p. 543), 
such as cadmium, chromium, copper, mercury, and zinc, which can 
negatively affect biological processes such as growth, filtration 
efficiency, enzyme activity, valve closure, and behavior (Naimo 1995, 
pp. 351-355; Keller and Zam 1991, p. 543; Jacobson et al. 1997, p. 
2390; Valenti et al. 2005, p. 1244). Metals occur in industrial and 
wastewater effluents and are often a result of atmospheric deposition 
from industrial processes and incinerators. Glochidia and juvenile 
freshwater mussels have recently been studied to determine the acute 
and chronic toxicity of copper to these life stages (Wang 2007a, pp. 
2036-2047; Wang 2007b, pp. 2048-2056). The chronic values determined 
for copper ranged from 8.5 to 9.8 micrograms per liter (ug/L) for 
survival and from 4.6 to 8.5 ug/L for growth of juveniles. These 
chronic values are below the EPA's 1996 chronic water quality criterion 
of 15 ug/L (hardness 170 mg/L) for copper (Wang 2007b, pp. 2052-2055). 
March (2007, pp. 2066, 2073) identifies that copper water quality 
criteria and modified State water quality standards may not be 
protective of mussels.
    Mercury is another heavy metal that has the potential to negatively 
affect mussel populations, and it is receiving attention due to its 
widespread distribution and potential to adversely impact the 
environment. Mercury has been detected throughout aquatic environments 
as a product of municipal and industrial waste and atmospheric 
deposition from coal burning plants. One recent study evaluated the 
sensitivity of early life stages of mussels to mercury (Valenti 2005, 
p. 1242). This study determined that, for the mussel species used 
(rainbow mussel, Villosa iris), glochidia were more sensitive to 
mercury than were juvenile mussels, with the median lethal 
concentration value of 14 ug/L compared to 114 ug/L for the juvenile 
life stage. The chronic toxicity tests conducted determined that 
juveniles exposed to mercury greater than or equal to 8 ug/L exhibited 
reduced growth. These observed toxicity values are greater than EPA's 
Criteria Continuous Concentration and Criteria Maximum Concentration, 
which are 0.77 ug/L and 1.4 ug/L, respectively. Based on these data we 
believe that EPA's water quality standards for mercury should be 
protective of juvenile mussels and glochidia, except in cases of 
illegal dumping, permit violations, or spills. However, impacts to 
mussels from mercury toxicity may be occurring in some streams. 
According to the National Summary Data reported by States to the EPA, 
3,770 monitored waters do not meet EPA standards for mercury in the 
United States (http://iaspub.epa.gov/waters10/attains_nation_cy.control?p_report_type=T, accessed 6/28/2010). Acute mercury 
toxicity was determined to be the cause of extirpation of a diverse 
mussel fauna for a 70-mile (112-km) portion of the North Fork Holston 
River (Brown et al. 2005, pp. 1455-1457).
    In addition to ammonia, agricultural sources of chemical 
contaminants include two broad categories that have the potential to 
adversely impact mussel species: Nutrients and pesticides. Nutrients 
(such as nitrogen and phosphorus) can impact streams when their 
concentrations reach levels that cannot be assimilated, a condition 
known as over-enrichment. Nutrient over-enrichment is primarily a 
result of runoff from livestock farms, feedlots, and heavily fertilized 
row crops (Peterjohn and Correll 1984, p. 1471). Over-enriched 
conditions are exacerbated by low-flow conditions, such as those 
experienced during typical summer-season flows and that might occur 
with greater frequency and magnitude as a result of climate change. 
Bauer (1988, p. 244) found that excessive nitrogen concentrations can 
be detrimental to the adult freshwater pearl mussel (Margaritifera 
margaritifera), as was evident by the positive linear relationship 
between mortality and nitrate concentration. Also, a study of mussel 
life span and size (Bauer 1992, p. 425) showed a negative correlation 
between growth rate and eutrophication, and longevity was reduced, as 
the concentration of nitrates increased. Nutrient over-enrichment can 
result in an increase in primary productivity, and the subsequent 
respiration depletes dissolved oxygen levels. This may be particularly 
detrimental to juvenile mussels that inhabit the interstitial spaces in 
the substrate where lower dissolved oxygen concentrations are more 
likely than on the sediment surface where adults tend to live (Sparks 
and Strayer 1998, pp. 132-133).
    Elevated concentrations of pesticide frequently occur in streams 
due to pesticide runoff, overspray application to row crops, and lack 
of adequate riparian buffers. Agricultural pesticide applications often 
coincide with the reproductive and early life stages of mussels, and 
thus impacts to mussels due to pesticides may be increased (Bringolf et 
al. 2007a, p. 2094). Little is known regarding the impact of currently 
used pesticides to freshwater mussels even though some pesticides, such 
as glyphosate (Roundup), are used globally. Recent studies tested the 
toxicity of glyphosate, its formulations, and a surfactant (MON 0818) 
used in several glyphosate formulations, to early life stages of the 
fatmucket (Lampsilis siliquoidea), a native freshwater mussel (Bringolf 
et al. 2007a, p. 2094). Studies conducted with juvenile mussels and 
glochidia determined that the surfactant (MON 0818) was the most toxic 
of the compounds tested and that L. siliquoidea glochidia were the most 
sensitive organism tested to date (Bringolf et al. 2007a, p. 2094). 
Roundup, technical grade glyphosate isopropylamine salt, and 
isopropylamine were also acutely toxic to juveniles and glochidia 
(Bringolf et al. 2007a, p. 2097). The impacts of other pesticides 
including atrazine, chlorpyrifos, and permethrin on glochidia and 
juvenile life stages have also recently been studied (Bringolf et al. 
2007b, p. 2101). This study determined that chlorpyrifos was toxic to 
both L. siliquoidea glochidia and juveniles (Bringolf et al. 2007b, p. 
2104). The above results indicate the potential toxicity of commonly 
applied pesticides and the threat to mussel species as a result of the 
widespread use of these pesticides. All of these pesticides are 
commonly used throughout the range of the rayed bean and snuffbox.
    A potential, but undocumented, threat to freshwater mussel species, 
including rayed bean and snuffbox, are contaminants referred to as 
``emerging contaminants'' that are being detected in aquatic ecosystems 
at an increasing rate. Pharmaceuticals, hormones, and other organic 
contaminants have been detected downstream from urban areas and 
livestock production (Kolpin et al. 2002, p. 1202). A large potential 
source of these emerging contaminants is wastewater being discharged 
through both permitted (National Pollutant Discharge Elimination System 
(NPDES)) and non-permitted sites throughout the country. Permitted 
discharge sites are

[[Page 67574]]

ubiquitous in watersheds with rayed bean and snuffbox populations, 
providing ample opportunities for contaminants to impact the species 
(for example, there are more than 250 NPDES sites in the Meramec River, 
Missouri system, which harbors a declining population of snuffbox; 
Roberts and Bruenderman 2000, p. 78).
    The information presented in this section represents some of the 
threats from chemical contaminants that have been documented both in 
the laboratory and field and demonstrates that chemical contaminants 
pose a substantial threat to the rayed bean and snuffbox. This 
information indicates the potential for contaminants to contribute to 
declining rayed bean and snuffbox populations--from spills that are 
immediately lethal to species to chronic contaminant exposure, which 
results in death, reduced growth, or reduced reproduction of rayed bean 
and snuffbox.
    Mining--The low pH commonly associated with coal mine runoff can 
reduce glochidial encystment rates, thus impacting mussel recruitment 
(Huebner and Pynn[ouml]nen 1992, p. 2350). Additionally, adverse 
impacts from heavy metal-rich drainage from coal mining and associated 
sedimentation has been documented in portions of historical rayed bean 
and snuffbox habitat in the upper Ohio River system in western 
Pennsylvania (Ortmann 1909c, p. 97), West Virginia, and southeastern 
Ohio. Likewise, coal mining has impacted rayed bean habitat in the 
upper Tennessee River system, Virginia (Kitchel et al. 1981, p. 21), 
and snuffbox habitat in eastern Kentucky (lower Ohio and Mississippi 
River systems in southeastern Illinois and western Kentucky; upper 
Cumberland River system in southeastern Kentucky and northeastern 
Tennessee; and upper Tennessee River system in southwestern Virginia) 
(Ortmann 1909c, p. 103; Neel and Allen 1964, pp. 428-430; Kitchel et 
al. 1981, p. 21; Anderson et al. 1991, pp. 6-7; Gordon 1991, p. 2; 
Bogan and Davis 1992, p. 2; Layzer and Anderson 1992, pp. 91-94; 
Ahlstedt and Tuberville 1997, p. 75; Milam et al. 2000, p. 53; Warren 
and Haag 2005, p. 1394). Acid mine drainage was implicated in the 
mussel die-off in the Little South Fork Cumberland River, Kentucky 
(Anderson et al. 1991, pp. 6-7; Layzer and Anderson, 1992, p. 94; 
Ahlstedt and Saylor 1995-96, pp. 92-93; Warren and Haag 2005, p. 1394). 
Tailings pond failures have also impacted aquatic resources (Powell 
River, Virginia; Butler 2007, p. 83). A decline of the snuffbox and 
other imperiled mussels in the Powell River was blamed on coal mining 
impacts (Ahlstedt and Tuberville 1997, p. 75). Increased mining 
activities in the upper Clinch River system is resulting in 
``blackwater'' events (Jones and Neves 2004, p. 2). Anecdotal evidence 
suggests that coal fines are increasing in the Clinch River reach that 
harbors a stronghold snuffbox population (Butler 2007, p. 84). A coal-
fired power plant planned for the upper Clinch River in Virginia would 
further increase mining in the Clinch and Powell watersheds.
    Currently, coal mining activities occur only in the Elk River in 
West Virginia (Douglas 2010, pers. comm.). However, if coal mining 
activities are reinitiated in western Pennsylvania, they could become a 
threat to populations of both species in the lower French Creek and the 
Allegheny River.
    Instream and alluvial (clay, silt, sand, or other material 
deposited by running water) gravel mining has been implicated in the 
destruction of several mussel populations (Hartfield 1993, pp. 135-136; 
Brown and Curole 1997, pp. 239-240). Negative impacts associated with 
gravel mining include stream channel modifications (altered habitat, 
disrupted flow patterns, sediment transport), water quality 
modifications (increased turbidity, reduced light penetration, 
increased temperature), macroinvertebrate population changes 
(elimination, habitat disruption, increased sedimentation), and changes 
in fish populations (impacts to spawning and nursery habitat, food web 
disruptions) (Kanehl and Lyons 1992, pp. 26-27; Roell 1999, p. 5). 
Gravel mining may continue to be a localized threat to rayed bean and 
snuffbox populations (Kankakee, Bourbeuse, Walhonding, Elk (Tennessee), 
and Strawberry Rivers; Big Darby and Buck (Kentucky) Creeks).
    Other mining activities that impact snuffbox populations include 
mining for metals (lead, cadmium, zinc) in Missouri. Mining has been 
implicated in the decline of mussels from the upper St. Francis River 
(Hutson and Barnhart 2004, pp. 86-87). Lead and barite mining is common 
in the Big River, a Meramec River tributary. A tailings-pond blowout 
discharged 81,000 cubic yards of mine tailings in 1977 that impacted 
approximately 80 river mi (129 river km) (Buchanan 1980, p. 9; Roberts 
and Bruenderman 2000, p. 24). As of 2000, high levels of heavy metals 
were still detected in the system (Roberts and Bruenderman 2000, p. 24) 
and may continue to hinder stream recovery. Forty-five tailings ponds 
and numerous tailings piles remain in the watershed (Roberts and 
Bruenderman 2000, p. 24).
    Oil and gas production may have contributed to the decline of the 
rayed bean and snuffbox in certain drainages (Sangamon River in the 
upper Mississippi River system; Slippery Rock and Connoquenessing 
Creeks in the upper Ohio River system; Green, Kentucky, Salamonie, and 
Mississinewa Rivers in the lower Ohio River system) (Ortmann 1909c, 
p.104; Schanzle and Cummings 1991, p. 1; ESI 1995, p. 39; Cicerello 
1999, p. 11). Pollutants include brines, high levels of potassium, and 
numerous organic compounds (Imlay 1971, p. 39). An increasing demand 
for domestic energy resources is expected to accelerate oil and gas 
exploration in certain rayed bean and snuffbox streams in the 
foreseeable future.
    Siltation--Excessive sedimentation affects an estimated 46 percent 
of all U.S. streams (Judy et al. 1984), including the majority of the 
streams with extant rayed bean and snuffbox populations. Sedimentation 
has been implicated in the decline of mussel populations nationwide, 
and is a threat to rayed bean and snuffbox (Kunz 1898, p. 328; Ellis 
1936, pp. 39-40; Marking and Bills 1979, p. 204; Vannote and Minshall 
1982, pp. 4105-4106; Dennis 1984, p. 212; Wolcott and Neves 1990, pp. 
74-75; Brim Box 1999, p. 79; Fraley and Ahlstedt 2000, p. 194; Poole 
and Downing 2004, pp. 119-120). Specific biological impacts include 
reduced feeding and respiratory efficiency from clogged gills, 
disrupted metabolic processes, reduced growth rates, limited burrowing 
activity, and physical smothering (Ellis 1936, pp. 39-40; Stansbery 
1971, p. 6; Imlay 1972, p. 76; Marking and Bills 1979, p. 210; Vannote 
and Minshall 1982, p. 4105; Waters 1995, p. 7).
    Studies indicate that excessive sediment level impacts are 
sublethal, with detrimental effects not immediately apparent (Brim Box 
and Mossa 1999, p. 101). Physical habitat effects include altered 
suspended and bed material loads, and bed sediment composition 
associated with increased sediment production and run-off; clogged 
interstitial habitats and reduced interstitial flow rates and dissolved 
oxygen levels; changed channels in form, position, and degree of 
stability; altered depth or width-depth ratio that affects light 
penetration and flow regime; aggraded (filling) or degraded (scouring) 
channels; and changed channel positions that dewater mussel beds 
(Vannote and Minshall 1982, p. 4105; Gordon et al. 1992, pp. 296-297; 
Kanehl and Lyons 1992, pp. 26-27; Brim Box and Mossa 1999, p. 102).

[[Page 67575]]

    Interstitial spaces in the substrate provide essential habitat for 
juvenile mussels. When clogged, interstitial flow rates and spaces may 
become reduced (Brim Box and Mossa 1999, p. 100), thus reducing 
juvenile habitat availability. The rayed bean burrows deep into 
interstitial substrates, making it particularly susceptible to 
degradation of this habitat. Sediment may act as a vector for 
delivering contaminants such as nutrients and pesticides to streams. 
Juveniles can readily ingest contaminants adsorbed to silt particles 
during normal feeding activities. These factors may explain, in part, 
why so many mussel populations, including those of the rayed bean and 
snuffbox, appear to be experiencing recruitment failures.
    Agricultural activities produce the most significant amount of 
sediment that enters streams (Waters 1995, pp. 17-18). Neves et al. 
(1997, p. 65) stated that agriculture (including both sediment and 
chemical run-off) affects 72 percent of the impaired river miles in the 
country. Unrestricted access by livestock is a significant threat to 
many streams and their mussel populations (Fraley and Ahlstedt 2000, p. 
193). Soil compaction for intensive grazing may reduce infiltration 
rates and increase run-off, and trampling of riparian vegetation 
increases the probability of erosion (Armour et al. 1991, pp. 8-10; 
Trimble and Mendel 1995, pp. 238-239; Brim Box and Mossa 1999, p. 103).
    The majority of extant rayed bean and snuffbox populations are 
threatened by some form of agricultural runoff (e.g., nutrients, 
pesticides, sediment). The Maumee River system, for example, has a 
drainage area that contains approximately 89 percent agricultural land 
(Sanders 2002, p. 10.1). The decline of rayed bean and snuffbox in this 
system may be largely attributed to stream habitat impacts resulting 
from intensive farming and associated runoff. The rayed bean and 
snuffbox once occurred in the Maumee River mainstem, as well as in up 
to nine of its tributaries. Currently, the snuffbox is extirpated from 
the Maumee River system and the rayed bean is only found in distinct 
but small reaches of the St. Joseph River, Fish Creek, Swan Creek, and 
Blanchard River. All of these remaining populations (which comprise 
about 20 percent of all remaining rayed bean populations rangewide) are 
currently threatened by ongoing agricultural activities. This scenario 
is echoed across the remaining extant range of the rayed bean and 
snuffbox.
    Other Activities Affecting Rayed Bean and Snuffbox Habitat--
Activities associated with urbanization can be detrimental to stream 
habitats (Couch and Hamilton 2002, p. 1) and were summarized by 
Feminella and Walsh (2005, pp. 585-587). Developmental activities may 
impact streams and their mussel fauna where adequate streamside buffers 
are not maintained and erosion of impacted land is allowed to enter 
streams (Brainwood et al. 2006, p. 511). Types of development may 
include highway construction, parking lots, building construction, 
general infrastructure (utilities, sewer systems), and recreation 
facilities. Factors impacting rayed bean and snuffbox populations in 
urban and suburban areas include lawn care chemicals (Conners and Black 
2004, pp. 366-367), sedimentation, toxic effluents, domestic sewage, 
road salts, and general runoff.
    Impervious surfaces are detrimental to mussel habitat by altering 
various hydrological factors, including: Increased volumes of flow, 
annual flow rates, peak flows and duration, and temperature; decreased 
base flow; and changes in sediment loadings (Galli 1991, p. 28; EPA 
1997, p. 4; DeWalle et al. 2000, p. 2655; Myers-Kinzie et al. 2002, p. 
822). These factors result in flooding, erosion, channel widening, 
altered streambeds, channel instability, riparian and instream habitat 
loss, and loss of fish populations (EPA 1997, p. 4). As little as 10 
percent of a watershed being impervious can cause channel instability 
and a host of other stream habitat effects (Booth 1991, p. 98; Booth 
and Reinelt 1993, p. 549). Impervious surfaces may reduce sediment 
input into streams but result in channel instability by accelerating 
stormwater runoff, which increases bank erosion and bed scouring (Brim 
Box and Mossa 1999, p. 103). Stream channels become highly unstable as 
they respond to increased flows by eroding a groove in the bottom of 
the channel (incising), which increases the force of the water against 
the channel (shear stress) and bed mobilization (Doyle et al. 2000, p. 
156). Hydrological variability influences the distribution of mussels 
in streams, with distinct communities associated with hydrologically 
flashy and hydrologically stable streams (Di Maio and Corkum 1995, p. 
669). High shear stress, peak flows, and substrate movement limits 
mussel communities, reduces abundance (particularly for juveniles), and 
increasingly dislodges mussels and moves them downstream (Layzer and 
Madison 1995, p. 337; Myers-Kinzie et al. 2002, p. 822; Gangloff and 
Feminella 2006, p. 70). Recruitment is also significantly reduced in 
high discharge years (Howard and Cuffey 2006, p. 688). Most rayed bean 
and snuffbox streams have been impacted by general developmental 
activities and increased impervious surface levels (Butler 2007, p. 88; 
Butler 2002, p. 25).
    All rayed bean or snuffbox streams are crossed by bridges and 
roads. Effects from these structures were reviewed by Wheeler et al. 
(2005). Categories of impacts include primary effects (construction), 
secondary effects (post-construction), and indirect effects 
(development associated with highway presence) (Angermeier et al. 2004, 
pp. 21-24). Culverts act as barriers to fish passage (Wheeler et al. 
2005, p. 149), particularly by increasing flow velocity (Warren and 
Pardew 1998, p. 637). Stream channels become destabilized when 
culverted or improperly bridged by interrupting the transport of woody 
debris, substrate, and water (Wheeler et al. 2005, p. 152).
    Anthropogenic activities can lower water tables, making rayed bean, 
snuffbox, and other mussel populations susceptible to depressed flow 
levels. Water withdrawals for irrigation, municipal, and industrial 
water supplies are an increasing concern. U.S. water consumption 
doubled from 1960 to 2000 and is likely to increase further (Naiman and 
Turner 2000, p. 960). Therefore, we anticipate water withdrawals and 
potential stream dewatering to be a threat to rayed bean and snuffbox 
in the foreseeable future.
    We have identified a number of threats to the habitat of the rayed 
bean and snuffbox which have operated in the past, are impacting the 
species now, and will continue to impact the species in the foreseeable 
future. On the basis of this analysis, we find that the present and 
threatened destruction, modification, or curtailment of the species' 
habitats is a threat to the rayed bean and snuffbox throughout all of 
their range. Based on our analysis of the best available information, 
we have no reason to believe that the present or threatened 
destruction, modification, or curtailment of rayed bean or snuffbox 
habitat will change in the foreseeable future. The decline of the 
freshwater mussels in the eastern United States is primarily the result 
the long-lasting effects of habitat alterations such as impoundments, 
channelization, chemical contaminants, mining, and sedimentation. 
Although efforts have been made to restore habitat in some areas, the 
long-term effects of large-scale and wide-ranging habitat modification, 
destruction, and curtailment will last far into the foreseeable future.

[[Page 67576]]

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The rayed bean and snuffbox are not commercially valuable species. 
Rare species like the rayed bean and snuffbox may increasingly be 
sought by lay and experienced collectors. Most stream reaches inhabited 
by these species are restricted, and their populations are generally 
small. Although scientific collecting is not thought to represent a 
significant threat, localized populations could become impacted and 
possibly extirpated by over-collecting, particularly if this activity 
is unregulated. Native Americans were known to harvest the rayed bean 
for food, but because of its size, utilization rates were very low 
(Bogan 1990, p. 134). Localized declines of snuffbox from use as bait 
by fishermen has been noted (Cumberland River; Wilson and Clark 1914, 
p. 45), although it is unlikely that exploitation activities have 
eliminated any snuffbox populations.
    On the basis of this analysis, we find that overutilization for 
commercial, recreational, scientific, or educational purposes is not 
now a threat to the rayed bean or snuffbox in any portion of their 
range or likely to become a significant threat in the foreseeable 
future.

C. Disease or Predation

    Little is known about diseases in freshwater mussels (Grizzle and 
Brunner 2007). However, mussel die-offs have been documented in rayed 
bean and snuffbox streams (Neves 1986, p. 9), and some researchers 
believe that disease may be a factor contributing to the die-offs 
(Buchanan 1986, p. 53; Neves 1986, p. 11). Mussel parasites include 
water mites, trematodes, oligochaetes, leeches, copepods, bacteria, and 
protozoa (Grizzle and Brunner 2007). Generally, parasites are not 
suspected of being a major limiting factor (Oesch 1984, p. 16), but a 
recent study provides contrary evidence. Reproductive output and 
physiological condition were negatively correlated with mite and 
trematode abundance, respectively (Gangloff and Feminella 2004). 
Stressors that reduce fitness may make mussels more susceptible to 
parasites (Butler 2007, p. 90). Furthermore, nonnative mussels may 
carry diseases and parasites that are potentially devastating to native 
mussel fauna, including rayed bean and snuffbox (Strayer 1999b, p.88).
    The muskrat (Ondatra zibethicus) is cited as the most prevalent 
mussel predator (Kunz 1898, p. 328; Hanson et al. 1989, p. 15). Muskrat 
predation may limit the recovery potential of endangered mussels or 
contribute to local extirpations of previously stressed populations, 
according to Neves and Odom (1989, p. 940), but they consider it 
primarily a seasonal or localized threat. The snuffbox ranked fourth 
among 12 species in a St. Croix River muskrat midden, being nearly four 
times more abundant than in quantitative surveys (Tyrrell and Hornbach 
1998, p. 304). Numbers were too low to determine selectivity indices or 
statistics.
    Muskrats were not thought to be a threat to the rayed bean by West 
et al. (2000, pp. 255-256), due to their general selection of mussels 
larger than 1.4-1.6 in (3.6-4.1 cm) long (Convey et al. 1989, p. 656; 
Hanson et al. 1989, p. 24). Neves and Odom (1989, pp. 938-939) also 
noted that muskrats did not select for small mussels. Nevertheless, 
some muskrat predation on the rayed bean has recently been documented 
in Cassadaga Creek, New York, but is generally considered 
insignificant.
    Other mammals (raccoon (Procyon lotor), mink (Mustela vison), river 
otter (Lutra Canadensis), striped skunk (Mephitis mephitis), hog (Sus 
scrofa), rat (Rattus spp.)), amphibians (hellbender (Cryptobranchus 
alleganiensis)), turtles, aquatic birds, and fishes (freshwater drum 
(Aplodinotus grunniens), redear sunfish (Lepomis microlophus)) feed on 
mussels (Kunz 1898, p. 328; Meek and Clark 1912, p. 6; Neck 1986, p. 
64; Tyrrell and Hornbach 1998, p. 301). Hydra, non-biting midge larvae, 
dragonfly larvae, crayfish, and especially flatworms are invertebrate 
predators on newly metamorphosed juveniles (Zimmerman and Neves 2003, 
p. 28; Klocker and Strayer 2004, p. 174). The overall threat posed by 
these predators on the rayed bean and snuffbox is not considered 
significant.
    Studies indicate that in some localized areas, disease and 
predation may have a negative impact on mussel populations. However, 
based on our analysis of the best available information, we do not 
believe that disease or predation is a significant threat to the 
overall status of rayed bean or snuffbox, nor do we believe that it is 
likely to become a significant threat in the foreseeable future.

D. The Inadequacy of Existing Regulatory Mechanisms

    Most States with extant rayed bean and snuffbox populations 
prohibit collection of mussels without a State collecting permit. 
However, enforcement of this permit requirement is difficult.
    Sources of nonpoint source pollution include timber clearcutting, 
clearing of riparian vegetation, urbanization, road construction, and 
other practices that allow bare earth to enter streams (The Nature 
Conservancy 2004, p. 13). Current laws do not adequately protect rayed 
bean and snuffbox habitat from nonpoint source pollution, as the laws 
to prevent sediment entering waterways are poorly enforced. Best 
management practices for sediment and erosion control are often 
recommended or required by local ordinances for construction projects; 
however, compliance, monitoring, and enforcement of these 
recommendations are often poorly implemented. Furthermore, there are 
currently no requirements within the scope of Federal environmental 
laws to specifically consider the rayed bean or snuffbox during Federal 
activities, or to ensure that Federal projects will not jeopardize 
their continued existence.
    Point source discharges within the range of the rayed bean and 
snuffbox have been reduced since the inception of the Clean Water Act 
(33 U.S.C. 1251 et seq.), but this may not provide adequate protection 
for filter-feeding organisms that can be impacted by extremely low 
levels of contaminants (see Chemical Contaminants discussion under 
Factor A). There is no specific information on the sensitivity of the 
rayed bean and snuffbox to common industrial and municipal pollutants, 
and very little information on other freshwater mussels. Therefore, it 
appears that a lack of adequate research and data prevents existing 
regulations, such as the Clean Water Act (administered by the EPA and 
the U.S. Army Corps of Engineers), from being fully used or effective.
    Despite these existing regulatory mechanisms, the rayed bean and 
snuffbox continue to decline due to the effects of habitat destruction, 
poor water quality, contaminants, and other factors. We find that these 
regulatory measures have been insufficient to significantly reduce or 
remove the threats to the rayed bean and snuffbox and, therefore, that 
the inadequacy of existing regulatory mechanisms is a threat to these 
species throughout all of their range.
    Based on our analysis of the best available information, we have no 
reason to believe that the aforementioned regulations, which currently 
do not offer adequate protection to the rayed bean and snuffbox, will 
be improved in the foreseeable future.

[[Page 67577]]

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    Other factors have played a role in the decline of rayed bean and 
snuffbox populations. Reduced numbers of host fish have an indirect 
impact by contributing to reduced recruitment (Watters 1996, p. 83; 
Khym and Layzer 2000, p. 183). Factors associated with climate change 
likely to affect regional mussel populations include changes in stream 
temperature regimes and precipitation levels that may indirectly result 
in reduced habitat and declines in host fish stocks (Hastie et al. 
2003, p. 44). Remedial (such as flood control structures) and 
preventative (for example, more renewable energy from hydroelectric 
facilities to reduce greenhouse gas emissions) measures to address 
climate change issues (Hastie et al. 2003, p. 45) may impact rayed bean 
and snuffbox populations in the future.
    Population Fragmentation and Isolation--The majority of the 
remaining populations of the rayed bean and snuffbox are generally 
small and geographically isolated. The patchy distributional pattern of 
populations in short river reaches makes them much more susceptible to 
extirpation from single catastrophic events, such as toxic chemical 
spills (Watters and Dunn 1993-94, p. 257). Furthermore, this level of 
isolation makes natural repopulation of any extirpated population 
unlikely without human intervention. Population isolation prohibits the 
natural interchange of genetic material between populations, and small 
population size reduces the reservoir of genetic diversity within 
populations, which can lead to inbreeding depression (Avise and 
Hambrick 1996, p. 461).
    The Scioto River system provides a good example of the impacts of 
population fragmentation and isolation. Historically, the rayed bean 
and snuffbox were widespread and locally abundant in the mainstem and 
numerous tributaries. The Scioto River became highly contaminated over 
a century ago (Trautman 1981, p. 33; Yoder et al. 2005, p. 410), and 
these species eventually died out in the mainstem and most tributaries. 
The population segments that persist have become increasingly isolated 
due to impoundments and other factors; all are very small, highly 
fragmented, and appear to be on a trend towards extirpation.
    Many rayed bean and snuffbox populations are potentially below the 
effective population size (EPS) required to maintain genetic 
heterogeneity and population viability (Soul[eacute] 1980, p. 162). 
Isolated populations eventually die out when population size drops 
below the EPS or threshold level of sustainability. Recruitment 
reduction or failure is a potential problem for many small rayed bean 
and snuffbox populations rangewide, a condition likely exacerbated by 
their reduced range and increasingly isolated populations. Evidence of 
recruitment has not been documented in many populations, indicating 
that recruitment reduction or outright failure is possible. Many 
populations of both species may be experiencing the bottleneck effect 
of not attaining EPS. Small, isolated, below EPS-threshold populations 
of short-lived species (most host fishes) theoretically die out within 
a decade or so, while below-threshold populations of long-lived species 
(like the rayed bean and snuffbox) might take decades to die out even 
given years of total recruitment failure.
    We find that fragmentation and isolation of small remaining 
populations of the rayed bean and snuffbox are current and ongoing 
threats to both species throughout all of their range that will 
continue into the foreseeable future.
    Exotic Species--Various exotic or nonnative species of aquatic 
organisms are firmly established in the range of the rayed bean and 
snuffbox. The exotic species that poses the most significant threat to 
the rayed bean and snuffbox is the zebra mussel (Dreissena polymorpha). 
The invasion of the zebra mussel poses a threat to the mussel fauna in 
many regions, and species extinctions are expected as a result of its 
continued spread in the eastern United States (Ricciardi et al. 1998, 
p. 616). Strayer (1999b, pp. 77-80) reviewed in detail the mechanisms 
by which zebra mussels impact native mussels. The primary means of 
impact is direct fouling of the shells of live native mussels. Zebra 
mussels attach in large numbers to the shells of live native mussels 
and are implicated in the loss of entire native mussel beds. Fouling 
impacts include impeding locomotion (both laterally and vertically), 
interfering with normal valve movements, deforming valve margins, and 
locally depleting food resources and increasing waste products. Heavy 
infestations of zebra mussels on native mussels may overly stress the 
animals by reducing their energy stores. They may also reduce food 
concentrations to levels too low to support reproduction, or even 
survival in extreme cases.
    Another way zebra mussels may impact native mussels is through 
filtering their sperm and possibly glochidia from the water column, 
thus reducing reproductive potential. Habitat for native mussels may 
also be degraded by large deposits of zebra mussel pseudofeces 
(undigested waste material passed out of the incurrent siphon) (Vaughan 
1997, p. 11). Additionally, an indirect impact is the proliferation of 
aquatic plants from increased water clarity in lakes, which in turn has 
prompted managers to increase the use of herbicides that may threaten 
mussels via food reduction (Marangelo 2005b, pers. comm.).
    Zebra mussels are thoroughly established in the Great Lakes 
drainages and much of the Ohio River system, overlapping much of the 
current range of the rayed bean and snuffbox. Zebra mussels have 
eliminated populations of the rayed bean in Lakes Erie and Tippecanoe 
and the Detroit River. The greatest current potential for zebra mussels 
to impact the rayed bean and snuffbox are in the Lake St. Clair 
drainages, Allegheny River, Tippecanoe River, French Creek, and Lake 
Maxinkuckee. In addition, there is long-term potential for zebra mussel 
invasions into other systems that currently harbor rayed bean and 
snuffbox populations. However, zebra mussels are not always a serious 
threat to rayed bean and snuffbox (Tippecanoe River, Fisher 2005, pers. 
comm.; Clinton River, Butler 2007, p. 94; French Creek, Butler 2007, p. 
94). Significant but highly fluctuating zebra mussel populations remain 
largely restricted to navigational waterways, although smaller streams 
have also had their mussel fauna virtually eliminated by them (Martel 
et al. 2001, p. 2188). At least two of the stronghold snuffbox 
populations (Wolf River and French Creek) presently have low numbers of 
zebra mussels.
    The Asian clam (Corbicula fluminea) has spread throughout the range 
of the rayed bean and snuffbox since its introduction in the mid-1900s. 
Asian clams compete with native mussels, especially juveniles, for 
food, nutrients, and space (Neves and Widlak 1987, p. 6; Leff et al. 
1990, p. 415) and may ingest sperm, glochidia, and newly metamorphosed 
juveniles of native mussels (Strayer 1999b, p. 82; Yeager et al. 2001, 
p. 257). Dense Asian clam populations actively disturb sediments that 
may reduce habitat for juvenile mussels (Strayer 1999b, p. 82).
    Asian clam densities vary widely in the absence of native mussels 
or in patches with sparse mussel concentrations, but clam density is 
never high in dense mussel beds, indicating that the clam is unable to 
successfully invade small-scale habitat patches with high unionid 
biomass

[[Page 67578]]

(Vaughn and Spooner 2006, p. 335). The invading clam therefore appears 
to preferentially invade sites where mussels are already in decline 
(Strayer 1999b, p. 82; Vaughn and Spooner 2006, p. 332) and does not 
appear be a causative factor in the decline of mussels in dense beds. 
However, an Asian clam population that thrives in previously stressed, 
sparse mussel populations can exacerbate unionid imperilment through 
competition and impeding mussel population expansion (Vaughn and 
Spooner 2006, p. 335).
    The round goby (Neogobius melanostomus) is another exotic fish 
species released into the Great Lakes that is well established and 
likely to spread through the Mississippi River system (Strayer 1999b, 
pp. 87-88). This species is an aggressive competitor of similar sized 
benthic fish (sculpins, darters) as well as a voracious carnivore 
despite its size (less than 10 in. (25.4 cm) in length), preying on a 
variety of foods, including small mussels and fishes that could serve 
as glochidial hosts (Strayer 1999b, p. 88; Janssen and Jude 2001, p. 
325). Round gobies may therefore have indirect effects on the rayed 
bean and snuffbox through negative impacts to their host fishes.
    Additional exotic species will invariably become established in the 
foreseeable future (Strayer 1999b, pp. 88-89). These include Limnoperna 
fortunei, a biofouling mussel (an animal that undesirably accumulates 
on wetted surfaces) from southeast Asia that has already spread to 
Japan and South America, and ``probably will have strong effects'' on 
native mussels (Strayer 1999b, p. 89). Exotic species could carry 
diseases and parasites that may be devastating to the native biota. 
Because of our ignorance of mollusk diseases and parasites, ``it is 
imprudent to conclude that alien diseases and parasites are 
unimportant'' (Strayer 1999b, p. 88).
    Exotic species, such as those described above, are an ongoing 
threat to the rayed bean and snuffbox--a threat that is likely to 
increase as these exotic species expand their occupancy within the 
range of the rayed bean and snuffbox.

Summary of Threats

    The decline of the rayed bean and snuffbox (described by Butler 
2002, 2007) is primarily the result of habitat loss and degradation 
(Neves 1991, p. 252). These losses have been well documented since the 
mid-19th century (Higgins 1858, p. 551). Chief among the causes of 
decline are impoundments, channelization, chemical contaminants, 
mining, and sedimentation (Neves 1991, pp. 260-261; 1993, p. 4-5; 
Williams et al. 1993, p. 7; Neves et al. 1997, pp. 60-72; Watters 2000, 
p. 269). These stressors have had profound impacts on rayed bean and 
snuffbox populations and their habitat.
    The majority of the remaining populations of the rayed bean and 
snuffbox are generally small and geographically isolated (Butler 2002, 
2007). The patchy distributional pattern of populations in short river 
reaches makes those populations much more susceptible to extirpation 
from single catastrophic events, such as toxic chemical spills (Watters 
and Dunn 1993-94, p. 257). Furthermore, this level of isolation makes 
natural repopulation of any extirpated population virtually impossible 
without human intervention. Various nonnative species of aquatic 
organisms are firmly established in the range of the rayed bean and 
snuffbox; however, the exotic species that poses the most significant 
threat to the rayed bean and snuffbox is the zebra mussel (Dreissena 
polymorpha) (Butler 2002, p. 27; 2007, p. 93).

Proposed Determination

    Section 3 of the Act defines an endangered species as any species 
that is ``in danger of extinction throughout all or a significant 
portion of its range'' and a threatened species as any species that 
``is likely to become an endangered species within the foreseeable 
future throughout all or a significant portion of its range.'' We find 
that the rayed bean and snuffbox are presently in danger of extinction 
throughout their entire range, based on the immediacy, severity, and 
scope of the threats described above. Although there are ongoing 
attempts to alleviate some threats, there appear to be no populations 
without current significant threats and many threats are without 
obvious or readily available solutions. Therefore, on the basis of the 
best available scientific and commercial information, we propose 
listing the rayed bean and snuffbox as endangered in accordance with 
sections 3(6) and 4(a)(1) of the Act.
    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. Threats to the rayed bean and 
snuffbox occur throughout their range. Therefore, we assessed the 
status of the species throughout their entire range. The threats to the 
survival of the species occur throughout the species' ranges and are 
not restricted to any particular significant portion of those ranges. 
Accordingly, our assessment and proposed determination applies to the 
species throughout their entire range.

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 results in public awareness and 
conservation by Federal, State, Tribal, and local agencies, private 
organizations, and individuals. The Act encourages cooperation with the 
States and requires that recovery actions be carried out for all listed 
species. The protection required by Federal agencies and the 
prohibitions against certain activities are discussed, in part, below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Subsection 4(f) of the Act requires the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed, preparation of a draft and final 
recovery plan, and revisions to the plan as significant new information 
becomes available. The recovery outline guides the immediate 
implementation of urgent recovery actions and describes the process to 
be used to develop a recovery plan. The recovery plan identifies site-
specific management actions that will achieve recovery of the species, 
measurable criteria that determine when a species may be downlisted or 
delisted, and methods for monitoring recovery progress. Recovery plans 
also establish a framework for agencies to coordinate their recovery 
efforts and provide estimates of the cost of implementing recovery 
tasks. Recovery teams (comprised of species experts, Federal and State 
agencies, non-government organizations, and stakeholders) are often 
established to develop recovery plans. When completed, the recovery 
outline, draft recovery plan, and the

[[Page 67579]]

final recovery plan will be available on our Web site (http://www.fws.gov/endangered), or from our Ohio Ecological Services Field 
Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribal, non-governmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands.
    If this species is listed, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost share grants for non-Federal landowners, the 
academic community, and nongovernmental organizations. Additionally, 
under section 6 of the Act, we would be able to grant funds to the 
States of Illinois, Indiana, Kentucky, Michigan, New York, Ohio, 
Pennsylvania, Tennessee, Virginia, and West Virginia for management 
actions promoting the conservation of the rayed bean and to the States 
of Alabama, Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, 
Michigan, Minnesota, Mississippi, Missouri, New York, Ohio, 
Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin for the 
conservation of the snuffbox. Information on our grant programs that 
are available to aid species recovery can be found at: http://www.fws.gov/grants.
    Although the rayed bean and snuffbox are only proposed for listing 
under the Act at this time, please let us know if you are interested in 
participating in recovery efforts for these species. Additionally, we 
invite you to submit any new information on these species whenever it 
becomes available and any information you may have for recovery 
planning purposes; if you submit information after the date listed in 
the DATES section above, you will need to send it to the street address 
provided in the FOR FURTHER INFORMATION CONTACT section.
    Section 7(a) of the Act 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 us 
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 us.
    Federal agency actions that may require conference or consultation 
as described in the preceding paragraph include the issuance of permits 
for reservoir construction, stream alterations, wastewater facility 
development, water withdrawal projects, pesticide registration, 
agricultural assistance programs, mining, road and bridge construction, 
and Federal loan programs. Activities will trigger consultation under 
section 7 of the Act if they may affect the rayed bean or snuffbox, or 
both species, addressed in this proposed rule.

Jeopardy Standard

    Prior to and following listing and designation of critical habitat, 
if prudent and determinable, the Service applies an analytical 
framework for jeopardy analyses that relies heavily on the importance 
of core area populations to the survival and recovery of the species. 
The section 7(a)(2) analysis is focused not only on these populations 
but also on the habitat conditions necessary to support them.
    The jeopardy analysis usually expresses the survival and recovery 
needs of the species in a qualitative fashion without making 
distinctions between what is necessary for survival and what is 
necessary for recovery. Generally, if a proposed Federal action is 
incompatible with the viability of the affected core area 
populations(s), inclusive of associated habitat conditions, a jeopardy 
finding is considered to be warranted, because of the relationship of 
each core area population to the survival and recovery of the species 
as a whole.

Section 9 Take

    The Act and implementing regulations set forth a series of general 
prohibitions and exceptions that apply to all endangered and threatened 
wildlife. If we finalize listing of the rayed bean and snuffbox, these 
prohibitions would be applicable to the rayed bean and snuffbox. The 
prohibitions of section 9(a)(2) of the Act, codified at 50 CFR 17.21 
for endangered wildlife, 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, capture, or 
collect, or to attempt any of these), import or export, deliver, 
receive, carry, transport, or ship in interstate or foreign 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. Further, it is illegal for any person to 
attempt to commit, to solicit another person to commit, or to cause to 
be committed, any of these acts. Certain exceptions apply to our agents 
and State conservation agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered wildlife under certain circumstances. We codified 
the regulations governing permits for endangered species at 50 CFR 
17.22. Such permits are available for scientific purposes, to enhance 
the propagation or survival of the species, or for incidental take in 
the course of otherwise lawful activities.
    It is our policy, published in the Federal Register on July 1, 1994 
(59 FR 34272), to identify, to the maximum extent practicable at the 
time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act and associated 
regulations at 50 CFR 17.21. The intent of this policy is to increase 
public awareness of the effect of this proposed listing on proposed and 
ongoing activities within a species' range. We believe, based on the 
best available information, that the following actions will not result 
in a violation of the provisions of section 9 of the Act, provided 
these actions are carried out in accordance with existing regulations 
and permit requirements:
    (1) Activities authorized, funded, or carried out by Federal 
agencies (e.g., bridge and highway construction, pipeline construction, 
hydropower licensing, etc.), when such activities are conducted in 
accordance with the consultation and planning requirements for listed 
species under section 7 of the Act.
    (2) Any action carried out for scientific research or to enhance 
the propagation or survival of the rayed bean or snuffbox that is 
conducted in

[[Page 67580]]

accordance with the conditions of a 50 CFR 17.22 permit.
    (3) Any incidental take of rayed bean or snuffbox resulting from an 
otherwise lawful activity conducted in accordance with the conditions 
of an incidental take permit issued under 50 CFR 17.22. Non-Federal 
applicants may design a habitat conservation plan (HCP) for the species 
and apply for an incidental take permit. HCPs may be developed for 
listed species and are designed to minimize and mitigate impacts to the 
species to the greatest extent practicable.
    We believe the following activities would be likely to result in a 
violation of section 9 of the Act; however, possible violations are not 
limited to these actions alone:
    (1) Unauthorized killing, collecting, handling, or harassing of 
individual rayed bean or snuffbox, or both species, at any life stage.
    (2) Sale or offer for sale of rayed bean or snuffbox in addition to 
delivering, receiving, carrying, transporting, or shipping in 
interstate or foreign commerce any rayed bean or snuffbox.
    (3) Unauthorized destruction or alteration of the species' habitat 
(instream dredging, channelization, impoundment, streambank clearing, 
discharge of fill material) that actually kills or injures individual 
rayed bean or snuffbox by significantly impairing their essential 
behavioral patterns, including breeding, feeding, or sheltering.
    (4) Violation of any discharge or water withdrawal permit within 
these species' occupied ranges that results in the death or injury of 
individual rayed bean or snuffbox by significantly impairing their 
essential behavioral patterns, including breeding, feeding, or 
sheltering.
    (5) Discharge or dumping of toxic chemicals or other pollutants 
into waters supporting the species that actually kills or injures 
individual rayed bean or snuffbox by significantly impairing their 
essential behavioral patterns, including breeding, feeding, or 
sheltering.
    We will review other activities not identified above on a case-by-
case basis to determine whether they may be likely to result in a 
violation of section 9 of the Act. We do not consider these lists to be 
exhaustive, and provide them as information to the public.
    You should direct questions regarding whether specific activities 
may constitute a future violation of section 9 of the Act to the Field 
Supervisor of the Service's Ohio Ecological Services Field Office (see 
FOR FURTHER INFORMATION CONTACT section). Requests for copies of 
regulations regarding listed species and inquiries about prohibitions 
and permits should be addressed to the U.S. Fish and Wildlife Service, 
Ecological Services Division, Henry Whipple Federal Building, 1 Federal 
Drive, Fort Snelling, MN 55111 (Phone 612-713-5350; Fax 612-713-5292).

Critical Habitat

Background

    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 geographical area occupied by a 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    ``Conservation'' is defined in section 3 of the Act as meaning 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.
    Critical habitat receives protection under section 7 of the Act 
through the prohibition against Federal agencies carrying out, funding, 
or authorizing the destruction or adverse modification of critical 
habitat. Section 7(a)(2) requires consultation on Federal actions that 
may affect critical habitat. The designation of critical habitat does 
not affect land ownership or establish a refuge, wilderness, reserve, 
preserve, or other conservation area. Such designation does not allow 
the government or public to access private lands. Such designation does 
not require implementation of restoration, recovery, or enhancement 
measures by non-Federal landowners. Where a landowner seeks or requests 
Federal agency funding or authorization for an action that may affect a 
listed species or critical habitat, the consultation requirements of 
section 7(a)(2) of the Act would apply, but even in the event of a 
destruction or adverse modification finding, Federal action agency's 
and the applicant's obligation is not to restore or recover the 
species, but to implement reasonable and prudent alternatives to avoid 
destruction or adverse modification of critical habitat.
    For inclusion in a critical habitat designation, the habitat within 
the geographical area occupied by the species at the time it was listed 
must contain the physical and biological features essential to the 
conservation of the species, and be included only if those features may 
require special management considerations or protection. Critical 
habitat designations identify, to the extent known using the best 
scientific and commercial data available, habitat areas that provide 
essential life cycle needs of the species (areas on which are found the 
physical and biological features (PBFs) laid out in the appropriate 
quantity and spatial arrangement for the conservation of the species). 
Under the Act and regulations at 50 CFR 424.12, we can designate 
critical habitat in areas outside the geographical area occupied by the 
species at the time it is listed only when we determine that those 
areas are essential for the conservation of the species and that 
designation limited to those areas occupied at the time of listing 
would be inadequate to ensure the conservation of the species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, our Policy on Information Standards Under the Endangered 
Species Act (published in the Federal Register on July 1, 1994 (59 FR 
34271)), the Information Quality Act (section 515 of the Treasury and 
General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658)), and our associated Information Quality 
Guidelines, provide criteria, establish procedures, and provide 
guidance to ensure that our decisions are based on the best scientific 
data available. They require our biologists, to the extent consistent 
with the Act and with the use of the best scientific data available, to 
use primary and original sources of information as the basis for 
recommendations to designate critical habitat.
    When we are determining which areas should be designated as 
critical habitat, our primary source of information is generally the 
information developed during the listing process for the species. 
Additional information sources may include the recovery plan for the 
species, articles in peer-reviewed journals, conservation plans 
developed by States and counties, scientific status surveys and 
studies, biological assessments, or other unpublished materials and 
expert opinion or personal knowledge.
    Habitat is often dynamic, and species may move from one area to 
another over time. Furthermore, we recognize that critical habitat 
designated at a particular point in time may not include all of the 
habitat areas that we may later determine are necessary for the 
recovery of the species. For these reasons, a

[[Page 67581]]

critical habitat designation does not signal that habitat outside the 
designated area is unimportant or may not be required for recovery of 
the species.
    Areas that are important to the conservation of the species, but 
are outside the critical habitat designation, will continue to be 
subject to conservation actions we implement under section 7(a)(1) of 
the Act. Areas that support populations are also subject to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available scientific 
information at the time of the agency action. Federally funded or 
permitted projects affecting listed species outside their designated 
critical habitat areas may still result in jeopardy findings in some 
cases. Similarly, critical habitat designations made on the basis of 
the best available information at the time of designation will not 
control the direction and substance of future recovery plans, habitat 
conservation plans (HCPs), or other species conservation planning 
efforts if new information available at the time of these planning 
efforts calls for a different outcome.
Prudency Determination
    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, we designate critical habitat at the time we 
determine that a species is endangered or threatened. Our regulations 
(50 CFR 424.12(a)(1)) state that the 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.
    There is currently no imminent threat of take attributed to 
collection or vandalism under Factor B (overutilization for commercial, 
recreational, scientific, or educational purposes) for the rayed bean 
or snuffbox, and identification of critical habitat is not expected to 
initiate such a threat. In the absence of finding that the designation 
of critical habitat would increase threats to a species, if there are 
any benefits to a critical habitat designation, then a prudent finding 
is warranted. The potential benefits include: (1) Triggering 
consultation under section 7(a)(2) of the Act, in new areas for actions 
in which there may be a Federal nexus where it would not otherwise 
occur because the species may not be present; (2) focusing conservation 
activities on the most essential habitat features and areas; (3) 
increasing awareness of important habitat areas among State or county 
governments, or private entities; and (4) preventing inadvertent harm 
to the species.
    Critical habitat designation includes the identification of the 
physical and biological features of the habitat essential to the 
conservation of each species that may require special management and 
protection. As such, these designations will provide useful information 
to individuals, local and State governments, and other entities engaged 
in activities or long-range planning that may affect areas essential to 
the conservation of the species. Conservation of the rayed bean and 
snuffbox and essential features of their habitats will require habitat 
management, protection, and restoration, which will be facilitated by 
disseminating information on the locations and the key physical and 
biological features of those habitats. In the case of the rayed bean 
and snuffbox, these aspects of critical habitat designation would 
potentially benefit the conservation of the species. Therefore, since 
we have determined that the designation of critical habitat will not 
likely increase the degree of threat to these species and may provide 
some measure of benefit, we find that designation of critical habitat 
is prudent for the rayed bean and snuffbox.
Critical Habitat Determinability
    As stated above, section 4(a)(3) of the Act requires the 
designation of critical habitat concurrently with the species' listing 
``to the maximum extent prudent and determinable.'' Our regulations at 
50 CFR 424.12(a)(2) state that critical habitat is not determinable 
when one or both of the following situations exist:
    (i) Information sufficient to perform required analyses of the 
impacts of the designation is lacking, or
    (ii) The biological needs of the species are not sufficiently well 
known to permit identification of an area as critical habitat.
    When critical habitat is not determinable, the Act provides for an 
additional year to publish a critical habitat designation (16 U.S.C. 
1533(b)(6)(C)(ii)).
    In accordance with sections 3(5)(A)(i) and 4(b)(1)(A) of the Act 
and regulations at 50 CFR 424.12, in determining which areas to propose 
as critical habitat, we must consider those physical and biological 
features essential to the conservation of the species. These include, 
but are not limited to:
    (1) Space for individual and population growth and for normal 
behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, and rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historical, geographical, and ecological 
distribution of a species.
    We are currently unable to identify the physical and biological 
features essential for the conservation of the rayed bean and snuffbox 
because information on those features for these species is not known at 
this time. The apparent poor viability of the species' occurrences 
observed in recent years indicates that current conditions are not 
sufficient to meet the basic biological requirements of these species 
in many rivers. Since the rayed bean and snuffbox have not been 
observed for decades in many of their historical locations, and much of 
the habitat in which they still persist has been drastically altered, 
the optimal conditions that would provide the biological or ecological 
requisites of these species are not known. Although we can surmise that 
habitat degradation from a variety of factors has contributed to the 
decline of these species, we do not know specifically what essential 
physical or biological features of that habitat are currently lacking 
for the rayed bean and snuffbox.
    Key features of the basic life history, ecology, reproductive 
biology, and habitat requirements of most mussels, including the rayed 
bean and snuffbox, are unknown. Species-specific ecological 
requirements have not been determined (for example, minimum water flow 
and effects of particular pollutants). Population dynamics, such as 
species' interactions and community structure, population trends, and 
population size and age class structure necessary to maintain long-term 
viability, have not been determined for these species. Of particular 
concern to both species is that many of the remaining rayed bean and 
snuffbox populations consist of very low densities, which limit our 
ability to investigate their population dynamics. Basics of 
reproductive biology for these species are unknown, such as age and 
size at earliest maturity, reproductive longevity, and the level of 
recruitment needed for species' survival and long-term viability. As we 
are unable to

[[Page 67582]]

identify many physical and biological features essential to the 
conservation of the rayed bean and snuffbox, we are unable to identify 
areas that contain these features. Therefore, although we have 
determined that the designation of critical habitat is prudent for the 
rayed bean and snuffbox, because the biological and physical 
requirements of these species are not sufficiently known, we find that 
critical habitat for the rayed bean and snuffbox is not determinable at 
this time.

Peer Review

    In accordance with our policy, ``Notice of Interagency Cooperative 
Policy for Peer Review in Endangered Species Act Activities,'' that was 
published on July 1, 1994 (59 FR 34270), we will seek the expert 
opinion of at least three appropriate independent specialists regarding 
this proposed rule. The purpose of such review is to ensure listing 
decisions are based on scientifically sound data, assumptions, and 
analysis. We will send copies of this proposed rule to the peer 
reviewers immediately following publication in the Federal Register. We 
will invite these peer reviewers to comment, during the public comment 
period, on the specific assumptions and the data that are the basis for 
our conclusions regarding the proposal to list rayed bean and snuffbox 
as endangered and our proposal regarding critical habitat for this 
species.
    We will consider all comments and information we receive during the 
comment period on this proposed rule during preparation of a final 
rulemaking. Accordingly, our final decision may differ from this 
proposal.

Public Hearings

    The Act provides for one or more public hearings on this proposal, 
if requested. Requests must be received within 45 days after the date 
of publication of this proposal in the Federal Register (see DATES). 
Such requests must be sent to the address shown in the FOR FURTHER 
INFORMATION CONTACT section. We will schedule public hearings on this 
proposal, if any are requested, and announce the dates, times, and 
places of those hearings, as well as how to obtain reasonable 
accommodation, in the Federal Register and local newspapers at least 15 
days before the hearing.
    Persons needing reasonable accommodation to attend and participate 
in a public hearing should contact the Ohio Ecological Services Field 
Office at 614-416-8993, ext. 22, as soon as possible. To allow 
sufficient time to process requests, please call no later than one week 
before the hearing date. Information regarding this proposed rule is 
available in alternative formats upon request.

Required Determinations

Clarity of Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (a) Be logically organized;
    (b) Use the active voice to address readers directly;
    (c) Use clear language rather than jargon;
    (d) Be divided into short sections and sentences; and
    (e) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in the ADDRESSES section. To 
better help us revise the rule, your comments should be as specific as 
possible. For example, you should tell us the names of the sections or 
paragraphs that are unclearly written, which sections or sentences are 
too long, the sections where you feel lists or tables would be useful, 
etc.

Paperwork Reduction Act (44 U.S.C. 3501, et seq.)

    This proposed rule does not contain any new collections of 
information that require approval by the Office of Management and 
Budget (OMB) under the Paperwork Reduction Act. This rule will not 
impose new recordkeeping or reporting requirements on State or local 
governments, individuals, businesses, or organizations. We may not 
conduct or sponsor and you are not required to respond to a collection 
of information unless it displays a currently valid OMB control number.

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have determined that we do not need to prepare an environmental 
assessment, as defined under the authority of the National 
Environmental Policy Act of 1969, in connection with regulations 
adopted under section 4(a) of the Act. We published a notice outlining 
our reasons for this determination in the Federal Register on October 
25, 1983 (48 FR 49244).

References Cited

    A complete list of all references cited in this proposed rule is 
available on the Internet at http://www.regulations.gov or upon request 
from the Field Supervisor, Ohio Ecological Services Field Office (see 
FOR FURTHER INFORMATION CONTACT section).

Author

    The primary author of this proposed rule is Angela Boyer of the 
Ohio Ecological Services Field Office (see FOR FURTHER INFORMATION 
CONTACT section).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend 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 Sec.  17.11(h) by adding new entries for ``Mussel, rayed 
bean'' and ``Mussel, snuffbox'' in alphabetical order under CLAMS to 
the List of Endangered and Threatened Wildlife as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                          Species                                                    Vertebrate
------------------------------------------------------------                         population
                                                                                       where                                      Critical     Special
                                                                 Historic range      endangered       Status       When listed    habitat       rules
            Common name                  Scientific name                                 or
                                                                                     threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
 

[[Page 67583]]

 
               Clams
 
                                                                      * * * * * * *
Mussel, rayed bean.................  Villosa fabalis.......  U.S.A. (IL, IN, KY,             NA  E                 ...........           NA           NA
                                                              MI, NY, OH, PA, TN,
                                                              VA, WV, WI).
 
                                                                      * * * * * * *
Mussel, snuffbox...................  Epioblasma triquetra..  U.S.A. (AL, AR, IL,             NA  E                 ...........           NA           NA
                                                              IN, IA, KS, KY, MI,
                                                              MN, MS, MO, NY, OH,
                                                              PA, TN, VA, WV, WI).
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *

    Dated: October 15, 2010.
Gary D. Frazer,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2010-27413 Filed 11-1-10; 8:45 am]
BILLING CODE 4310-55-P