Eno River State Park Aquatic Inventory
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ENO RIVER STATE PARK AQUATIC INVENTORY by Gabriela B. Mottesi and Mara E. Savacool edited by John M. Alderman Cooperating Agencies: Division of Parks and Recreation, NC Natural Heritage Program NC Wildlife Resources Commission US Fish and Wildlife Service Funded by NC Natural Heritage Trust Fund NC Nongame and Endangered Wildlife Fund National Fish and Wildlife Foundation NORTH CAROLINA WILDLIFE RESOURCES COMMISSION JULY 1, 1996 145 9/2:A68e ENO RIVER STATE PARK AQUATIC INVENTORY Few's Ford tote Liters* of North Gamins' Raleigh MS tf/L £, 9 Table of Contents Page Introduction and Acknowledgments 1 Aquatic Snails 3 Freshwater Mussels and Sphaeriid Clams 10 Crayfish 1 Freshwater Fish 27 Point Sources and Animal Facilities 35 Digitized by the Internet Archive in 2017 with funding from State Library of North Carolina https://archive.org/details/enoriverstatepar1996mott Eno River State Park Aquatic Inventory Introduction Eno River State Park is located in Durham and Orange counties and encompasses 1,568 acres. The main attractions of this state park are the Eno River and its bordering woodlands. The park is divided into the following 5 areas through which the river can be accessed: the Cabe Lands, Cole Mill, Few’s Ford, Pleasant Green, and the Pump Station. Lands were initially purchased in 1975 by the State after concerned citizens led a campaign to prevent reservoir construction on the lower Eno River. Before the lands were purchased, they were used largely for agriculture. At that time, more than 30 mills were located on the Eno River. The Eno River, along with the Little and Flat Rivers, form the headwaters of the Neuse River, which is essentially our modern-day Falls Lake. The purpose of this project was to survey for aquatic species, including crayfish, fish, snails, mussels, and sphaeriid clams. Our inventory included the main waterway of the park as well as its tributaries in Durham and Orange counties. The Eno River was inventoried by canoe from just below Lake Orange in Orange County downstream to NC 157 in Durham County. Figure 1 details the localities of all stations surveyed, as well as the canoed river reaches. The following sections provide information on the species in the above taxa documented at each site in the Eno River Subbasin. Acknowledgments The completion of this project would not have been possible without the invaluable assistance of the following people: William F. Adams, J. Eric Alderman, John M. Alderman, Alvin Braswell, Allen Boynton, Mike B. Carraway, John E. Cooper, Mark A. Hartman, Tom Henson, Merrill Lynch, Gerald L. Mackie, Chris McGrath, Lawrence M. Page, William M. Palmer, Tim Savidge, Danny Smith, Kenneth R. Taylor, Fred G. Thompson, and Randall C. Wilson. We also thank the state park staff and the landowners who allowed us to work on their properties. Gabriela B. Mottesi Aquatic Snails Gabriela B. Mottesi, Nongame Biologist Nongame and Endangered Wildlife Program Division of Wildlife Management NC Wildlife Resources Commission Introduction There are approximately 500 species of aquatic snails currently recognized in North America. These 500 species are divided into 78 genera and 15 families (Burch 1989). In North Carolina, there are approximately 52 species representing 8 families (Adams 1990). Snails are grouped into one of two subclasses. Prosobranch snails are gill -breathing and have an operculum, which is a calcareous plate that closes the aperture when the snail withdraws into its shell. Pulmonate snails are lung-breathing and do not have an operculum to seal their aperture (Burch 1989). These animals graze on algae and other microscopic organisms using radular teeth to grind food to an appropriate size for consumption. Snails are an essential part of aquatic ecosystems, as well as indicators of water quality. However, they are typically overlooked. The lack of information and knowledge of snails can be attributed, in part, to their minute size, perceived lack of activity, cryptic habits, and difficulty in identification. Methods Study areas for this project included certain aquatic habitats associated with the Eno River and its tributaries (Fig. 1, Introduction Section). Most habitats can be described as riffle/run with medium to fast flows. Pools of different sizes with low flows were also present. Substrate included combinations of silt, sand, gravel, cobble, boulder, and bedrock. Some aquatic vegetation and organic debris were also present. The headwater streams of this subbasin do not have the large cobble and boulder substrate of the Eno River proper, and their flows are considerably slower. Specimens were collected using visual and tactile searches. Due to the cryptic habits of some snail species, it was necessary to sift and dredge the substrate. Snails were collected at bridge crossings and during canoe runs. All available habitats were sampled. Snails were preserved and stored in 70% ethanol. Snails and limpet snails were identified by using Burch (1989) and Basch (1963). Verifications of a subset of specimen identifications were made by Dr. Fred G. Thompson. Expected distributions and the following characteristics were used to identify the specimens: presence/absence of an 3 operculum, direction of coiling, shell size and shape, texture of the shell, shape and number of the whorls. With additional information, the identifications may be subject to change. Results and Discussion Snails were located at 22 of the sites surveyed (Fig. 1). Twelve species representing seven families and both subclasses were found within the Eno River Subbasin (Table 1). In 1954, Walderman M. Walter completed a survey of the mollusks of the Upper Neuse River Basin. He found the following species within the Eno River Subbasin: Campeloma decisum, Somatogyrus virginicus Walker, 1904, Leptoxis (Mudalia) carinata , Elimia catenaria, Elimia proximo, Pseudosuccinea columella, Helisoma anceps, Menetus dilatatus, Ferrisia hendersoni Walker, 1925, and Laevapex diaphanus (Haldeman, 1841). Flowers and Miller (1993) were able to find all of the above listed species in a 1993 survey of the Neuse River Basin except for Ferrisia hendersoni and Laevapex diaphanus. Flowers and Miller also found new records of Ferrisia fragilis (Tryon, 1863) and Laevapex fuscus (Adams, 1841) within the Neuse River Basin. During the present survey, Elimia catenaria, Elimia proximo, Elimia virginica, Leptoxis (Mudalia) carinata, were found Lioplax subcarinata , and Pseudosuccinea columella attached to rocks in the fast current. Elimia proximo was only found in the uppermost headwaters of the Eno River. These findings concur with the findings of Walter (1954). Campeloma decisum , Physella sp., and Helisoma anceps were collected in the backwater areas with low flow in the mud/silt substrate. Helisoma anceps was also found in the aquatic vegetation. Campeloma decisum is considered a species complex (Adams, pers. comm. 1995). Therefore, when more information is acquired, this species complex may be separated into a few recognizable species. Menetus dilatatus and Somatogyrus sp. were collected in the Podostemum attached to rocks. The limpet snail, Ferrisia rivularis was common on the underside of rocks in the slower current. The Somatogyrus sp. could possibly be Somatogyrus virginicus, but a verification by Dr. Fred G. Thompson did not bring the identification to the species level. According to a key by Basch (1963), the creeping ancylid ( Ferrisia rivularis), occurs in rivers and streams, whereas Ferrisia fragilis inhabits ditches and other small bodies of standing water, which are often temporary and stagnant. Therefore, because of the difficulty in identification using morphological characteristics, the habitat in which the limpet snails were found was used to further help in their identification. 4 The Eno River subbasin supports a great abundance and diversity of snails. As is shown in Table 2, most species were found in good numbers at each site. The snails preferring the faster current were dominant due to the almost constant fast flow of the Eno River. References Adams, W. F. 1995. Personal communication. Adams, W. F. (ed). 1990. A Report on the Conservation Status of North Carolina's Freshwater and Terrestrial Molluscan Fauna. The Scientific Council on Freshwater and Terrestrial Mollusks. 246 pp. Basch, P. F. 1963. A Review of the Recent Freshwater Limpet Snails of North America (Mollusca: Pulmonata). Bulletin: Museum of Comparative Zoology, Harvard University. 129(8): 399-461. Burch, J. B. 1989. North American Freshwater Snails. Malacological Publications. Hamburg, MI. 365 pp. J. Flowers, R. and G. C. Miller. 1993. New Molluscan ( Gastropoda and Bivalvia ) Records for the Neuse River Basin, North Carolina. Brimleyana. 19: 61-64. Walter, W. M. 1954. Mollusks of the Upper Neuse River, North Carolina. Ph.D. Thesis. Duke University. 220 pp. 5 — . ( H 1 i « < Q OOn o z , nr nf cn <N T— cn »— r— on — — O CN — o cn <N c un CN CN o on © cn o nr VO — oo .— nr CN f— — «— V— 1— »— »— CN i—* — © CN — (N o o ON o ON r- u- r- r- r- r- O r- On On r- ON ON r- ON O *— 55 o o o o o o o o ON o o o O o o o -o o o o o on on on on on vo on on on on VO on on VO c on VO c VO on VO VO •O 55 ON ON ON ON ON On On ON ON ON ON ON ON On os Os ON c3 On ON ON ON C Q DC a> J <D o S-H Z M m t VO NO so INVENTORY SUBBASIN SPECIES RIVER SNAIL ENO AQUATIC 6 Table 1 . Snails found in the Eno River Subbasin Prosobranchia Hydrobiidae Somatogyrus sp. Pleuroceridae Elimia catenaria (Say, 1 822) Gravel elimia Elimia proxima (Say, 1 825) Sprite elimia Elimia virginica (Say, 1817) Piedmont elimia Leptoxis (Mudalia) carinata (Bruguiere, 1 792) Crested mudalia Viviparidae Campeloma decisum (Say, 1816) Pointed campeloma Lioplax subcarinata (Say, 1816) Ridged lioplax Pulmonata Lymnaeidae Pseudosuccinea columella (Say, 1817) Mimic lymnaea Physidae Physella sp.