SUMMARY

Little is known about the distribution of freshwater mussels inMississippi national forests. Review of the scant available infor-mation revealed that the national forests harbor a diverse mus-sel fauna of possibly 46 or more species (including confirmed,probable, and potential occurrences). Occurrence of 33 species isconfirmed. Because of the geographic, physiographic, and drain-age basin diversity of Mississippi national forests, there is con-siderable variation in mussel communities among the nationalforests. Three distinct fauna1 groups are represented in Missis-sippi national forests, each with a characteristic assemblage ofspecies. One species of potential occurrence is a federally endan-gered species, 1 species of confirmed occurrence is a candidate forlisting, and 11 species of confirmed or probable occurrence areconsidered of special concern by the American Fisheries Society(Williams and others 1993). None of the national forests have beensurveyed adequately, and specific population data are almost com-pletely lacking. This review of existing information represents thefirst of a three-phase program needed to comprehensively evalu-ate the mussel resources of Mississippi national forests. Phasetwo involves an exhaustive, qualitative field survey of Mississippinational forests to document precise distribution of species andlocation of important communities. Phase three consists of a quan-titative study of important communities in order to assess repro-ductive characteristics and viability and to establish baselinedensity estimates for monitoring of future population trends.

Cover: left, Lampsilis cardium; top right, Utterbackia imbecillis; bottom right, Potamilus ohiensis.

Current Distributional Information onFreshwater Mussels (family Unionidae)

in Mississippi National Forests

Wendell R. Haagand

Melvin L. Warren, Jr.

INTRODUCTION

There are 6 national forests (NF’s) in Mississippi(fig. 11, with proclamation boundaries covering a totalof 936,165 ha in 33 counties, of which 461,787 ha arepublicly owned and under USDA Forest Service man-agement. The remaining land within the proclama-tion boundaries is privately owned. These forests arewidely distributed across the State and lie in severalphysiographic regions. Consequently, Mississippi NF’sencompass streams within most major river drainagesin the State and provide a diversity of habitats foraquatic organisms.

In many Mississippi streams, freshwater musselsare a conspicuous element of the fauna. However,mussel populations have declined precipitously in thepast 100 years due to a variety of human-inducedchanges to streams, such as channelization, impound-ment, and water pollution. Currently, 72 percent ofthe freshwater mussel fauna of North America is con-sidered threatened, endangered, or of special concern(Williams and others 1993). In many regions, streamson NF’s may be less impacted by poor land-use prac-tices and water pollution than nearby lands and serveas refugia for rare or endangered organisms. There-fore, Mississippi NF’s potentially represent importanthabitat for freshwater mussels.

There is little published information available onthe distributions of freshwater mussels in Mississippi,and virtually nothing is known of mussel distributionson NF lands in the State. National Forest personnelneed accurate current information on mussel distri-butions and status in order to effectively manage thiscomponent of the aquatic resource. Our goal in thisreport is to present available information on musseldistributions, including the presence of threatened orendangered species, on NF lands in Mississippi and toprioritize information gaps that need urgent attention.

HOMOCHllTO

Figure 1. - Locations of the six national forests in Mississippi aredesignated by shaded areas.

M E T H O D S

Information on mussel distributions was obtainedfrom three sources: (1) published mussel surveys; (2)

Wendell R. Haag is a biological science technician and Melvin L. Warren, Jr., is a research biologist at the U.S. Department ofAgriculture,Forest Service, Southern Forest Experiment Station, Forest Hydrology Laboratory, P.O. Box 947, Oxford, MS 38655.

1

, /

mussel collection records of the Mississippi Museumof Natural Science (MMNS), Mississippi Departmentof Wildlife, Fisheries, and Parks, Jackson, MS, andthe Ohio State University Museum of Biological Di-versity (OSU), Columbus, OH; and (3) field collectionrecords of the Forest Hydrology Laboratory (FHL),Southern Forest Experiment Station, USDA ForestService, Oxford, MS. Occurrence of mussel species onNF lands is classified in one of three categories: (1)confirmed sites-confirmed record of a species withinthe proclamation boundary of a NF; (2) probable oc-currence-a species for which there are confirmedrecords near the forest and in streams of the samedrainage as those in the NF; or (3) potential occurrence-a species that is known to occur in the same drainagesand in similar habitats as those present in the NF butfor which there are no known records near the NF.

Conservation status of each species was obtainedfrom Williams and others (1993) and the U.S. Depart-ment of the Interior (USDI) Fish and Wildlife Service(USDI FWS 1994a, b). Mussel nomenclature followsWilliams and others (1993). Streams were classifiedfollowing Ross and Brenneman (1991). Physiographicregions are from Stephenson and Monroe (1940).

RESULTS AND DISCUSSION

At least 46 species of mussels may occur in Missis-sippi NF’s (table 1). Occurrence was confirmed for 33species, and 13 other species are considered of prob-able or potential occurrence. The Delta National For-est had the greatest number of species, with at least27 total and 22 confirmed species. The Homochitto Na-tional Forest had the fewest number of species withat least 11 total and 8 confirmed species. Tombigbeeand Bienville National Forests had the fewest con-firmed species (3 and 1, respectively), although thetotal number of species, including probable or poten-tial occurrences was higher (at least 14 and 18 spe-cies, respectively). DeSoto and Holly Springs NationalForests were intermediate in diversity, with each hav-ing at least 20 total and 12 confirmed species.

Mississippi NF’s contain streams belonging to 7 ofthe 10 major drainages in Mississippi identified byRoss and Brenneman (1991) (table 2). The three drain-ages not represented on NF lands are the Big BlackRiver, Lake Pontchartrain, and the Tennessee River.This drainage diversity is responsible for the relativelyhigh mussel species diversity found in MississippiNF’s. There are three distinct mussel fauna1 groupsrepresented in NF streams: (1) Mississippian, (2) Pont-chartrain/Pearl/Pascagoula, and (3) Mobile Bay. Spe-cies found in Mississippi NF’s characteristic of theMississippian fauna include Actinonaias ligumentina,Fusconaia flaua, Lampsilis cardium, L. siliquoidea,

2

Obovaria subrotunda, Pleurobema pyramidatum,Potamilus ohiensis, Quadrula nodulata, Q. pustulosa,and Q. quadrula. Species of the Mississippian faunaare found in Delta, Holly Springs, and HomochittoNational Forests. Species unique to the PonchartrairYPearVPascagoula fauna are Pleurobema beadleanumand Q. refulgens; these species are found in the DeSotoNational Forest and potentially in the Bienville Na-tional Forest. Species characteristic of the Mobile Bayfauna include P. de&urn and Q. asperata; these spe-cies are potentially found in the Tombigbee NationalForest. Several species are found only in the Gulf ofMexico basin and are absent from the Mississippianbasin. These include Elliptio arctata, Ii: cerina, L.ornata, L. straminea straminea, L. s. claibornensis,0. unicolor, Strophitus subvexus, and Villosa vibex.Species of this group are found in the DeSoto NationalForest and potentially in Bienville and TombigbeeNational Forests. The remaining species show no par-ticular drainage affinities and are distributed widelyin appropriate habitats. Uniomerus tetralasmus andU. declivos are collectively referred to as Uniomerusspp. because of confusion about reidentification andthe validity of these taxa.

Precise information on distributions of mussel spe-cies is scarce for Mississippi NF’s. Even NF’s with themost available information were represented by onlyfour or five collection sites. Other NF’s had one or zerocollection sites. Most stream reaches in MississippiNF’s have not been surveyed for mussels; therefore,the fauna1 lists presented here should be consideredpreliminary and incomplete. The only population dataavailable for Mississippi NF’s are for a single site inthe Big Sunflower River in the Delta National Forest(Miller and others 1992).

INDMDUAL FOREST ACCOUNTS

Bienville National Forest

The Bienville National Forest proclamation bound-aries encompass 155,043 ha in the Jackson Prairiesand Longleaf Pine Hills physiographic regions insouth-central Mississippi. The Bienville is located intwo major drainages, the Pearl and Pascagoula Riv-ers. The northern portion of the Bienville is drainedby small tributaries of Tuscolameta Creek of the PearlRiver drainage. The southwestern portion of theBienville is drained by headwaters of the Strong Riversystem, also a Pearl River tributary. The southeast-ern portion of the Bienville is drained by headwatersof the Leaf River system within the Pascagoula Riverdrainage. Aquatic habitat within the Bienville consistsmostly of small streams with scattered small wetlandsand reservoirs.

Table 1. -Mussels of confirmed, probable, orpotential occurrence in Mississippi national forests

National forest*

B DL D S H S HO T

Actinonaias ligamentinaAmblema plicataAnodonta suborbiculataAnodontoides radiatustArcidens confragosusElliptio arctata+E. crassidensFusconaia cerinaI? ebenaF flavaGlebula rotundataLampsilis cardium+L. ornata+L. siliquoideaL. straminea straminea+L. s. claibornensisL. teresLasmigona complanataLeptodea fragilisLigumia subrostrataMegalonaias nervosaObliquaria reflexaObovaria subrotunda+0. unicolor+Plectomerus dombeyanusPleurobema beadleanumlP decisumaP pyramidatumsPotamilus ohiensisP purpuratusPyganodon grandisQuadrula apiculataQ. asperata+Q. nodulataQ. pustulosaQ. quadrulaQ. refulgens+Strophitus subvexustToxolasma parvusT texasensisDitogonia verrucosalFuncilla donaciformis!l! truncataUniomerus spp.Utterbackia imbecillisVillosa lienosaV vibex

X

X

X

XX

XX

X

X

XX

XX

X

XXXX

XXX

X

X

XXX

X

X

X

XX

X

XXXX

XXX

XXXXXX

XXXX

X

X

XXX

XXX

XX

X

X

X

XXX

XXXX

X

X

X

XX

X

X

XX

XX

XXX

XXX

X

XXX

X

X

X

X

XX

X

XXX

*National forests: B = Bienville; DL = Delta; DS = DeSoto; HS = Holly Springs; HO = Homochitto;T = Tombigbee.

tconsidered of special concern by American Fisheries Society.*Listed as endangered by the U.S. Department of the Interior Fish and Wildlife Service (USDI FWS).SCandidate for listing by USDI FWS.

There is only one mussel collection record available Records from nearby areas are also scarce, being lim-from within the proclamation boundaries of the ited to sites on the Leaf and Strong River mainstems,Bienville: downstream of the Bienville boundary (MMNS).

Roadside ditch along Interstate 20, 0.4 km west of Bienville has a possible mussel fauna of at least 18Forest community, Scott County, MS. 17 April 1972. species (table 3). Only one species is confirmed from(MMNS). within the proclamation boundaries. Twelve species

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Table 2, -Hierarchical classification of stream systems found in Mississippi national forests (stream classifica-tions from Ross and Brenneman 1991)

National forest Basin Drainage System

Holly Springs

Bienville

Delta

DeSoto

Gulf of Mexico

Mississippi River

Gulf of Mexico

Pearl

Pascagoula

Yazoo

Pascagoula

Coastal Rivers

Tuscolameta CreekStrong RiverLeaf River

Sunflower River

Red CreekBlack CreekLeaf RiverChickasawhay RiverBiloxi RiverTchoutacabouffa River

Mississippi River Yazoo

Lower Mississippi North

Tallahatchie RiverYalobusha RiverColdwater RiverHatchie RiverWolf River

Homochitto Mississippi River Lower Mississippi South Homochitto RiverBayou PierreBuffalo River

Tombigbee Gulf of Mexico Tombigbee

Pearl

Noxubee RiverTibbee CreekYockanookany River

are considered of probable occurrence based on theirpresence in other small streams in the upper Pearland Pascagoula River drainages. Five species are con-sidered of potential occurrence based on their pres-ence in larger streams in the Pearl and Pascagouladrainages downstream of the Bienville boundary.

Delta National Forest

Delta National Forest proclamation boundaries en-compass 47,885 ha in the Yazoo Delta physiographicregion in west-central Mississippi. The Delta isdrained entirely by the Sunflower River system of theYazoo drainage. Aquatic habitat consists of large riv-ers, including the mainstems of the Big SunflowerRiver and Little Sunflower River (a side channel ofthe Big Sunflower) and numerous lowland streams andbayous.

There is only one mussel collection record availablewithin the proclamation boundaries of the Delta:

Big Sunflower River, River Mile 35.2, SharkeyCounty, MS (Miller and others 1992).

There are no other collection records available for ar-eas near the Delta, but there are several records forstreams and wetlands within the Delta region of theYazoo drainage (FHL).

The Delta has a possible mussel fauna of at least 27species (table 4). Twenty-two species of mussels are

known to occur in the Big Sunflower River at the pre-viously mentioned site. Five species are considered ofpotential occurrence based on their presence elsewherein the Delta physiographic region in habitats similarto those found within the Delta. One species known tooccur in the Delta, Pleurobema pyramidatum, is con-sidered a candidate for listing under the EndangeredSpecies Act (Category 2, listed as P rubrum, USDIFWS 1994a), and is considered threatened by theAmerican Fisheries Society (Williams and others1993). The record ofActinonaias ligamentina from theBig Sunflower River is the only known occurrence ofthis species in Mississippi (Miller and others 1992).

DeSoto National Forest

The DeSoto National Forest proclamation bound-aries encompass 323,133 ha in the Longleaf Pine Hillsand Coastal Pine physiographic regions in southeast-ern Mississippi. The northern part of the DeSoto isdrained by tributaries of the Leaf and ChickasawhayRiver systems, both major tributaries of the Pasca-goula River drainage. The central part of the DeSotois drained by the Black and Red Creek systems, whichare direct tributaries of the Pascagoula River. Thesouthern part of the DeSoto is drained by smallstreams that flow directly into the Gulf of Mexico(Coastal Rivers drainage) including the Biloxi and

4

Table 3, --Mussels of confirmed, probable, or potential occurrence in the Bienville National Forest

Occurrence*

Species CF PR PO

Elliptio arctatafFusconaia cerinaLampsilis ornata?L. straminea claibornensisL. teresLeptodea fragilisLigumia subrostrataObovaria unicolortPleurobema beadleanumtPotamilus purpuratusPyganodon grandisStrophitus subvexustToxolasma parvuslFitogonia verrucosaUniomerus sp.Utterbackia imbecillisVillosa lienosaI! vibex

XXXXX

X

XXX

XXXX

X

*CF = confirmed; PR = probable; PO = potential.tconsidered of special concern by the American Fisheries Society.

Tchoutacabouffa River systems. Aquatic habitat con-sists of small and medium-sized lowland streams, ashort reach of the Leaf River mainstem, wetlands, andsmall reservoirs.

Mussel records within the proclamation boundariesof the DeSoto are available for five sites:

1 .

2 .

3 .

4 .

5 .

Leaf River from New Augusta to the mouth ofTallahala Creek, Township 3 North, Range 11West, Sections 23 and 24, Perry County, MS.19 August 1980,26 June 1985. (MMNS).Black Creek between Brooklyn and CypressCreek landings, Perry County, MS. 14 June1980,29 June 1980. (MMNS).Red Creek at Interstate 59 crossing, 19 kmnortheast of Poplarville, Township 1 South,Range 14 West, Section 5, Pearl River County,MS. 27 May 1967. (MMNS).Ashe Lake, 19 km north of Wiggins, 26 km eastof Lumberton, Township 1 North, Range 12West, Section 23, Forest County, MS. 1 July1968. (MMNS).Big Biloxi River at Interstate 49 crossing, 8 kmsouth of Saucier, 16 km north of Jet Interstate10 and Interstate 49 in Gulfport, Township 5South, Range 11 West, Section 31, HarrisonCounty, MS. 21 October 1964. (MMNS).

Records near the DeSoto but outside the proclama-tion boundary include sites on lower Red, lower Black,Tallahala, and Bogue Homa Creeks; the Leaf River;and the Little Biloxi River (MMNS and OSU>.

The DeSoto has a possible mussel fauna of at least20 species (table 5). Twelve species of mussels are re-

Table 4. -Mussels ofconfirmed orpotential occurrence in the DeltaNational Forest

Occurrence*

Species CF PO

Actinonaias ligmentina XAmblema plicata XAnodonta suborbiculata XArcidens confragosus XElliptio crassidens XFusconaia ebena Xl? flava XGlebula rotundata XLampsilis siliquoidea XL. teres XLeptodea fragilis XMegalonaias nervosa XObliquaria reflexa XPlectomerus dombeyanus XPleurobema pyramidatumt XPotamilus ohiensis XI? purpuratus XPyganodon grandis XQuadrula nodulata XQ. pustulosa XQ. quadrula XToxolasma texasensis XTritogonia verrucosa X!lYuncilla donaciformis X

T truncata X

Uniomerus sp. XUtterbackia imbecillis X

*CF = confirmed; PO = potential.tcandidate for listing by the U.S. Department of Interior Fish

and Wildlife Service.

5

corded from the five sites listed, and eight other spe- of the Holly Springs are drained by the Coldwater,cies are considered of probable occurrence in the Wolf, and Hatchie River systems, and a small area ofDeSoto based on their presence just outside the proc- the southern portion of the Holly Springs is drainedlamation boundary. No species known to occur in the by the Yalobusha River system. The largest tributar-DeSoto are listed currently as federally threatened or ies of the Tallahatchie River system within the Hollyendangered. Pleurobema beadleanum and Quadrula Springs are the Little Tallahatchie River, Cypress andrefulgens are considered species of special concern by Big Spring Creeks, and the Tippah River (includingthe American Fisheries Society (Williams and others Chewalla and Oaklimiter Creeks). Aquatic habitat1993). These species, both of which are endemic to consists primarily of three types: large river and reser-southern Mississippi and Louisiana, occur in Black voir habitat of the Little Tallahatchie River mainstem,Creek and the Leaf River and are likely to occur in small upland streams, and small lakes and reservoirs.other streams within the DeSoto. Two species of prob- Mussel survey records within the proclamationable occurrence in the DeSoto, Elliptio arctata and boundaries of the Holly Springs are available for fourObovaria unicolor, are considered species of special localities:concern (Williams and others 1993). These species 1 . Cypress Lake, 6 km south-southeast of Puskusoccur in Red and Black Creeks and the Leaf River near Lake, 18 km east of Oxford, Township 8 South,the DeSoto boundary and likely occur within the Range 1 West, Section 17, Lafayette County,DeSoto as well. MS. 15 October 1993. (FHL).

Holly Springs National Forest

The Holly Springs National Forest proclamationboundaries encompass 210,581 ha in the North Cen-tral Hills physiographic region in northern Mississippi.Most of the Holly Springs is drained by tributaries ofthe Tallahatchie River system although northern parts

2. Puskus Lake, 3 km southeast of Cambridge,18 km northeast of Oxford, Township 7 South,Range 1 West, Section 30, Lafayette County,MS. 28 July 1993. (FHL).

3. Chewalla Creek downstream of Chewalla Lakedam, 5 km southwest of Lake Center, 12 kmsoutheast of Holly Springs. Township 4 South,Range 1 West, Section 19. Marshall County,MS. 14 July 1993. (FHL).

Table 5. -Mussels of confirmed or probable occurrence in the DeSoto National Forest

Occurrence*

C F P R

Site

Species 1 2 3 4 5

Elliptio arctutu+E. crassidensFusconaia cerinaF ebenaGlebula rotundataLampsilis ornata+L. straminea claibornensisL. teresLasmigona complanataObovaria unicolor+Plectomerus dombeyanusPleurobema beadleanum+Pyganodon grandisQuadrula apicu la taQ. refulgens+Toxolasma parvusfiitogonia verrucosaUtterbackia imbecillisVillosa lienosaV vibex

XX

XX

X

XXX

XX

X

XXX

XX X

X XX X

*CF = confirmed; PR = probable.tconsidered of special concern by the American Fisheries Society.

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4. Cypress Creek at Hwy 30 crossing, 15 kmnorth-northwest of Lafayette Springs, 23 kmeast-northeast of Oxford, Township 7 South,Range 1 West, Section 27, Lafayette County,MS. 25 May 1993,23 August 1993,5 April 1994.(FHL).

Records from areas near the Holly Springs but out-side the proclamation boundary include sites on themainstem Little Tallahatchie River downstream of theHolly Springs (FHL, MMNS) and small tributaries ofthe Tallahatchie (FHL) and Yalobusha (MMNS) sys-tems. There are no collection records for any tributar-ies of the Wolf, Hatchie, or Coldwater Rivers withinor near the Holly Springs boundary.

The Holly Springs has a possible mussel fauna of atleast 21 species (table 6). Twelve species of musselsare known from the four sites listed, and nine otherspecies are considered of probable occurrence in theHolly Springs based on: (1) their presence in the LittleTallahatchie River just downstream of the HollySprings boundary or (2) their presence in small tribu-taries outside the Holly Springs but within theTallahatchie River system. No species known to occurin the Holly Springs are listed currently as federallythreatened or endangered. Lamp&s cardium, knownto occur in Chewalla Creek, is considered a species of

special concern by the American Fisheries Society(Williams and others 1993). One species of probableoccurrence in the Holly Springs, Anodontoides rad-iatus, is considered a species of special concern (Will-iams and others 1993). This species occurs in a smallTallahatchie tributary near the Holly Springs bound-ary, and the presence of similar habitat within theHolly Springs suggests that it likely occurs there aswell.

Homochitto National Forest

Homochitto National Forest proclamation bound-aries encompass 151,266 ha in the Loess Hills andLongleaf Pine Hills physiographic regions in south-western Mississippi. Most of the Homochitto is drainedby the Homochitto River system, although small ar-eas in the northern and southern portion of theHomochitto are drained by the Bayou Pierre and Buf-falo River systems, respectively.

Mussel records within the proclamation boundariesof the Homochitto are available for five sites:

1. Homochitto River at Forest Service Road 109crossing, 10 km southeast of Union Church, 18km northeast of Bude, Township 7 North,

Table 6. -Mussels of confrmed or probable occurrence in the Holly Springs National Forest

Occurrence*

CF PR

Site

1 2 3 4

Amblema plicataAnodontasuborbiculataAnodontoides radiatustArcidens confragosusLampsilis cardiumtL. siliquoideaL. teresLeptodea fragilisLigumia subrostrataObliquaria reflexaPlectomerus dombeyanusPotamilus purpuratusPyganodon grandisQuadrula pustulosaQ. quadrulalbxolasma parvusl! texasensisfiitogonia verrucosaUniomerus sp.Utterbackia imbecillisVillosa lienosa

XXXX

XX X

XX

X

X

XX

XX X

X

X

X XX X

X

XX

XX

X

*CF=confirmed; PR=probable.tconsidered of special concern by the American Fisheries Society.

7

Range 5 East, Section 8, Franklin County, MS.7 May 1982. (Hartfield and Ebert 1986,MMNS).

2. Homochitto River at State Route 550 crossing,7 km east of Union Church, Township 8 North,Range 5 East, Section 16, Lincoln County, MS.5 April 1972,12 May 1982. (Hartfield and Ebert1986, MMNS).

3. Homochitto River at Forest Service Road 128crossing, 5 km southeast of Pleasant Hill, 10km northeast of Union Church, Township 9North, Range 5 East, Section 34, CopiahCounty, MS. 1982. (Hartfield and Ebert 1986,MMNS).

4. Clear Springs Creek below Clear Springs Lakedam, 11 km southwest of Meadville, 12 kmsoutheast of Roxie. Township 5 North, Range2 East, Section 2, Franklin County, MS. 19-20May 1982. (Hartfield and Ebert 1986, MMNS,OSU).

5. Clear Springs Lake, 11 km southwest ofMeadville, 12 km southeast of Roxie, Township5 North, Range 2 East, Section 2, FranklinCounty, MS.l

One other collection record is available from McCallsCreek, a Homochitto River tributary, approximately3 km upstream from the Homochitto boundary(MMNS).

The Homochitto has a possible mussel fauna of atleast 11 species (table 7). Eight species of mussels areknown to occur in the Homochitto, and an additionalthree species are considered of probable occurrencebased on their presence in McCalls Creek, a tributaryof the Homochitto River that flows through theHomochitto. One species of probable occurrence,Obovaria subrotunda, is considered a species of spe-cial concern by the American Fisheries Society (Will-iams and others 1993).

Tombigbee National Forest

Tombigbee National Forest proclamation boundariesencompass 48,258 ha in the Flatwoods, Pontotoc Hills,and Black Prairies physiographic regions in centraland northeastern Mississippi. Most of the Tombigbeeis drained by tributaries of the Tombigbee River sys-tem, although a small area in the southwestern por-tion of the Tombigbee is drained by headwatertributaries of the Yockanookany River (Pearl Riverdrainage). Most Tombigbee tributaries within theTombigbee are part of the Noxubee River or TibbeeCreek systems. Aquatic habitat in the Tombigbee con-sists of small streams and small reservoirs.

1 Hartfield, Paul. 1995. USDI FWS, Jackson, Mississippi, per-sonal communication with the authors.

8

Mussel survey records within the proclamationboundaries of the Tombigbee are available for one site:

Davis Lake, 18 km west-northwest of Okolona,18 km north-northeast of Houston, Township 11South, Range 3 East, Sections 12-14, ChickasawCounty, MS2

Records for areas near the Tombigbee but outsidethe proclamation boundaries include one site each onChuguatonchee and Houlka Creeks in the Tibbee Creeksystem (MMNS). These streams drain portions of theTombigbee, and the available sites are both less than3 km downstream of the Tombigbee boundary. Thereare also records available for Chewawah Creek (TibbeeCreek system) in Chickasaw County (MMNS). In ad-dition, there are numerous records available for othersections of the Tibbee Creek and Noxubee River sys-tems (MMNS, OSU).

The Tombigbee has a possible mussel fauna of atleast 15 species (table 8). Three species are confirmedfrom the Tombigbee and nine species are consideredof probable occurrence based on their occurrence innearby small streams of the Tibbee Creek and NoxubeeRiver systems. Three species are considered of poten-tial occurrence based on their presence in largerstreams downstream from the Tombigbee. Three spe-cies of probable occurrence in the Tombigbee, Lamp-silis straminea straminea, L. ornata, and Strophitussubvexus, are considered species of special concern bythe American Fisheries Society (Williams and others1993). Pleurobema decisum, a federally endangeredspecies (USDI FWS 1994b), is known to occur in smallstreams elsewhere in the Tombigbee drainage (van derSchalie 1981, Williams and others 1992) and is con-sidered of potential occurrence in the Tombigbee.

CONCLUSIONS AND RECOMMENDATIONS

Current knowledge of distributions of mussel spe-cies and locations of important mussel communitiesin Mississippi NF’s is inadequate to support informedmanagement decisions. Very little mussel survey dataexist, but the available information revealed that Mis-sissippi NF’s harbor a diverse freshwater mussel faunaof at least 33 species but possibly including 46 or morespecies. Considerable variation in mussel communitycomposition exists among NF’s because of the diver-sity of physiography and river drainages in which theNF’s lie and the resulting diversity of aquatic habi-tats. Three distinct fauna1 groups are present in theNF’s. These are characterized by species endemic tothe: (1) Mississippi River basin; (2) Lake Pont-

’ McDougal, L.A. 1995. Forest Service, Blacksburg, Virginia, per-sonal communication with the authors.

Table 7.-Mussels of confirmed orprobable occurrence in the Homochitto National Forest

Occurrence*

C F P R

Site

Species 1 2 3 4 5

Amblema plicata XElliptio crassidens XFusconaia ebena XI? flava XLampsilis siliquiodea X XObovaria subrotundat XPyganodon grandis XToxolasma texasensis X X XUniomerus sp. XUtterbackia imbecillis XVillosa lienosa X X X X

*CF = confirmed; PR = probable.+Considered of special concern by the American Fisheries Society.

chartrain, Pearl River, and Pascagoula River drain-ages; and (3) Mobile Bay drainages. Another group ofspecies was widely distributed and showed no drain-age affinities. Because of the paucity of survey dataon NF lands, the distribution of many species withinMississippi NF’s was necessarily inferred from sur-veys near the NF’s.

A systematic, three-phase approach is needed to ef-ficiently and accurately assess mussel resources inMississippi NF streams. This study represents the firstphase in which a review of existing information is com-piled. The second phase involves an exhaustive, quali-tative field survey to document current distributionsof species and the location of important communities.The third phase consists of establishing selected siteswithin the drainage(s) for intensive quantitative de-scriptions of ecological characteristics and monitor-ing of population trends. National forests should beprioritized for inventory according to potential diver-sity and conservation status of species occurring orpotentially occurring in each NF. Using this rationale,we recommend that the DeSoto National Forest be in-ventoried first due to its high number of potential spe-cies (20) and species with special conservation status(5). The Delta National Forest should be surveyed nextdue to its high number of potential species (27). Theremaining NF’s should be surveyed in the followingorder: Bienville, Tombigbee, Holly Springs, andHomochitto.

Currently, there are no mussels present on the For-est Service Southern Region (R-8) Sensitive Specieslist for NF’s in Mississippi. However, 11 species of con-firmed or probable occurrence in Mississippi NF’s areconsidered species of special concern by the American

Table 8. -Mussels of confirmed, probable, or potential occurrencein the Tombigbee National Forest

Occurrence*

Species C F P R PO

Fusconaia cerina XLamps& ornata+ XL. straminea straminea+ XL. s. claibornensis XL. teres XLigumia subrostrata XPleurobema decisumt XPyganodon grandis XQuadrula asperata+ XStrophitus subvexust XToxolasma parvus X59itogonia verrucosa XUniomerus sp. XUtterbackia imbecillis XVillosa lienosa X

*CF = confirmed; PR = probable; PO = potential.tconsidered of special concern by the American Fisheries Society*Listed as endangered by the U.S. Department of the Interior FWS.

Fisheries Society (Williams and others 1993), 1 spe-cies of confirmed occurrence is a candidate for listingunder the Endangered Species Act, and 1 species ofpotential occurrence is listed as endangered by USDIFWS. In total, there are potentially at least 13 spe-cies with special conservation status in MississippiNF’ s, suggesting that more distributional and popu-lation data are urgently needed to assess the sensi-tive status of these and other mussel species in NFstreams.

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ACKNOWLEDGMENTS

We thank the following individuals and their respec-tive institutions and agencies for their assistance withthis project: Robert Jones and Libby Hartfield, Mis-sissippi Museum of Natural Science; Paul Hartfield,USDI FWS; Kathy Borror and David Stansbery, theOhio State University Museum of Biological Diversity;Rick Dillard and Leigh Ann McDougal, Forest Service;James Williams, USDI National Biological Survey.

LITERATURE CITED

Hartfield, P.; Ebert, D. 1986. The mussels of south-west Mississippi streams. American MalacologicalBulletin. 4: 21-23.

Miller, A.C.; Payne, B.S.; Hartfield, P.D. 1992. Char-acterization of a freshwater mussel (Unionidae) com-munity in the Big Sunflower River, Sharkey County,Mississippi. Journal of the Mississippi Academy ofSciences. 37: 8-11.

Ross, S.T, Brenneman, W.M. 1991. Distribution offreshwater fishes in Mississippi. Freshwater Fish-

eries Report No. 108. Jackson, MS: Mississippi De-partment of Wildlife, Fisheries, and Parks. 548 p.

Stephenson, L.W.; Monroe, W.H. 1940. The upper Cre-taceous deposits. Mississippi State Geological Sur-vey Bulletin 40. 296 p.

U.S. Department of the Interior (USDI) FWS. 1994a.Endangered and threatened wildlife and plants;animal candidate review for listing as endangeredor threatened species. Federal Register. 56:58804-58836.

U.S. Department of the Interior (USDI) FWS. 199413.Endangered and threatened wildlife and plants, 50CFR 17.11 & 17.12. Washington, DC: Division ofEndangered Species, USDI FWS.

van der Schalie, H. 1981. Mollusks of the Alabama Riverdrainage, past and present. Sterkiana. 71: 24-41

Williams, J.D.; Fuller, S.L.H.; Grace, R. 1992. Effectsof impoundment on freshwater mussels in the mainchannel of the Black Warrior and Tombigbee Riversin western Alabama. Bulletin of the Alabama Mu-seum of Natural History. 13: l-10.

Williams, J.D.; Warren, M.L. Jr.; Cummings, K.S.;Harris, J.L.; Neves, R.J. 1993. Conservation statusof freshwater mussels of the United States andCanada. Fisheries. 18: 6-22.

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Haag, Wendell R.; Warren, Melvin L., Jr. 1995. Current distributionalinformation on freshwater mussels (family Unionidae) in Mississippinational forests. Gen. Tech. Rep. SO-119. New Orleans, LA: U.S. De-partment of Agriculture, Forest Service, Southern Forest ExperimentStation. 10 p.

A review of freshwater mussel distribution data showed that Missis-sippi national forests harbor a diverse fauna of potentially 46 or morespecies. Occurrence of 33 species is confirmed. Three distinct fauna1groups are represented, each with a characteristic assemblage of spe-cies. A three-phase program for evaluation of the resou.rce is outlined.

Keywords: Field survey, sensitive species.

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