20181192_Freshwater Mussel Survey Report - February 2012_20151201

Freshwater Mussel Survey Report
Triangle Expressway Southeast Extension
(TIP No R-2721/R-2828/R-2829)
Wake and Johnston Counties, North Carolina
Prepared for:
H.W. Lochner, Inc.
2840 Plaza Place, Suite 202
Raleigh, NC 27612
Prepared by:
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The Catena Group, Inc.
410-B Millstone Drive
Hillsborough, NC 27278
February 2012

EXECUTIVE SUMMARY
The freshwater mussel fauna within the project study corridor for the proposed Triangle
Expressway Southeast Extension project (TIP #s R-2721, R-2828, R-2829) was evaluated
by The Catena Group Inc. (TCG) to establish a planning level baseline status of the
freshwater mussel resources within the project study corridor, with particular emphasis
on the federally protected Dwarf Wedgemussel and Tar River Spinymussel, and other
mussel species with assigned conservation statuses in North Carolina of Endangered.
Habitat evaluations and mussel surveys were performed in selected portions of perennial
water bodies within the study corridor in an effort to identify particular streams that
contain significant freshwater mussel populations, particularly those that support listed
species.
A total of 110 separate stream reaches were evaluated for the presence of mussels
(Figures 1 and 2, Appendix A), with 15 freshwater mussel species, as well as 2
freshwater clam species and 4 aquatic snail species found. For purposes of data analysis
and discussion, the project study area was segmented into three sections based on general
watersheds: Western Section (Middle Creek and tributaries), Central Section (Swift
Creek and tributaries), and Eastern section (Neuse River and tributaries).
Western Section: Middle Creek drains the western section of the project corridor study
area, and from a freshwater mussel standpoint, is the most significant water body in the
Western section. Middle Creek was known to support several rare mussel species,
including the Dwarf Wedgemussel; however, this species has not been detected during
any survey effort since 1992, where it was found at the NC 50 crossing downstream of
the study area in Johnston County. In addition, occurrences and numbers of other rare
mussel species known from the stream have declined in recent years. The results of this
survey effort further support this declining trend, as only very low numbers of four rare
mussel species were found. Observations of habitat conditions also support the apparent
decline.
The proposed project will cross Middle Creek in the upper limits of the watershed
upstream of Sunset Lake. While it is possible that the Dwarf Wedgemussel still occurs in
Middle Creek further downstream in Johnston County, the presence of Sunset Lake
between the proposed crossing and potentially occupied habitat downstream makes the
potential far any direct impacts very unlikely. No rare mussel species were found in any
of the tributaries; however, some of these streams such as Basal Creek, Little Creek, and
Guffy Branch support fairly high abundances of the Eastern Elliptio, and contain areas of
"good" mussel habitat, which may be suitable for the Dwarf Wedgemussel.
Central Section: The Central section of the project study area drains to the Swift Creek
Subbasin, which is considered an aquatic habitat of national signiiicance, as it supports
the Dwarf Wedgemussel. Historically, at least 18 species of freshwater mussels have
been reported to occur in the Swift Creek subbasin. This study confirms the relatively
high species diversity (for Atlantic Slope drainages) of this stream, as at least 14 species
were collected. The study also confirms the persistence of the Dwarf Wedgemussel in
Swift Creek below Lalce Benson, as three individuals were found within the study
corridor. In addition, two other individuals were found downstream of the project
Triangle Expressway Southeast Extension i The Catena Group
February 2012 Job # 3271

corridor, as part of a concurrent study carried out by TCG for the City of Raleigh. Other
targeted mussel species, including the Atlantic Pigtoe and Yellow Lance, were also
located along with several other rare mussel species. Thus, direct impacts to these
species are possible from project construction within this section of Swift Creek.
Because of the existence of the Dwarf Wedgemussel in Swift Creek, the study corridor
for this project was expanded to include an avoidance alternative (Red Route), which
would cross Swift Creek upstream of Lake Benson. This section of Swift Creek is not
believed to support the Dwarf Wedgemussel, and the results of this study further support
this assumption, as it was not found, nor were any of the associate rare mussel species. In
addition, Lake Benson occurs between this section of the creek and occupied habitat
downstream. As such, direct impacts to the Dwarf Wedgemussel are unlikely to occur if
the Red Corridor is constructed; however, conclusions regarding Indirect and Cumulative
Impacts to the population cannot be determined at this time, and will need to be
addressed with all alternates within the study area.
No rare mussel species were found in any of the tributaries to Swift Creek within the
study area; however, both White Oak Creek and Little Creek are known to support Dwarf
Wedgemussel and other rare species farther downstream of the study area. In both
instances, artificial impoundments are present between any of the proposed crossing
locations and occupied habitat downstream; therefore direct impacts are unlikely.
Eastern Section: The Eastern section of the project corridor drains to the Neuse River
from the US 64/264 Bypass crossing of the river downstream to the vicinity of the
Wake/Johnston County line. Tributaries to the Neuse River within this section include
Walnut Creek and Beddingfield Creek to the south; Mango Creek, Unnamed Tributary
(UT) to Neuse River, Poplar Creek, and Mark's Creek to the north.
Historically, at least 18 species of freshwater mussels have been reported to occur in the
mainstem of the Neuse River within the project study area. While this study indicates
relatively high species diversity (for Atlantic Slope drainages) of this section of the river
(10 species), including the targeted Green Floater, species like the Dwarf Wedgemussel,
Atlantic Pigtoe, Yellow Lance and Notched Rainbow, which historically occurred in this
area, were not found. The presence of the Green Floater is the first documented
occurrence of this species in this section of the Neuse River since the early 1950's.
While the Dwarf Wedgemussel is unlikely to still occur in this section of the Neuse
River, the re-discovery of the Green Floater, which was believed to have been extirpated
from this area, may indicate that some of the other species formerly reported from this
area may still exist in low numbers, as the Green Floater was obviously present, but in
such low numbers that it was not found during surveys since that time. The presence of
Green Floater at multiple sites (8) and the fact that the majority of individuals found were
of the same size (age) class, suggest a recent popu]ation expansion. Additional surveys
will need to be done once an alternate is chosen. No rare mussel species were found in
any of the tributaries in this section. Habitat conditions are generally unsuitable for the
Dwarf Wedgemussel; thus it is very unlikely to occur in any of the water bodies within
this section of the study corridor.
Triangle Expressway Southeast Extension ii The Catena Group
February 2012 Job # 3271

TABLE OF CONTENTS
1.0 INTRODUCTION ................................................................................................... 1
2.0 MUSSEL SURVEY EFFORTS ............................................................................... 2
2.1. Mussel Survey Methodology ............................................................................... 2
2.2. Mussel Survey Results ......................................................................................... 3
2.2.1. Western Section ................................................................................................ 4
2.2.2. Central Section ............................................................................................... 13
2.2.3. Eastern Section ............................................................................................... 47
3.0 MUSSEL SPECIES DESCRIPTIONS .................................................................. 56
3.1. Federally Protected Species ............................................................................... 56
3. L 1. Alasmidonta heterodon (Dwarf Wedgemussel) ............................................. 56
3.1.2. Elliptio steinstansana (Tar River Spinymussel) ............................................. 59
3.2. Target Federal Species of Concern (FSC) .......................................................... 60
3.21. Elliptio lanceolata (Yellow Lance) ................................................................ 60
3.2.2. Fusconaia masoni (Atlantic Pigtoe) ............................................................... 61
3.2.3. Lasmigona subviridis (Green Floater) ............................................................ 61
3.2.4. Lampsilis cariosa (Yellow Lampmussel) ....................................................... 62
3.3. Other Mussel Species Located ........................................................................... 62
3.3.1 Alasmidonta undulata (Triangle Floater) ....................................................... 62
3.3.2 Elliptio complanata (Eastern Elliptio) ............................................................ 63
3.3.3 Elliptio congarea (Carolina Slabshell) ........................................................... 63
3.3.4 Elliptio icterina (Variable Spike) ................................................................... 63
3.3.5. Elliptio mediocris (No Common Name) ........................................................ 63
3.3.6. Elliptio producta (Atlantic Spike) .................................................................. 64
3.3.7. Elliptio roanokensis (Roanoke Slabshell) ...................................................... 64
3.3.8. Lampsilis radiata (Eastern Lampmussel) ....................................................... 64
3.3.9. Pyganodon cataracta (Eastern Floater) .......................................................... 65
3.3.10. Strophitus undulatus (Creeper) ....................................................................... 65
3.3.11. Utte�backia imbecillis (Paper Pondshell) ....................................................... 66
4.0 DISCUSSION ........................................................................................................66
4.1. Western Section .................................................................................................. 66
4.2. Central Section ................................................................................................... 67
4.3. Eastern Section ................................................................................................... 68
5.0 LITERATURE CITED .......................................................................................... 70
Table 1. Rare Aquatic Species Neuse River Basin in Wake/Johnston Counties ............................................ 2
Table 2. Study Corridor: Mollusk Species Found .......................................................................................... 4
Table 3. Middle Creek Site-100428.1: Mollusk Species Found ..................................................................... 5
Table 4. Middle Creek Site-100428.2: Mollusk Species Found ..................................................................... 5
Table 5. Middle Creek Site-1004283: Mollusk Species Found ..................................................................... 6
Table 6. Middle Creek Site-100611.1: Mollusk Species Found ..................................................................... 6
Table 7. Middle Creek Site-100616.2: Mollusk Species Found ..................................................................... 7
Table 8. Middle Creek Site-100616.1: Mollusk Species Found ..................................................................... 7
Table 9. Basal Creek Site-100623.3: Mollusk Species Found ........................................................................ 8
Table 10. Basal Creek Site-100618.1: Mollusk Species Found ..................................................................... 8
Table 11. UT Middle Creek Site-100507.2: Mollusk Species Found ............................................................. 8
Table 12. Rocky Branch Site-100507.1: Mollusk Species Found .................................................................. 9
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Table 13. UT Middle Creek (Bell's Lake Creek) Site-100618.3: Mollusk Species Found ........................
Table 14. Terrible Creek Site-100618.2: Mollusk Species Found ..............................................................
Table 15. Terrible Creek Site-100624.2: Mollusk Species Found ..............................................................
Table 16. Terrible Creek Site-100624.1: Mollusk Species Found ..............................................................
Table 17. Panther Branch Site-1006113: Mollusk Species Found ............................................................
Table 18. Little Creek Site-100623.1: Mollusk Species Found ..................................................................
Table 19. Little Creek Site-100623.2: Mollusk Species Found ..................................................................
Table 20. Guffy Branch Site-100623.4: Mollusk Species Found ...............................................................
Table 21. Guffy Branch Site-100623.5: Mollusk Species Found ...............................................................
Table 22. Buffalo Branch Site-100623.6: Mollusk Species Found ............................................................
Table 23. Swift Creek Site-101124.4: Mollusk Species Found ..................................................................
Table 24. Swift Creek Site-101124.3: Mollusk Species Found ..................................................................
Table 25. Swift Creek Site-101124.2: Mollusk Species Found ..................................................................
Table 26. Swift Creek Site-101124.1: Mollusk Species Found ..................................................................
Table 27. Swift Creek Site-101123.6: Mollusk Species Found ..................................................................
Table 28. Swift Creek Site-101123.5: Mollusk Species Found ..................................................................
Table 29. Swift Creek Site-101123.4: Mollusk Species Found ..................................................................
Table 30. Swift Creek Site-101123.3: Mollusk Species Found ..................................................................
Table 31. Mahlers Creek Site-101124.5: Mollusk Species Found .............................................................
Table 32. Mahlers Creek Site-101124.8: Mollusk Species Found .............................................................
Table 33. Swift Creek Site-101124.6: Mollusk Species Found ..................................................................
Table 34. Swift Creek Site-101124.7: Mollusk Species Found ..................................................................
Table 35. Swift Creek Site-100708.5: Mollusk Species Found ..................................................................
Table 36. Swift Creek Site-100708.4: Mollusk Species Found ..................................................................
Table 37. Swift Creek Site-100708.3: Mollusk Species Found ..................................................................
Table 38. Swift Creek Site-100708.2: Mollusk Species Found ..................................................................
Table 39. Swift Creek Site-1007081: Mollusk Species Found ..................................................................
Table 40. Swift Creek Site-101123.2: Mollusk Species Found ..................................................................
Table 41. Swift Creek Site-101123.1: Mollusk Species Found ..................................................................
Table 42. Swift Creek Site-101027.1: Mollusk Species Found ..................................................................
Table 43. Swift Creek Site-101027.4: Mollusk Species Found ..................................................................
Table 44. Swift Creek Site-101027.3: Mollusk Species Found ..................................................................
Table 45. Swift Creek Site-1010272: Mollusk Species Found ..................................................................
Table 46. Swift Creek Site-101007.6: Mollusk Species Found ..................................................................
Table 47. Swift Creek Site-101007.5: Mollusk Species Found ..................................................................
Table 48. Swift Creek Site-101007.1: Mollusk Species Found ..................................................................
Table 49. Swift Creek Site-101007.4: Mollusk Species Found ..................................................................
Table 50. Swift Creek Site-101007.3: Mollusk Species Found ..................................................................
Table 51. Swift Creek Site-101007.2: Mollusk Species Found ..................................................................
Table 52. Swift Creek Site-101027.10: Mollusk Species Found ................................................................
Table 53. Swift Creek Site-101027.9: Mollusk Species Found ..................................................................
Table 54. Swift Creek Site-101027.8: Mollusk Species Found ..................................................................
Table 55. Swift Creek Site-101027.7: Mollusk Species Found ..................................................................
Table 56. Swift Creek Site-101027.6: Mollusk Species Found ..................................................................
Table 57. Swift Creek Site-101027.5: Mollusk Species Found ..................................................................
Table 58. Swift Creek Site-101021.7: Mollusk Species Found ..................................................................
Table 59. Swift Creek Site-101021.6: Mollusk Species Found ..................................................................
Table 60. Swift Creek Site-101021.5: Mollusk Species Found ..................................................................
Table 61. Swift Creek Site-101021.4: Mollusk Species Found ..................................................................
Table 62. Swift Creek Site-101021.3: Mollusk Species Found ..................................................................
Table 63. Swift Creek Site-101021.2: Mollusk Species Found ..................................................................
Table 64. Swift Creek Site-101021.1: Mollusk Species Found ..................................................................
Table 65. Swift Creek Site-101012.8: Mollusk Species Found ..................................................................
Table 66. Swift Creek Site-101012.7: Mollusk Species Found ..................................................................
Table 67. Swift Creek Site-101012.6: Mollusk Species Found ..................................................................
Table 68. Swift Creek Site-101012.5: Mollusk Species Found ..................................................................
Table 69. Swift Creek Site-101012.4: Mollusk Species Found ..................................................................
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Table 70. Swift Creek Site-101012.3: Mollusk Species Found ..................................................................
Table 71. Swift Creek Site-101012.2: Mollusk Species Found ..................................................................
Table 72. Swift Creek Site-101012.1: Mollusk Species Found ..................................................................
Table 73. Swift Creek Site-100713.4: Mollusk Species Found ..................................................................
Table 74. Swift Creek Site-101013.9: Mollusk Species Found ..................................................................
Table 75. Swift Creek Site-101013.8: Mollusk Species Found ..................................................................
Table 76. Swift Creek Site-101013.7: Mollusk Species Found ..................................................................
Table 77. Swift Creek Site-101013.6: Mollusk Species Found ..................................................................
Table 78. Swift Creek Site-101013.5: Mollusk Species Found ..................................................................
Table 79. Swift Creek Site-101013.3: Mollusk Species Found ..................................................................
Table 80. Swift Creek Site-101013.2: Mollusk Species Found ..................................................................
Table 81. Swift Creek Site-101013.4: Mollusk Species Found ..................................................................
Table 82. Swift Creek Site-101013.1: Mollusk Species Found ..................................................................
Table 83. Swift Creek Site-101026.4: Mollusk Species Found ..................................................................
Table 84. Swift Creek Site-101026.3: Mollusk Species Found ..................................................................
Table 85. Swift Creek Site-101026.2: Mollusk Species Found ..................................................................
Table 86. Swift Creek Site-101026.1: Mollusk Species Found ..................................................................
Table 87. Swift Creek Site-101019.4: Mollusk Species Found ..................................................................
Table 88. Swift Creek Site-1010193: Mollusk Species Found ..................................................................
Table 89. White Oak Creek Site-100722.1: Mollusk Species Found .........................................................
Table 90. White Oak Creek Site-100713.1: Mollusk Species Found .........................................................
Table 91. Little Creek Site-100720.4: Mollusk Species Found ..................................................................
Table 92. Little Creek Site-100713.3: Mollusk Species Found ..................................................................
Table 93. Big Branch Site-1007222: Mollusk Species Found ...................................................................
Table 94. Walnut Creek Site-100623.4: Mollusk Species Found ...............................................................
Table 95. Neuse River Site-100726.1: Mollusk Species Found .................................................................
Table 96. Neuse River Site-100726.2: Mollusk Species Found .................................................................
Table 97. Neuse River Site-100726.3: Mollusk Species Found .................................................................
Table 98. Neuse River Site-100726.4: Mollusk Species Found .................................................................
Table 99. Neuse River Site-100726.5: Mollusk Species Found .................................................................
Table 100. Neuse River Site-100726.6: Mollusk Species Found ...............................................................
Table 101. Neuse River Site-100726.7: Mollusk Species Found ...............................................................
Table 102. Neuse River Site-100726.8: Mollusk Species Found ...............................................................
Table 103. Neuse River Site-100726.9: Mollusk Species Found ...............................................................
Table 104. Neuse River Site-1007202: Mollusk Species Found ...............................................................
Table 105. Neuse River Site-100720.1: Mollusk Species Found ...............................................................
Table 106. Neuse River Site-100720.3: Mollusk Species Found ...............................................................
Table 107. Mango Creek Site-1007022: Mollusk Species Found .............................................................
Table 108. Mango Creek Site-100702.1: Mollusk Species Found .............................................................
Table 109. UT Neuse River Site-100722.3: Mollusk Species Found .........................................................
Table 110. Poplar Creek Site-100702.3: Mollusk Species Found ..............................................................
Table 111. Marks Creek Site 100722.4: Mollusk Species Found ...............................................................
Table 112. Mussel Species by Study Corridor Section ..............................................................................
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Triangle Expressway Southeast Extension v The Catena Group
March 20l 1 Job # 3271

1.0 INTRODUCTION
The North Carolina Turnpike Authority (NCTA) a division of the North Carolina
Department of Transportation (NCDOT), proposes the construction of a new road
corridor from NG55 near Apex south and east to US-64/264 Bypass near Knightdale
within Wake and Johnston Counties, referred to as the Triangle Expressway Southeast
Extension. The entire project area occurs within the Neuse River Basin.
Two freshwater mussel species federally designated and protected as Endangered under
the Endangered Species Act of 1973 as amended are known to occur within the Neuse
River Basin in Wake and Johnston Counties, the Dwarf Wedgemussel (Alasmidonta
heterodon) and the Tar River Spinymussel (Elliptio steinstansana). To assess the
potential for these two species to occur within the project area, The Catena Group, Inc.
(TCG) was retained by H.W. Lochner (Lochner), to gather updated mussel survey data
for streams within the project corridor during the preliminary planning phase of the
project in order to assist in selection of potential corridors and to initiate any potential
consultation with the agencies as early as possible to avoid project delays.
In addition, four species listed as state Endangered and Federal Species of Concern
(FSC), � the Atlantic Pigtoe (Fusconaia masoni), Green Floater (Lasmigona subviridis),
Yellow Lampmussel (Lampsillis cariosa), and Yellow Lance (Elliptio lanceolata), have
been previously documented in this portion of the Neuse River Basin, and were also
targeted in this survey because the US Fish and Wildlife Service (USFWS) is in the
process of putting together "Elevation to Candidate Species Status" packages for some of
these species as they may be formally listed as Threatened, or Endangered in the near
future (John Fridell, USFWS Recovery Biologist, personal communication). In addition,
The Center for Biological Diversity (CBD), a nonprofit conservation arganization
dedicated to the protection of endangered species and wild places
(www.biologicaldiversity.org) recently petitioned the USFWS to list 404 aquatic species
in the southeastern United States, including three of these four species as either
Threatened or Endangered under the Endangered Species Act (CBD 2010). As such, it
has been determined that it would be prudent to address these species during this phase of
project planning in the event that they become federally listed as Threatened or
Endangered. Several other mussel species that are considered to be rare in North
Carolina and have assigned various conservation statuses are also known from this
portion of the Neuse River Basin (Table 1).
� Federal Species of Concern (FSC) are defined as species that are under consideration for
listing for which there is insufficient information to support listing. FSCs are not afforded federal
protection under the Endangered Species Act and are not subject to any of its provisions,
including Section 7, until they are formally proposed or listed as Threatened or Endangered.
However, the status of these species is subject to change, and so should be included for
consideration.
Triangle Expressway Southeast Extension 1 The Catena Group
March 20l 1 Job # 3271

Table 1. Rare Aquatic Species Neuse River Basin in Wake/Johnston Counties
Scientific Name Common Name Federal Status NC Status
Alasinidonta heterodon Dwarf Wedgemussel E E
Alasmidonta undulata Triangle Floater � T
Elliptio congarea Carolina Slabshell � W3/WS
Elliptio lanceolata Yellow Lance FSC E
Elliptio producta Atlantic Spike � W3/WS
Elliptio roanokensis Roanoke Slabshell � T
Fusconaia masoni Atlantic Pigtoe FSC E
Lampsilis cariosa Yellow Lampmussel FSC E
Lampsilis radiata Eastern Lampmussel � T
Lasmigona subviridis Green Floater FSC E
Strophitus undulatus Creeper � T
Villosa constncta Notched Rainbow � SC
See Appendix B for status designations
2.0 MUSSEL SURVEY EFFORTS
Portions of all perennial water bodies within the project study corridor were evaluated for
the presence of freshwater mussels and other aquatic mussel species, with particular
emphasis on the federally protected Dwarf Wedgemussel and Tar River Spinymussel, as
well as four state Endangered /FSC mussel species, three of which have been included in
a petition for consideration for federal listing as Endangered or Threatened.
2.1. Mussel Survey Methodology
Survey locations were chosen based on mapping as provided by Lochner, pre-survey
investigations, accessibility, and appropriate habitat for the target species as determined
in the field. Surveys were conducted by TCG personnel on the following dates in 2010:
• Tim Savidge: April 28; June 11, 16, 18, 23, 24; July 2, 8, 13, 20, 26; October 7,
12, 13, 21, 26, 27; November 23, 24
• Tom Dickinson: Apri128; May 7; June 1l, 16, 23; July 8, 22, 26; October 7, 19,
21, 26, 27; November 23, 24
• Chris Sheats: June 16, 18, 23; July 8, 20, 26; October 7, 12, 13, 19; November 23,
24
• Jonathan Hartsell: July 8
• Kate Montieth: May 7
• David Zitlow: July 8
• Daniel Savidge: June 23, 24; July 2, 8, 13; October 7, 26
• Ivy Kimbrough: July 20; October 7, 12, 13, 19, 21, 26, 27; November 24
• Maggie Griffin: October 19, 21, 26, 27; November 23, 24
The following non-TCG personnel assisted with the surveys on the following dates:
• Sarah McRae-USFWS: October 7
• John Fridell-USFWS: October 21, 26, 27
• Karen Lynch-NCDOT: October 27
• Jason Mays-NCDOT: October 7, 21, 27
Triangle Expressway Southeast Extension 2 The Catena Group
March 20l 1 Job # 3271

• Mike Sanderson-NCDOT: October 21, 27
• Logan Williams-NCDOT: October 27
• Hal Bain-RK&K: October 12, 13
• Matt Smith-ESL• November 24
In each stream segment, a habitat evaluation was first performed by accessing a specific
stream or stream system downstream of the corridor and walking the drainage for at least
0.5 person-hour. If it was determined by professional judgment that further efforts were
not warranted, then survey efforts were stopped. This decision by the respective
investigator to discontinue survey effort on a particular stream was based on a lack of
suitable habitat for freshwater mussels. Within the surveyed reaches, all habitat types
(riffle, run, pool, slack-water, etc.) were sampled by a minimum of a two-person team.
The survey team began at the downstream end of the survey reach and proceeded
upstream with the team spread across the stream into survey lanes. A combination of
visual using bathyscopes (glass-bottom view buckets) or mask and snorkle, and tactile
methodologies were employed as appropriate. Upstream and downstream survey limits
were recorded using a hand-held Garmin 12 or e-Trex Vista GPS unit. Timed searches
were employed in each reach to provide a catch per unit effort (CPUE). Searches were
also conducted for relict shells. Presence of fresh shell material was equated with species
presence, but was not factored into CPUE.
Relative abundance for freshwater snails and the freshwater clam species were estimated
using the following criteria:
• Very abundant > 30 observed at survey station
• Abundant 16-30 observed at survey station
• Common 6-15 observed at survey station
• Uncommon 3-5 observed at survey station
• Rare 1-2 observed at survey station
• Patchy indicates an uneven distribution of the species within the sampled site.
2.2. Mussel Survey Results
A total of 111 separate stream reaches within the study corridor were evaluated far the
presence of mussels (Figures 1 and 2, Appendix A), with 15 freshwater mussel species,
as well as 2 freshwater clam species and 4 aquatic snail species being found (Table 2).
Stream survey segments are reported by USGS stream name, the date surveyed, and
respective sequence within that date. Unnamed tributaries are noted as "UT" to the
named receiving water body. Habitat descriptions and survey results are summarized
below for each site in order from West to East. Site numbers (i.e., 101010.1) indictate
the date in YYMMDD (year, month, day) format with survey sequence from that day of
sampling listed after the decimal point. Survey segments are depicted in their respective
figures in Appendix A.
Triangle Expressway Southeast Extension 3 The Catena Group
March 20l 1 Job # 3271

Table 2. Study Corridor: Mollusk Species Found
# Sites Conservation
Scientific Name Common Name Found Status
Freshwater Mussels � � �
Alasmidonta hete�odon Dwarf Wedgemussel 3 Federally E
Alasmidonta undulata Triangle Floater 28 State T
Elliptio complanata Eastern Elliptio 100 None
Elliptio congarea Carolina Slabshell 43 State W
Elliptio icterina Variable Spike 81 None
Elliptio lanceolata Yellow Lance 8 State E
Elliptio mediocris No Common Name 17 None
Elliptio producta Atlantic Spike 8 State W
Elliptio roanokensis Roanoke Slabshell 34 State T
Pusconaia masoni Atlantic Pigtoe 23 State E
Lampsilis radiata Eastern Lampmussel 44 State T
Lasmigona subviridis Green Floater 8 State E
Pyganodon cataracta Eastern Floater 24 None
Strophitus undulatus Creeper 32 State T
Utterbackia imbecillis Paper Pondshell 14 None
Freshwater Snails and Clams � � �
Campeloma decisum Pointed Campeloma 40 None
Corbicula fluminea Asian Clam 101 Exotic
Helisoma anceps Two-ridge Ram's Horn 2 Common
Physidae A Physid Snail 4 None
Planorbella trivolvis Marsh Ram's Horn 1 None
Sphaeriidae A Sphaeriid Clam 2 None
For purposes of data analysis and discussion, the project study area was segmented into
three sections based on general watersheds: Western Section (Middle Creek and
tributaries), Central Section (Swift Creek and tributaries), and Eastern section (Neuse
River and tributaries).
2.2.1. Western Section
The western section of the project corridor occurs within the Middle Creek Subbasin
between NC 55 and NC 50. Six reaches of Middle Creek, were evaluated, as were
portions of all perennial tributaries to Middle Creelc within the study corridor (15 sites).
Middle Creek Site-100428.1
This section of Middle Creek was accessed off the Holly Springs Road (SR 1152)
crossing. Channel width ranges from 4 to 5 meters with relatively stable 1-meter high
banks. In order of dominance, substrate consists of sand, gravel, silt, cobble, and mud.
Water levels were normal and water visibility was clear. A wastewater treatment plant
(wwtp) discharge was noted and the smell of effluent was present. An extensive natural
buffer surrounds the reach. Mussel surveys were conducted for a total of 3.07 person
hours.
Triangle Expressway Southeast Extension 4 The Catena Group
March 20l 1 Job # 3271

Table 3. Middle Creek Site-100428.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 96 31.27/hr
Elliptio icterina Variable Spike 2 0.65/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Abundant
Middle Creek Site-100428.2
This section of Middle Creek was accessed off Sunset Lake Road (SR 1301). Channel
width ranges from 2 to 5 meters with 1-meter high banks showing some signs of erosion.
In order of dominance, substrate consists of silt, sand, clay, gravel, and mud. The smell
of wwtp effluent was noted. Surveys were conducted for a total of 1.40 person hours.
Table 4. Middle Creek Site-100428.2: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 8 5.71/hr
Elliptio icterina Variable Spike 2 1.43/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula fluminea Asian Clam � Abundant
Patchy,
Physella sp. A Physid Snail � Common
Middle Creek Site-100428.3
This section of Middle Creek was located within the tailrace of Sunset Lake. Channel
width ranges from 6 to 10 meters with <1-meter high relatively stable banks. In order of
dominance, substrate consists of boulder, gravel, sand, cobble, bedrock, and silt. Surveys
were conducted for 1.00 person hour.
Triangle Expressway Southeast Extension 5 The Catena Group
March 20l 1 Job # 3271

Table 5. Middle Creek Site-100428.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 6 6.00/hr
Lampsilis radiata Eastern Lampmussel 2 2.00/hr
Pyganodon cataracta Eastern Floater 0 Shell only
Utterbackia imbecillis Paper Pondshell 0 Shell only
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisuin Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Abundant
Sphaeriidae A Sphaeriid clam � Uncommon
Middle Creek Site-100611.1
This mid section of Middle Creek within the study area was accessed off the Lake
Wheeler Road Crossing (SR 1371). Channel width ranges from 6 to 10 meters with 1- to
2-meter high moderately eroded banks. In order of dominance, substrate consists of sand,
silt, gravel, clay, and cobble. Mussels were concentrated in small patches of suitable
habitat. Surveys were conducted for 4.67 person hours.
Table 6. Middle Creek Site-100611.1: Mollusk Species Found
Scientific Name Common Name # Abundance/
CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 02 Uhr
Elliptio complanata Eastern Elliptio 225 48.18/hr
Elliptio icterina Variable Spike 154 32.98/hr
Strophitus undulatus Creeper 2 0.43/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Middle Creek Site-100616.2
This section of Middle Creek occurs off the Old Stage Road (SR 1006) crossing.
Channel width ranges from 10 to 12 meters with 2-meter high banks that range from
fairly stable to moderately eroded. In order of dominance, substrate consists of sand, silt,
clay, cobble, and boulder. Surveys were conducted for 5.15 person hours.
Triangle Expressway Southeast Extension 6 The Catena Group
March 20l 1 Job # 3271

1�able �/. Nllctctle l;reeK �1te-1 UUb 1 b.G: N1ollusK �pecles r ouncl
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 241 46.80/hr
Elliptio icterina Variable Spike 121 23.50/hr
Elliptio producta Atlantic Spike 1 0.19/hr
Relative
Freshwater Snails and Clams � � Abundance
Very
Corbicula fluminea Asian Clam � Abundant
Middle Creek Site-100616.1
This most downstream section of Middle Creek within the study area was accessed off
the Barber Bridge Road (SR 2739) crossing. Channel width ranges from 10 to 15 meters
with 2-meter high banks that ranged from stable to severely eroded. In order of
dominance, substrate consists of sand, clay, gravel, silt, and cobble. Mussels were fairly
common in areas associated with stable clay and rock outcrops, and uncommon to absent
in the rest. Surveys were conducted for 6.25 person hours.
i anie ts. iviiaaie Lreex �ite- i uue i e. i: ivio►iusx �pecies r ouna
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 393 62.88/hr
Elliptio icterina Variable Spike 146 23.36/hr
Lampsilis radiata Eastern Lampmussel 1 0.16/hr
Strophitus undulatus Creeper 1 0.16/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Very
Corbicula flun�inea Asian Clam � Abundant
Basal Creek Site-100623.3
This section of Basal Creek upstream of Bass Lake was accessed off the NC 55 crossing.
Channel width ranges from 3 to 6 meters with <1-meter high moderately eroded banks.
In order of dominance, substrate consists of sand, gravel, silt, clay, cobble, and bedrock.
There is an extensive wetland complex created by beaver (Castor canadensis) dams
upstream of the reach. Surveys were conducted for 2.13 person hours.
Triangle Expressway Southeast Extension 7 The Catena Group
March 20l 1 Job # 3271

Table 9. Basal Creek Site-100623.3: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Pointed Campeloma
Asian Clam
#
414
139
Abundance/
CPUE
CPUE
194.3 7/hr
65.26/hr
Relative
Abundance
Common
Common
Basal Creek Site-100618.1
This section of Basal Creek extends from the Basal Creek arm of Sunset Lake upstream
to the SR 1393 crossing just below the tailrace of Bass Lake. The stream consists of a
series of braided channels within a floodplain wetland created by beaver dams. There is a
large amount of detritus and woody debris. The channels range from 2 to 4 meters wide
with <1-meter high banks. In order of dominance, substrate consists of sand, clay and
gravel. Surveys were conducted for 4.0 person hours.
Table 10. Basal Creek Site-100618.1: Mollusk Species Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Pyganadon cataracta
Utterbackia imbecillis
Freshwater Snails and Clams
Campeloma decisum
Corbicula fZuminea
Common Name
Eastern Elliptio
Eastern Floater
Paner Pondshell
Pointed Campeloma
Asian Clam
Abundance/
CPUE
CPUE
12.75/hr
0.50/hr
0.50/hr
Relative
Abundance
Common
Uncommon
UT to Middle Creek Site-100507.2
This section of a UT to Middle Creek was accessed from the Optimist Farm Road (SR
1390) crossing. Channel width ranges from 2 to 4 meters with 1-meter high banks that
showed signs of erosion. In order of dominance, substrate consists of sand, gravel, and
silt. A mixture of residential development and forested landscape occurs adjacent to this
reach. Mussel surveys were conducted for 2.5 person hours.
Table 11. UT Middle Creek Site-100507.2: Mollusk Species Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Freshwater Snails and Clams
Corbicula fluminea
Triangle Expressway Southeast Extension
March 20l 1
Common Name #
Eastern Elliptio 2
Asian Clam �
8
Abundance/
CPUE
CPUE
0.80/hr
Relative
Abundance
Rare
The Catena Group
Job # 3271

Rocky Branch Site-100507.1
This section of Rocky Branch was accessed off the Optimist Farm Road (SR 1390)
crossing. Channel width ranges from 2 to 4 meters with 1-meter high banks that showed
signs of erosion. Surveys were conducted upstream of a section of the channel that was
impounded by beavers. In order of dominance, substrate consists of gravel, sand, cobble,
and boulder. Surveys were conducted for 2.17 person hours.
Table 12. Rocky Branch Site-100507.1: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Pointed Campeloma
Asian Clam
Abundance/
CPUE
CPUE
0.46/hr
Relative
Abundance
Common
Rare
UT Middle Creek (Bell's Lake Creek) Site-100618.3
This stretch of UT to Middle Creek (Bell's Lake Creek) which originates from Bell's
Lake extends from approximately 100 meters below the Optimist Farm Road (SR 1390)
crossing to a point approximately 650 meters upstream. The channel ranges from 2 to 4
meters wide, with eroded banks 1 meter high. Substrate is dominated by sand, gravel and
cobble. No mussels were located during the 1.5 person hours of search time.
Table 13. UT Middle Creek
Scientific Name
Freshwater Mussels
None
Freshwater Snails and Clams
Corbicula fZuminea
's Lake Creek) Site-100618.3: Mollusk S
Common Name #
0
Asian Clam
�cies Found
Abundance/
CPUE
CPUE
Relative
Abundance
Uncommon
Terrible Creek Site-100618.2
This section of Terrible Creek extends from approximately 0.5 mile downstream of the
Johnson Pond Road (SR 1404) crossing upstream to the bridge. The channel, which
ranges from 2 to 4 meters with <1-meter high banks, flows through a floodplain marsh
wetland system, that appears to be a relict bed of a former impoundment. Numerous
small beaver dams are present throughout. In order of dominance, substrate consists of
sand, gravel, and cobble. Surveys were conducted for 2.67 person hours.
Triangle Expressway Southeast Extension 9 The Catena Group
March 20l 1 Job # 3271

Table 14. Terrible Creek Site-100618.2: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 5 1.87/hr
Pyganodon cataYacta Eastern floater 7 2.62/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Patchy,
Corbicula flu�ninea Asian Clam � Common
Terrible Creek Site-100624.2
This section of Terrible Creek extends from the WWTP discharge in Terrible Creek
above Hilltop Road (SR 2751) upstream to the US 401 crossing. The channel width
ranges from 3 to 4 meters, and the fairly stable banks are between 1 and 1.5 meters high.
The substrate is dominated by sand, cobble, and gravel. Fairly extensive woodland is
present on both sides of the stream. Surveys were conducted for 2.73 person hours.
Table 15. Terrible Creek Site-100624.2: Mollusk Species Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Ellintio icterina
Freshwater Snails and Clams
Corbicula fluminea
Common Name
Eastern Ellip
Varaible Spi
Asian Clam
Abundance/
CPUE
CPUE
31.14/hr
2.93/hr
Relative
Abundance
Common
Terrible Creek Site-100624.1
This section of Terrible Creek extends from the Hilltop Road (SR 2751) crossing
upstream to the WWTP discharge point. The channel ranges from 3 to 4 meters wide,
and the highly eroded banks are between 1 and 1.5 meters high. The substrate is
dominated by sand, cobble, and silt. Fairly extensive woodland is present on both sides
of the stream. Surveys were conducted for 0.8 person hour.
Triangle Expressway Southeast Extension 10 The Catena Group
March 20l 1 Job # 3271

Table 16. Terrible Creek Site-100624. ]: Mollusk
Scientific Name
Freshwater Mussels
Elliptio complanata
Freshwater Snails and Clams
Corbicula fluminea
Common Name
Eastern Elliptio
Asian Clam
Found
#
1
Abundance/
CPUE
CPUE
1.25/hr
Relative
Abundance
Common
UT Middle Creek Site-100611.2
This UT to Middle Creek was accessed from its confluence with Middle Creek near the
Lake Wheeler Road (SR 1371) crossing of Middle Creek. Channel is approximately 2
meters wide before it broadens into a larger inundated wetland system with no defined
channel. The wetland complex also encompasses another UT to Middle Creek that flows
into Middle Creek, approxiinately 160 meters upstream of this UT confluence. Substrate
is dominated by silt and mud. No mollusks were located during the 0.5 person hour of
search time. The survey endpoint depicted on Figure 2, Sheet 4 occurs within this
wetland complex, and not within a defined channel.
Panther Branch Site-100611.3
This section of Panther Branch was accessed off the Old Stage Road (SR 1006) crossing.
The incised channel ranges from 3 to 4 meters wide with unstable 2-meter high banks. In
order of dominance, substrate consists of sand, gravel, silt, cobble, and clay. Surveys
were conducted for 1.5 person hours.
Table 17. Panther Branch Site-100611.3: Mollusk Snecies Found
Scientific Name
Freshwater Mussels
Elliptio icterina
Freshwater Snails and Clams
Campeloma decisum
Common Name
Variable Spike
Pointed Camneloma
#
38
Abundance/
CPUE
CPUE
25.33/hr
Relative
Abundance
Uncommon
Little Creek Site-100623.1
This section of Little Creek was accessed off the NC 42 crossing. Channel width ranges
from 3 to 5 meters with relatively stable 1- to 2-meter high banks. In order of
dominance, substrate consists of sand, pebble, gravel, clay, silt, and cobble. Surveys
were conducted for 4.33 person hours.
Triangle Expressway Southeast Extension 11 The Catena Group
March 20l 1 Job # 3271

Table 18. Little Creek Site-100623.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 316 72.98/hr
Elliptio icterina Variable Spike 173 39.95/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Common
Little Creek Site-100623.2
This section of Little Creek is located just upstream of Site-100623.1. Channel width
ranges from 2 to 5 meters with 1-meter high moderately eroded banks. In order of
dominance, substrate consists of sand, pebble, gravel, clay, silt, and cobble. Surveys
were conducted for LS person hours.
Table 19. Little Creek Site-100623.2: Mollusk Snecies Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Elliptio icterina
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Common Name
Eastern Elliptio
Variable Spike
Pointed Campeloma
Asian Clam
#
143
25
�
�
Abundance/
CPUE
CPUE
95.33/hr
16.67/hr
Relative
Abundance
Common
Common
Guffy Branch Site-100623.4
This section of Guffy Branch extends from the confluence with Little Creek upstream to
the Saul's Road (SR 2727) crossing. The channel width ranges from 3 to 4 meters, and
the slightly eroded banks are between 1 and LS meters high. The substrate is dominated
by sand, and cobble. A mixture of forest and pastureland occurs along the stream.
Surveys were conducted for 3.0 person hours.
Table 20. Guffy Branch Site-100623.4: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Snike
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Triangle Expressway Southeast Extension
March 20l 1
Pointed Campeloma
Asian Clam
12
#
135
14
Abundance/
CPUE
CPUE
45.00/hr
4.67/hr
Relative
Abundance
Uncommon
Patchy,
Common
The Catena Group
Job # 3271

Guffy Branch Site-100623.5
This section of Guffy Branch extends from the Saul's Road (SR 2727) crossing to a point
approximately 600 meters upstream. The channel width ranges from 2 to 3 meters, and
the fairly stable banks are 1 meter high. The substrate is dominated by sand, and cobble,
with areas of bedrock interspersed. A mixture of forest and fallow agricultural land
occurs along the stream. Surveys were conducted for 1.17 person hours.
Table 21. Guffy Branch Site-100623.5: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Freshwater Snails and Clams
Campeloma decisum
Corbicula lluminea
0
Pointed Campeloma
Asian Clam I �
Abundance/
CPUE
CPUE
81. 20/hr
11.95/hr
Relative
Abundance
Uncommon
Patchy,
Common
Buffalo Branch Site-100623.6
This section of Buffalo Branch extends from the NC 50 crossing to a point approximately
450 meters upstream, near the Johnston/Wake County line. The channel width ranges
from 3 to 4 meters, and the fairly stable banks are 1 meter high. The substrate is
dominated by sand, and cobble. The surrounding landscape is forested. Surveys were
conducted for 2.00 person hours.
Table 22. Buffalo Branch Site-100623.6: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 92 46.00/hr
Elliptio icterina Variable Spike 14 7.00/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Abundant
2.2.2. Central Section
The Central section of the project corridar occurs within the Swift Creek Subbasin
between NC 50 and US 70. Two general areas of Swift Creek were evaluated: 1) Swift
Creek between Lake Wheeler and Lake Benson (8 sites); and 2) Swift Creek between
Lake Benson and the Cornwallis Road (SR 1525) crossing (55 Sites). Tributaries to
Swift Creek that were evaluated include Mahler's Creek, UT to Swift Creek, White Oak
Creek, and Little Creek (7 sites).
Triangle Expressway Southeast Extension 13 The Catena Group
March 20l 1 Job # 3271

Swift Creek between Lake Wheeler and Lake Benson Site-101124.4
This section of Swift Creek extends from a point approximately 250 meters below the
spillway of Lake Wheeler upstream to the spillway. The stream channel ranges from 8 to
10 meters wide, with relatively stable banks up to 2 meters high. The substrate is
dominated by sand and gravel, with clay and silt along the banks. Surveys were
conducted for 3.58 person hours.
Table 23. Swift Creek Site-101124.4: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Utterbackia imbecillis Paper Pondshell
Freshwater Snails and Clams �
Corbicula fluminea Asian Clam
#
105
9
5
Abundance/
CPUE
CPUE
29.33/hr
2.51 /hr
1. 40/hr
Relative
Abundance
Abundant
Swift Creek between Lake Wheeler and Lake Benson Site-101124.3
This site occurs in an extensive riffle habitat in a bend of Swift Creek approximately
halfway between the Lake Wheeler spillway and the US 401 crossing of the creek. The
stream channel is 6 meters wide, with relatively stable banks 1 meter high. The substrate
is dominated by cobble and gravel, with clay and silt along the banks. Surveys were
conducted for 3.67 person hours.
Table 24. Swift Creek Site-101124.3: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Sbike
Freshwater Snails and Clams �
Corbicula fluminea Asian Clam
Abundance/
CPUE
CPUE
22.89/hr
8.99/hr
Relative
Abundance
Abundant
Swift Creek between Lake Wheeler and Lake Benson Site-101124.2
This site occurs in a long run and pool habitat sequence approximately 600 meters above
the US 401 crossing of the creek. The stream channel is 6 to 9 meters wide, with
relatively stable banks 1.5 meters high. The substrate is dominated by sand and gravel,
with clay and silt along the banks. Surveys were conducted for 3.5 person hours.
Triangle Expressway Southeast Extension 14
March 20l 1
The Catena Group
Job # 3271

Table 25. Swift Creek Site-101124.2: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Pointed Campeloma
Asian Clam
#
82
17
Abundance/
CPUE
CPUE
23.43/hr
4.86/hr
Relative
Abundance
Uncommon
Abundant
Swift Creek between Lake Wheeler and Lake Benson Site-101124.1
This site occurs in an extensive shallow run and riffle habitat approXimately 400 meters
above the US �401 crossing of the creek. The stream channel is 6 to 8 meters wide, with
relatively stable banks 1.5 meters high. The substrate is dominated by sand and gravel,
with clay and silt along the banks. Surveys were conducted for 3.08 person hours.
Table 26. Swift Creek Site-101124.1: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Pointed Campeloma
Asian Clam
#
54
23
Abundance/
CPUE
CPUE
17.53/hr
7.47/hr
Relative
Abundance
Uncommon
Abundant
Swift Creek between Lake Wheeler and Lake Benson Site-101123.6
This site occurs in a long run, pool and slack-water habitat sequence, approximately 200
meters below the CSX crossing of the creek near US 401. The stream channel is 7 to 9
meters wide, with moderately eroded banks 2 meters high. The substrate is dominated by
unconsolidated sand with clay and silt banks. Surveys were conducted for 1.33 person
hours.
Table 27. Swift Creek Site-101123.6: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Snike
Freshwater Snails and Clams
Corbicula fluminea
Asian Clam
#
27
7
0
Abundance/
CPUE
CPUE
20.30/hr
5.26/hr
Relative
Abundance
Common
Triangle Expressway Southeast Extension I S The Catena Group
March 20l 1 Job # 3271

Swift Creek between Lake Wheeler and Lake Benson Site-101123.5
This site occurs in a long pool and slack-water section with limited riffle and run habitat,
approximately 1,050 meters above the Old Stage Road (SR 1006) crossing of the creek.
The stream channel is 8 to 10 meters wide, with moderately eroded banks 2 meters high.
The substrate is dominated by unconsolidated sand with clay and silt banks. Surveys
were conducted for 2.13 person hours.
Table 28. Swift Creek Site-101123.5: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Elliptio producta Atlantic Spike
Freshwater Snails and Clams �
Corbicula fluminea Asian Clam
Abundance/
CPUE
CPUE
9.86/hr
5.16/hr
0.47/hr
Relative
Abundance
Common
Swift Creek between Lake Wheeler and Lake Benson Site-101123.4
This site occurs in a long (60 meter) extensive riffle and run habitat sequence
approximately 650 meters above the Old Stage Road (SR 1006) crossing of the creek.
The stream channel is 6 to 8 meters wide, with moderately eroded banks 2 meters high.
The substrate is dominated by gravel and sand with clay banlcs. Surveys were conducted
for 2.20 person hours.
Table 29. Swift Creek Site-101123.4: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Elliptio producta Atlantic Snike
Freshwater Snails and Clams �
Corbicula fluminea Asian Clam
Abundance/
CPUE
CPUE
34.09/hr
43.64/hr
0.45/hr
Relative
Abundance
Common
Swift Creek between Lake Wheeler and Lake Benson Site-101123.3
This site occurs in a long run, pool, and slack-water habitat sequence approximately 400
meters above the Old Stage Road (SR 1006) crossing of the creek. The stream channel is
8 to 10 meters wide, with moderately eroded banks 2 meters high. The substrate is
dominated by unconsolidated sand, gravel, and cobble with clay banks. Surveys were
conducted for 1.80 person hours.
Triangle Expressway Southeast Extension 16 The Catena Group
March 20l 1 Job # 3271

Table 30. Swift Creek Site-101123.3: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Freshwater Snails and Clams � �
Corbicula fluminea Asian Clam
0
�
0
0
�
Abundance/
CPUE
CPUE
2.22/hr
Relative
Abundance
Common
Mahler's Creek Site-101124.5
This section of Mahler's Creek occurs in the vicinity of the New Bethel Church Road
(SR 2708) crossing. The channel ranges from 2 to 4 meters wide with 1- to 2-meter high
moderately eroded banks. The substrate is dominated by shifting sand and silt. Surveys
were conducted for LS person hours.
Table 3L Mahlers Creek Site-101124.5: Mollusk Sbecies Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Freshwater Snails and Clams
Corbicula fluminea
Common Name
Eastern Elli
Asian Clam
0
�
0
0
Abundance/
CPUE
CPUE
1.33/hr
Relative
Abundance
Uncommon
Mahler's Creek Site-101124.8
This section of Mahler's Creelc extends from the confluence with Swift Creek to a point
approximately 370 meters upstream. The channel ranges from 2 to 3 meters wide with 1-
to 2-meter high severely eroded banks. The substrate is dominated by shifting sand and
silt. Surveys were conducted for 1.5 person hours.
Table 32. Mahlers Creek Site-101124.8: Mollusk Species Found
Scientific Name
Freshwater Mussels
Elliptio comblanata
Freshwater Snails and Clams
Corbicula fluminea
Common Name
Eastern Elliptio
Asian Clam
0
�
0
0
Abundance/
CPUE
CPUE
4.0/hr
Relative
Abundance
Patchy,
Common
Swift Creek between Lake Benson and Cornwallis Road Site-101124.6
This site extends from the Mahler's Creek confluence upstream to a point approximately
250 meters below the NC 50 crossing of Swift Creek. The stream channel is 8 to 10
meters wide, with moderately eroded banks 2.5 meters high. A small beaver dam occurs
within this reach, creating slack-water pool habitat. The substrate is dominated by sand
and silt, with large amounts of detritus and woody debris. Surveys were conducted far
1.25 person hours.
Triangle Expressway Southeast Extension 17 The Catena Group
March 20l 1 Job # 3271

Table 33. Swift Creek Site-101124.6: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Elliptio mediocris No Common Name
Freshwater Snails and Clams � �
Corbicula fluminea Asian Clam
0
Abundance/
CPUE
CPUE
4.00/hr
0.80/hr
0.80/hr
Relative
Abundance
Common
Swift Creek between Lake Benson and Cornwallis Road Site-101124.7
This site occurs in a shallow riffle habitat within an island channel on the left descending
side of Swift Creek, approximately 50 meters in length just below the Mahler's Creek
confluence. The island stream channel is 5 meters wide, with severely eroded banks 2.5
meters high. The substrate is dominated by shifting sand and pebble. Surveys were
conducted for 1.0 person hour.
Table 34. Swift Creek Site-101124.7: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Ellintio comnlanata Eastern Ellit�tio
Freshwater Snails and Clams � �
Corbicula flumin�ea Asian Clam
0
�
0
�
Abundance/
CPUE
CPUE
6.00/hr
Relative
Abundance
Common
Swift Creek between Lake Benson and Cornwallis Road Site-100708.5
This site occurs in a riffle/run/pool habitat sequence approximately 500 meters
downstream of the Mahler's Creek confluence. The stream channel is 8 to 10 meters
wide, with moderately eroded banks 2.5 meters high. The substrate is dominated by sand
and gravel. Surveys were conducted for 2.08 person hours.
Triangle Expressway Southeast Extension 18 The Catena Group
March 20l 1 Job # 3271

1 able 3�. �w1Tt l;reeK �1te- l UU /U�.J: 1V1o11usK �pecles rounct
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 110 52.88/hr
Elliptio icterina Variable Spike 6 2.88/hr
Lampsilis radiata Eastern Lampmussel 1 0.48/hr
Pyganodon cataracta Eastern Floater 1 0.48/hr
Utterbackia imbecillis Paper Pondshell 13 6.25/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-100708.4
This site occurs in wide bend of Swift Creek, approximately 750 meters downstream of
the Mahler's Creek confluence. The habitat consists of shallow sandbar/riffles grading to
a deep scoured run. The stream channel is 8 to 10 meters wide, with moderately eroded
banks 2.5 meters high. The substrate is dominated by sand and gravel, with clay banks.
Surveys were conducted for 4.17 person hours.
Table 36. Swift Creek Site-100708.4: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 238 57.07/hr
Elliptio icterina Variable Spike 4 0.96/hr
Pyganodon cataracta Eastern Floater 1 0.24/hr
Utterbackia imbecillis Paper Pondshell 16 3.84/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-100708.3
This site occurs in a shallow sandbar/riffle and run habitat, approximately 920 meters
downstream of the Mahler's Creek confluence. The stream channel is 8 to 10 meters
wide, with moderately eroded banks 2.5 meters high. The substrate is dominated by sand
and pebble, with clay banks. Surveys were conducted for 4.17 person hours.
Triangle Expressway Southeast Extension 19 The Catena Group
March 20l 1 Job # 3271

Table 37. Swift Creek Site-100708.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 575 137.89/hr
Elliptio congaYea Carolina Slabshell 1 0.24/hr
Elliptio icterina Variable Spike 30 7.19/hr
Elliptio roanokensis Roanoke Slabshell 1 0.24/hr
Lampsilis radiata Eastern Lampmussel 3 0.72/hr
Pyganodon cataracta Eastern Floater 11 2.64/hr
Utterbackia imbecillis Paper Pondshell 20 4.80/hr
Relative
Freshwater Snails and Clams � � Abundance
Patchy,
Campeloma decisum Pointed Campeloma � Common
Patchy,
Physella sp. A Physid Snail � Common
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-100708.2
This site occurs in a narrow riffle and run habitat, approximately 1,020 meters
downstream of the Mahler's Creek confluence. The stream channel is 6 meters wide,
with moderately eroded banl�s 2.5 meters high. The substrate is dominated by sand and
pebble, with clay banks. Surveys were conducted for 3.0 person hours.
Table 38. Swift Creek Site-100708.2: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 250 83.33/hr
Elliptio congarea Carolina Slabshell 1 0.33/hr
Elliptio icterina Variable Spike 11 3.67/hr
Lampsilis radiata Eastern Lampmussel 5 1.67/hr
Strophitus undulatus Creeper 1 0.33/hr
Utterbackia imbecillis Paper Pondshell 5 1.67/hr
Freshwater Snails and Clams � � Relative
Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-1007081
This site occurs in a narrowly meandering section of the creek, approximately 1,350
meters downstream of the Mahler's Creek confluence. The stream channel is 6 to 10
meters wide, with moderately eroded banks 2.5 meters high. The habitat consists of a
series of short riffle run sequences dominated by cobble, sand, and gravel substrate, with
clay banlcs. Surveys were conducted for 2.92 person hours.
Triangle Expressway Southeast Extension 20 The Catena Group
March 20l 1 Job # 3271

Table 39. Swift Creek Site-100708.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 307 105.14/hr
Elliptio congaYea Carolina Slabshell 3 1.03/hr
Elliptio icterina Variable Spike 28 9.59/hr
Elliptio roanokensis Roanoke Slabshell 1 0.34/hr
Lampsilis radiata Eastern Lampmussel 2 0.68/hr
Pyganodon cataracta Eastern Floater 1 0.34/hr
Relative
Freshwater Snails and Clams � � Abundance
Co�bicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101123.2
This site occurs in a long straight section of Swift Creek, approximately 1,800 meters
downstream of the Mahler's Creelc confluence. The stream channel is 10 to 12 meters
wide, with moderately eroded banks 2 meters high. Habitat consists of a shallow run
grading to a slackwater pool created by a small beaver dam. Substrate is dominated by
sand, with clay along the banks. Surveys were conducted for 2.13 person hours.
Table 40. Swift Creek Site-101123.2: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 144 67.60/hr
Elliptio congarea Carolina Slabshell 2 0.94/hr
Elliptio icterina Variable Spike 20 9.39/hr
Elliptio mediocris No Common Name 3 1.41/hr
Elliptio roanokensis Roanoke Slabshell 1 0.47/hr
Lampsilis radiata Eastern Lampmussel 1 0.47/hr
Pyganodon cataracta Eastern Floater 9 4.22/hr
Utterbackia imbecillis Paper Pondshell 4 1.88/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101123.1
This site occurs adjacent to the Indian Overlook Residential Community and extends
from the WWTP discharge point upstream for 167 meters. Habitat consists of a straight
relatively shallow pool habitat, with small sandbar and log jam created riffles
interspersed. The stream channel is 10 meters wide, with moderately eroded banks 2
meters high. Substrate is dominated by sand and gravel, with clay along the banks.
Surveys were conducted for 8.53 person hours.
Triangle Expressway Southeast Extension 21 The Catena Group
March 20l 1 Job # 3271

Table 41. Swift Creek Site-101123.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 578 67.76/hr
Elliptio congaYea Carolina Slabshell 6 0.70/hr
Elliptio icterina Variable Spike 51 5.98/hr
Elliptio producta Atlantic Spike 3 0.35/hr
Elliptio roanokensis Roanoke Slabshell 1 0.12/hr
Lampsilis radiata Eastern Lampmussel 3 0.35/hr
Pyganodon cataracta Eastern Floater 47 5.51/hr
Utterbackia imbecillis Paper Pondshell 2 0.23/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula flumin�ea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-1010271
This site occurs adjacent to the Indian Overlook Residential Community and extends
from a point approximately 167 meters downstream of the WWTP discharge point up to
the discharge point. The site occurs in a broad bend of the creek, and contains shallow
riffle and run habitats dominated by gravel, sand, and cobble substrate. The stream
channel is 10 to 12 meters wide, with moderately eroded banks 2 meters high. Surveys
were conducted for 10.58 person hours.
Table 42. Swift Creek Site-101027.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 185 17.48/hr
Elliptio icterina Variable Spike 17 1.61lhr
Fusconaia masoni Atlantic Pigtoe 2 0.19/hr
Lampsilis radiata Eastern Lampmussel 1 0.09/hr
Pyganodon cataracta Eastern Floater 83 7.84/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.4
This site occurs in short, cobble and gravel dominated, riffle habitat, in a narrow bend of
the creek, approximately 180 meters below the Indian Overlook WWTP discharge. The
stream channel is 8 meters wide, with moderately eroded banks 2 meters high. Surveys
were conducted far 0.53 person hours.
Triangle Expressway Southeast Extension 22 The Catena Group
March 20l 1 Job # 3271

Table 43. Swift Creek Site-101027.4: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Freshwater Snails and Clams � �
Corbicula flur�cinea Asian Clam
0
Abundance/
CPUE
CPUE
9.43/hr
1.89/hr
Relative
Abundance
Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.3
This site occurs in wide straight section of the creek approximately 240 meters below the
Indian Overlook WWTP discharge. The stream channel is 15 meters wide, with
moderately eroded banks 2 meters high. Habitat consists of a series of small riffle, run,
and pool habitats. Surveys were conducted for 1.0 person hour.
Table 44. Swift Creek Site-101027.3: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels
Elliptio complanata
Elliptio icterina
Pyganodon cataracta
Freshwater Snails and Clams
Corbicula fluminea
Eastern Elliptio
Variable Spike
Eastern Floater
Asian Clam
#
61
7
3
Abundance/
CPUE
CPUE
61.00/hr
7.00/hr
3.00/hr
Relative
Abundance
Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.2
This site occurs in wide straight section of the creek approximately 470 meters below the
Indian Overlook WWTP discharge. The stream channel is 15 meters wide, with severely
eroded banks 2 meters high. Large sandbars and log jams occur throughout this reach,
and the habitat consists of shallow runs dominated by shifting sand, and deep pools above
the log jams with clay banks. Surveys were conducted for 1.47 person hours.
Table 45. Swift Creek Site-101027.2: Mollusk St�ecies Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Elliptio icterina
Lampsilis radiata
Pv�anodon cataracta
Freshwater Snails and Clams
Corbicula fZuminea
Common Name
Eastern Elliptio
Variable Spike
Eastern Lampmussel
Eastern Floater
Asian Clam
#
29
Shell
Shell
4
0
Abundance/
CPUE
CPUE
19.73/hr
0.0/hr
0.0/hr
2.72/hr
Relative
Abundance
Abundant
Triangle Expressway Southeast Extension 23 The Catena Group
March 20l 1 Job # 3271

Swift Creek between Lake Benson and Cornwallis Road Site-101007.6
This site was accessed from the Garner WWTP Spray Field facility off Wrenn Road, and
occurs in a narrow bend of the creek approximately 1,300 meters below the Indian
Overlook WWTP discharge. The stream channel is 15 meters wide, with moderately
eroded banks 1.5 meters high. Habitat consists of shallow riffles and runs dominated by
sand with clay banks. Surveys were conducted for 2.67 person hours.
Table 46. Swift Creek Site-101007.6: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 3 1.12/hr
Elliptio complanata Eastern Elliptio 219 82.02/hr
Elliptio congarea Carolina Slabshell 1 0.37/hr
Elliptio icterina Variable Spike 30 11.24/hr
Elliptio mediocris No Common Name 1 0.37/hr
Lampsilis radiata Eastern Lampmussel 1 0.37/hr
Pyganodon cataracta Eastern Floater 1 0.37/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula flu�ninea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101007.5
This 30 meter long site was accessed from the Garner WWTP Spray Field facility off
Wrenn Road, and occurs in a narrow, straight run habitat approximately 1,370 meters
below the Indian Overlook WWTP discharge. The stream channel is 15 meters wide,
with moderately eroded banks 1.5 meters high. Substrate is dominated by sand and
pebble with clay banks. Surveys were conducted for 1.92 person hours.
Table 47. Swift Creek Site-101007.5: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Fusconaia masoni Atlantic Pi�toe
Freshwater Snails and Clams �
Corbicula flu�ninea Asian Clam
#
154
40
2
Abundance/
CPUE
CPUE
80.21 /hr
20.83/hr
1.04/hr
Relative
Abundance
Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101007.1
This 30-meter long site was accessed from the Garner WWTP Spray Field facility off
Wrenn Road, and occurs in a bend with shallow riffle/run habitat approximately 1,630
meters below the Indian Overlook WWTP discharge. The stream channel is 15 meters
wide, with moderately eroded banks 1.5 meters high. Substrate is dominated by sand and
pebble with clay banks. Surveys were conducted for 3.13 person hours.
Triangle Expressway Southeast Extension 24 The Catena Group
March 20l 1 Job # 3271

1 able 4tS. �w1Tt �;reeK �1te-1 U 1 UU /.1 : 1V1o11usK �pecles rounct
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 211 67.41/hr
Elliptio icterina Variable Spike 36 11.50/hr
Elliptio mediocris No Common Name 1 0.32/hr
Elliptio producta Atlantic Spike 1 0.32/hr
Strophitus undulatus Creeper 1 0.32/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101007.4
This site was accessed from the Garner WWTP Spray Field facility off Wrenn Road, and
occurs in a wide, straight section of the creek approximately 1,830 meters below the
Indian Overlook WWTP discharge. The stream channel is 18 meters wide, with severely
eroded banks 2 meters high. Habitat is classified as a shallow run dominated by sand and
pebble with clay banks. A large amount of woody debris is present. Surveys were
conducted for 2.06 person hours.
Table 49. Swift Creek Site-101007.4: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 113 54.85/hr
Elliptio icterina Variable Spike 18 8.74/hr
Elliptio producta Atlantic Spike 1 0.48/hr
Fusconaia masoni Atlantic Pigtoe 1 0.48/hr
Lampsilis radiata Eastern Lampmussel 1 0.48/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101007.3
This site was accessed from the Garner WWTP Spray Field facility off Wrenn Road, and
occurs in a narrow bend at the confluence with an intermittent tributary from the north,
approximately 1,930 meters below the Indian Overlook WWTP discharge. The stream
channel is 12 meters wide, with severely eroded banks 1.5 meters high. Habitat is
classified as a shallow riffle/run dominated by sand and pebble with clay banks. A large
amount of woody debris is present. Surveys were conducted for 2.75 person hours.
Triangle Expressway Southeast Extension 25 The Catena Group
March 20l 1 Job # 3271

Table 50. Swift Creek Site-101007.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 280 101.82/hr
Elliptio congaYea Carolina Slabshell 3 1.09/hr
Elliptio icterina Variable Spike 48 17.45/hr
Lampsilis radiata Eastern Lampmussel 1 0.36/hr
Pyganodon cataracta Eastern Floater 1 0.36/hr
Strophitus undulatus Creeper 1 0.36/hr
Relative
Freshwater Snails and Clams � � Abundance
Co�bicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101007.2
This site was accessed from the Garner WWTP Spray Field facility off Wrenn Road, and
occurs in a long, straight section of the stream approximately 1,100 meters above the
Wake/Johnston County line. The stream channel is 15 meters wide, with severely eroded
banks 1.5 meters high. Habitat consists primarily of deep runs and pools with a few
small riffle areas that have formed below fallen trees. The substrate is dominated by sand
and pebble with clay banks. Surveys were conducted for 4.0 person hours.
Table 51. Swift Creek Site-101007.2: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Pvuanodon cataracta Eastern Floater
Freshwater Snails and Clams � �
Corbicula fluminea Asian Clam
0
�
Abundance/
CPUE
CPUE
86.75/hr
3.50/hr
0.25/hr
Relative
Abundance
Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.10
This site was accessed from the I-40 crossing of the creek, and occurs in a wide section of
the stream approximately 100 meters above the Wake/Johnston County line. The stream
channel is 12 meters wide, with moderately eroded banks 2 meters high. Habitat consists
primarily of deep runs and pools with a few small riffle areas that have farmed below
fallen trees. The substrate is dominated by sand and pebble with clay banks. Surveys
were conducted for 2.33 person hours.
Triangle Expressway Southeast Extension 26 The Catena Group
March 20l 1 Job # 3271

Table 52. Swift Creek Site-101027.10: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 2 0.86/hr
Elliptio complanata Eastern Elliptio 221 94.85/hr
Elliptio congarea Carolina Slabshell 1 0.43/hr
Elliptio icterina Variable Spike 35 15.02/hr
Elliptio lanceolata Yellow Lance 1 0.43/hr
Fusconaia rnasoni Atlantic Pigtoe 1 0.43/hr
Strophitus undulatus Creeper 1 0.43/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.9
This site was accessed from the I-40 crossing of the creek, and occurs in a narrow straight
section of the stream in the vicinity of the Wake/Johnston County line. The stream
channel ranges from 8 to 10 meters wide, with moderately eroded banks 2 meters high.
The site consists of a sequence of shallow glide, riffle, and run habitat sequences. The
substrate is dominated by sand and gravel with clay banks. Surveys were conducted for
3.73 person hours.
Table 53. Swift Creek Site-101027.9: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.27/hr
Elliptio complanata Eastern Elliptio 336 90.08/hr
Elliptio congarea Carolina Slabshell 3 0.80/hr
Elliptio icterina Variable Spike 50 13.40/hr
Lampsilis radiata Eastern Lampmussel Shell 0.0/hr
Pyganodon cataracta Eastern Floater 2 0.54/hr
Strophitus undulatus Creeper 2 0.54/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.8
This 30-meter long site was accessed from the I-40 crossing of the creek, and occurs in a
broad bend of the stream approximately 280 meters downstream of the Wake/Johnston
County line. The stream channel ranges from 6 to 10 meters wide, with moderately
eroded banks 2 to 3-meters high. The site consists of a sequence of shallow, glide, riffle
and run habitat sequences. The substrate is dominated by bedrock overlain with sand,
gravel and cobble with clay banks. Surveys were conducted for 3.67 person hours.
Triangle Expressway Southeast Extension 27 The Catena Group
March 20l 1 Job # 3271

1 able �4. �w1Tt l;reeK �1te- l U l UG /.�: 1V1o11usK �pecles r ounci
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta hete�odon Dwarf Wedgemussel 1 0.27/hr
Alasmidonta undulata Triangle Floater 4 1.09/hr
Elliptio complanata Eastern Elliptio 915 249.32/hr
Elliptio congarea Carolina Slabshell 14 3.81/hr
Elliptio icterina Variable Spike 133 36.24/hr
Elliptio lanceolata Yellow Lance 1 0.27/hr
Elliptio roanokensis Roanoke Slabshell 5 1.36/hr
Fusconaia masoni Atlantic Pigtoe 2 0.54/hr
Lampsilis radiata Eastern Lampmussel 1 0.27/hr
Strophitus undulatus Creeper 2 0.54/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.7
This site was accessed from the I-40 crossing of the creek, and occurs in a narrow straight
section between two bends of the stream in approximately 320 meters downstream of the
Wake/Johnston County line. The stream channel ranges from 6 to 8 meters wide, with
moderately eroded banks 2 meters high. The site contains a sequence of shallow, glide,
riffle and run habitat sequences. The substrate is dominated by sand and pebble with clay
banks. Surveys were conducted for 3.0 person hours.
Table 55. Swift Creek Site-101027.7: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 2 0.67/hr
Elliptio complanata Eastern Elliptio 190 63.33/hr
Elliptio congarea Carolina Slabshell 5 1.67/hr
Elliptio icterina Variable Spike 17 5.67/hr
Elliptio mediocris No Common Name 2 0.67/hr
Elliptio roanokensis Roanoke Slabshell 3 1.00/hr
Fusconaia masoni Atlantic Pigtoe 1 0.33hr
Lampsilis radiata Eastern Lampmussel 1 0.33/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.6
This site was accessed from the I-40 crossing of the creek, and occurs between two
narrow bends approximately 300 meters upstream of I-40. The stream channel ranges
from 6 to 8 meters wide, with moderately eroded banks 2 meters high. Habitat consists
Triangle Expressway Southeast Extension 28 The Catena Group
March 20l 1 Job # 3271

primarily of runs and pools, with limited riffles. The substrate is dominated by sand and
pebble with clay banks and scattered boulders. Surveys were conducted for 3.67 person
hours.
Table 56. Swift Creek Site-101027.6: Mollusk Species Found
Abundance/
Scientif"ic Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 2 0.54/hr
Elliptio complanata Eastern Elliptio 284 77.38/hr
Elliptio congarea Carolina Slabshell 11 3.00/hr
Elliptio icterina Variable Spike 29 7.90/hr
Elliptio mediocris No Common Name 2 0.54/hr
Elliptio roanokensis Roanoke Slabshell 1 0.27/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluininea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101027.5
This site was accessed from the I-40 crossing of the creek, and occurs in a long, straight,
narrow section of the stream approximately 200 meters upstream of I-40. The stream
channel ranges from 5 to 8 meters wide, with moderately eroded banks 2 meters high.
Habitat consists primarily of runs and pools, with limited riffles. The substrate is
dominated by sand and pebble with clay banks and scattered boulders. Surveys were
conducted for 2.87 person hours.
Table 57. Swift Creek Site-101027.5: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 63 21.95/hr
Elliptio congarea Carolina Slabshell 3 1.04/hr
Elliptio icterina Variable Spike 13 4.53/hr
Elliptio roanokensis Roanoke Slabshell 2 0.70/hr
Lampsilis �adiata Eastern Lampmussel 2 0.70/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101021.7
This site occurs just below the I-40 crossing of the creek. The stream channel ranges
from 8 to 10 meters wide, with severely eroded banks 2.5 meters high. Habitat consists
primarily of runs and pools, with limited riffles created by sandbars and log jams. The
substrate is dominated by shifting sand. Surveys were conducted for 2.92 person hours.
Triangle Expressway Southeast Extension 29 The Catena Group
March 20l 1 Job # 3271

Table 58. Swift Creek Site-101021.7: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.34/hr
Elliptio complanata Eastern Elliptio 55 18.84/hr
Elliptio congarea Carolina Slabshell 5 1.71/hr
Elliptio icterina Variable Spike 8 2.74/hr
Lampsilis radiata Eastern Lampmussel 1 0.34/hr
Strophitus undulatus Creeper 1 0.34/hr
Relative
Freshwater Snails and Clams � � Abundance
Co�bicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101021.6
This site occurs approximately 380 meters below the I-40 crossing of the creek in a long
straight section. The stream channel ranges from 8 to 10 meters wide, with moderately
eroded banks 2.5 meters high. The site contains a sequence of shallow, glide, riffle and
run habitat sequences. The substrate is dominated by sand and pebble with clay banks.
Surveys were conducted for 6.42 person hours.
Table 59. Swift Creek Site-101021.6: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 2 0.31/hr
Elliptio complanata Eastern Elliptio 200 31.15/hr
Elliptio congarea Carolina Slabshell 1 0.16/hr
Elliptio icterina Variable Spike 39 6.07/hr
Elliptio lanceolata Yellow Lance 1 0.16/hr
Elliptio roanokensis Roanoke Slabshell 3 0.47/hr
Fusconaia masoni Atlantic Pigtoe 3 0.47/hr
Lampsilis radiata Eastern Lampmussel 2 0.31/hr
Pyganodon cata�acta Eastern Floater 1 0.16/hr
Strophitus undulatus Creeper 1 0.16/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula flun�inea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101021.5
This site occurs approximately 480 meters below the I-40 crossing of the creek in a long
straight run habitat. The stream channel ranges from 7 to 9 meters wide, with moderately
eroded banks 2 meters high. The substrate is dominated by sand and gravel, with clay
banks and occasional cobble and boulder. Surveys were conducted for 3.85 person hours.
Triangle Expressway Southeast Extension 30 The Catena Group
March 20l 1 Job # 3271

1 able bU. �w1Tt l;reeK �1te-1 U 1 UL 1.J: 1V1o11usK �pecles rounct
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 62 16.10/hr
Elliptio congaYea Carolina Slabshell 9 2.34/hr
Elliptio icterina Variable Spike 16 4.16/hr
Elliptio roanokensis Roanoke Slabshell 2 0.52/hr
Fusconaia masoni Atlantic Pigtoe 2 0.52/hr
Pyganodon cataracta Eastern Floater 1 0.26/hr
Strophitus undulatus Creeper 1 0.26/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101021.4
This site occurs approximately 580 meters below the I-�}0 crossing of the creek in a long,
straight section. The stream channel ranges from 8 to 10 meters wide, with moderately
eroded banks 2.5 meters high. The site contains a sequence of shallow glide, riffle, and
run habitat sequences. The substrate is dominated by sand and pebble with clay banks.
Surveys were conducted for 3.25 person hours.
Table 61. Swift Creek Site-101021.4: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.31/hr
Elliptio complanata Eastern Elliptio 231 71.08/hr
Elliptio congarea Carolina Slabshell 10 3.08/hr
Elliptio icterina Variable Spike 28 8.62/hr
Elliptio roanokensis Roanoke Slabshell 2 0.62/hr
Fusconaia masoni Atlantic Pigtoe 2 0.62/hr
Strophitus undulatus Creeper 1 0.31/hr
Relative
Freshwater Snails and Clams � � Abundance
Patchy,
Campeloma decisu�n Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101021.3
This 30 meter long site occurs approximately 620 meters below the I-40 crossing of the
creek in a long, straight section. The stream channel ranges from 8 to 10 meters wide,
with moderately eroded banks 2.5 meters high. Habitat consists of a shallow riffle
transitioning to a deep run. The substrate is dominated by sand and gravel with clay
banks. Surveys were conducted for 2.83 person hours.
Triangle Expressway Southeast Extension 31 The Catena Group
March 20l 1 Job # 3271

Table 62. Swift Creek Site-101021.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 126 44.52/hr
Elliptio congaYea Carolina Slabshell 2 0.71/hr
Elliptio icterina Variable Spike 16 5.65/hr
Lampsilis radiata Eastern Lampmussel 1 0.35/hr
Strophitus undulatus Creeper 1 0.35/hr
Relative
Freshwater Snails and Clams � � Abundance
Patchy,
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101021.2
This site occurs approximately 700 meters below the I-40 crossing of the creek in a long,
straight, narrow section. The stream channel ranges from 6 to 8 meters wide, with fairly
stable banks 2 meters high. The site contains a braided channel of shallow glide, riffle,
and run habitat sequences created by sandbars. The substrate is dominated by sand and
pebble with clay banks. Surveys were conducted for 4.67 person hours.
Table 63. Swift Creek Site-101021.2: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.21/hr
Elliptio complanata Eastern Elliptio 234 SO.11/hr
Elliptio congarea Carolina Slabshell 4 0.86/hr
Elliptio icterina Variable Spike 62 13.28/hr
Elliptio mediocris No Common Name 1 0.21/hr
Elliptio roanokensis Roanoke Slabshell 2 0.43/hr
Fusconaia masoni Atlantic Pigtoe 2 0.43/hr
Lampsilis radiata Eastern Lampmussel 4 0.86/hr
Strophitus undulatus Creeper 8 1.71/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101021.1
This site occurs approximately 800 meters below the I-40 crossing of the creek in a long,
straight section. The stream channel ranges from 8 to 10 meters wide, with fairly stable
banks 2 meters high. The site contains riffle and run habitats. The substrate is dominated
by sand and pebble with clay banks. Surveys were conducted for 3.5 person hours.
Triangle Expressway Southeast Extension 32 The Catena Group
March 20l 1 Job # 3271

Table 64. Swift Creek Site-101021.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 2 0.57/hr
Elliptio complanata Eastern Elliptio 147 42.00/hr
Elliptio congarea Carolina Slabshell 4 1.14/hr
Elliptio icterina Variable Spike 23 6.57/hr
Elliptio lanceolata Yellow Lance 1 0.28/hr
Elliptio producta Atlantic Spike 1 0.28/hr
Elliptio roanokensis Roanoke Slabshell 1 0.28/hr
Fusconaia masoni Atlantic Pigtoe 1 0.28/hr
Strophitus undulatus Creeper 1 0.28/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula flumin�ea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101012.8
This site occurs approximately 1,000 meters below the I-40 crossing of the creek in a
long straight run. The stream channel ranges from 6 to 8 meters wide, with moderately
eroded banks 1.5 meters high. The substrate is dominated by sand and gravel with clay
banks. Surveys were conducted for 1.33 person hours.
Table 65. Swift Creek Site-101012.8: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 3 2.26/hr
Elliptio complanata Eastern Elliptio 140 105.26/hr
Elliptio congarea Carolina Slabshell 1 0.75/hr
Elliptio icterina Variable Spike 28 21.05/hr
Elliptio roanokensis Roanoke Slabshell 1 0.75/hr
Strophitus undulatus Creeper 1 0.75/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101012.7
This site occurs approximately 1,100 meters below the I-40 crossing of the creek in a
broad bend. The stream channel ranges from 6 to 8 meters wide, with eroded banks 2
meters high. Habitat consists of a shallow riffle grading into a deep run. The substrate is
dominated by sand and gravel with clay banks. Surveys were conducted for 2.67 person
hours.
Triangle Expressway Southeast Extension 33 The Catena Group
March 20l 1 Job # 3271

Table 66. Swift Creek Site-101012.7: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 2 0.75/hr
Elliptio complanata Eastern Elliptio 243 91.01/hr
Elliptio congarea Carolina Slabshell 4 1.50/hr
Elliptio icterina Variable Spike 21 7.86/hr
Elliptio mediocris No Common Name 4 1.50/hr
Elliptio roanokensis Roanoke Slabshell 1 0.37/hr
Strophitus undulatus Creeper 1 0.37/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101012.6
This site occurs approximately 800 meters above the NC 42 crossing of the creek in long
straight pool and glide habitat. The stream channel ranges from 6 to 8 meters wide, with
eroded banks 3 meters high. The substrate is dominated by sand and silt with clay banks
and occasional boulders. Surveys were conducted for 1.62 person hours.
Table 67. Swift Creek Site-101012.6: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio co�nplanata Eastern Elliptio 112 69.14/hr
Elliptio icterina Variable Spike 7 4.32/hr
Fusconaia masoni Atlantic Pigtoe 1 0.62/hr
Lampsilis radiata Eastern Lampmussel 1 0.62/hr
Strophitus undulatus Creeper 2 1.23/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101012.5
This site occurs approximately 700 meters above the NC 42 crossing of the creek in
broad bend with glide, riffle, and run habitat sequences. The stream channel ranges from
6 to 8 meters wide, with moderately eroded banks 2 meters high. The substrate is
dominated by sand with clay banks. Surveys were conducted for 1.67 person hours.
Triangle Expressway Southeast Extension 34 The Catena Group
March 20l 1 Job # 3271

Table 68. Swift Creek Site-101012.5: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 91 54.49/hr
Elliptio icterina Variable Spike 7 4.19/hr
Elliptio lanceolata Yellow Lance 1 0.60/hr
Fusconaia masoni Atlantic Pigtoe 1 0.60/hr
Strophitus undulatus Creeper 1 0.60/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101012.4
This site occurs approximately 600 meters above the NC 42 crossing of the creek in
straight section between two bends with riffle and run habitats. The stream channel
ranges from 6 to 8 meters wide, with moderately eroded banlcs 2 meters high. The
substrate is dominated by sand with clay banks. Surveys were conducted for 2.0 person
hours.
Table 69. Swift Creek Site-101012.4: Mollusk Species Found
Abundance
Scientific Name Common Name # /CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 88 44.00/hr
Elliptio congarea Carolina Slabshell 3 1.50/hr
Elliptio icterina Variable Spike 16 8.00/hr
Elliptio roanokensis Roanoke Slabshell 2 1.00/hr
Fusconaia masoni Atlantic Pigtoe 1 0.50/hr
Lampsilis �adiata Eastern Lampmussel 2 1.00/hr
Strophitus undulatus Creeper 1 0.50/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101012.3
This site occurs approximately 400 meters above the NC 42 crossing of the creek in
straight section just below the confluence of an unnamed tributary to the north. The
stream channel ranges from 6 to 8 meters wide, with severely eroded banks 2 meters
high. Habitat consists of deep pool grading into a swift run. The substrate is dominated
by shifting sand with clay banks. Surveys were conducted for 1.0 person hour.
Triangle Expressway Southeast Extension 35 The Catena Group
March 20l 1 Job # 3271

Table 70. Swift Creek Site-101012.3: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio congaYea Carolina Slabshell
Elliptio icterina Variable Snike
Freshwater Snails and Clams � �
Corbicula fluminea Asian Clam
0
Abundance/
CPUE
CPUE
60.00/hr
1.00/hr
6.00/hr
Relative
Abundance
Common
Swift Creek between Lake Benson and Cornwallis Road Site-101012.2
This site occurs approximately 300 meters above the NC 42 crossing of the creek just
above a narrow bend of the creek. The stream channel ranges from 6 to 8 meters wide,
with severely eroded banks 2 meters high. Habitat consists of a shallow riffle grading
into a swift run. The substrate is dominated by shifting sand with clay banlcs. Surveys
were conducted for 1.0 person hour.
Table 71. Swift Creek Site-101012.2: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 64 64.00/hr
Elliptio congarea Carolina Slabshell 1 1.00/hr
Elliptio icterina Variable Spike 12 12.00/hr
Elliptio roanokensis Roanoke Slabshell 1 1.00/hr
Lampsilis radiata Eastern Lampmussel Shel1 0.0/hr
Strophitus undulatus Creeper 1 1.00/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101012.1
This site occurs approximately 200 meters above the NC 42 crossing of the creek in a
narrow bend of the creek. The stream channel ranges from 5 to 6 meters wide, with
severely eroded banks 2 meters high. Habitat consists of a shallow riffle grading into a
swift run. The substrate is dominated by shifting sand with clay banks. Surveys were
conducted for 1.5 person hours.
Triangle Expressway Southeast Extension 36 The Catena Group
March 20l 1 Job # 3271

Table 72. Swift Creek Site-101012.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.67/hr
Elliptio complanata Eastern Elliptio 116 77.33/hr
Elliptio congarea Carolina Slabshell 1 0.67/hr
Elliptio icterina Variable Spike 20 13.33/hr
Lampsilis radiata Eastern Lampmussel Shell 0.0/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Common
UT Swift Creek Site-100713.4
This UT to Swift Creek, which flows into Swift Creek approximately 400 meters
upstream of NC 42, extends from the SR 1548 crossing of the stream to a point
approximately 260 meters upstream. Numerous beaver dams within the stream and
adjacent floodplain have created a braided channel wetland system. Substrate consists of
sand and mud, with large amounts of detritus and aquatic vegetation. Surveys were
conducted for a total of 1.00 person hour. No freshwater mussels were found; however,
three aquatic snail species were common, and the Asian clam was also present.
Table 73. Swift Creek Site-100713.4: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
None �
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Helisoma anceps
Pointed Campeloma
Asian Clam
Two-ridge Ram's Horn
A Phvsid Snail
Abundance/
CPUE
CPUE
Relative
Abundance
Common
Uncommon
Common
Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.9
This site occurs approximately 100 meters below the NC 42 crossing of the creelc in a
narrow bend. The stream channel ranges from 5 to 6 meters wide, with relatively stable
banks 2 meters high. Habitat consists of a shallow glide grading into a swift run. The
substrate is dominated by gravel and sand with clay banks. Surveys were conducted for
2.0 person hours.
Triangle Expressway Southeast Extension 37 The Catena Group
March 20l 1 Job # 3271

Table 74. Swift Creek Site-101013.9: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.50/hr
Elliptio complanata Eastern Elliptio 251 125.50/hr
Elliptio congarea Carolina Slabshell 2 1.00/hr
Elliptio icterina Variable Spike 54 27.00/hr
Elliptio mediocris No Common Name 2 1.00/hr
Elliptio roanokensis Roanoke Slabshell 2 1.00/hr
Fusconaia masoni Atlantic Pigtoe 2 1.00/hr
Lampsilis radiata Eastern Lampmussel 1 0.50/hr
Pyganodon cataracta Eastern Floater 1 0.50/hr
Strophitus undulatus Creeper 5 2.50/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.8
This site occurs in a long straight section of the stream below a broad bend approximately
170 meters below the NC 42 crossing of the creek. The stream channel ranges from 5 to
6 meters wide, with moderately eroded banks 2 meters high. Habitat consists of a long
pool grading into a short riffle. The substrate is dominated by gravel and sand with clay
banks. Surveys were conducted for 0.67 person hour.
Table 75. Swift Creek Site-101013.8: Mollusk Snecies Found
Scienti�c Name
Freshwater Mussels
Elliptio complanata
Elliptio congarea
Elliptio icterina
Elliptio mediocris
Freshwater Snails and Clams
Corbicula fZuminea
Common Name
Eastern Elliptio
Carolina Slabshell
Variable Spike
No Common Name
Asian Clam
#
33
1
5
1
Abundance/
CPUE
CPUE
49.25/hr
1.49/hr
7.46/hr
1.49/hr
Relative
Abundance
Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.7
This site occurs in a long straight section of the stream below a broad bend approximately
200 meters below the NC 42 crossing of the creek. The stream channel ranges from 5 to
6 meters wide, with severely eroded banks 2 meters high. Habitat consists of a long pool
grading into a short run. Large amounts of woody debris are present. The substrate is
dominated by gravel and sand with clay banks. Surveys were conducted for 0.67 person
hour.
Triangle Expressway Southeast Extension 38 The Catena Group
March 20l 1 Job # 3271

Table 76. Swift Creek Site-101013.7: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Elliptio complanata Eastern Elliptio
Elliptio icterina Variable Spike
Freshwater Snails and Clams � �
Corbicula fluminea Asian Clam
#
12
2
0
Abundance/
CPUE
CPUE
17.91/hr
2.98/hr
Relative
Abundance
Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.6
This site occurs in a long, straight, constricted section of the stream approximately 230
meters below the NC 42 crossing of the creek. The stream channel ranges from 5 to 6
meters wide, with moderately eroded banks 2 meters high. Habitat consists of a riffle and
run series. The substrate is dominated by gravel and sand with clay banks. Surveys were
conducted for 1.33 person hours.
Table 77. Swift Creek Site-101013.6: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 3 2.26/hr
Elliptio complanata Eastern Elliptio 137 103.00/hr
Elliptio congarea Carolina Slabshell 1 0.75/hr
Elliptio icterina Variable Spike 17 12.78/hr
Elliptio mediocris No Common Name 1 0.75/hr
Fusconaia masoni Atlantic Pigtoe 1 0.75/hr
Lampsilis radiata Eastern Lampmussel 1 0.75/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.5
This site occurs in a long pool above a broad bend approximately 260 meters below the
NC 42 crossing of the creek. The stream channel ranges from 5 to 6 meters wide, with
severely eroded banks 2 meters high. The substrate is dominated by sand and silt with
clay banks. A large amount of woody debris and detritus is present. Surveys were
conducted for 1.0 person hour.
Triangle Expressway Southeast Extension 39 The Catena Group
March 20l 1 Job # 3271

Table 78. Swift Creek Site-101013.5: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 96 96.00/hr
Elliptio congaYea Carolina Slabshell 4 4.00/hr
Elliptio icterina Variable Spike 11 11.00/hr
Fusconaia masoni Atlantic Pigtoe 1 1.00/hr
Utterbackia imbecillis Paper Pondshell 1 1.00/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Co�bicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.3
This site occurs in a broad bend approximately 660 meters below the NC 42 crossing of
the creek. The stream channel ranges 6 to 7 meters wide, with relatively stable banks 2
meters high. Habitat consists of a shallow glide transitioning to a run. The substrate is
dominated by sand and pebble with clay banks. Surveys were conducted for 2.88
person hours.
Table 79. Swift Creek Site-101013.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 4 1.39/hr
Elliptio complanata Eastern Elliptio 425 147.57/hr
Elliptio congarea Carolina Slabshell 1 0.35/hr
Elliptio icterina Variable Spilce 38 13.19/hr
Fusconaia masoni Atlantic Pigtoe 3 1.04/hr
Lampsilis radiata Eastern Lampmussel 6 2.08/hr
Strophitus undulatus Creeper 4 1.39/hr
Utterbackia imbecillis Paper Pondshell 1 0.35/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.2
This site occurs in straight wide section approximately 700 meters below the NC 42
crossing of the creek. The stream channel ranges 8 to 9 meters wide, with moderately
eroded banks 2 meters high. Habitat is characterized as a glide to riffle to run sequence,
with sand and gravel substrate. Surveys were conducted for 1.33 person hours.
Triangle Expressway Southeast Extension 40 The Catena Group
March 20l 1 Job # 3271

1 able tSU. �w1Tt l;reeK �1te-1 U 1 U l.�.1: 1V1o11usK �pecles rounct
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 3 2.26/hr
Elliptio complanata Eastern Elliptio 121 90.98/hr
Elliptio congarea Carolina Slabshell 1 0.75/hr
Elliptio icterina Variable Spike 11 8.27/hr
Elliptio lanceolata Yellow Lance 1 0.75/hr
Elliptio mediocris No Common Name 3 2.26/hr
Lampsilis radiata Eastern Lampmussel 6 4.51/hr
Strophitus undulatus Creeper 2 1.50/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula flumin�ea Asian Clam � Common
Physidae A Physid Snail � Uncommon
Swift Creek between Lake Benson and Cornwallis Road Site-101013.4
This site occurs in small riffle section at the confluence of an intermittent channel from
the south, approximately 730 meters below the NC 42 crossing of the creek. The stream
channel ranges from 7 to 8 meters wide, with relatively stable banks 2 meters high. The
substrate is dolninated by sand and pebble with clay banks. Surveys were conducted for
0.58 person hour.
Table 81. Swift Creek Site-101013.4: Mollusk Species Found
Abundance/
Scienti�c Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 1.72/hr
Elliptio complanata Eastern Elliptio 25 43.10/hr
Elliptio icterina Variable Spike 14 24.14/hr
Elliptio mediocris No Common Name 1 1.72/hr
Lampsilis radiata Eastern Lampmussel 1 1.72/hr
Strophitus undulatus Creeper 2 3.45/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Common
Swift Creek between Lake Benson and Cornwallis Road Site-101013.1
This site occurs in straight wide section approximately 750 meters below the NC 42
crossing of the creek. The stream channel ranges from 8 to 9 meters wide, with
moderately eroded banks 2 meters high. Habitat is characterized as a glide to riffle to run
sequence, with sand and gravel substrate. Surveys were conducted for 2.33 person
hours.
Triangle Expressway Southeast Extension 41 The Catena Group
March 20l 1 Job # 3271

Table 82. Swift Creek Site-101013.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta hete�odon Dwarf Wedgemussel 1 0.43/hr
Alasmidonta undulata Triangle Floater 7 3.00/hr
Elliptio complanata Eastern Elliptio 180 77.25/hr
Elliptio icterina Variable Spike 28 12.02/hr
Elliptio roanokensis Roanoke Slabshell 1 0.43/hr
Lampsilis radiata Eastern Lampmussel 1 0.43/hr
Strophitus undulatus Creeper 2 0.86/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula fluminea Asian Clam � Common
Planorbella trivolvis Marsh Ram's Horn � Rare
Swift Creek between Lake Benson and Cornwallis Road Site-101026.4
This site occurs in straight wide section approximately 770 meters below the NC 42
crossing of the creek. The stream channel ranges from 8 to 10 meters wide, with
moderately eroded banks 2 meters high. Habitat is characterized as a series of glide to
riffle to run sequences, with sand and gravel substrate. Surveys were conducted for 6.50
person hours.
Table 83. Swift Creek Site-101026.4: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta heteNodon Dwarf Wedgemussel 1 0.15/hr
Alasmidonta undulata Triangle Floater 11 1.69/hr
Elliptio complanata Eastern Elliptio 489 75.23/hr
Elliptio congarea Carolina Slabshell 8 1.23/hr
Elliptio icterina Variable Spike 89 13.69/hr
Elliptio lanceolata Yellow Lance 1 0.15/hr
Elliptio mediocris No Common Name 9 1.38/hr
Elliptio producta Atlantic Spike 1 0.15/hr
Elliptio roanokensis Roanoke Slabshell 2 0.31/hr
Fusconaia masoni Atlantic Pigtoe 1 0.15/hr
Lampsilis radiata Eastern Lampmussel 1 0.15/hr
Pyganodon cataracta Eastern Floater 2 0.31 /hr
Strophitus undulatus Creeper 5 0.77/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula flu�ninea Asian Clam � Abundant
Triangle Expressway Southeast Extension 42 The Catena Group
March 20l 1 Job # 3271

Swift Creek between Lake Benson and Cornwallis Road Site-101026.3
This site occurs in narrow bend approximately 950 meters below the NC 42 crossing of
the creek. The stream channel ranges from 6 to 8 meters wide, with moderately eroded
banks 2 meters high. Habitat is characterized as a riffle to run sequence, with sand and
gravel substrate. Surveys were conducted for 5.58 person hours.
Table 84. Swift Creek Site-101026.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 8 1.43/hr
Elliptio complanata Eastern Elliptio 515 92.29/hr
Elliptio congarea Carolina Slabshell 7 1.25/hr
Elliptio icterina Variable Spike 173 31.00/hr
Elliptio mediocris No Common Name 10 1.79/hr
Elliptio roanokensis Roanoke Slabshell 1 0.18/hr
Fusconaia masoni Atlantic Pigtoe 6 1.08/hr
Pyganodon cataracta Eastern Floater 1 0.18/hr
Strophitus undulatus Creeper 6 1.08/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Uncommon
Corbicula fluniinea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101026.2
This site occurs in a short run between two narrow bends approximately 980 meters
below the NC 42 crossing of the creek. The stream channel ranges from 7 to 9 meters
wide, with moderately eroded banks 2 meters high. Habitat consists of sand and pebble
with clay banks. Surveys were conducted for 1.17 person hours.
Table 85. Swift Creek Site-101026.2: Mollusk Species Found
Abundance/
Scienti�c Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.85/hr
Elliptio complanata Eastern Elliptio 130 111.11/hr
Elliptio congarea Carolina Slabshell 2 1.71/hr
Elliptio icterina Variable Spike 23 19.66/hr
Fusconaia masoni Atlantic Pigtoe 1 0.85/hr
Lampsilis radiata Eastern Lampmussel 2 1.71/hr
Strophitus undulatus Creeper 2 1.71/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Triangle Expressway Southeast Extension 43 The Catena Group
March 20l 1 Job # 3271

Swift Creek between Lake Benson and Cornwallis Road Site-101026.1
This site occurs in straight section approximately 1,010 meters below the NC 42 crossing
of the creek. The stream channel ranges from 8 to 10 meters wide, with moderately
eroded banks 2 meters high. Habitat is characterized as a glide to riffle to run sequence,
with sand and pebble substrate. Surveys were conducted for 3.75 person hours.
Table 86. Swift Creek Site-101026.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.27/hr
Elliptio complanata Eastern Elliptio 257 68.53/hr
Elliptio congarea Carolina Slabshell 5 1.33/hr
Elliptio icterina Variable Spike 86 22.93/hr
Elliptio lanceolata Yellow Lance 1 0.27/hr
Elliptio mediocris No Common Name 4 1.07/hr
Elliptio roanokensis Roanoke Slabshell 1 0.27/hr
Fusconaia masoni Atlantic Pigtoe 2 0.53/hr
Lampsilis radiata Eastern Lampmussel 1 0.27/hr
St�ophitus undulatus Creeper 3 0.80/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Rare
Corbicula fluminea Asian Clam � Abundant
Swift Creek between Lake Benson and Cornwallis Road Site-101019.4
This site occurs in narrow, straight section approximately 1,000 meters above the
Cornwallis Road (SR 1525) crossing of the creek. The stream channel ranges from 8 to
10 meters wide, with moderately eroded banks 2 meters high. Habitat is characterized as
a scoured run, with sand and pebble substrate with occasional cobble. Surveys were
conducted for 3.73 person hours.
Table 87. Swift Creek Site-101019.4: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 246 65.95/hr
Elliptio icterina Variable Spike 23 6.17/hr
Elliptio roanokensis Roanoke Slabshell 1 0.27/hr
Fusconaia masoni Atlantic Pigtoe 2 0.54/hr
Strophitus undulatus Creeper 2 0.54/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Rare
Corbicula fluminea Asian Clam � Abundant
Triangle Expressway Southeast Extension 44 The Catena Group
March 20l 1 Job # 3271

Swift Creek between Lake Benson and Cornwallis Road Site-101019.3
This site occurs in broad bend approximately 600 meters above the Cornwallis Road (SR
1525) crossing of the creek. The stream channel ranges from 8 to 10 meters wide, with
moderately eroded banks 2 meters high. Habitat is characterized as a scoured run, with
sand and pebble substrate with occasional cobble. Surveys were conducted for 4.0
person hours.
Table 88. Swift Creek Site-101019.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.25/hr
Elliptio complanata Eastern Elliptio 291 72.75/hr
Elliptio congarea Carolina Slabshell 2 0.50/hr
Elliptio icterina Variable Spike 32 8.00/hr
Elliptio mediocris No Common Name 1 0.25/hr
Lampsilis radiata Eastern Lampmussel 2 0.50/hr
Strophitus undulatus Creeper 3 0.75/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula flu�ninea Asian Clam � Abundant
White Oak Creek Site-1007221
This section of White Oak Creek was accessed off the Raynor Road (SR 2555) crossing.
Channel width ranged from 2 to 4 meters with relatively stable 1-meter high banks. In
order of dominance, substrate consisted of sand, clay, silt, and pebble. Water levels were
normal and water visibility was clear. Mussel surveys were conducted for a total of 1.83
person hours.
Table 89. White Oak Creek Site-100722.1: Mollusk Species Found
Scientific Name
Freshwater Mussels
EZliptio complanata
Ellintio icterina
Freshwater Snails and Clams
Campeloma decisum
Common Name
Eastern Elliptio
Variable Spike
Pointed Campeloma
Abundance/
CPUE
CPUE
18.58/hr
1.09/hr
Relative
Abundance
Uncommon
White Oak Creek Site-100713.1
This section of White Oak Creek extends from the SR 1550 (Winston Road) crossing of
the creek to a point approximately 300 meters upstream. The poorly defined channel is
approximately 1.5 meters wide and meanders through a marsh wetland system. The
substrate consists of firm clay and sand. Surveys were conducted for a total of 2.00
person hours.
Triangle Expressway Southeast Extension 45 The Catena Group
March 20l 1 Job # 3271

Table 90. White Oak Creek Site-1007 ] 3.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
None � � �
Relative
Freshwater Snails and Clams � � Abundance
Patchy
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Common
Little Creek Site-100720.4
This section of Little Creek occurs between a point approximately 200 meters upstream
of the Amelia Church Road (SR 1553) crossing to a point approximately 600 meters
upstream and was accessed off the Raynor Road (SR 2555) crossing. Channel width
ranged from 3 to 4 meters with relatively stable 1-meter high banks. Habitat consists of
shallow pool to riffle to run sequences, with sand and cobble dominated substrate.
Surveys were conducted for a total of 3.0 person hours.
Table 91. Little Creek Site-100720.4: Mollusk Species Found
Abundance
Scientific Name Common Name # /CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 262 87.33/hr
Elliptio icterina Variable Spike 10 3.33/hr
Relatiive
Freshwater Snails and Clams � � Abundance
Patchy,
Campeloina decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Rare
Little Creek Site-100713.3
This section of Little Creek extends from the Amelia Church Road (SR 1553) crossing to
a point approximately 200 meters upstream. Channel width ranged from 3 to 4 meters
with relatively stable 1-meter high banks. Habitat consists of shallow pool to riffle to run
seguences, with sand and cobble dominated substrate. Surveys were conducted for a total
of 1.0 person hour.
Triangle Expressway Southeast Extension 46 The Catena Group
March 20l 1 Job # 3271

Table 92. Little Creek Site-100713.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 78 78.00/hr
Elliptio icterina Variable Spike 5 5.00/hr
Relative
Freshwater Snails and Clams � � Abundance
Patchy,
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Rare
2.2.3. Eastern Section
The Eastern section of the project corridor occurs between Business 70 north to the US
64/US 264 Bypass, and drains to the Neuse River from the US 64/264 Bypass crossing of
the river downstream to the vicinity of the Wake/Johnston County line. Tributaries to the
Neuse River within this section include: Walnut Creek and Beddingfield Creek to the
south; Mango Creek, Unnamed Tributary (UT) to Neuse River, Poplar Creek, and Mark's
Creek to the north.
Big Branch Site-100722.2
This section of Big Branch, a tributary to Walnut Creek, was accessed off the Auburn
Church Road (SR 2548) crossing. Channel width ranged from 3 to 5 meters with 1-meter
high banks that showed signs of erosion. Substrate was dominated by a heavy load of
unconsolidated sand. Water levels were normal and water visibility was clear. A few
shells of Asian clam were the only evidence of mollusks found in 1.0 person hour.
Table 93. Big Branch Site-100722.2: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
None �
Freshwater Snails and Clams � �
Corbicula fluminea Asian Clam
Abundance/
# CPUE
� CPUE
Relative
� Abundance
� Rare
Walnut Creek Site-100623.4
This section of Walnut Creek extends from the Barwell Road (SR 2551) crossing to a
point approximately 700 meters upstream. Channel width ranges from 10 to 12 meters
with moderately eroded banlcs 2 to 3 meters high. Substrate consists of shifting sand with
numerous boulders. No mussels were found in 2.5 person hours of survey time.
Triangle Expressway Southeast Extension 47 The Catena Group
March 20l 1 Job # 3271

Table 94. Walnut Creek Site-] 00623.4: Mollusk Species Found
Scientific Name
Freshwater Mussels
None
Freshwater Snails and Clams
Corbicula fluminea
Common Name
Asian Clam
Abundance/
# CPUE
� CPUE
Relative
� Abundance
� Abundant
Beddingfield Creek Site-100713.2
This section of Beddingfield Creek extends from approximately 30 meters below the
Shotwell Road (SR 1553) crossing to a point approximately 400 meters upstream of the
crossing. The channel width ranges from 3 to 4 meters with severely eroded banks 2 to 4
meters high. Substrate consists of shifting sand. No mollusk species were found in 1.5
person hours.
Neuse River Site-100726.1
This site occurs in a slack-water section of Neuse River approximately 50 meters
upstream of the Poole Road (SR 1007) crossing at a canoe access. The river is
approximately 40 meters wide with moderately eroded banks 2 to 3 meters high.
Substrate consists of bedrock overlain with silt and sand. Surveys were conducted for
0.41 person hour.
Table 95. Neuse River Site-100726.1: Mollusk Species Found
Scientific Name Common Name #
Freshwater Mussels � �
Elliptio complanata Eastern Elliptio 25
Elliptio roanokensis Roanoke Slabshell 2
Lasini�ona subvi�idis Green Floater 1 shell
Freshwater Snails and Clams � �
Corbicula flun�inea Asian Clam
0
�
Abundance/
CPUE
CPUE
60.98/hr
4.88/hr
0.0/hr
Relative
Abundance
Abundant
Neuse River Site-100726.2
This site occurs at the Poole Road (SR 1007) crossing of the Neuse River in a deep run
habitat. The river is approximately 40 meters wide with moderately eroded banks 2 to 3
meters high. Substrate consists of sand and gravel with clay banks, and occasional
boulders. Surveys were conducted for 1.05 person hours.
Triangle Expressway Southeast Extension 48 The Catena Group
March 20l 1 Job # 3271

Table 96. Neuse River Site-100726.2: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 41 39.05/hr
Elliptio congaYea Carolina Slabshell 2 1.90/hr
Elliptio icterina Variable Spike 2 1.90/hr
Elliptio roanokensis Roanoke Slabshell 59 56.19/hr
Lampsilis radiata Eastern Lampmussel 1 0.95/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100726.3
This site occurs approximately 300 meters below the Poole Road (SR 1007) crossing of
the Neuse River in a riffle to run habitat sequence. The river is approximately 40 meters
wide with moderately eroded banks 2 to 3 meters high. Substrate consists of sand and
gravel with clay banks. Surveys were conducted for 225 person hours.
Table 97. Neuse River Site-100726.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 214 95.11/hr
Elliptio congarea Carolina Slabshell 8 3.56/hr
Elliptio icterina Variable Spike 16 7.11/hr
Elliptio roanokensis Roanoke Slabshell 426 189.33/hr
Lampsilis radiata Eastern Lampmussel 4 1.78/hr
Lasmigona subviridis Green Floater 23 10.22/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100726.4
This site occurs approximately 200 meters below the Walnut Creek confluence with the
river. The river is approximately 40 meters wide with moderately eroded banks 2 to 3
meters high. The habitat consists of a bedrock cascade and plunge pooL Mussels were
mostly found within bedrock crevices and pockets of accumulated sand. Surveys were
conducted for 1.0 person hour.
Triangle Expressway Southeast Extension 49 The Catena Group
March 20l 1 Job # 3271

Table 98. Neuse River Site-100726.4: Mollusk Species Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Elliptio congaYea
Elliptio roanokensis
Lasmi�ona subviYidis
Freshwater Snails and Clams
Corbicula flun�inea
Common Name
Eastern Elliptio
Carolina Slabshell
Roanoke Slabshell
Green Floater
Asian Clam
#
37
1 shell
19
1
0
Abundance/
CPUE
CPUE
37.00/hr
0.0/hr
19.00/hr
1.00/hr
Relative
Abundance
Abundant
Neuse River Site-100726.5
This site occurs approximately 600 meters below the Walnut Creek confluence with
Neuse River in a run habitat. The river is approximately 26 meters wide with moderately
eroded banks 2 to 3 meters high. Substrate consists of sand and gravel with clay banks.
Surveys were conducted for 1.0 person hour.
Table 99. Neuse River Site-100726.5: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 66 66.00/hr
Elliptio congarea Carolina Slabshell 1 1.00/hr
Elliptio icterina Variable Spike 1 1.00/hr
Elliptio roanokensis Roanoke Slabshell 26 26.00/hr
Lampsilis radiata Eastern Lampmussel 1 1.00/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100726.6
This site occurs approximately 1,100 meters below the Walnut Creek confluence with the
Neuse River in a riffle to run habitat sequence. The river is approximately 28 meters
wide with moderately eroded banks 2 to 3 meters high. Substrate consists mostly of
unconsolidated sand with clay banks, and occasional pockets of gravel in the thalweg.
Surveys were conducted for 1.75 person hours.
Triangle Expressway Southeast Extension 50 The Catena Group
March 20l 1 Job # 3271

Table 100. Neuse River Site-100726.6: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 2 1.14/hr
Elliptio complanata Eastern Elliptio 197 ll2.57/hr
Elliptio congarea Carolina Slabshell 2 1.14/hr
Elliptio icterina Variable Spike 2 1.14/hr
Elliptio roanokensis Roanoke Slabshell 211 120.57/hr
Lampsilis radiata Eastern Lampmussel 1 0.57/hr
Lasmigona subviridis Green Floater 5 2.86/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100726.7
This site occurs approximately in the middle of a large broad bend of the river,
approximately 1,900 meters above the Auburn-Knightdale Road (SR 2555) crossing in a
riffle to run habitat sequence. The river is approximately 28 meters wide with
moderately eroded banks 2 to 3 meters high. Substrate consists of sand, gravel, and
cobble with clay banks, and occasional boulders. A large sandbar occurs along the left
descending bank, extending into the river for one-third the width. Surveys were
conducted for 1.75 person hours.
Table 101. Neuse River Site-100726.7: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 107 61.14/hr
Elliptio congarea Carolina Slabshell 2 1.14/hr
Elliptio icterina Variable Spike 2 1.14/hr
Elliptio roanokensis Roanoke Slabshell 57 32.57/hr
Lampsilis radiata Eastern Lampmussel 2 1.14/hr
Lasmigona subviridis Green Floater 5 2.86/hr
Strophitus undulatus Creeper 1 shell 0.0/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100726.8
This site occurs in a straight section between two broad bends of the river, approximately
1,000 meters above the Auburn-Knightdale Road (SR 2555) crossing. The habitat
consists of a riffle to run habitat sequence. The river is approximately 28 meters wide
with moderately eroded banks 2 to 3 meters high. Substrate consists of sand, gravel, and
cobble with clay banks and occasional boulders. Surveys were conducted for 1.75 person
hours.
Triangle Expressway Southeast Extension 51 The Catena Group
March 20l 1 Job # 3271

Table 102. Neuse River Site-100726.8: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 104 59.43/hr
Elliptio roanokensis Roanoke Slabshell 219 125.14/hr
Lampsilis radiata Eastern Lampmussel 1 0.57/hr
Lasmigona subviYidis Green Floater 1 0.57/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula.flun�inea Asian Clam � Abundant
Neuse River Site-100726.9
This site occurs in a relatively narrow straight section of the river, approximately 300
meters above the Auburn-Knightdale Road (SR 2555) crossing. The river is
approximately 24 meters wide with moderately eroded banks 2 to 3 meters high. The
habitat consists of a bedrock cascade and plunge pooL Mussels were mostly found
within bedrock crevices and pockets of accumulated sand. Surveys were conducted for
1.25 person hours.
Table 103. Neuse River Site-100726.9: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 18 14.40/hr
Elliptio roanokensis Roanoke Slabshell 52 41.60/hr
Lampsilis radiata Eastern Lampmussel 1 0.80/hr
Lasmigona subviridis Green Floater 1 0.80/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100720.2
This site occurs in the vicinity of the Auburn-Knightdale Road (SR 2555) crossing, in a
run and pool habitat sequence. The river is approximately 32 meters wide with
moderately eroded banks 2 to 3 meters high. Substrate consists of sand and cobble with
clay banks. The right descending bank has been stabilized with rip rap that extends into
the channel. Surveys were conducted far 1.16 person hours.
Triangle Expressway Southeast Extension 52 The Catena Group
March 20l 1 Job # 3271

1 able l U4. l�leuse K1ver �1te- l UU /LU.L: 1V1o11usK �pecles rouncl
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 55 47.41/hr
Elliptio �oanokensis Roanoke Slabshell 25 21.55/hr
Lampsilis radiata Eastern Lampmussel 2 1.72/hr
Lasmigona subviYidis Green Floater 3 2.59/hr
Pyganodon cataracta Eastern Floater 1 0.86/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100720.1
This site occurs approximately 220 meters below the Auburn-Knightdale Road (SR 2555)
crossing in a deep run. A large sandbar extends from the left descending bank to the
center of the channel. The river is approximately 30 meters wide with moderately eroded
banks 2 to 3 meters high. Substrate consists of sand and gravel with some areas of
exposed bedrock. Surveys were conducted for 2.83 person hours.
Table 105. Neuse River Site-100720.1: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 8 2.82/hr
Elliptio roanokensis Roanoke Slabshell 188 66.43/hr
Lampsilis radiata Eastern Lampmussel 1 0.35/hr
Utterbackia imbecillis Paper Pondshell 1 0.35/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Neuse River Site-100720.3
This site occurs in the vicinity of the Mail Plantation Road (SR 2509) crossing in a small
riffle to long, deep run habitat sequence. The river is approximately 34 meters wide with
moderately eroded banks 2 to 3 meters high. Substrate consists of sand, gravel and
cobble with clay banks. A large sandbar occurs along the left descending bank,
extending into the river for one-quarter the width. Surveys were conducted for 2.5 person
hours.
Triangle Expressway Southeast Extension 53 The Catena Group
March 20l 1 Job # 3271

Table 106. Neuse River Site-100720.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Alasmidonta undulata Triangle Floater 1 0.40/hr
Elliptio complanata Eastern Elliptio 45 18.0/hr
Elliptio congarea Carolina Slabshell 3 1.20/hr
Elliptio roanokensis Roanoke Slabshell 18 7.20/hr
Lampsilis radiata Eastern Lampmussel 2 0.80/hr
Relative
Freshwater Snails and Clams � � Abundance
Corbicula fluminea Asian Clam � Abundant
Mango Creek Site-100702.2
This site occurs approximately 100 meters downstream of the Hodge Road (SR 2516)
crossing in a side channel 2 to 3 meters wide of Mango Creek created by a beaver dam
across the main channel. Habitat is characterized as a shallow run with a sand and clay
substrate. Surveys were conducted for 1.5 person hours.
Table 107. Mango Creek Site-100702.2: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
Pyganodon cataracta Eastern Flaoter
Utterbackia imbecillis Paper Pondshell
Freshwater Snails and Clams
Campeloma decisum
Corbicula fluminea
Pointed Campeloma
Asian Clam
Abundance/
CPUE
CPUE
4.00/hr
2.67/hr
Relative
Abundance
Common
Abundant
Mango Creek Site-100702.1
This site extends from the Hodge Road (SR 2516) crossing to a point approximately 600
meters upstream. Habitat consists of a large, braided channel, beaver created, wetland
complex. Substrate consists of sand, clay, mud, and detritus. Surveys were conducted
for 3.0 person hours.
Triangle Expressway Southeast Extension 54 The Catena Group
March 20l 1 Job # 3271

1 able l UtS. 1vlango Lreex ��te-1 uu �u1,.1: 1v1o11us1c �pec�es rouna
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Pyganodon cataracta Eastern Flaoter 12 4.0/hr
Utterbackia imbecillis Paper Pondshell 4 1.33/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Abundant
Patchy,
Helisoina anceps Two-ridge Ram's Horn � Common
Patchy,
Physidae A Physid Snail � Uncommon
Sphaeriidae A Sphaeriid Clam � Uncommon
UT Neuse River Site-100722.3
This UT to the Neuse River was accessed off the Poole Road crossing. Channel width
ranges from 1 to 2 meters with relatively unstable 1- to 2-meter high banks. In order of
dominance, substrate consists of sand, clay, gravel, silt, and pebble. Mussel surveys were
conducted for a total of 1.33 person hours.
Table 109. UT Neuse River Site-100722.3: Mollusk Species Found
Abundance/
Scientific Name Common Name # CPUE
Freshwater Mussels � � CPUE
Elliptio complanata Eastern Elliptio 6 4.51/hr
Relative
Freshwater Snails and Clams � � Abundance
Campeloma decisum Pointed Campeloma � Common
Corbicula fluminea Asian Clam � Abundant
Patchy,
Helisoma anceps Two-ridge Ram's Horn � Common
Patchy,
Physidae A Physid Snail � Uncommon
Sphaeriidae A Sphaeriid Clam � Uncommon
Poplar Creek Site-100702.3
This site extends from the Grasshopper Road (SR 2511) crossing upstream to the Poole
Road (SR 1007) crossing. The channel ranges from 3 to 4 meters wide, with severely
eroded banks 3 meters high. The substrate consists of unconsolidated sand with scattered
cobble. A WWTP discharge is located near the Poole Road crossing. Surveys were
conducted for 2.33 person hours.
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March 20l 1 Job # 3271

Table 110. Poplar Creek Site-] 00702.3: Mollusk Species Found
Scientific Name Common Name
Freshwater Mussels �
None �
Freshwater Snails and Clams � �
Corbicula fluminea Asian Clam
Abundance/
# CPUE
� CPUE
Relative
� Abundance
� Common
Marks Creek 100722.4
This section of Marks Creek was accessed off Marks Creek Road (SR 2234). Channel
width ranges from 3 to 6 meters with 2-meter high banks that showed signs of erosion. In
order of dominance, substrate consists of sand, silt, granitic bedrock, clay, and gravel.
Surveys were conducted for a total of 1.0 person hour.
Table llL Marks Creek Site 100722.4: Mollusk St�ecies Found
Scientific Name
Freshwater Mussels
Elliptio complanata
Freshwater Snails and Clams
Camneloma decisum
Common Name
Eastern Elliptio
Pointed Camneloma
3.0 MUSSEL SPECIES DESCRIPTIONS
#
12
0
�
Abundance/
CPUE
CPUE
12.00/hr
Relative
Abundance
Common
Brief descriptions of the six targeted mussel species, four of which were found during
this survey effort, are provided below as are descriptions of the 11 other mussel species
found.
3.1.Federally Protected Species
The two federally endangered freshwater mussel species known to occur within the
Neuse River Basin in Wake and Johnston Counties were the main focus of this study.
Prior to these surveys, the Dwarf Wedgemussel had been found in Swift Creek and
Middle Creek, and was historically known from the Neuse River in Wake County. The
only known occurrence of the Tar River Spinymussel in the Neuse River Basin is from
the Little River in Johnston County. This species has never been found in Swift Creek,
and was not found during this study.
311. Alasmidonta heterodon (Dwarf Wedgemussel)
Characteristics
The Dwarf Wedgemussel was ariginally described as Unio heterodon (Lea 1829).
Simpson (1914) subsequently placed it in the genus Alasmidonta. Ortmann (1914)
placed it in a monotypic subgenus Prolasmidonta, based on the unique soft-tissue
anatomy and conchology. Fuller (1977) believed the characteristics ofProlasmidonta
warranted elevation to full generic rank and renamed the species Prolasmidonta
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hete�odon. Clarke (1981) retained the genus name Alasmidonta and considered
Prolasmidonta to be a subjective synonym of the subgenus P�essodonta (Simpson 1900).
The specific epithet heterodon, refers to the chief distinguishing characteristic of this
species, which is the only North American freshwater mussel that consistently has two
lateral teeth on the right valve and only one on the left (Fuller 1977). All other laterally
dentate freshwater mussels in North America normally have two lateral teeth on the left
valve and one on the right. The Dwarf Wedgemussel is generally small, with a shell
length ranging between 25 mm and 38 mm. The largest specimen reported by Clarke
(1981) was 56.5 mm long, taken from the Ashuelot River in New Hampshire. The
periostracum is generally olive green to dark brown; nacre bluish to silvery white, turning
to cream or salmon colored towards the umbonal cavities. Sexual dimorphism occurs in
DWM, with the females having a swollen region on the posterior slope, and the males are
generally flattened. Clarke (1981) provides a detailed description of the species.
Nearly all freshwater mussel species have similar reproductive strategies; a larval stage
(glochidium) becomes a temporary obligatory parasite on a fish. Many mussel species
have specific fish hosts, which must be present to complete their life cycle. Based upon
laboratory infestation experiments, Michaelson and Neves (1995) determined that
potential fish hosts far the Dwarf Wedgemussel in North Carolina include the tesselated
darter (Etheostoma olmstedi) and the Johnny darter (E. nigrum). McMahon and Bogan
(2001) and Pennak (1989) should be consulted for a general overview of freshwater
mussel reproductive biology.
Distribution and Habitat Requirements
The historic range of the Dwarf Wedgemussel was confned to Atlantic slope drainages
from the Peticodiac River in New Brunswick, Canada, south to the Neuse River, North
Carolina. Occurrence records exist from at least 701ocations, encompassing 15 major
drainages, in 11 states and 1 Canadian Province (USFWS 1993). When the recovery plan
for this species was written, the Dwarf Wedgemussel was believed to have been
extirpated from all but 361ocalities, 14 of them in North Carolina (USFWS 1993). The
most recent assessment (2007 5-Year Review) indicates that the Dwarf Wedgemussel is
currently found in 15 major drainages, comprising approximately 70 "sites" (one site may
have multiple occurrences). At least 45 of these sites are based on less than five
individuals ar solely on relict shells. It appears that the populations in North Carolina,
Virginia, and Maryland are declining as evidenced by low densities, lack of reproduction,
or inability to relocate any individuals in follow-up surveys. Populations in New
Hampshire, Massachusetts, and Connecticut appear to be stable, while the status
of populations in the Delaware River watershed affected by the recent floods of
2005 is uncertain (USFWS 2007).
Strayer et aL (1996) conducted range-wide assessments of remaining Dwarf
Wedgemussel populations, and assigned a population status, to each of the populations.
The status rating is based on range size, number of individuals and evidence of
reproduction. Seven of the 20 populations assessed were considered "poor", and two
others are considered "poor to fair" and "fair to poor" respectively. In North Carolina,
populations are found in portions of the Neuse and Tar River basins; however it is
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believed to have been extirpated from the main-stem of the Neuse River. It was found at
3 sites within the study area, all in Swift Creek.
The Dwarf Wedgemussel inhabits creeks and rivers of varying sizes (down to
approximately two meters wide), with slow to moderate flow. A variety of preferred
substrates have been described that range from coarse sand, to firm muddy sand to gravel
(USFWS 1993). In North Carolina, Dwarf Wedgemussel often occur within submerged
root mats along stable streambanks. The wide range of substrate types used by �his
species suggests that the stability of the substrate is likely as important as the
composition.
Threats to Species
The cumulative effects of several factors, including sedimentation, point and non-point
discharge, and stream modifications (impoundments, channelization, etc.), have
contributed to the decline of this species throughout its range. With the exception of the
Neversink River population in New Yark, which has an estimated population of over
80,000 Dwarf Wedgemussel individuals, all of the other populations are generally small
in numbers and restricted to short reaches of isolated streams. The low numbers of
individuals and the restricted range of most of the surviving populations make them
extremely vulnerable to extirpation from a single catastrophic event or activity (Strayer et
al. 1996). Catastrophic events may consist of natural events such as flooding or drought,
as well as human influenced events such as toxic spills associated with highways,
railroads, or industrial-municipal complexes.
Siltation resulting from substandard land-use practices associated with activities such as
agricultural, forestry and land development has been recognized as a major contributing
factor to degradation of mussel populations (USFWS 1996). Siltation has been
documented to be extremely detrimental to mussel populations by degrading substrate
and water quality, increasing potential exposure to other pollutants, and by direct
smothering of mussels (Ellis 1936, Markings and Bills 1979). Sediment accumulations
of less than 25 mm have been shown to cause high mortality in most mussel species (Ellis
1936). In Massachusetts, a bridge construction project decimated a population of the
Dwarf Wedgemussel because of accelerated sedimentation and erosion (Smith 1981).
Sewage treatment effluent has been documented to significantly affect the diversity and
abundance of mussel fauna (Goudreau et al. 1988). Goudreau et al. (1988) found that
recovery of mussel populations may not occur for up to 3,218 meters (two miles) below
points of chlarinated sewage effluent.
The impact of impoundments on freshwater mussels has been well documented (USFWS
1992a, Neves 1993). Construction of dams transforms lotic habitats into lentic habitats,
which results in changes in aquatic community composition. The changes associated
with inundation adversely affect both adult and juvenile mussels as well as fish
community structure, which could eliminate possible fish hosts for upstream transport of
glochidia. Muscle Shoals on the Tennessee River in northern Alabama, once the richest
site for naiads (mussels) in the world, is now at the bottom of Wilson Reservoir and
covered with 5.79 meters (19 feet) of muck (USFWS 1992b). Large portions of all of the
river basins within the Dwarf Wedgemussel's range have been impounded and this is
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believed to be a major factor contributing to the decline of the species (Master 1986,
USFWS 1993).
The introduction of exotic species such as the Asian Clam (Corbicula fluminea) and
zebra mussel (Dreissena polymorpha) has also been shown to pose significant threats to
native freshwater mussels. The Asian Clam is now established in most of the major river
systems in the United States (Fuller and Powell 1973), including those streams still
supporting surviving populations of the Dwarf Wedgemussel. Concern has been raised
over competitive interactions for space, food and oxygen with this species and native
mussels, possibly at the juvenile stages (Neves and Widlak 1987, Alderman 1995). The
zebra mussel, native to the drainage basins of the Black, Caspian and Aral Seas, is an
exotic freshwater mussel that was introduced into the Great Lakes in the 1980s and has
rapidly expanded its range into the surrounding river basins, including those of the South
Atlantic slope (O'Neill and MacNeill 1991). This species competes for food resources
and space with native mussels, and is expected to contribute to the extinction of at least
20 freshwater mussel species if it becomes established throughout most of the eastern
United States (USFWS 1992b). The zebra mussel is not currently known from any river
supporting DWM populations.
31.2. Elliptio steinstansana (Tar River Spinymussel)
Characteristics
The Tar River Spinymussel grows to a maximum length of 60 millimeters. Short spines
are arranged in a radial row anterior to the posterior ridge on one valve and symmetrical
to the other valve. The shell is generally smooth in texture with as many as 12 spines that
project perpendicularly from the surface and curve slightly ventrally. However, adult
specimens tend to lose their spines as they mature (USFWS 1992a). The Tar River
Spinymussel is distinguished by its shiny periostracum, parallel pseudocardinal teeth, and
the linear ridges on the inside surface of the shell.
Little is known about the reproductive biology of the Tar River Spinymussel USFWS
1992c), however, nearly all freshwater mussel species have similar reproductive
strategies, which involves a larval stage (glochidium), that becomes a temporary
obligatory parasite on a fish. Many mussel species have specific fish hosts, which must
be present to complete their life cycle. McMahon and Bogan (2001) and Pennak (1989)
should be consulted for a general overview of freshwater mussel reproductive biology.
Distr�ibution and Habitat Requirements
Previously this mussel was believed to be endemic to the Tar River system, currently
occurring in relatively short stretches of the Tar River and three creeks (Shocco,
Sandy/Swift and Fishing/Little Fishing) in the Tar drainage. Historically, the Tar River
Spinymussel was collected in the Tar River from near Louisburg in Franklin County to
Fallcland in Pitt County, a range of approximately 125.5 kilometers (78 river miles).
Clarke (1983) located Tar River Spinymussel in only a 19.31 km (12-mile) stretch of the
Tar River in Edgecombe County. Since 1998, five individuals of this species have been
found in the Little River of the Neuse River Basin in Johnston (NCWRC unpublished
data). Tbis species is also listed as being found in the Little River in site recards of
Clarke (1983), but was not mentioned in the report. The Tar River Spinymussel has never
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March 20l 1 Job # 3271

been found in any of the water bodies in the project area, nor was it found during this
study.
The preferred habitat of the Tar River Spinymussel in Swift Creek of the Tar River Basin
was described as relatively fast flowing, well oxygenated, circumneutral pH water in sites
prone to significant swings in water velocity, with a substrate comprised of relatively
silt-free loose gravel and/or coarse sand.
Threats to Species
The cumulative effects of several factors, including sedimentation, point and non-point
discharge, and stream modifications (impoundments, channelization, etc.), have
contributed to the decline of this species throughout its range. The remaining populations
of Tar River Spinymusse are generally small in numbers. The low numbers of
individuals and the restricted range of most of the surviving populations make ihem
extremely vulnerable to extirpation from a single catastrophic event or activity (Strayer et
al. 1996). Catastrophic events may consist of natural events such as flooding or drought,
as well as human influenced events such as toxic spills associated with highways,
railroads or industrial-municipal discharges. Other threats are similar to those described
above for Dwarf Wedgemussel.
3.2.Target Federal Species of Concern (FSC)
The four FSC species targeted have been previously reported in the study area; however,
prior to this survey, no recent records of the Green Floater, or Yellow Lampmussel were
known.
3.21. Elliptio lanceolata (Yellow Lance)
ChaNacteristics
The yellow lance was described from the Tar River at Tarbaro, North Carolina by I. Lea
in 1828. This species differs from other lance-shaped elliptios by having a"waxy" bright
yellow periostracum that lacks rays. The posterior ridge is distinctly rounded and curves
dorsally towards the posterior end.
Distr�ibution and Habitat Requirements
This species is distributed from the Neuse River Basin north to the Rappahannocic, but is
not believed to occur in the Roanoke or James River Basin. It is in considerable decline
throughout its range. Extant populations occur in the Neuse, Tar/Pamlico, Chowan and
York River basins. This species is found in small streams to large rivers in substrates
primarily consisting of clean sand, and occasionally gravel. It was found at 8 sites within
Swift Creek during this study.
Thr�eats to Species
Threats to this and many other freshwater mussel species are similar to those described
above for the Dwarf Wedgemussel This species is a FSC and is listed as Endangered in
North Carolina. Williams et aL (1993) list this species as Endangered. There appears to
be sufficient data to warrant elevation of the yellow lance to Candidate status in the very
near future (John Fridell, Recovery Biologist USFWS, Personal Communication).
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March 20l 1 Job # 3271

3.2.2. Fusconaia masoni (Atlantic Pigtoe)
Characteristics
The Atlantic Pigtoe was described by Conrad (1834) from the Savannah River in
Augusta, Georgia. Shells of the Atlantic pigtoe are subrhomboidal in outline, with a
parchment-like yellow to dark brown periostracum. The posterior ridge is very distinct,
and the umbos extend well above the dorsal margin.
The Atlantic pigtoe is a tachytictic (short-term) breeder, brooding young and releasing
glochidia in early summer. The bluegill (Lepomis macrochirus) and shield darter
(Pe�cina peltata) have been identified as potential fish hosts for this species (O'Dee and
Waters 2000).
Distribuiion and Habitat Requirements
The Atlantic Pigtoe ranges from the Ogeechee River Basin in Georgia north to the James
River Basin in Virginia. It occurs in medium size streams to large rivers, but has
experienced major declines throughout its entire range. The preferred habitat for this
species is a substrate composed of gravel and coarse sand, usually at the base of riffles,
however, it can be found in a variety of other substrates and habitat conditions (personal
observations). It was found at 23 sites within Swift Creek during this study effort.
ThYeats to Species
Threats to this and many other freshwater mussel species are similar to those described
above for the Dwarf Wedgemussel. This species is a FSC and is listed as Endangered in
North Carolina. Williams et aL (1993) list this species as Endangered. There appears to
be sufficient data to warrant elevation of the Atlantic pigtoe to Candidate status in the
very near future (John Fridell, Recovery Biologist USFWS, Personal Communication).
3.2.3. Lasmigona subviridis (Green Floater)
Characte�istics
The green floater was described by Conrad (1835) from the Schuykill River in Lancaster
County, Pennsylvania. The small mussel species has a thin slightly inflated subovate
shell that is narrower in front, higher behind. The dorsal margin forms a blunt angle with
the posterior margin. The shell is dull yellow or tan to brownish green, usually with
concentrations of dark green rays.
Distr�ibution and Habitat Requirements
The Green Floater occurs along the Atlantic slope from the Savannah River in Geargia
north to the Hudson River in New York, as well as in the "interior" basins (New,
Kanawah, and Watauga Rivers) of the Tennessee River basin. It occurs in small size
streams to large rivers, in quiet waters such as pools, or eddies, with gravel and sand
substrates. It has experienced major declines throughout its entire range. It was found at
8 sites within the Neuse River during this study.
Threais to Species
Threats to this and many other freshwater mussel species are similar to those described
above for the Dwarf Wedgemussel This species is a FSC and is listed as Endangered in
North Carolina. Williams et al. (1993) list this species as Threatened. Based on
preliminary genetics research, the southern populations of the Green Floater (Tar
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Pamlico, Neuse, and Yadkin/Pee Dee River Basins) appear to be genetically distinct from
populations from the Roanoke River to the north and west (Morgan Railey and Arthur
Bogan, North Carolina Museum of Natural Sciences, 2007 personal communication).
Further research is needed to determine if these differences warrant classification of the
southern populations as a distinct species.
3.2.4. Lampsilis cariosa (Yellow Lampmussel)
Characteristics
This species was described from the Schuylkill River near Philadelphia (Say 1817). The
waxy-yellow shell is obovate in outline, with a rounded anterior margin and slightly
curved posterior margin, and is rarely rayed. The shell thickness begins as thin in
juveniles becoming thicker with age. The moderately inflated shell attains a length of
120 mm (Bogan 2002). Male shells are elliptical and somewhat elongate in outline with
the ventral margin evenly convex. Female shells are subovate to obovate in outline with
the ventral margin expanded near the posterior margin, sloping up to a very bluntly
rounded posterior margin. Posterior ridge is poorly developed and rounded, posterior
slope slightly convex to flat. Beaks moderately swollen but not elevated much above the
hinge line, located anterior of the middle of the shell, beak sculpture consist of about five
poorly defined bars, the first ridge concentric with the remainder slightly double-looped.
The left valve has two compressed pseudocardinal teeth, the posterior tooth low and
immediately under the umbo, and two delicate lateral teeth. The right valve has a single
compressed pseudocardinal tooth, and a single lamellar lateral tooth. The pseudocardinal
teeth tend to become more stumpy and ragged with age. The interdentum is practically
absent, and the beak cavity is open and moderately deep. Older specimens become
brownish and loose much of the luster. Nacre color is bluish-white, often tinged with
cream or salmon.
Distribution and Habitat Requirements
The yellow lampmussel is found from the lower Ottawa River, Canada eastward to the
Sydney River, Nova Scotia then south to the Ogeechee River Drainage Basin in Georgia
(Johnson 1970). At one time this species probably ranged throughout most of the Atlantic
drainages in North Carolina; however, historical records provided by Johnson (1970) and
recent records (Bogan 2002, NCWRC Unpublished data) indicate the species occurs in the
Catawba, Pee Dee, Waccamaw, Cape Fear, Neuse, Tar/Pamlico, and Chowan drainages.
Threats to Species
Threats to this and many other freshwater mussel species are similar to those described
above for the Dwarf Wedgemussel. This species is a FSC and is listed as Endangered in
North Carolina. Williams et aL (1993) also list this species as Endangered.
3.3. Other Mussel Species Located
3.3.1 Alasmidonta undulata (Triangle Floater)
This species was described from the Schuykill River near Philadelphia (Say 1817). Its
range extends from the Catawba River in North Carolina north to the lower St. Lawrence
River. The shell shape is subtriangular to ovate and inflated. The anterior and ventral
shell margins are rounded. The periostracum is yellowish green with broad green or
black rays. This species is considered Special Concern throughout its range (Williams et
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March 20l 1 Job # 3271

al. 1993). It is considered Threatened in North Carolina. This species was found at 1 site
in Middle Creek, 28 sites in Swift Creek, and 2 sites in the Neuse River.
3.3.2 Elliptio complanata (Eastern Elliptio)
This species was described as Mya complanata from the Potomac River in Maryland
(Lightfoot 1786). Shell characteristics are highly variable. Shell shape is typically
trapezoidal to rhomboid and compressed to inflated. The usually straight ventral margin
is mostly parallel with the dorsal margin and the posterior margin is broadly rounded.
Shell thickness varies from thin to solid. This species is widely distributed along the
Atlantic Slope from Altamaha River Basin in Georgia north to the St. Lawerence River
Basin, and west to Lake Superior and parts of the Hudson Bay Basin. It can be found in a
variety of habitats from large rivers and, lakes to small headwater streams. The species is
widespread and common throughout its range and considered stable (Williams et al.
1993). It was found at 100 sites in all three watershed sections of the study area.
3.3.3 Elliptio congarea (Carolina Slabshell)
This species was described from the Congaree River, South Carolina by Lea (1831). The
range of this species extends from the Ogeechee River, Georgia north to the Chowan
River, North Carolina and Virginia. The shell is rhomboid and subcompressed with
moderately full beaks. The front of the shell is wedge-shaped, with the posterior end
obliquely truncate above and biangulate below. The posterior slope usually has
numerous cross corrugations or wrinkles. The periostracum is greenish-yellow or tawny.
(Williams et al. 1993) list this species as Special Concern. It is considered a Watch
2/Watch 5 species, which indicates that the species is rare to uncommon, but probably not
in trouble (W2), but has known increasing threats to its habitat, whether populations are
known to be declining or not (WS) (LeGrand et al. 2010). This species was found at 43
sites within Swift Creek and the Neuse River.
3.3.4 Elliptio icteYina (Variable Spike)
Described from the Savannah River near Augusta, Georgia (Conrad 1834), this highly
variable species represents a complex of nearly 50 named species (Johnson 1970). The
shell shape is oblong, subelliptical, or subrhomboid, with a prominent posterior ridge, and
moderately elevated beaks. The periostracum is usually smooth and greenish yellow to
tawny-brown. This species is considered common and currently stable throughout its
range (Williams et al. 1993). It was found at 81 sites in all three watershed sections of
the study area.
3.3.5. Elliptio mediocris (No Common Name)
This species was described from the Neuse River 6 miles east of Raleigh (Lea 1863).
Although Johnson (1970) synonomized this into the E. complanata complex and even
though there has been no subsequent publication recognizing it as a distinct species, most
aquatic biologists working with freshwater mussels on the Atlantic slope recognize it as
such. Shell shape is typically rhomboid, and inflated. The usually straight ventral
margin is mostly parallel with the dorsal margin and the posterior margin is broadly
rounded. Unlike most forms of E. complanata, the beaks are moderately full, and the
periostrachum is covered with dark green rays of varying width that remain conspicuous
even with older individuals. The posterior slope is high, but more rounded than E.
congarea. This species was found at 17 sites only within Swift Creek.
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3.3.6. Elliptio producta (Atlantic Spike)
This species was described from the Savannah River, Georgia by Conrad (1836). The
range of this species eXtends from the Savannah River, Georgia north to the Potomac
River Basin in Maryland and Virginia. The Atlantic spike was once synonymized with
Elliptio lanceolata (Johnson 1970), but is now considered a separate species. The
anterior shell margin is rounded and the posterior margin roundly pointed with the most
posterior point slightly above the midline of the shell. The periostracum is often shiny,
dark reddish brown to greenish brown, generally with out rays. Shell nacre is variable
shades of purple. Williams et aL (1993) list this species as Special Concern. The
Atlantic spike was found at two sites in Middle Creek and six sites in Swift Creek.
3.3.7. Elliptio roanokensis (Roanoke Slabshell)
The Roanoke slabshell was described from the Roanoke River (exact location unknown)
by L Lea (1838). The reported range of this species extends from the Connecticut River
in Massachusetts south to the Savannah River in Georgia (Walter 1954). Based on shell
morphologies, Johnson (1970) synominized this and 100 other species into the Elliptio
cornplanata complex, however it is now widely recognized as being a valid species. The
periostracum is generally very smooth, often with placations (furrows) and reddish
yellow in color. Shells of this species reach lengths exceeding 150 mm. This species is
listed as Threatened in North Carolina. Williams et aL (1993) list this species as Special
Concern. This species was found at 22 sites in Swift Creek, and all 12 sites in the Neuse
River sites in Swift Creek and the Neuse River
3.3.8. Lampsilis radiata (Eastern Lampmussel)
Lampsilis radiata radiata (eastern lampmussel) and Lampsilis radiata conspicua
(Carolina fatmucket). Gmelin (1791) described Mya �adiata and used Malabar, a region
of southern India as the type locality. Ortmann (1919) reported this locality as incorrect
and noted Lamarck (1819) had listed it from Saratoga Lake in New York and
recommended "if there should not be any other earlier record, we might select this as the
type locality." Simpson (1914) had earlier listed Virginia as the type locality, thus
Johnson (1970) restricted the type locality to Potomac River, District of Columbia
(approximately opposite, Farifax Co., Virginia). Lea (1872) described Unio conspicuous
from the Yadkin River in Rowan County, North Carolina, which Simpson (1914) treated
as a variety of Lampsilis �adiata �adiata, which Johnson (1970) agreed with.
This large mussel is subelliptical to subovate in outline. Shells are generally thick and
solid, with rounded anterior and posterior margins and vary from hardly inflated to very
inflated. The periostracum is usually yellowish or brownish green with dark green rays
over the entire surface. Like other members of this genus, this species is sexually
dimorphic, with the shells of the male being more elongate, and the females more
rounded and swollen, particularly in the posterior margin. Left valve has two
pseudocardinal teeth, the posteriar one located under the umbo, and two straight lateral
teeth. The right valve has two separate pseudocardinal teeth, the upper is smaller and
compressed, and has a single straight lateral tooth. Interdentum is lacking, umbo cavity is
shallow, compressed. Nacre color is white, may be tinged with pink or salmon or may be
completely pink or salmon. Shells of the Carolina fatmucket are much ]arger and heavier
than the shells of the Eastern lampmussel (Adams et al. 1990) and tend to be more shiny
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March 20l 1 Job # 3271

and smooth than the Eastern lampmussel, which is usually rough with close concentric
wrinkles (Johnson, 1970, Timothy W. Savidge, personal observations). Also, the posterior
ridge is much more broadly rounded in the Carolina fatmucket and, in general, the umbos
are not as inflated. Adams et aL (1990) suggested that "because of these differences and
because L. r. radiata is thought to parasitize an anadromous fish host and L. r. conspicua is
found in areas without such fish species being present, it is possible that L. �. radiata and
L. r. conspicua are separate species".
The taxonomic status of the Lampsilis radiata complex is still uncertain. Both the eastern
lampmussel and the Carolina fatmucket forms are known to occur in the Neuse River
basin. This large mussel is subelliptical to subovate in outline. Shells are generally thick
and solid, with rounded anterior and posterior margins. The periostracum is usually
yellowish or brownish green with dark green rays over the entire surface. Like other
members of this genus, this species is sexually dimorphic, with the shells of the male
being more elongate, and the females more rounded and swollen, particularly in the
posterior margin. Williams et al. (1993) consider this species to be Stable; however, both
the eastern lampmussel and the Carolina fatmucket are considered Threatened in North
Carolina. This species was found at 44 sites, two within Middle Creek, 32 within Swift
Creek, and 10 within the Neuse River.
3.3.9. Pyganodon cataracta (Eastern Floater)
Described by Say (1817) in the deep part of a milldam presumably near Philadelphia, this
species is wide ranging in the Atlantic drainages from the lower St. Lawrence River
Basin south to the Altamaha River Basin, Georgia, and in the Alabama-Coosa River
drainage, and the Apalachicola and Coctawhatchee River Basins, Florida. The shells of
this species are uniformly thin, and lack hinge teeth. The shell shape is ovate,
subelliptical and elongate, with an evenly rounded anterior margin and a broadly rounded
ventral margin. The periostracum is light to dark green with broad green rays on the
posteriar slope. Ortman (1919) recognized three generalized shell forms, the pond form,
the creek/small river form and the big river form, that were related to environmental
conditions. The pond form occurs in small ponds with muddy substrates, and is
characterized by very thin elongate inflated shells. The creek form occurs in riffle-pool
habitats in gravel substrates, and is much thicker and more compressed. The big river
form is generally short and inflated and occurs in soft substrates. This species is
considered common and currently stable throughout its range (Williams et al. 1993). It
was found at 24 sites in all three watershed sections of the study area.
3.3.10. Strophitus undulatus (Creeper)
This mussel was described from the Schuylkill River near Philadelphia (Say 1817). Its
range extends from throughout much of the Interior River Basin and Atlantic Slope
regions. The shell is elliptical to rhomboid in outline and somewhat inflated. The
anterior end is rounded, and the posterior end is bluntly pointed. The periostracum is
yellowish green to brown, with dark green rays. Williams et al. (1993) consider this
species to be Stable; however it is considered Threatened in North Carolina. It was found
at two sites within Middle Creek, 29 sites in Swift Creek, and one site in the Neuse River.
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3.3.11. Utterbackia imbecillis (Paper Pondshell)
Described from the Wabash River in Indiana (Say 1829), this mussel occurs throughout
the Mississippi River and Great Lakes drainages, south to northeastern Mexico and east
along the Gulf Coast to Florida, as well as along the Atlantic Slope. It has an extremely
thin shell that is oblong and inflated. The dorsal and ventral margins are nearly straight
and parallel. The periostracum is greenish yellow with fine green rays. This species is
considered common throughout its range (Williams et al. 1993). It was found at 14 sites
in all three watershed sections of the study area, although mostly within Swift Creek.
4.0 DISCUSSION
These survey efforts provide a comprehensive updated evaluation of freshwater mussel
species occurring within the project study area. This information helps to identify which
water bodies within the study area contain significant mussel faunas, and can then be
used to minimize impacts to these resources. At least one freshwater mussel species was
found in 102 of the 110 stream sites sampled. Four of the six targeted mussel species
were found during this study, including: the federally Endangered Dwarf Wedgemussel,
which was found only within Swift Creek; the FSC and North Carolina listed Endangered
Atlantic Pigtoe (Swift Creek), Yellow Lance which were found only within Swift Creek;
and the FSC and North Carolina listed Endangered Green Floater which was found only
within the Neuse River. Neither the Tar River Spinymussel, nor the Yellow Lampmussel
was found during this study, although habitat that could potentially support both species
is present in much of the study area. The Tar River Spinymussel has only ever been
found in the Little River in the Neuse River Basin. There are historic records of the
Yellow Lampmussel from the Neuse River and an unnamed tributary to Swift Creek in
Wake County (Johnson 1970); however, this species has not been found in these areas in
recent years (NCWRC Unpublished Data).
Although significant freshwater mussel resources occur within all three sections of the
study area, habitat degradation and low relative abundances and species diversity is
evident in some areas, particularly in the Western Section. As depicted in Table 111, the
highest species diversity and number of rare species (as identified in Table 1) occur in the
Central Section (Swift Creek and tributaries), followed by the Eastern Section (Neuse
River and tributaries) and then Western Section (Middle Creek and tributaries).
Table 112. Mussel Snecies
Section #
Western
Central
Eastern
4.1. Western Section
14
10
�tudy Corridor Section
# Rare # FSC # Federal
0
0
0
�pecies Species
0 0
2 1
0
Middle Creek drains the western section of the project corridor study area, and from a
freshwater mussel standpoint, is the most significant water body in the Western section.
Like Swift Creek, Middle Creek was known to support several rare mussel species,
including the Dwarf Wedgemussel; however, this species has not been detected during
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any survey effort since 1992 (NCWRC unpublished data), where it was found at the NC
50 crossing downstream of the study area in Johnston County. In addition, occurrences
and numbers of other rare mussel species known from the stream have declined in recent
years (NCWRC Unpublished Database of Aquatic Species 2010). The results of this
survey effort further support this declining trend, as only four rare mussel species were
found in very low numbers (three Eastern Lampmussel, three Creeper, one Ttriangle
Floater, and one Atlantic Spike). Observations of habitat conditions also support the
apparent decline, as heavy sediment loads, stream-bed scour and stream-bank instability
were evident at all sites sampled in Middle Creek. In addition, numerous WWTP
discharges are located within the subbasin. The proposed project will cross Middle Creek
in the upper limits of the watershed upstream of Sunset Lake. While it is possible that
Dwarf Wedgemussel still occurs in Middle Creek further downstream in Johnston
County, the presence of Sunset Lake between the proposed crossing and potentially
occupied habitat downstream would eliminate the potential for any direct impacts to
occur. Given the fact that the Tar River Spinymussel has never been found in Middle
Creek and Swift Creek, despite multiple surveys throughout both stream systems, it is
unlikely to occur in this section of the project.
No rare mussel species were found in any of the tributaries; however, some of these
streams such as Basal Creek, Little Creek, and Guffy Branch support fairly high
abundances of the Eastern Elliptio, and contain areas of "good" mussel habitat, which
may be suitable for the Dwarf Wedgemussel. However, given the results of this study,
and other survey efforts in these tributaries, its presence is unlikely.
4.2. Central Section
The Central section of the project study area drains to the Swift Creek Subbasin. The
NCWRC identified the Swift Creek watershed as one of 25 areas in North Carolina
considered essential far the continued survival of endangered ar threatened aquatic
wildlife species (Alderman et al. 1993). As required by the Nature Preserves Act (NCGS
113A-164 of Article 9), the North Carolina Natural Heritage Program (NHP) compiles
the North Carolina Department of Environment and Natural Resources (DENR) priority
list of "Natural Heritage Areas" in which natural areas (sites) are inventoried and
evaluated on the basis of rare plant and animal species, rare or high quality natural
communities, and geologic features occurring in the particular site. The sites are rated
with regard to national, state and regional significance, and Swift Creek is rated as having
"National Significance", due to the presence of the Dwarf Wedgemussel. It is noted that
sites on the list should be given priority for protection; however, it does not imply that all
of the areas currently receive protection (NCDENR 2005).
Historically, at least 18 species of freshwater mussels have been reported to occur in the
Swift Creek subbasin. This study confirms the relatively high species diversity (for
Atlantic Slope drainages) of this stream, as at least 14 species were collected, including
the Dwarf Wedgemussel. It is very possible that the E. complanata and E. icterina
complexes are represented by several species, which would further raise the number of
species in the subbasin. The only three species reported to occur in Swift Creek that were
not found in this study are the Green Floater, Carolina lance (Elliptio angustata) and
Notched Rainbow. The green floater was reported as occurring in Swift Creek by Walter
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(1956) and one specimen was found by Alderman (1991); however, it has not been found
in Swift Creek in subsequent surveys. Taxonomic uncertainties with lanceolate elliptios
exist; thus, specimens reported as the Carolina lance in previous surveys may in fact be
the same species as what is reported in this study as the Atlantic spike, or the northern
lance, two other lanceolate elliptio species. The Notched Rainbow was found in the
study area in 2007 (TCG 2008).
The results of this study confirm the persistence of the Dwarf Wedgemussel in Swift
Creek below Lake Benson, as three individuals were found within the study corridor. In
addition, two other individuals were found downstream of the project corridor, as part of
a concurrent study carried out by TCG for the City of Raleigh. The targeted FSC
Atlantic Pigtoe and Yellow Lance and several other rare mussel species were also
confirmed to persist in this section of Swift Creek. Thus, direct impacts to these species
are possible from project construction within this section of Swift Creek.
Because of the existence of the Dwarf Wedgemussel in Swift Creek, the study corridor
for this project was expanded to include an avoidance alternative (Red Route), which
would cross Swift Creek upstream of Lake Benson. This section of Swift Creek is not
believed to support the Dwarf Wedgemussel, and the results of this study further support
this assumption, as it was not found, nor were any of the associate rare mussel species. In
addition, Lake Benson occurs between this section of the creek and occupied habitat
located downstream. As such, direct impacts to the Dwarf Wedgemussel are unlikely to
occur if the Red Corridor is constructed; however, conclusions regarding Indirect and
Cumulative Impacts to the population cannot be determined at this time, and will need to
be addressed with all alternates within the study area.
The Tar River Spinymussel was not found in Swift Creek during this study, and it has
never been found in this subbasin, despite the presence of apparently suitable habitat.
Given this, it is very unlikely to occur in this section of the project.
No rare mussel species were found in any of the tributaries to Swift Creek within the
study area; however, both White Oak Creek and Little Creek are known to support Dwarf
Wedgemussel and other rare species further downstream of the study area. In both
instances artificial impoundments are present between any of the proposed crossing
locations and occupied habitat downstream; therefore direct impacts are unlikely.
4.3. Eastern Section
The Eastern section of the project corridor drains to the Neuse River from the US 64/264
Bypass crossing of the river downstream to the vicinity of the Wake/Johnston County
line. Tributaries to the Neuse River within this section include: Walnut Creek and
Beddingfield Creek to the south; Mango Creek, Unnamed Tributary (UT) to Neuse River,
Poplar Creek, and Mark's Creek to the north.
Historically, at least 18 species of freshwater mussels have been reported to occur in the
mainstem of the Neuse River within the project study area (Walter 1956, Johnson 1970),
including the Dwarf Wedgemussel. While this study indicates relatively high species
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diversity (for Atlantic Slope drainages) of this section of the river (10 species), species
like the Dwarf Wedgemussel, Atlantic Pigtoe, Yellow Lance and Notched Rainbow,
which historically occurred in this area, were not found. The presence of the Green
Floater is the first documented occurrence of this species in this section of the Neuse
River since the early 1950's (Walter 1956).
The population of the Dwarf Wedgemussel in the main-stem of the Neuse River has long
been considered extirpated (USFWS 1993). This section of the Neuse River is drained
by an extensive urban area (City of Raleigh). Given this, and the fact that it has not been
found in the Neuse River in recent years, including during this study, it is unlikely to still
occur in this section of the Neuse River. However, the re-discovery of the targeted FSC
Green Floater, which was also believed to have been extirpated from this area, casts some
uncertainty on this conclusion. Some of the other species formerly reported from this
area like the Dwarf Wedgemussel and Atlantic Pigtoe (Johnson 1970) may still exist in
low numbers, as the Green Floater was obviously present, but in such low numbers that it
was not detected during surveys in recent years (NCWRC Unpublished Data). The
presence of the Green Floater at multiple sites (8) and the fact that the majority of
individuals found were of the same size (age) class, suggest a recent population
expansion. Unless future surveys detect the Dwarf Wedgemussel in the Neuse River, it
should still be considered a"Historic" population. However, intensive surveys will need
to be conducted at the proposed Neuse River crossing once an alternate is chosen.
The Tar River Spinymussel was not found in the Neuse River during this study, nor has it
ever been found in the Neuse River. As mentioned previously, the only population of
this species in the Neuse River Basin is the Little River. As such, it is very unlikely that
the Tar River Spinymussel occurs within the main-stem of the Neuse River in the study
area.
No rare mussel species were found in any of the tributaries in this section. Habitat
conditions in these tributaries are generally unsuitable for the Dwarf Wedgemussel, and
Tar River Spinymussel, in that they are either highly degraded (Beddingfield Branch,
Poplar Creek, Walnut Creek etc.), or they are more lentic (still water) in nature (Mango
Creek) than lotic habitats (flowing water) where these species occur. Therefore, it is very
unlikely that the Dwarf Wedgemussel, or Tar River Spinymussel occur in any of the
Neuse River tributaries within this section of the study corridor.
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5.0 LITERATURE CITED
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Annual Report 1990-1991, Nongame and Endangered Wildlife Program, Division
of Wildlife Management, North Carolina Wildlife Resources Commission,
September 1991.
Alderman, J. M. (1995). Monitoring the Swift Creek Freshwater mussel community.
Unpublished report presented at the UMRCC symposium on the Conservation and
Management of Freshwater Mussels II Initiative for the Future. Rock Island, IL,
UMRCC.
Alderman, J. M., R. C. Wilson and C. McGrath. 1993. Conservation of aquatic critical
habitats in North Carolina. Proc. Annu. Con£ Southeast. Assoc. Fish and Wildl.
Agencies 47:348-352.
Bogan, A. E. (2002). Workbook and key to the freshwater bivalves of North Carolina.
North Carolina Freshwater Mussel Conservation Partnership, Raleigh, NC, 101
pp, 10 color plates.
Center for Biological Diversity. 2010. Petition To List 404 Aquatic, Riparian and Wetland
Species From The Southeastern United States, As Threatened Or Endangered Under
The Endangered Species Act. Apri120, 2010, 1,145 pp. Available online at:
http://sero.nmfs.noaa. gov/pr/esa/Candiate%20Spp/SE_Petition.pdf
Clarke, A. H. 198 L The Tribe Alasmidontini (Unionidae: Anodontinae), Part L• Pegias,
Alasinidonta, and Arcidens. Smithsonian Contributions to Zoology, No. 326. 101 pp.
Clarke, A. H. 1983. Status survey of the Tar River spiny mussel. Final Report to U.S. Fish and
Wildlife Service with supplement. 63 pp.
Conrad, T. A. (1834). "Descriptions of some new species of fresh water shells from
Alabama, Tennessee, etc." American Journal of Science and Arts 25(2): 338-343.
Conrad, T. A. (1835). Additions to, and corrections of, the Catalogue of species of
American Naiades, with descriptions of new species and varieties of Fresh
Water Shells. Pp. 1-8, pl. 9. Appendix to: Synoptical table to New freshwater
shells of the United States, with coloured illustrations; and a monograph of the
genus Anculotus of Say; also a synopsis of the Ame�ican naiades. J. Dobson,
108 Chestnut Street, Philadelphia, Pennsylvania.
Ellis, M. M. (1936). Erosion Silt as a Factor in Aquatic Environments. Ecology 17: 29-
42.
Gmelin, J. F. 1791. Systema Natu�ae. 13th edition. Leipzig. Vol.l part 6:3021-3910.
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Fuller, S. L. H. 1977. Freshwater and terrestrial mollusks. In: John E. Cooper, Sarah
S.Robinson, John B. Fundeburg (eds.) Endangered and Threatened Plants and
Animals of North Carolina. North Carolina State Museum of Natural History,
Raleigh.
Fuller, S. L. H. and C. E. Powell (1973). Range extensions of Corbicula manilensis
(Philippi) in the Atlantic drainage of the United States. Nautilus 87(2): 59.
Goudreau, S. E., R. J. Neves, and R. J. Sheehan (1988). Effects of Sewage Treatment
Effluents on Mollusks and Fish of the Clinch River in Tazewell County, Virginia.
USFWS: 128 pp.
Johnson, R. L(1970). The Systematics and Zoogeography of the Unionidae (Mollusca:
Bivalva) of the Southern Atlantic Slope Region. Bulletin of the Museum of
Comparative Zoology 140(6): 263-449.
Lamarck, J. B. P. A. 1815-1822. Histoire naturelle des Animaux sans Vertebres.
volumes.
Lea, L 1829. Description of a new genus of the family of naiades, including eight species,
four of which are new; also the description of eleven new species of the genus
Unio from the rivers of the United States: with observations on some of the
characters of the naiades. Transactions of the American Philosophical Society
3[New Series]:403�57, pls. 7-14.
Lea, L 1831. Observations on the naiades, and descriptions of new species of that and
other families. T�ansactions of'the American Philosophical Society 4[New
Series]:63-121, pls. 3-18.
Lea, I. 1834. Observations on the naiades; and descriptions of new species of that, and
other families. Transactions of the American Philosophical Society 5[New
Series]:23-119, pls. 1-19.
LeGrand, H. E., Jr., S. P. Hall, S. E. McRae, and J. T. Finnegan. 2010. Natural Heritage
Program List of the Rare Animal Species of North Carolina. North Carolina
Natural Heritage Program, Raleigh, North Carolina. 124 pp.
Lightfoot, J. (1786). A catalogue of the Portland Museum, lately the property of the
duchess Dowager of Portland, deceased, which will be sold at auction by Mr.
Skinner and Co. London. Vii = 194 pp.
Markings, L. L. and T. D. Bills (1979). Acute Effects of Silt and Sand Sedimentation on
Freshwater Mussels. UMRCC Symposium on the Upper Mississippi River
bivalve Mollusks, Rock Island, IL, UMRCC.
Master, L. 1986. Alasmidonta heterodon: results of a global status survey and proposal
to list as an endangered species. A report submitted to Region 5 of the U.S. Fish
and Wildlife Service. 10 pp. and appendices.
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McMahon, R. F. and A. E. Bogan. (2001). Mollusca: Bivalvia. Pp. 331-429. IN:
J.H. Thorpe and A.P. Covich. Ecology and classification of North
nd
American freshwater invertebrates. 2 edition. Academic Press.
Michaelson, D.L. and R.J. Neves. 1995. Life history and habitat of the endangered dwarf
wedgemussel Alasmidonta heterodon (Bivalvia: Unionidae). .Tournal of the North
American Benthological Society 14(2):324-340.
NCDENR-Division of Parks and Recreation, 2005. North Carolina Natural Heritage
Program Biennial Protection Plan, Natural Heritage Areas Priority List, Raleigh
Dept. of Environment Health and Natural Resources, 115 pp.
Neves, R. J. and J. C. Widlak (1987). Habitat Ecology of Juvenile Freshwater Mussels
(Bivalva: Unionidae) in a Headwater Stream in Virginia. American Malacological
Bulletin 1(5): 1-7.
Neves, R.J. 1993. A state of the Unionids address. Pp. 1-10 in K.S. Cummings, A.C.
Buchanan, and L.M. Kooch, eds. Proc. of the UMRCC symposium on the
Conservation and Management of Freshwater Mussels. UMRCC. Rock Island
IL.189 pp.
O'Dee, S. H., and G. T. Watters. 2000. New or confirmed host identification for ten
freshwater mussels. pp. 77-82 in R.A. Tankersley, D.I. Warmolts, G.T. Watters,
B.J. Armitage, P.D. Johnson, and R.S. Butler (eds.). Freshwater Mollusk
Symposia Proceedings. Part I. Proceedings of the Conservation, Captive Care and
Propagation of Freshwater Mussels Symposium. Ohio Biological Survey Special
Publication, Columbus.
O'Neill, C. R., Jr., and D. B. MacNeill. 1991. The zebra mussel (Dreissena
polymorpha): an unwelcome North American invader. Sea Grant, Coastal
Resources Fact Sheet. New York Sea Grant Ex�ension. 12 pp.
Ortmann, A.E. 1919. A monograph of the naiades of Pennsylvania. Part IIL• Systematic
account of the genera and species. Memoirs of the Carnegie Museum 8(1):xvi—
384, 21 pls.
Pennak, R. W. (1989). Fresh-water Invertebrates of the United States, Protozoa to
Mollusca. New York, John Wiley & Sons, Inc.
Savidge, Timothy W. Personal Observation. The Catena Group, Inc.
Say, T., Ed. (1817). Article Conchologv. American Edition of the British Encyclopedia of
Dictionary of Arts and Sciences, Comprising an Accurate and Popular View of
the Present Improved State of Human Knowledge. Philadelphia, Samuel A.
Mitchel and Horace Ames.
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Say, T. (1829). Descriptions of some new terrestrial and fluviatile shells of North
America. The Disseminator of Useful Knowledge; containing hints to the youth of
the United States, from the School of Industrv 2(19-23): 291-356.
Simpson, C.T. 1900. Synopsis of the naiades, or pearly fresh-water mussels. Proceedings
of the United States National Museum 22(1205):501-1044.
Simpson, C.T. 1914. A descriptive catalogue of the naiades, or pearly fresh-water
mussels. Parts I—III. Bryant Walker, Detroit, Michigan, xii + 1540 pp.
Smith, D. 1981. Selected freshwater invertbrates proposed for special concern status in
Massachussetts (Mollusca, Annelida, Arthropoda). MA Dept. of Env. Qual.
Engineering, Div. of Water Pollution Control. 26 pp.
Strayer, D. L., S. J. Sprague and S. Claypool, 1996. A range-wide assessment of
populations of Alasmidonta heterodon, an endangered freshwater mussel
(Bivalva:Unionidae). J.N. Am. Benthol. Soc., 15(3):308-317.
The Catena Group Inc. 2008. Swift Creek Freshwater Mussel Surveys The Dempsey
E.Benton Water Treatment Project: Wake and Johnston Counties, North
Carolina.Unpublished Final Report prepared for Arcadis, Raleigh, North Carolina.
29 ppplus figures.
USFWS 1992a. Special report on the status of freshwater mussels.
USFWS 1992b. Endangered and Threatened species of the southeast United States (The
Red Book). FWS, Ecological Services, Div. of Endangered Species, Southeast
Region. Govt Printing Office, Wash, DC: 1,070.
U.S. Fish and Wildlife Service. 1992c. Tar River Spinymussel (Elliptio (Cathyria)
steinstansana) Recovery Plan. Atlanta, Georgia. 34 pp.
U.S. Fish and Wildlife Service. 1993. Dwarf Wedgemussel Mussel (Alasmidonta
heterodon) Recovery Plan. Hadley, Massachusetts. 527 pp.
USFWS (1996). Revised Technical/Agency Draft Carolina Heelsplitter Recovery Plan,
Atlanta, GA: 47.
Walter, W. M. (1954). Mollusca of the upper Neuse River basin, North Carolina.
Durham, North Carolina, Duke University. Ph. D. dissertation: i-x + 220.
Walter, W. M. (1956). Mollusca of the upper Neuse River basin, North Carolina.
Durham. J. of the Elisha Mitchell Scientific Society (72 (2):262-274.
Williams, J. D., M. L. Warren, Jr., K. S. Cummings, J. L. Harris, and R. J. Neves.
(1993). Conservation status of the freshwater mussels of the United States and
Canada. Fisheries 18 (9): 6-22.
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APPENDIX A
PROJECT FIGURES/SURVEY LOCATION SHEETS
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APPENDIX B
DEFINITIONS OF FEDERAL AND STATE LISTING CATEGORIES
(FROM LEGRAND ET AL. 2010)
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United States Status. This status is designated by the U.S. Fish and Wildlife Service.
Federally listed Endangered and Threatened species are protected under the
provisions of the Endangered Species Act of 1973, as amended through the 100th
Congress. Unless otherwise noted, definitions are taken from the Federal Register,
Vol. 56, No. 225, November 21, 1991 (50 CFR Part 17).
STATUS
CODE STATUS STATUS DEFINITION
E Endangered A taxon "which is in danger of extinction throughout all or a
significant portion of its range" (Endangered Species Act,
Section 3).
T Threatened A taxon "which is likely to become an endangered species
within the foreseeable future throughout all or a significant
portion of its range" (Endangered Species Act, Section 3).
FSC (Federal) "... the Service is discontinuing the designation of Category
Species of 2 species as candidates in this notice. The Service remains
Concern concerned about these species, but further biological
[also research and field study are needed to resolve the
known as conservation status of these taxa. Many species of concern
Species at will be found not to warrant listing, either because they are
Risk] not threatened or endangered or because they do not qualify
as species under the definition in the [Endangered Species]
Act. Others may be found to be in greater danger of
extinction than some present candidate taxa. The Service is
working with the States and other private and public
interests to assess their need for protection under the Act.
Such species are the pool from which future candidates for
listing will be drawn." (Federal Register, February 28,
1996). The Service suggests that such taxa be considered as
"Species of Concern" or "Species at Risk", neither of which
has official status. The N.C. Natural Heritage Program uses
"(Federal) Species of Concern" in this document far those
taxa formerly considered as Category 2.
P Proposed Species proposed in the Federal Register as a status
different from its current Federal status.
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STATUS
CODE STATUS STATUS DEFINITION
T(S/A) Threatened "Section 4(e) of the [Endangered Species] Act authorizes
due to the treatment of a species (subspecies or population
Similarity of segment) as endangered or threatened even though it is not
Appearance otherwise listed as endangered or threatened if -- (a) the
species so closely resembles in appearance an endangered
or threatened species that enforcement personnel would
have substantial difficulty in differentiating between the
listed and unlisted species; (b) the effect of this substantial
difficulty is an additional threat to an endangered or
threatened species; and (c) such treatment of an unlisted
species will substantially facilitate the enforcement and
further the policy of the Act." (Federal Register, November
4, 1997). [The American Alligator is listed as T(S/A) due to
Similarity of Appearance with other rare crocodilians, and
the southern population of the Bog Turtle is listed as T
(S/A) due to Similarity of Appearance with the northern
population of the Bog Turtle (which is federally listed as
Threatened and which does not occur in North Carolina).]
XN Nonessential "Section 10 (j) of the Endangered Species Act of 1973, as
Experimental amended, provides for the designation of introduced
Population populations of federally listed species as nonessential
experimental. This designation allows for greater flexibility
in the management of these populations by local, state, and
Federal agencies. Specifically, the requirement for Federal
agencies to avoid jeopardizing these populations by their
actions is eliminated and allowances for taking the species
are broadened." (U.S. Fish and Wildlife Service, 1995).
D De-listed Species has been proposed by the U.S. Fish and Wildlife
Service for de-listing from the List of Endangered and
Threatened Wildlife. However, at the present time, the
species is still on the List of Endangered and Threatened
Wildlife and is thus protected under the Endangered Species
Act. Because such species still have legal Federal
protection, the NHP will maintain existing recards on the
species, though new records might not necessarily be added.
If the status becomes law prior to the next publication of the
NHP Rare Animal List, the Program will remove the
Federal designation from its database (and thus the species
will no longer appear on printouts of Federally listed
species). NHP may or may not continue to track the species,
depending on its legal State status and other factors such as
overall abundance and range in the state.
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North Carolina Status. Endangered, Threatened, and Special Concern species of
mammals, birds, reptiles, amphibians, freshwater fishes, freshwater and terrestrial
mollusks, and crustaceans have legal protection status in North Carolina (Wildlife
Resources Commission). In addition to the above categories, the Natural Heritage
Program maintains computer and map files on Significantly Rare species, as well
as species considered Extirpated. Paper files only are maintained for a few of the
above species; these species are indicated by the phrase "not tracking."
STATUS
CODE STATUS STATUS DEFINITION
E Endangered "Any native or once-native species of wild animal
whose continued existence as a viable component
of the State's fauna is determined by the Wildlife
Resources Commission to be in jeopardy or any
species of wild animal determined to be an
'endangered species' pursuant to the Endangered
Species Act." (Article 25 of Chapter 113 of the
General Statutes; 1987).
T Threatened "Any native or once-native species of wild animal
which is likely to become an endangered species
within the foreseeable future throughout all or a
significant portion of its range, or one that is
designated as a threatened species pursuant to the
Endangered Species Act." (Article 25 of Chapter
113 of the General Statutes; 1987).
SC Special "Any species of wild animal native or once-native
Concern to North Carolina which is determined by the
Wildlife Resources Commission to require
monitoring but which may be taken under
regulations adopted under the provisions of this
Article." (Article 25 of Chapter 113 of the General
Statutes; 1987).
P Proposed Species has been proposed by a Scientific Council
as a status (Endangered, Threatened, Special
Concern, Watch List, or for Delisting) that is
different from the current status, but the status has
not yet been adopted by the General Assembly as
law. In the lists of rare species in this book, these
proposed statuses are listed in parentheses below
the current status. Only those proposed statuses
that are different from the current statuses are
listed.
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STATUS
CODE STATUS STATUS DEFINITION
SR Significantly Any species which has not been listed by the N.C.
Rare Wildlife Resources Commission as an
Endangered, Threatened, or Special Concern
species, but which exists in the state in small
numbers and has been determined by the N.C.
Natural Heritage Program to need monitoring.
(This is a N.C. Natural Heritage Program
designation.) Significantly Rare species include
"peripheral" species, whereby North Carolina lies
at the periphery of the species' range (such as
Hermit Thrush).
EX Extirpated A species which is no longer believed to occur in
the state. (This is a N.C. Natural Heritage Program
designation, though WRC also uses this status; the
NHP list includes those on the WRC list.)
W Watch List Any other species believed to be of conservation
concern in the state because of scarcity, declining
populations, threats to populations, or inadequacy
of information to assess its rarity (see page 59 for
a more complete discussion). (This is a N.C.
Natural Heritage Program designation.)
G Species is a game animal, and therefore (by law)
cannot be listed for State protection as E, T, or SC.
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