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A Survey of Freshwater Mussels (Unionidae) in Little River, Blount County, Tennessee
Daniel E. Schilling, Andrew T. Phipps, Jess W. Jones, and Eric M. Hallerman

Southeastern Naturalist, Volume 16, Issue 1 (2017): 105–116

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Southeastern Naturalist 105 D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 22001177 SOUTHEASTERN NATURALIST 1V6o(1l.) :1160,5 N–1o1. 61 A Survey of Freshwater Mussels (Unionidae) in Little River, Blount County, Tennessee Daniel E. Schilling*,1, Andrew T. Phipps1, Jess W. Jones1,2, and Eric M. Hallerman1 Abstract - Following the collection of a putative undescribed species in the genus Pleurobema in 2012, we surveyed the freshwater mussel fauna of Little River, Blount County, TN, to determine species diversity and relative abundances. At 18 main-stem sites, we sampled 3053 live specimens representing 12 mussel species and 1 fresh-dead individual representing another. An additional species represented by a relic shell was collected, bringing the total to 14 mussel species sampled during this survey. Villosa species comprised 77% of total live mussels sampled. Among the extant mussels were two federally endangered species: Fusconaia cuneolus (Finerayed Pigtoe) was confirmed to persist in the river, while Pleuronaia dolabelloides (Slabside Pearlymussel) represents a new drainage record. Several other mussels collected are considered imperiled globally, including Alasmidonta viridis (Slippershell Mussel), Lampsilis ovata (Pocketbook), Medionidus conradicus (Cumberland Moccasinshell), Pleurobema oviforme (Tennessee Clubshell), Pleuronaia barnesiana (Tennessee Pigtoe), and Villosa vanuxemensis (Mountain Creekshell). A total of 319 individuals of the putative new species Pleurobema sp. cf. oviforme were sampled at 9 sites, 215 at 1 site. A total of 857 individuals of a putative undescribed species in the genus Villosa were sampled at 9 sites. These 2 putative species (Pleurobema sp. cf. oviforme and Villosa sp. cf. iris) are likely endemic to Little River, TN, and may be in need of state and federal protection. Mussel densities declined downstream from the mouth of Ellejoy Creek, indicating that water-quality issues may be occurring in this reach of the river. Introduction North America has the highest diversity of freshwater mussels in the world, with 302 recognized species (Haag 2012). However, the number of recognized mussel species is increasing with the description of new taxa based primarily on the application of more intensive morphological and molecular genetic assessments (Haag and Williams 2014). Such assessments, especially molecular genetics, have revealed previously unrecognized cryptic species (Bickford et al. 2007). Because freshwater taxa extinction rates are 5 times greater than those of terrestrial taxa (Ricciardi and Rasmussen 1999), it is likely that many unrecognized freshwater taxa have already gone extinct. The Tennessee River system contains the most diverse mussel fauna in North America, with a total of 102 mussels recorded as native and 15 as endemic (Parmalee and Bogan 1998). The upper Tennessee River system above Walden’s Gorge 1Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0321. 2US Fish and Wildlife Service, Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0321. *Corresponding author: Daniel Schilling - dschilli@vt.edu. Manuscript Editor: Arthur Bogan Southeastern Naturalist D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 106 historically contained 82 species (Parmalee and Bogan 1998). Little River is located in east Tennessee and flows into the Tennessee River at approximately river kilometer (rkm) 1022.7 (river mile 635.5). Only 2 previous studies documented the mussel fauna of the Little River drainage (Table 1). Ortmann (1918) reported on collections from 4 sites in Little River and 1 site in a tributary, Pistol Creek, documenting 12 species in the mainstem and 5 species from Pistol Creek, for a total of 14 species. However, visual inspection of specimen photographs by D. Schilling in 2016 provided by the Carnegie Museum of Natural History revealed that Ortmann likely also collected the 2 additional putative species sampled and reported in this study, which could bring the total known historically from the drainage to 16 species. The Tennessee Valley Authority (TVA) sampled mussels from 2 mainstem sites in 1981 and recorded 7 species in their unpublished report (Hickman and Harned 1981). Because the mussel fauna of the river is not well known, contains species that are now federally listed, and contains putative undescribed species in the genera Pleurobema and Villosa (Schilling et al. 2015), a systematic survey of the river’s mussel fauna was undertaken to document mussel diversity and abundance in the river. Table 1. Freshwater mussels of the Little River, Blount County, TN, recorded by Ortmann (1918)A at 4 sites sampled in the early 1900s and by Hickman and Harned (1981) at 2 sites sampled in 1981, and by the current study at 18 sites sampled in the river mainstem. * indicates federally endangered species; + indicates collections made during previous surveys in Little River at sites now inundated by Fort Loudoun Reservoir. This Scientific name Common name Authority 1918 1981 study Actinonaias pectorosa Pheasantshell (Lamark) X Alasmidonta viridis Slippershell Mussel (Rafinesque) X FD Amblema plicata+ Threeridge+ (Say) X Cumberlandia monodonta*+ Spectaclecase*+ (Say) X Elliptio dilatata Spike (Rafinesque) X X Epioblasma triquetra*+ Snuffbox*+ (Rafinesque) X Fusconaia cuneolus* Finerayed Pigtoe* (Lea) X X Lampsilis fasciola Wavyrayed Lampmussel Rafinesque X X X Lampsilis ovata Pocketbook (Say) X X X Lasmigona costata Flutedshell (Rafinesque) R Medionidus conradicus Cumberland Moccasinshell (Lea) X X Pleurobema oviforme Tennessee Clubshell (Conrad) X X Pleurobema sp. cf. oviforme X X Pleuronaia barnesiana Tennessee Pigtoe (Lea) X X X Pleuronaia dolabelloides* Slabside Pearlymussel* (Lea) X Villosa iris Rainbow (Lea) X X X Villosa sp. cf. iris X X Villosa vanuxemensis Mountain Creekshell (Lea) X X X Total 14 7 14 A Visual inspection of specimen photographs provided by Carnegie Museum of Natural History revealed that Ortmann likely collected Pleurobema sp. cf. oviforme and Villosa sp. cf. iris in addition to P. oviforme and V. iris. Ortmann (1918) also reported Fusconaia cuneolus and Toxolasma lividum Rafinesque (Purple Lilliput) from Pistol Creek, a tributary to Little River that confluences at rkm 8.2. Southeastern Naturalist 107 D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 Field-Site Description The study area for this project was the Little River mainstem located in Blount County, TN (Fig. 1). The Little River originates in Great Smoky Mountains National Park (GSMNP) and flows northwest for ~95 rkm until its confluence with Tennessee River. The Little River drains ~982 km2, of which ~65% is forested, 20% agricultural, 10% residential, 4% commercial, and 1% water or wetlands (TVA 2003). The Little River watershed is within 2 physiographic provinces: the Blue Ridge occupying 649 km2 or ~66% of the upper watershed, and the Ridge and Valley occupying 333 km2 or ~34% of the lower watershed. Transition between these 2 provinces occurs at approximately rkm 29.9. The headwaters of the Little River are protected by GSMNP until rkm 56.0, contributing to excellent water quality in its headwaters. The Little River has 3 intact low-head dams at rkm 54.1, 35.2, and 10.5, respectively. Immediately downstream of the third intact low-head dam, the course of the Little River is inundated by the Fort Loudoun impoundment for 10.5 km before reaching the Tennessee River. Methods We qualitatively sampled live mussels during 2013 and 2014 at 18 sites in the Little River mainstem based on ability to survey without scuba equipment and each site having a minimum of a riffle, run, and pool (Fig. 1, Table 2). No tributaries Figure 1. Sampling localities for mussels in the Little River, Blount County, TN, from 2013 through 2014. River km are shown for each site. Southeastern Naturalist D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 108 were surveyed during this study because most are listed as water-quality impaired by the Tennessee Department of Environment and Conservation (TDEC 2014a). Sample sites were distributed across 41.5 rkm of the mainstem, with sites 1.4 to 3.9 kms apart. The upper 13 sites were located in the Blue Ridge Physiographic Province, while the lower 5 sites were located in the Valley and Ridge Physiographic Province. Each site was 200 m in length irrespective of stream width, and we used a Nikon rangefinder to measure boundary extents of each site. Experienced surveyors began at the downstream survey boundary, snorkeling or slowly walking side-to-side (where too shallow to snorkel) in an upstream direction. We sampled all surface-visible mussels and flipped some larger rocks to search underneath. We recorded search time to estimate catch-per-unit-effort (CPUE). Mussels were identified to species, enumerated, and measured to the nearest millimeter (mm) using calipers; gender was recorded for sexually dimorphic species. We did not count fresh dead shells except for Alasmidonta viridis (Slippershell Mussel), which was represented by a single fresh dead specimen during our study and included in the live mussels totals. We retained select mussels for genetic analyses and returned all others to the substrate. Fresh dead and relic shells were placed in bags labeled with site and date and deposited at the Parmalee Malacological Collection located in McClung Museum at the University of Tennessee. Results An average of 10.5 person hours (h) was spent at each site, for a total of 189.5 h for the entire survey of Little River (Table 3). During the survey, 3053 individuals were found, representing 12 live species and 1 species obtained only as fresh-dead Table 2. Locality information of sites sampled for mussels during this study in the Little River, Blount County, TN, from 2013 through 2014. Site name River mile River km Latitude Longitude Lazy Daze Campground 34.2 55.0 35.67839 -83.71786 Wears Valley Road 33.3 53.6 35.68036 -83.73205 Webb Road 31.8 51.2 35.67807 -83.75499 Handicap Access 30.0 48.3 35.68006 -83.78287 Kinzel Springs 29.2 47.0 35.68473 -83.79350 Capshaw Branch 28.1 45.2 35.69740 -83.79805 Picnic Stop 26.5 42.6 35.70272 -83.81465 Foothills Parkway 25.0 40.2 35.71812 -83.81609 Walland 24.2 38.9 35.72551 -83.81806 Mystic Campground 22.9 36.9 35.73893 -83.82698 Below Melrose Dam 21.9 35.2 35.74978 -83.83699 Coulters Bridge 20.6 33.2 35.76372 -83.85268 Davis Ford 19.4 31.2 35.77712 -83.85373 US Route 411 17.2 27.7 35.78721 -83.88261 Above River Jons 14.8 23.8 35.79638 -83.88695 Brakebill Island 12.4 20.0 35.81029 -83.89973 Singleton Bend 10.4 16.7 35.81584 -83.92414 TN State Route 33 8.4 13.5 35.81964 -83.93701 Southeastern Naturalist 109 D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 Table 3. Species and counts of live mussels sampled at sites in the Little River, Blount County, TN, from 2013 through 2014. * indicates federally endangered species. + indicates survey in same locale as TVA survey; ‡ indicates sites in which Villosa sp. cf. iris was present, but we recognized it as V. iris at the time of collection; FD = single fresh dead specimen. River River Person Total Total Site name mile km hours number species Lazy Daze Campground 34.2 55.0 6.0 0 0 Wears Valley Road 33.3 53.6 6.0 10 10 1 Webb Road 31.8 51.2 12.0 49 3 6 358 416 4 Handicap Access ‡ 30.0 48.3 12.0 3 5 215 68 127 418 5 Kinzel Springs 29.2 47.0 15.0 FD 5 3 30 57 7 81 184 7 Capshaw Branch 28.1 45.2 11.5 7 13 21 56 202 299 5 Picnic Stop ‡ 26.5 42.6 7.0 3 55 35 93 3 Foothills Parkway 25.0 40.2 13.0 4 2 4 2 73 425 98 608 7 Walland 24.2 38.9 10.0 6 4 2 4 37 131 41 225 7 Mystic Campground 22.9 36.9 10.5 4 2 2 103 215 23 349 6 Below Melrose Dam 21.9 35.2 8.0 2 4 15 1 22 4 Coulters Bridge ‡ 20.6 33.2 12.0 14 30 1 3 58 70 1 177 7 Davis Ford 19.4 31.2 9.0 8 3 1 3 6 1 22 6 US Route 411 17.2 27.7 10.0 13 2 3 7 13 1 1 40 7 Above River Jons 14.8 23.8 11.0 5 7 5 6 34 4 4 1 66 8 Brakebill Island 12.4 20.0 15.5 1 1 10 1 13 3 29 6 Singleton Bend+ 10.4 16.7 11.0 1 7 14 1 2 11 3 1 40 8 TN State Route 33 8.4 13.5 10.0 11 6 1 2 32 2 1 55 7 Totals 189.5 1 7 19 106 9 53 11 319 164 4 522 857 981 3053 13 Alasmidonta viridis Elliptio dilatata Fusconaia cuneolus Lampsilis fasciola Lampsilis ovata Medionidus conradicus Pleurobema oviforme P. sp. cf. oviforme Pleuronaia barnesiana Pleuronaia dolabelloides Villosa iris V. sp. cf. iris Villosa vanuxemensis Southeastern Naturalist D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 110 (Table 3). The CPUE per site ranged from 0 to 46.8 mussels/h and averaged 16.1 mussels/h. The most abundant species sampled during the survey, in order of relative abundance, were: Villosa vanuxemensis (Mountain Creekshell; 32.1%), Villosa sp. cf. iris (28.1%), Villosa iris (Rainbow; 17.1%), and Pleurobema sp. cf. oviforme (10.5%). The remaining 8 species sampled live represented a combined 12.2% of total relative abundance. Lasmigona costata (Flutedshell) was added to the fauna from a relic shell, raising the total number of species sampled to 14. Two of these species are listed as federally endangered, Fusconaia cuneolus (Finerayed Pigtoe) and Pleuronaia dolabelloides (Slabside Pearlymussel), with the latter being a new record for the Little River. Villosa sp. cf. iris was not recognized as distinct from V. iris during the surveys at 3 sites (rkms 48.3, 42.6, and 33.2), but visual inspection of photographs for sampled specimens suggests it was present at these sites; thus, abundances of each of these 2 species at these 3 sites are unknown. Based on field-level observations of morphological differences, we performed molecular genetic analyses and concluded that there is a putative taxon separate from V. iris in the Little River (Schilling et al. 2015). Lasmigona costata was collected at rkm 23.8 during preliminary reconnaissance to locate suitable sampling localities; this individual was not included in results for the survey, as it was obtained without CPUE estimates, but is listed as collected during the year of the surveys in Table 1. A total of 319 individuals of Pleurobema sp. cf. oviforme were sampled at 9 sites; 215 individuals were sampled at 1 site, rkm 48.3. Shell lengths of live individuals ranged from 17 mm to 100 mm and averaged 60.6 mm (Table 4); however, an individual was collected for additional analyses outside of the survey that had a length of 104 mm. Minimum length of P. sp. cf. oviforme typically increased at collection sites downstream from the Townsend, TN, area. Discussion Mussel sampling Historically, 14 mussel species have been recorded in the Little River drainage. Excluding the relic shell and the putative new species, we sampled 11 of those 14 mussel species. Mussels were patchily distributed at sites in Little River, with the highest mussel abundances being found in areas of the stream with stable substrate, including stream edges and areas adjacent to islands containing Justicia spp. (water willow). Mussels were occasionally located away from these areas, but in most instances they typically were found between or under large rocks with interstitial spaces. Any future studies aimed at determining quantitative abundances using techniques such as quadrat sampling should be aware of the patchy mussel distribution in this river. Four federally endangered mussel species are now known from Little River, including Cumberlandia monodonta (Spectaclecase), Epioblasma triquetra (Snuffbox), Fusconaia cuneolus, and Pleuronaia dolabelloides. Pleuronaia dolabelloides had not been documented in Little River until our survey. While the minimum size sampled was 62 mm, 2 of the 4 individuals sampled during this survey were gravid, suggesting that reproduction and possibly recruitment may be occurring. This Southeastern Naturalist 111 D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 Table 4. Mean length and range of lengths (mm) of each mussel species by site sampled in the Little River, Blount County, TN, from 2013 to 2014. - indicates none or too few specimens to analyze; FD = fresh dead specimen only. River km 55.0 53.6 51.2 48.3 46.8 45.2 42.6 41.0 38.9 Alasmidonta viridis - - - - FD - - - - - - - - - - - - - Fusconaia cuneolus - - - - - - - - - - - - - - - - - - Elliptio dilatata - - - - - - - - - - - - - - - - - - Lampsilis fasciola - - - 59 50 63 59 55 54 - - - (45–69) (26–71) (41–80) (53–65) (37–64) (29–78) Lampsilis ovata - - - - - - - - - - - - - - - - - - Medionidus conradicus - - - 40 48 - - 53 43 - - - (35–56) (38–53) - - (48–57) (36–46) Pleurobema oviforme - - - - - - - - - - - - - - - - - - Pleurobema sp. cf. oviforme - - 47 65 53 56 - 49 64 - - (21–88) (29–100) (17–77) (32–85) - (39–57) (63–64) Pleuronaia barnesiana - - - - - - - 53 57 - - - - - - - (44–62) (46–68) Pleuronaia dolabelloides - - - - - - - - - - - - - - - - - - Villosa iris - - 42 40 40 46 38 39 46 - - (30–53) (20–60) (15–73) (30–63) (15–52) (15–58) (22–63) Villosa sp. cf. iris - - 39 - 42 41 - 38 37 - - (30–56) - (34–48) (21–57) - (11–57) (12–56) Southeastern Naturalist D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 112 Table 4, continued. River km 55.0 53.6 51.2 48.3 46.8 45.2 42.6 41.0 38.9 Villosa vanuxemensis - 39 35 40 38 39 39 38 39 - (33–54) (10–55) (14–55) (14–56) (15–58) (20–49) (11–58) (24–55) Alasmidonta viridis - - - - - - - - - - - - - - - - - - Fusconaia cuneolus - - - - - - 34 54 48 - - - - - - - (37–72) (24–70) Elliptio dilatata - - - - - 73 57 76 - - - - - - (34–119) - - - Lampsilis fasciola 56 56 59 54 54 64 50 56 49 (39–72) (44–67) (32–88) (29–78) (36–68) (51–72) (30–60) (31–74) (38–67) Lampsilis ovata - - - - 109 104 - 78 97 - - - - (105-113) (39-124) - - - Medionidus conradicus 37 - 40 43 44 - 43 - - (28–45) - (18–53) (40–48) (41–46) - - - - Pleurobema oviforme - - 66 - - 62 - 42 41 - - - - - (42–78) - (36–48) (34–48) Pleurobema sp. cf. oviforme 62 - 72 68 - - - - - (57–66) - (66–80) - - - - - - Pleuronaia barnesiana - - 59 52 53 47 37 45 38 - - (24–87) (48–54) (36–73) (23–79) (18–55) (25–60) (19–58) Pleuronaia dolabelloides - - - - - 75 - - - - - - - - (62–86) - - - Villosa iris 40 39 48 42 50 45 39 50 38 (19–59) (31–46) (20–66) (25–55) (31–63) (43–48) (23–63) (44–57) (28–48) Villosa sp. cf. iris 34 32 - 38 52 - - - - (12–53) (20–46) - - - - - - - Villosa vanuxemensis 34 31 39 - 48 67 - 39 37 (15–52) - - - - - - - - Southeastern Naturalist 113 D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 observation adds a new river of occurrence for the species, which could assist recovery efforts aimed to downlist or delist the species. This species may also occur in lower reaches of the Little River that were not included in this survey. Fusconaia cuneolus previously has been documented in the Little River by TVA (Hickman and Harned 1981), but due to lack of sampling in Little River over the last few decades, its range and occurrence in the river was unknown; their study documented 1 individual F. cuneolus at rkm 15.4. During our survey, 19 individuals of this species were sampled at 3 sites from rkm 20.0 to 13.5. Shell lengths ranged from 24 mm to 72 mm and averaged 49.2 mm, which indicates multiple year-classes and recent recruitment. We did not find Cumberlandia monodonta or Epioblasma triquetra during the survey of the Little River. Both species were recorded over a century ago by Ortmann (1918) only from the lower-most portions of the Little River in Knox County that are now inundated. It is possible that C. monodonta persists in unsampled lower reaches of the river if appropriate habitat occurs (large slab boulders or bedrock shelves); however, E.triquetra is likely extirpated from Little River. In addition to the 2 federally listed mussels, several other extant species from Little River are considered imperiled globally (Williams et al. 2008). These species include Alasmidonta viridis, Lampsilis ovata (Pocketbook), Medionidus conradicus (Cumberland Moccasinshell), Pleurobema oviforme (Tennessee Clubshell), Pleuronaia barnesiana (Tennessee Pigtoe), and Villosa vanuxemensis. Thus, about 70% of the currently recognized mussel species extant in Little River are imperiled; this proportion excludes the 2 putative new species. Two of the 3 sites contained individuals that were field-identified by 3 biologists as Fusconaia cor (Conrad) (Shiny Pigtoe), but molecular genetic analyses using the mitochondrial gene ND1 and the nuclear gene ITS1 determined that all individuals were F. cuneolus (Schilling 2015). Misidentification of multiple individuals of F. cuneolus as F. cor suggests that either contemporary morphological identification characters are inadequate, or perhaps that introgression and/or hybridization has occurred between these 2 species and was not detected at the molecular markers used. Ortmann (1918) reported Actinonaias pectorosa (Pheasantshell) from the Little River. This imperiled species is known only from this single record of 1 specimen. Steve Ahlstedt, retired United States Geological Survey malacologist, examined the specimen and noted that it resembles Lampsilis fasciola (Wavyrayed Lampmussel) and therefore, it could be misidentified (S. Ahlstedt, Knoxville, TN, 13 December 2015 pers. comm.). The highest densities of Pleurobema sp. cf. oviforme occurred upstream of Chilhowie Mountain toward the lower-gradient section of the river near Townsend, TN. Live individuals were sampled at sites in a 20-rkm reach from rkm 51.2 to rkm 31.2. Populations of P. sp. cf. oviforme and Pleurobema oviforme overlapped for only 2.0 km, with P. sp. cf. oviforme occurring in the upper portions, and P. oviforme occurring in the lower portions. Failure to obtain individuals of P. sp. cf. oviforme at sites sampled outside of Little River drainage coupled with no mention of this species outside of the drainage in the historical literature indicates that P. sp. cf. oviforme may be endemic to Little River. Schilling (2015) recorded the maximum Southeastern Naturalist D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 114 size of P. sp. cf. oviforme as 104 mm, while he recorded the largest size of P. oviforme as 94 mm from North Fork Holston River, Smyth County, VA, indicating that maximum size differences between the 2 species may exist. The Villosa sp. cf. iris were sampled in a 23.5-rkm reach from rkm 51.2 to rkm 27.7, with several smaller-sized individuals less than 30 mm observed (Table 4), indicating recent recruitment of this putative species. This species closely resembles V. iris and therefore was not recognized in past surveys in the drainage. The maximum size of V. iris sampled during the survey was 73 mm, while the maximum size of V. sp. cf. iris was 57 mm. While V. iris occurred broadly throughout our survey sites, the largest densities of V. sp. cf. iris occurred from rkm 25.5 to rkm 22.9. Future surveys to document species’ ranges outside of Little River should be cognizant of cryptic species such as P. sp. cf. oviforme and V. sp. cf. iris. Little River water quality Generally, mussel densities declined downstream from the confluence of Ellejoy Creek just upstream of Davis Ford (rkm 31.2). Areas upstream of this confluence contained more mussels based on higher CPUE metrics; fine sediment in the substrate also appeared to be lower upstream of the creek’s confluence with Little River. Little River watershed quality is of concern; pristine waters originating from the GSMNP are degraded downstream towards its confluence with the Tennessee River. For example, Jett (2010) quantitatively documented a drastic increase in turbidity after the entry of water from Ellejoy Creek relative to upstream reaches. TVA (2003) estimated that the Ellejoy Creek drainage has the most linear meters of eroding stream bank and the most eroding hectares of unpaved roads within the Little River watershed. While Hart (2006) did not find significant differences in total suspended solids from headwater to downstream sites, she suspected that solids remained suspended in the water column in upstream or higher-gradient areas and were being deposited from the water column in the downstream, lower-gradient areas of the river. Hart (2006) also noted high turbidity levels in Ellejoy Creek, but suspected the sediments were deposited from the water column before reaching her next mainstem site of Little River. While we did not collect quantitative data on sediment attributes, we noticed higher substrate instability, increased fine sediment, and higher embeddedness during mussel surveys in 2013 and 2014 in lower reaches of Little River downstream of Ellejoy Creek. The additional deposited sediments could be negatively impacting the benthic communities in lower reaches. Thus, more analyses are needed to understand sediment impacts of Ellejoy Creek and other tributaries on the water quality and aquatic fauna of the Little River. The river topologies and historical mussel faunas of Little River and its neighbor, Little Pigeon River, are similar. However, Little Pigeon River mussels have declined in its West Prong due to a range of anthropogenic impacts of commercial, industrial, and residential development. Most notable was a spill in 2011 that resulted in an estimated 1.5–3.2 million gallons of raw or treated sewage entering the river (Donovan 2011). Previous elevated levels of fecal coliform in 1993 led to warnings by the Tennessee Department of Environment and Conservation for Southeastern Naturalist 115 D.E. Schilling, A.T. Phipps, J.W. Jones, and E.M. Hallerman 2017 Vol. 16, No. 1 citizens to avoid contact with water in the river (TDEC 2014b). No recent mussel surveys exist for the West Prong Little Pigeon River or sections downstream of this area due to these advisories; however, large mussel declines were observed in the 1980s and 1990s (G. Dinkins, Curator of Malacology and Natural History, McClung Museum of Natural History and Culture, University of Tennessee, Knoxville, TN, 12 January 2016 pers. comm.). Summary The Little River has a unique and imperiled fauna with 14 extant species, of which 2 are federally endangered species (F. cuneolus and Pleuronaia dolabelloides), 2 are putative new species (Pleurobema sp. cf. oviforme and V. sp. cf. iris), and several other imperiled mussels. Due to the maintenance of excellent water quality in upstream areas of the Little River, the waterway should be the focus for future conservation efforts in order to avoid negative impacts observed in the West Prong Little Pigeon and other nearby systems. Previous mussel surveys of Little River did not document Lasmigona costata, Pleuronaia dolabelloides, Pleurobema sp. cf. oviforme, or V. sp. cf. iris. Brief survey attempts during this study did not locate additional populations of P. sp. cf. oviforme or V. sp. cf. iris outside of the Little River drainage. The similar-looking shells of mussel species in the genera Fusconaia, Pleurobema, and Pleuronaia have led to inconsistent identification and estimates of species abundance in Little River and throughout the Tennessee River valley (Schilling 2015). Future conservation efforts should focus on intensive spatial sampling in the Tennessee River basin and additional molecular genetic characterization in order to determine cryptic biodiversity and the conservation status of putative species. Acknowledgments We are grateful to Bill Reeves and Don Hubbs of the Tennessee Wildlife Resources Agency (TWRA) for financial support of this project. We especially thank Jon Mollish for his assistance with field work and providing valuable resources to complete this project. We also appreciate Hugh Faust’s willingness to travel to sites and assist with field sampling for this project. We thank Bob Butler of United States Fish and Wildlife Service, Bobby Brown and Allen Pyburn of TWRA, Chuck Howard of Tennessee Valley Authority, and Jen Rogers of Virginia Tech for assistance with field sampling. Gerry Dinkins and Steve Ahlstedt contributed valuable knowledge to complete sampling. We also are indebted to Tim Pearce of Carnegie Museum of Natural History for photographing and lending the specimen of Actinonaias pectorosa. Support for E.M. Hallerman’s participation in this work was provided in part by the Virginia Agricultural Experiment Station and the Hatch Program of the National Institute of Food and Agriculture, US Department of Agriculture. 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