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20080868 Ver 2_I-29 thru I-82 Ponar_20190628
Table 1-29. Raw data from benthic ponar grab samples collected in May 2018 at each station in all 13 creeks in the PCS study. Benthic organisms were not counted beyond 100 individuals in any sample. Taxonomic hierarchy Jacks Creek Little Creek (control) Jacobs Creek PA2 (control) Drinkwater Creek Long Creek (control) Tooley Creek Muddy Creek (control) Huddles Cut Porter Creek DCUT11 DCUT19 (control) Duck Creek (control) Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Annelida Clitel lata Enchytraeidae sp. 1 - 3 - - - - - - - - - - - - - - 3 - - - - - - - - Naididae Naididae sp. - - - - - - - - - - - - - - - - - 4 - - - - - - - - Naididae sp. w/o hair - - 62 - 2 - 13 65 9 - 1 - 4 - - - - 40 - - - - - 95 - - Limnodrilus hoffineisteri - - - - - - - - - - - - - - - - - - - - 2 - - - - - Paranais litoralis 7 - - - - - - - - - - - - - - - - 12 - - - - - - - - Tubificoides heterochaetus - - - - - 3 - 2 - 1 - - - 2 - - - - - 21 - - - - - - Polychaeta Ampharetidae Amphicteis floridus 1 - 464 20 - - 17 117 46 5 1 1 - - 2 6 - - 28 - 148 6 - - 3 2 Capitellidae Heteromastus filiformis - 2 - 10 - 2 - 5 4 2 3 10 1 5 - 3 35 26 - - - 10 - - - - Mediomastus ambiseta - 32 1 188 - 226 - 44 - 266 10 17 2 250 - 29 6 16 4 212 - 2 - 2 - 104 Nereididae Laeonereis culveri - - 10 1 1 - 6 21 2 - - - - - - - - - - - - - - - - - Neanthes succinea - - - - - - - - - 1 5 3 - - - 2 50 19 - - - - - 10 - 1 Orbiniidae Leitoscoloplos fragilis - - - - - - - - - - - - - - - - - 12 - - - - - - - - Phyllodocidae Eteone heteropoda 8 20 - 46 13 5 1 31 5 9 20 7 4 34 5 6 3 11 16 9 2 10 21 4 - - Spionidae Marenzelleria viridis - 20 - - 2 1 - 2 - 20 - 3 - 2 - - - 475 - 84 - 14 - 4 - - Polydora cornuta - - - 2 - - - 10 - - 1 2 - 5 - - 1 - - - - - - - - 1 Streblos io benedicti 19 8 - 361 1 44 19 174 2 123 74 49 12 45 22 49 4 - 78 74 - 8 - - 3 48 Arthropoda Arachnida Acari sp. - - - - 2 - - - - - - - - - - - - - - - - - - - - - Insecta Coleoptera Hydrophilidae Berosus sp. 2 - 4 - - - - - 1 1 1 - - - - - - - - - 4 - 1 - - - Haliplidae Peltodytes sp. - - - - - - - - - - - - - - - - - - - - 3 - - - - - Diptera Ceratopogonidae Bezzia/Palpomyia complex 1 - 14 2 9 1 21 15 6 - - - 2 - - - 3 - 11 - 21 18 26 5 - - Chironomidae Apedilum sp. - - - - - - - - - - 1 - - - - - - - - - - - - - - - Chironomus decorus 71 2 242 21 117 122 138 265 359 142 35 21 49 85 85 5 3 - 19 8 5 6 7 - - 156 Chironomus sp. - - - - - - - - - - - - - - - - - - - 1 - - - - - - 1-35 Table 1-29. (continued). Taxonomic hierarchy Jacks Creek Little Creek (control) Jacobs Creek PA2 (control) Drinkwater Creek Long Creek (control) Tooley Creek Muddy Creek (control) Huddles Cut Porter Creek DCUT11 DCUT19 (control) Duck Creek (control) Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Chironomus stigmaterus - - - 4 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Cladotanytarsus sp. - - - - - - - - - - 1 - - - - Coelotanypus sp. - - - - - - - - - - - - - - - - - - - 2 - - - - - 15 Cdcotopus sp. 1 - - 1 - - 3 - 2 - 1 - - - - - - - - - - - - - - 15 Dicrotendipes nervosus - - 2 - 2 - - - - - - - - - - - - - 2 - 10 88 - - - 7 Goeldichironomus devineyae 2 - - 1 - - - - - - 2 - - 1 - - 3 - - - 3 - 1 - - - Glyptotendipes sp. - - - - - - - - - - - - - - - - - - - - - - 2 - - - Parachironomus sp. 44 - 2 5 4 - 8 34 4 22 12 1 2 2 - - 4 - - - - 2 - - - - Polypedilum sp. - - - - - - - 2 - - - - - - - - - - - - - - - - - - Tanypus neopunctipennis 9 - 15 2 - - 2 1 - - - - - - 3 - 1 - - - - 2 - - - - Tanytarsus sp. 12 2 35 3 2 - - 1 12 - 9 2 - - - - 8 - 14 - 11 102 16 - 16 3 Hemiptera Corixidae Corixidae sp. 4 - 2 1 - - - - - - - - - - - 2 - - - - - - - - - - Odonata Coenagrionidae Enallagma sp. - - - - - - - - - - - - - - - - - - - - - 2 - - - - Libellulidae Pachydiplax longipennis - - - - - - - - - - - - - - - - - - - - 2 - - - - - Malacostraca Amphipoda Corophiidae Apocorophium lacustre 1 2 - - - - - 2 - - - - - - - - 6 - 32 1 - 318 - 3 - 17 Apocorophium louisianum 3 24 - 12 32 2 17 29 13 18 6 13 14 8 - 30 5 - - - - - 37 - - - Apocorophium sp. 44 138 - 29 121 16 62 144 83 36 35 30 18 24 4 66 13 - 8 6 4 456 136 31 - 21 Gammaridae Gammarus mucronatus 1 20 - 34 - 6 4 16 - 93 66 31 1 23 5 59 1 - - - - - - 2 - 2 Gammarustigrinus 330 142 306 150 57 48 80 287 145 127 130 20 19 14 51 118 2 30 400 27 356 462 22 433 55 384 Haustoriidae Haustodus sp. - - - - - - - - - - - - - - - - - 62 - - - - - - - - Lepidactylus dytiscus - - - - - - - - - - - - - - - - - 42 - - - - - - - - Decapoda Palaemonidae Palaemonetes pugio - - - - - 1 - - - - 3 - - - - - 8 - - - - - - - - - Panopeidae Rhithropanopeus harrisii - - - - - - - - - - 1 - - - - - 7 - - - - - - - - - Isopoda Anthuridae Cyathura polita - 6 - - - - - 23 - - - - - - - - - 3 - - - - 2 2 - - Bopyridae Proboyrus pandalicola - - - - - - - - - - 2 - - - - - - - - - - - - - - - Idoteidae Edotia montosa - - - - - - - 3 - 3 1 - - - - - - - - - - - - 9 - - Sphaeromatidae Cassidinidea lunifrons 1 - - - - - - - 2 - - - - - - - - - - - - - - 3 - - Table 1-29. (concluded). Taxonomic hierarchy Jacks Creek Little Creek (control) Jacobs Creek PA2 (control) Drinkwater Creek Long Creek (control) Tooley Creek Muddy Creek (control) Huddles Cut Porter Creek DCUT11 DCUT19 (control) Duck Creek (control) Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Mysida Mysidae Americamysis almyra 1 - - - - - - - - 4 4 2 1 1 - 3 - - - - - - - - - 12 Tanaidacea Leptocheliidae Hargeria rapax - - - - 1 - - - - 101 - 1 1 2 - - - 4 - 1 - - - 15 - 1 Maxillopoda Balanus improvisus - - - 18 - 20 - - 3 12 29 46 - 214 - 11 150 - - 1 - - - - - 101 Ostracoda Candonidae Candonidae sp. 24 - 16 - 12 1 54 3 52 - 2 - 8 1 80 1 - 8 2 - 16 2 290 11 95 - Cytherideidae Cyprideis littoralis 4 - 45 5 2 42 - - - 3 8 - 3 5 1 7 18 12 9 1 107 4 2 2 126 26 Cnidaria Anthozoa Actiniaria sp. - - - 4 - - - - - - 2 - - - - - - - - - - - - - - - Mollusca Bivalvia Bivalvia sp. - - - - - - - - - - - - - - - - 1 - - - 2 - - - - - Dreissenidae Mytilopsis leucophaeata - - 46 - - - - - - - - - - - - 2 - - 6 - 6 8 - - 16 - Mactridae Mulinia lateralis - - - - - 1 - - - 3 1 7 - 7 - 2 - - - 3 - - - - - - Rangia cuneata - - - 2 - - - - - - 1 - - - - - 3 - 2 - 1 - - 2 - 1 Mytilidae Geukensia demissa - - - - - - - - - - - - - - - - - 4 - - - - - - - - Tellinidae Macoma balthica 2 14 - 55 69 20 30 38 - 30 67 26 51 141 16 77 11 - - 83 - - - - - 10 Macoma tenta - 4 - 8 2 130 - 5 - 45 7 39 1 154 - 21 19 4 - ill - 2 - - - 19 Gastropoda Elysiidae Elysia chlorotica - - - - - - - - - - - 1 - - - - - - - - - - - - - - Hydrobiidae Littoridinops sp. 43 - 24 7 42 17 32 53 17 71 20 19 5 31 28 1 12 7 64 13 81 26 67 3 51 52 Total taxa 24 14 19 25 19 19 16 25 18 1 23 1 32 22 18 22 1 12 20 25 1 18 15 1 16 18 20 13 17 8 21 — = Species not collected at station 1-37 Table 1-30. Taxa collected from benthic ponar grab samples collected in May 2018 in all 13 creeks in the PCS study. Taxa for which EBI was calculated are shown with a * and other are shown with a ✓ Taxonomic hierarchy Jacks Creek Little Creek (control) Jacobs Creek PA2 (control) Drinkwater Creek Long Creek (control) Tooley Creek Muddy Creek (control) Huddles Cut Porter Creek DCUT11 DCUT19 (control) Duck Creek (control) Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Annelida Clitellata Enchytraeidae sp.- Naididae Naididae sp.- Naididae sp. w/o hair- Limnoddlus hoffineisteri- Paranais litoralis- Tubificoides heterochaetus- Polychaeta Ampharetidae Amphicteis floridus Capitellidae Heteromastus filiformis- Mediomastus ambiseta- Nereididae Laeonereis culveri- Neanthes succinea- Orbiniidae Leitoscoloplos fragilis- Phyllodocidae Eteone heteropoda- Spionidae Marenzelleria viddis- Po/ydora cornuta- Streblos io benedicti- Arthropoda Arachnida Acari sp. - - - - ✓ - - - - - - - - - - - - - - - - - - - - - Insecta Coleoptera Hydrophilidae Berosus sp.- Haliplidae Pe/todytes sp.- Diptera Ceratopogonidae Bezzia/Palpomyia complex- Chironomidae Apedilum sp.- Chironomus decorus- Chironomus sp.- Chironomus stigmaterus - - ✓ - - - - - - - - - - - - - - - - - - - - - - - C/adotanytarsus sp.- Coelotanypus sp. Cricotopus sp. Dicrotendipes nervosus- Goeldichironomus devineyae- Glyptotendipes sp.- Parachironomus sp.- Polypedilum sp. - - - - - - - 2 - - - - - - - - - - - - - - - - - - 1-38 Table 1-30. (continued). Taxonomic hierarchy Jacks Creek Little Creek (control) Jacobs Creek PA2 (control) Drinkwater Creek Long Creek (control) Tooley Creek Muddy Creek (control) Huddles Cut Porter Creek DCUT11 DCUT19 (control) Duck Creek (control) Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Tanypus neopunctipennis- Tanytarsus sp.- Hemiptera Corixidae Corixidae sp.- Odonata Coenagrionidae Enallagma sp.- Libellulidae Pachydiplax longipennis- Malacostraca Amphipoda Corophiidae Apocorophium lacustre Apocorophium louisianum- Apocorophium sp. Gammaridae Gammarus mucronatus Gammarus tigrinus * * * * * * * * * * * * * * * * Haustoriidae Haustodus sp. - - - - - - - - - - - - - - - - - ✓ - - - - - - - - Lepidactylus dytiscus- Decapoda Palaemonidae Palaemonetes pugio- Panopeidae Rhithropanopeus harrisii- Isopoda Anthuridae Cyathura polita- Bopyridae Proboyrus pandalicola - - - - - - - - - - ✓ - - - - - - - - - - - - - - - Idoteidae Edotia montosa- Sphaeromatidae Cassidinidea lunifrons- Mysida Mysidae Americamysis almyra Tanaidacea Leptocheliidae Hargeria rapax Maxillopoda Balanus improvisus Ostracoda Candonidae Candonidae sp. ✓ - ✓ - ✓ ✓ ✓ ✓ ✓ - ✓ - ✓ ✓ ✓ ✓ - ✓ ✓ - ✓ ✓ ✓ ✓ ✓ - Cytherideidae Cypridets littoralis ✓ - ✓ ✓ ✓ ✓ - - - ✓ ✓ - ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ 1-39 Table 1-30. (concluded). Taxonomic hierarchy Jacks Creek Little Creek (control) Jacobs Creek PA2 (control) Drinkwater Creek Long Creek (control) Tooley Creek Muddy Creek (control) Huddles Cut Porter Creek DCUT11 DCUT19 (control) Duck Creek (control) Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Up Down Cnidaria Anthozoa - - ✓ - - Actiniaria sp. - - - ✓ - - - - - - - - - - - - - - - Mollusca Bivalvia Bivalvia sp. - - - - - - - - - - - - - - - - ✓ - - - ✓ - - - - - Dreissenidae Mytilopsis leucophaeata- Mactridae Mulinia lateralis- Rangia cuneata Mytilidae Geukensia demissa- Tellinidae Macoma balthica Macoma tents Gastropoda Elysiidae Elysia chlorotica - - - - - - - - - - - ✓ - - - - - - - - - - - - - - Hydrobiidae Littoridinops sp. Total taxa 24 14 19 25 19 19 16 25 18 23 32 22 18 22 12 20 25 18 15 16 18 20 13 17 8 21 = Species not collected at station 1-40 Table 1-31. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Jacks Creek upstream station in May 2018. Species/taxon Jacks Creek Upstream Samples 1 2 3 4 5 Average Annelida Clitellata Enchytraeidae sp. 0 0 0 1 0 0.2 Paranais litoralis 5 2 0 0 0 1.4 Polychaeta Amphicteis floridus 1 0 0 0 0 0.2 Eteone heteropoda 0 4 2 2 0 1.6 Streblospio benedicti 6 4 2 1 6 3.8 Arthropoda Insecta Coleoptera Berosus sp. 2 0 0 0 0 0.4 Diptera Bezzia/Palmonyia complex 0 0 1 0 0 0.2 Chironomus decorus 8 18 9 20 16 14.2 Cricotopus sp. 0 0 0 1 0 0.2 Goeldichironomus devineyae 1 1 0 0 0 0.4 Parachironomus sp. 1 8 1 12 22 8.8 Tanypus neopunctipennis 4 0 1 2 2 1.8 Tanytarsus sp. 1 2 0 3 6 2.4 Hemiptera Corixidae sp. 0 0 1 1 2 0.8 Malacostraca Amphipoda Apocorophium lacustre 0 0 1 0 0 0.2 Apocorophium louisianum 1 0 0 0 2 0.6 Apocorophium sp. 12 10 2 4 16 8.8 Gammarus mucronatus 1 0 0 0 0 0.2 Gammarus tigrinus 100 62 19 49 100 66.0 Isopoda Cassidinidea lunifrons 1 0 0 0 0 0.2 Mysida Americamysis almyra 1 0 0 0 0 0.2 Ostracoda Candonidae sp. 7 8 5 2 2 4.8 Cyprideis littoralis 1 0 0 1 2 0.8 Mollusca Bivalvia Macoma balthica 0 2 0 0 0 0.4 Gastropoda Littoridinops sp. 9 0 2 2 30 8.6 Total taxa by sample 162 121 46 101 206 Total abundance = 636 Total taxa present = 24 Shannon -Wiener diversitv = 1.83 1-41 Table 1-32. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Jacks Creek upstream station in May 2018. Speciesltaxona Number of individualsb Sensitivity value (SV)` Abundance value (n) Product of (SV) n Annelida Clitellata Enchytraeidae sp. 1 1.0 1 1.0 Paranais litoralis 7 1.1 3 3.3 Polychaeta Amphicteis floridus 1 2.0 1 2.0 Eteone heteropoda 8 1.6 3 4.8 Streblospio benedicti 19 1.1 10 11.0 Arthropoda I nsecta Coleoptera Berosus sp. 2 1.5 1 1.5 Diptera Bezzia/Palmonyia complex 1 2.3 1 2.3 Chironomus decorus 71 1.0 30 30.0 Cricotopus sp. 1 1.4 1 1.4 Goeldichironomus devineyae 2 2.0 1 2.0 Parachironomus sp. 44 1.1 30 33.0 Tanypus neopunctipennis 9 1.0 3 3.0 Tanytarsus sp. 12 2.3 10 23.0 Hemiptera Corixidae sp. 4 1.3 3 3.9 Malacostraca Amphipoda Apocorophium lacustre 1 2.2 1 2.2 Apocorophium louisianum 3 2.2 3 6.6 Apocorophium sp. 44 2.2 30 66.0 Gammarus mucronatus 1 2.3 1 2.3 Gammarus tigrinus 330 2.0 100 200.0 Isopoda Cassidinidea lunifrons 1 2.0 1 2.0 Mysida Americamysis almyra 1 2.2 1 2.2 Mollusca Bivalvia Macoma balthica 2 1.5 1 1.5 Gastropoda Littoridinops sp. 43 2.0 30 60.0 Total 266 465.0 Estuarine Biotic Index = 1.75 Total taxa = 24 Total taxa with sensitivity values = 22 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-42 Table 1-33. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Jacks Creek downstream station in May 2018. S ecies/taxon Jacks Creek Downstream Samples 1 2 3 4 5 Average Annelida Polychaeta Eteone heteropoda 4 2 10 0 4 4.0 Heteromastus filiformis 0 0 2 0 0 0.4 Marenzelleria viddis 2 6 10 0 2 4.0 Mediomastus ambiseta 20 0 10 0 2 6.4 Streblospio benedicti 2 0 6 0 0 1.6 Arthropoda Insecta Diptera Chironomus decorus 0 0 2 0 0 0.4 Tanytarsus sp. 0 0 2 0 0 0.4 Malacostraca Amphipoda Apocorophium lacustre 2 0 0 0 0 0.4 Apocorophium louisianum 12 2 10 0 0 4.8 Apocorophium sp. 64 16 48 0 10 27.6 Gammarus mucronatus 8 2 10 0 0 4.0 Gammarus tigrinus 68 14 46 0 14 28.4 Isopoda Cyathura polita 4 0 2 0 0 1.2 Mollusca Bivalvia Macoma balthica 6 2 2 2 2 2.8 Macoma tenta 2 0 0 2 0 0.8 Total taxa by sample 194 44 160 4 34 Total abundance = 436 Total taxa present = 14 Shannon -Wiener diversitv = 1.89 1-43 Table 1-34. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Jacks Creek downstream station in May 2018. Species/taxona Number of individuals" Sensitivity value (SV)` Abundance value (n) Product of SV)(n) Annelida Polychaeta Eteone heteropoda 20 1.6 10 16.0 Heteromastus filiformis 2 1.1 1 1.1 Marenzelleria viridis 20 2.6 10 26.0 Mediomastus ambiseta 32 2.0 30 60.0 Streblospio benedicti 8 1.1 3 3.3 Arthropoda Insecta Diptera Chironomus decorus 2 1.0 1 1.0 Tanytarsus sp. 2 2.3 1 2.3 Malacostraca Amphipoda Apocorophium lacustre 2 2.2 1 2.2 Apocorophium louisianum 24 2.2 10 22.0 Apocorophium sp. 138 2.2 100 220.0 Gammarus mucronatus 20 2.3 10 23.0 Gammarus tigrinus 142 2.0 100 200.0 Isopoda Cyathura polity 6 2.0 3 6.0 Mollusca Bivalvia Macoma balthica 14 1.5 10 15.0 Macoma tenta 4 2.0 3 6.0 Total 293 603.9 Estuarine Biotic Index = 2.06 Total taxa = 14 Total taxa with sensitivitv values = 14 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-44 Table 1-35. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Little Creek upstream station in May 2018. S ecies/taxon Little Creek Upstream Samples 1 2 3 4 5 Average Annelida Clitellata Enchytraeidae sp. 0 0 0 3 0 0.6 Naididae sp. w/o hair 12 24 2 24 0 12.4 Polychaeta Amphicteis floridus 100 100 100 100 64 92.8 Laeonereis culveri 4 4 2 0 0 2.0 Mediomastus ambiseta 0 0 1 0 0 0.2 Arthropoda Insecta Coleoptera Berosus sp. 0 4 0 0 0 0.8 Diptera Bezzia/Palpomyia complex 4 4 1 3 2 2.8 Chironomus decorus 44 100 16 60 22 48.4 Chironomus stigmaterus 4 0 0 0 0 0.8 Dicrotendipes nervosus 0 0 0 0 2 0.4 Parachironomus sp. 0 0 0 0 2 0.4 Tanypus neopuntipennis 12 0 0 3 0 3.0 Tanytarsus sp. 4 12 3 12 4 7.0 Hemiptera Corixidae sp. 0 0 0 0 2 0.4 Malacostraca Amphipoda Gammarus tigrinus 100 64 26 100 16 61.2 Ostracoda Candonidae sp. 0 16 0 0 0 3.2 Cyprideis littoralis 8 20 0 3 14 9.0 Mollusca Bivalvia Mytilopsis leucophaeata 16 8 6 6 10 9.2 Gastropoda Littoridinops sp. 4 16 0 0 4 4.8 Total taxa by sample 312 372 157 314 142 Total abundance = 1,297 Total taxa present = 19 Shannon -Wiener diversity = 1.85 1-45 Table 1-36. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Little Creek upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance Product of value (n) (SV)(n) Annelida Clitellata Enchytraeidae sp. 3 1.0 3 3.0 Naididae sp. w/o hair 62 1.0 30 30.0 Polychaeta Amphicteis floridus 464 2.0 100 200.0 Laeonereis culveri 10 1.0 10 10.0 Mediomastus ambiseta 1 2.0 1 2.0 Arthropoda Insecta Coleoptera Berosus sp. 4 1.5 3 4.5 Diptera Bezzia/Palpomyia complex 14 2.3 10 23.0 Chironomus decorus 242 1.0 100 100.0 Dicrotendipes nervosus 2 1.0 1 1.0 Parachironomus sp. 2 1.1 1 1.1 Tanypus neopuntipennis 15 1.0 10 10.0 Tanytarsus sp. 35 2.3 30 69.0 Hemiptera Corixidae sp. 2 1.3 1 1.3 Malacostraca Amphipoda Gammarus tigrinus 306 2.0 100 200.0 Mollusca Bivalvia Mytilopsis leucophaeata 46 1.5 30 45.0 Gastropoda Littoridinops sp. 24 2.0 10 20.0 Total 440 719.9 Estuarine Biotic Index = 1.64 Total taxa = 19 Total taxa with sensitivity values = 16 a Only those taxa for which a sensitivity value is available are displayed bTotal number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. .R Table 1-37. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Little Creek downstream station in May of 2018. Species/taxon Little Creek Downstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 1 4 6 3 6 4.0 Eteone heteropda 7 7 14 6 12 9.2 Heteromastus filiformis 0 2 2 4 2 2.0 Laeonereis culveri 0 0 0 1 0 0.2 Mediomastus ambiseta 36 52 54 30 16 37.6 Polydora cornuta 2 0 0 0 0 0.4 Streblospio benedicti 33 100 100 28 100 72.2 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 0 1 0 1 0 0.4 Chironomus decorus 5 2 10 4 0 4.2 Cricotopus sp. 1 0 0 0 0 0.2 Goeldichironomus devineyae 0 1 0 0 0 0.2 Parachironomus sp. 1 1 0 3 0 1.0 Tanypus neopunctipennis 0 0 0 0 2 0.4 Tanytarsus sp. 3 0 0 0 0 0.6 Hemiptera Corixidae sp. 1 0 0 0 0 0.2 Malacostraca Amphipoda Apocorophium louisianum 6 3 0 1 2 2.4 Apocorophium sp. 6 6 6 5 6 5.8 Gammarus mucronatus 7 4 2 11 10 6.8 Gammarus tigrinus 21 34 22 21 52 30.0 Maxillopoda Balanus improvisus 0 2 4 6 6 3.6 Ostracoda Cyprideis littoralis 1 0 4 0 0 1.0 Cnidaria Anthozoa Actiniaria sp. 0 0 2 0 2 0.8 Mollusca Bivalvia Macoma balthica 11 9 12 9 14 11.0 Macoma tenta 2 3 0 1 2 1.6 Rangia cuneata 0 0 0 0 2 0.4 Gastropoda Littoridinops sp. 0 3 4 0 0 1.4 Total taxa by sample 144 234 242 134 234 Total abundance = 988 Total taxa present = 25 Shannon -Wiener diversity = 2.07 1-47 Table 1-38. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Little Creek downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value SV ° Abundance value n Product of SV n Annelida Polychaeta Amphicteis floridus 20 2.0 10 20.0 Eteone heteropda 46 1.6 30 48.0 Heteromastus filiformis 10 1.1 10 11.0 Laeonereis culveri 1 1.0 1 1.0 Mediomastus ambiseta 188 2.0 100 200.0 Polydora cornuta 2 1.2 1 1.2 Streblospio benedicti 361 1.1 100 110.0 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 2 2.3 1 2.3 Chironomus decorus 21 1.0 10 10.0 Cricotopus sp. 1 1.4 1 1.4 Goeldichironomus devineyae 1 2.0 1 2.0 Parachironomus sp. 5 1.1 3 3.3 Tanypus neopunctipennis 2 1.0 1 1.0 Tanytarsus sp. 3 2.3 3 6.9 Hemiptera Corixidae sp. 1 1.3 1 1.3 Malacostraca Amphipoda Apocorophium louisianum 12 2.2 10 22.0 Apocorophium sp. 29 2.2 10 22.0 Gammarus mucronatus 34 2.3 30 69.0 Gammarus tigrinus 150 2.0 100 200.0 Maxillopoda Balanus improvisus 18 2.0 10 20.0 Mollusca Bivalvia Macoma balthica 55 1.5 30 45.0 Macoma tenta 8 2.0 3 6.0 Rangia cuneata 2 1.0 1 1.0 Gastropoda Littoridinops sp. 7 2.0 3 6.0 Total 470 810.4 Estuarine Biotic Index = 1.72 Total taxa = 25 Total taxa with sensitivitv values = 23 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-48 Table 1-39. Numbers of benthic macroi nverteb rates collected in each ponar grab sample at the Jacobs Creek upstream station in May 2018. S ecies/taxon Jacobs Creek Upstream Samples 1 2 3 4 5 Average Annelida Clitellata Naididae sp. w/o hair 0 0 2 0 0 0.4 Polychaeta Eteone heteropoda 5 2 2 2 2 2.6 Laeonereis culveri 1 0 0 0 0 0.2 Marenzellaria viridis 0 0 0 2 0 0.4 Streblospio benedicti 1 0 0 0 0 0.2 Arthropoda Arachnida Acari sp. 0 2 0 0 0 0.4 Insecta Diptera Bezzia/Palmonyia complex 1 6 0 2 0 1.8 Chironomus decorus 33 28 6 34 16 23.4 Dicrotendipes nervosus 0 0 0 0 2 0.4 Parachironomus sp. 0 2 0 0 2 0.8 Tanytarsus sp. 0 2 0 0 0 0.4 Malacostraca Amphipoda Apocorophium louisianum 4 12 2 8 6 6.4 Apocorophium sp. 11 42 6 38 24 24.2 Gammarus tigrinus 9 40 0 8 0 11.4 Tanaidacea Hargeria rapax 1 0 0 0 0 0.2 Ostracoda Candonidae sp. 0 0 0 8 4 2.4 Cyprideis littoralis 0 2 0 0 0 0.4 Mollusca Bivalvia Macoma balthica 17 12 10 16 14 13.8 Macoma tenta 0 0 0 2 0 0.4 Gastropoda Littoridinops sp. 8 16 8 8 2 8.4 Total taxa by sample 91 166 36 128 72 Total abundance = 493 Total taxa present = 19 Shannon -Wiener diversity = 2.09 1-49 Table 1-40. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Jacobs Creek upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance value (n) Product of (SV)(n) Annelida Clitellata Naididae sp. w/o hair 2 1.0 1 1.0 Polychaeta Eteone heteropoda 13 1.6 10 16.0 Laeonereis culveri 1 1.0 1 1.0 Marenzellaria viridis 2 2.6 1 2.6 Streblospio benedicti 1 1.1 1 1.1 Arthropoda Insecta Diptera Bezzia/Palmonyia complex 9 2.3 3 6.9 Chironomus decorus 117 1.0 100 100.0 Dicrotendipes nervosus 2 1.0 1 1.0 Parachironomus sp. 4 1.1 3 3.3 Tanytarsus sp. 2 2.3 1 2.3 Malacostraca Amphipoda Apocorophium louisianum 32 2.2 30 66.0 Apocorophium sp. 121 2.2 100 220.0 Gammarus tigrinus 57 2.0 30 60.0 Tanaidacea Hargeria rapax 1 1.6 1 1.6 Mollusca Bivalvia Macoma balthica 69 1.5 30 45.0 Macoma tenta 2 2.0 1 2.0 Gastropoda Littoridinops sp. 42 2.0 30 60.0 Total 344 589.8 Estuarine Biotic Index = 1.71 Total taxa = 19 Total taxa with sensitivitv values = 16 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. Sensitivity values provided by NCDWR. 1-50 Table 1-41. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Jacobs Creek downstream station in May 2018. S ecies/taxon Jacobs Creek Downstream Samples 1 2 3 4 5 Average Annelida Clitellata Tubificoides heterochaetus 3 0 0 0 0 0.6 Polychaeta Eteone heteropoda 2 2 0 1 0 1.0 Heteromastus filiformis 1 0 0 1 0 0.4 Marenzellaria viddis 0 0 0 1 0 0.2 Mediomastus ambiseta 62 74 24 59 7 45.2 Streblospio benedicti 19 8 8 8 1 8.8 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 0 1 0 0 0 0.2 Chironomus decorus 31 23 13 36 19 24.4 Malacostraca Amphipoda Apocorophium louisianum 0 0 1 0 1 0.4 Apocorophium sp. 1 2 1 5 7 3.2 Gammarus mucronatus 0 3 1 0 2 1.2 Gammarus tigrinus 4 11 2 21 10 9.6 Decapoda Palaemonetes pugio 0 0 0 0 1 0.2 Maxillopoda Balanus improvisus 1 1 1 17 0 4.0 Ostracoda Candonidae sp. 0 0 0 1 0 0.2 Cyprideis littoralis 5 15 8 11 3 8.4 Mollusca Bivalvia Macoma balthica 3 5 4 6 2 4.0 Macoma tenta 38 36 21 25 10 26.0 Mulinia lateralis 0 0 1 0 0 0.2 Gastropoda Littoridinops sp. 0 4 2 5 6 3.4 Total taxa by sample 170 185 87 197 69 Total abundance = 708 Total taxa present = 19 Shannon -Wiener diversitv = 2.06 1-51 Table 1-42. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Jacobs Creek downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)c Abundance value (n) Product of SV)(n) Annelida Clitellata Tubificoides heterochaetus 3 1.1 3 3.3 Polychaeta Eteone heteropoda 5 1.6 3 4.8 Heteromastus filiformis 2 1.1 1 1.1 Marenzellaria viridis 1 2.6 1 2.6 Mediomastus ambiseta 226 2.0 100 200.0 Streblospio benedicti 44 1.1 30 33.0 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 1 2.3 1 2.3 Chironomus decorus 122 1.0 100 100.0 Malacostraca Amphipoda Apocorophium louisianum 2 2.2 1 2.2 Apocorophium sp. 16 2.2 10 22.0 Gammarus mucronatus 6 2.3 3 6.9 Gammarus tigrinus 48 2.0 30 60.0 Decapoda Palaemonetes pugio 1 2.5 1 2.5 Maxillopoda Balanus improvisus 20 2.0 10 20.0 Mollusca Bivalvia Macoma balthica 20 1.5 10 15.0 Macoma tenta 130 2.0 100 200.0 Mulinia lateralis 1 2.3 1 2.3 Gastropoda Littoridinops sp. 17 2.0 10 20.0 Total 415 698.0 Estuarine Biotic Index = 1.68 Total taxa = 19 Total taxa with sensitivitv values = 17 a Only those taxa for which a sensitivity value is available are displayed. bTotal number of individuals caught in all five ponar replicates. Sensitivity values provided by NCDWR. 1-52 Table 1-43. Numbers of benthic macro invertebrates collected in each ponar grab sample at the PA2 upstream station in May 2018. Species/taxon PA2 Creek Upstream Samples 1 2 3 4 5 Average Annelida Clitellata Naididae sp. w/o hair 6 0 5 2 0 2.6 Polychaeta Amphicteis floridus 6 0 4 6 1 3.4 Eteone heteropoda 0 0 1 0 0 0.2 Laeonereis culveri 1 1 2 1 1 1.2 Streblospio benedicti 2 0 3 13 1 3.8 Arthropoda I nsecta Diptera Bezzia/Palpomyia complex 4 1 2 8 6 4.2 Chironomus decorus 33 22 9 43 31 27.6 Cricotopus sp. 0 1 0 1 1 0.6 Parachironomus sp. 4 1 3 0 0 1.6 Tanypus neopunctipennis 0 0 1 1 0 0.4 Malacostraca Amphipoda Apocorophium louisianum 3 1 5 6 2 3.4 Apocorophium sp. 7 1 24 27 3 12.4 Gammarus mucronatus 2 1 0 0 1 0.8 Gammarus tigrinus 14 4 41 13 8 16.0 Ostracoda Candonidae sp. 1 0 9 26 18 10.8 Mollusca Bivalvia Macoma balthica 9 2 11 8 0 6.0 Gastropoda Littoridinops sp. 13 1 7 4 7 6.4 Total taxa by sample 105 36 127 159 80 Total abundance = 507 Total taxa present = 16 Shannon -Wiener diversitv = 2.28 1-53 Table 1-44. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the PA2 upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance Product of value (n) (SV)(n) Annelida Clitellata Naididae sp. w/o hair 13 1.0 10 10.0 Polychaeta Amphicteis floridus 17 2.0 10 20.0 Eteone heteropoda 1 1.6 1 1.6 Laeonereis culveri 6 1.0 3 3.0 Streblospio benedicti 19 1.1 10 11.0 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 21 2.3 10 23.0 Chironomus decorus 138 1.0 100 100.0 Cricotopus sp. 3 1.4 3 4.2 Parachironomus sp. 8 1.1 3 3.3 Tanypus neopunctipennis 2 1.0 1 1.0 Malacostraca Amphipoda Apocorophium louisianum 17 2.2 10 22.0 Apocorophium sp. 62 2.2 30 66.0 Gammarus mucronatus 4 2.3 3 6.9 Gammarus tigrinus 80 2.0 30 60.0 Mollusca Bivalvia Macoma balthica 30 1.5 30 45.0 Gastropoda Littoridinops sp. 32 2.0 30 60.0 Total 284 437.0 Estuarine Biotic Index = 1.54 Total taxa = 16 Total taxa with sensitivity values = 15 a Only those taxa for which a sensitivity value is available are displayed bTotal number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-54 Table 1-45. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the PA2 downstream station in May 2018. S ecies/taxon PA2 Creek Downstream Samples 1 2 3 4 5 Average Annelida Clitellata Naididae sp. w/o hair 7 1 18 24 15 13.0 Tubificoides heterochaetus 0 2 0 0 0 0.4 Polychaeta Amphicteis floridus 23 13 29 27 25 23.4 Eteone heteropoda 4 8 7 4 8 6.2 Heteromastus filiformis 2 1 1 0 1 1.0 Marenzelleria viridis 0 0 1 1 0 0.4 Mediomastus ambiseta 4 2 1 8 29 8.8 Laeonereis culveri 3 1 10 2 5 4.2 Polydora cornuta 1 2 3 4 0 2.0 Streblospio benedecti 23 20 63 46 22 34.8 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 1 5 2 3 4 3.0 Chironomus decorus 59 43 33 30 100 53.0 Parachironomus sp. 4 14 9 2 5 6.8 Polypedilum sp. 0 0 2 0 0 0.4 Tanypus neopunctipennis 1 0 0 0 0 0.2 Tanytarsus sp. 0 1 0 0 0 0.2 Malacostraca Amphipoda Apocorophium lacustre 1 1 0 0 0 0.4 Apocorophium louisianum 0 4 5 19 1 5.8 Apocorophium sp. 17 28 46 52 1 28.8 Gammarus mucronatus 11 0 2 3 0 3.2 Gammarus tigrinus 100 54 37 71 25 57.4 Isopoda Cyathura polita 1 2 15 3 2 4.6 Edotia montosa 0 1 1 1 0 0.6 Ostracoda Candonidae sp. 0 0 1 0 2 0.6 Mollusca Bivalvia Macoma balthica 7 6 10 13 2 7.6 Macoma tenta 1 1 1 2 0 1.0 Gastropoda Littoridinops sp. 15 18 9 9 2 10.6 Total taxa by sample 285 228 306 324 249 Total abundance = 1,392 Total taxa present = 25 Shannon -Wiener diversity = 2.46 1-55 Table 1-46. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the PA2 downstream station in May 2018. Number of Sensitivity Abundance Product of Species/taxona individualsb value (SV)` value (n) (SV)(n) Annelida Clitellata Naididae sp. w/o hair 65 1.0 30 30.0 Tublficoides heterochaetus 2 1.1 1 1.1 Polychaeta Amphicteis floridus 117 2.0 100 200.0 Eteone heteropoda 31 1.6 30 48.0 Heteromastus filiformis 5 1.1 3 3.3 Marenzelleria viridis 2 2.6 1 2.6 Mediomastus ambiseta 44 2.0 30 60.0 Laeonereis culveri 21 1.0 10 10.0 Polydora cornuta 10 1.2 10 12.0 Streblospio benedecti 174 1.1 100 110.0 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 15 2.3 10 23.0 Chironomus decorus 265 1.0 100 100.0 Parachironomus sp. 34 1.1 30 33.0 Po/ypedilum sp. 2 1.5 1 1.5 Tanypus neopunctipennis 1 1.0 1 1.0 Tanytarsus sp. 1 2.3 1 2.3 Malacostraca Amphipoda Apocorophium lacustre 2 2.2 1 2.2 Apocorophium louisianum 29 2.2 10 22.0 Apocorophium sp. 144 2.2 100 220.0 Gammarus mucronatus 16 2.3 10 23.0 Gammarus tigrinus 287 2.0 100 200.0 Isopoda Cyathura polita 23 2.0 10 20.0 Edotia montosa 3 2.6 3 7.8 Mollusca Bivalvia Macoma balthica 38 1.5 30 45.0 Macoma tenta 5 2.0 3 6.0 Gastropoda Littoridinops sp. 53 2.0 30 60.0 Total 755 1,243.8 Estuarine Biotic Index = 1.65 Total taxa = 25 Total taxa with sensitivity values = 24 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-56 Table 1-47. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Drinkwater Creek upstream station in May 2018. Species/taxon Drinkwater Creek Upstream Samples 1 2 3 4 5 Average Annelida Clitellata Naididae sp. w/o hair 8 0 1 0 0 1.8 Polychaeta Amphicteis floridus 36 4 2 1 3 9.2 Eteone heteropoda 2 2 1 0 0 1.0 Heteromastus filiformis 4 0 0 0 0 0.8 Laeonereis culveri 0 2 0 0 0 0.4 Streblospio benedicti 2 0 0 0 0 0.4 Arthropoda Insecta Coleoptera Berosus sp. 0 0 0 1 0 0.2 Diptera Bezzia/Palpomyia complex 2 2 1 0 1 1.2 Chironomus decorus 100 76 50 33 100 71.8 Cricotopus sp. 0 0 0 1 1 0.4 Parachironomus sp. 0 0 3 0 1 0.8 Tanytarsus sp. 6 0 1 2 3 2.4 Malacostraca Amphipoda Apocorophium louisianum 2 2 9 0 0 2.6 Apocorophium sp. 34 12 29 0 8 16.6 Gammarus tigrinus 46 18 59 5 17 29.0 Isopoda Cassidinidea lunifrons 2 0 0 0 0 0.4 Maxillopoda Balanus improvisus 0 2 0 0 1 0.6 Ostracoda Candonidae sp. 48 4 0 0 0 10.4 Mollusca Gastropoda Littoridinops sp. 2 6 2 0 7 3.4 Total taxa by sample 294 130 158 43 142 Total abundance = 767 Total taxa present = 18 Shannon -Wiener diversitv = 1.75 1-57 Table 1-48. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Drinkwater Creek upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)c Abundance value (n) Product of SV)(n) Annelida Clitellata Naididae sp. w/o hair 9 1.0 3 3.0 Polychaeta Amphicteis floridus 46 2.0 30 60.0 Eteone heteropoda 5 1.6 3 4.8 Heteromastus filiformis 4 1.1 3 3.3 Laeonereis culveri 2 1.0 1 1.0 Streblospio benedicti 2 1.1 1 1.1 Arthropoda Insecta Coleoptera Berosus sp. 1 1.5 1 1.5 Diptera Bezzia/Palpomyia complex 6 2.3 3 6.9 Chironomus decorus 359 1.0 100 100.0 Cricotopus sp. 2 1.4 1 1.4 Parachironomus sp. 4 1.1 3 3.3 Tanytarsus sp. 12 2.3 10 23.0 Malacostraca Amphipoda Apocorophium louisianum 13 2.2 10 22.0 Apocorophium sp. 83 2.2 30 66.0 Gammarus tigrinus 145 2.0 100 200.0 Isopoda Cassidinidea lunifrons 2 2.0 1 2.0 Maxillopoda Balanus improvisus 3 2.0 3 6.0 Mollusca Gastropoda Littoridinops sp. 17 2.0 10 20.0 Total 313 525.3 Estuarine Biotic Index = 1.68 Total taxa = 18 Total taxa with sensitivitv values = 17 a Only those taxa for which a sensitivity value is available are displayed. bTotal number of individuals caught in all five ponar replicates. Sensitivity values provided by NCDWR. 1-58 Table 1-49. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Drinkwater Creek downstream station in May 2018. Drinkwater Creek Downstream Samples Species/taxon 1 2 3 4 5 Average Clitellata Tubificoides heterochaetus 0 1 0 0 0 0.2 Polychaeta Amphicteis floridus 0 1 2 1 1 1.0 Eteone heteropoda 1 1 1 4 2 1.8 Heteromastus filiformis 0 0 0 1 1 0.4 Marenzelleria viridis 4 1 5 6 4 4.0 Mediomastus ambiseta 42 93 15 40 76 53.2 Neanthes succinea 0 0 0 1 0 0.2 Streblospio benedicti 12 9 14 50 38 24.6 Arthropoda Insecta Coleoptera Berosus sp. 0 0 0 0 1 0.2 Diptera Chironomus decorus 29 11 21 49 32 28.4 Parachironomus sp. 5 7 2 4 4 4.4 Malacostraca Amphipoda Apocorophium louisianum 5 2 8 3 0 3.6 Apocorophium sp. 12 7 10 7 0 7.2 Gammarus mucronatus 28 27 18 11 9 18.6 Gammarus tigrinus 33 40 25 21 8 25.4 Isopoda Edotia montosa 0 0 1 2 0 0.6 Mysida Americamysis almyra 2 0 0 1 1 0.8 Tanaidacea Hargeria rapax 22 24 13 35 7 20.2 Maxillopoda Balanus improvisus 0 2 1 9 0 2.4 Ostracoda Cyprideis littoralis 1 0 0 0 2 0.6 Mollusca Bivalvia Macoma balthica 3 7 5 7 8 6.0 Macoma tenta 8 12 11 7 7 9.0 Mulinia lateralis 0 0 2 0 1 0.6 Gastropoda Littoridinops sp. 25 16 15 8 7 14.2 Total taxa by sample 232 261 169 267 209 Total abundance = 1,138 Total taxa present = 23 Shannon -Wiener diversity = 2.43 1-59 Table 1-50. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Drinkwater Creek downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value SV ° Abundance value n Product of SV n Annelida Clitellata Tubificoides heterochaetus 1 1.1 1 1.1 Polychaeta Amphicteis floridus 5 2.0 3 6.0 Eteone heteropoda 9 1.6 3 4.8 Heteromastus filiformis 2 1.1 1 1.1 Marenzelleria viridis 20 2.6 10 26.0 Mediomastus ambiseta 266 2.0 100 200.0 Neanthes succinea 1 1.7 1 1.7 Streblospio benedicti 123 1.1 100 110.0 Arthropoda Insecta Coleoptera Berosus sp. 1 1.5 1 1.5 Diptera Chironomus decorus 142 1.0 100 100.0 Parachironomus sp. 22 1.1 10 11.0 Malacostraca Amphipoda Apocorophium louisianum 18 2.2 10 22.0 Apocorophium sp. 36 2.2 30 66.0 Gammarus mucronatus 93 2.3 30 69.0 Gammarus tigrinus 127 2.0 100 200.0 Isopoda Edotia montosa 3 2.6 3 7.8 Mysida Americamysis almyra 4 2.2 3 6.6 Tanaidacea Hargeria rapax 101 1.6 100 160.0 Maxillopoda Balanus improvisus 12 2.0 10 20.0 Mollusca Bivalvia Macoma balthica 30 1.5 30 45.0 Macoma tenta 45 2.0 30 60.0 Mulinia lateralis 3 2.3 3 6.9 Gastropoda Littoridinops sp. 71 2.0 30 60.0 Total 709 1,186.5 Estuarine Biotic Index = 1.67 Total taxa = 23 Total taxa with sensitivitv values = 22 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. Table 1-51. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Long Creek upstream station in Mav 2018. Species/taxon Long Creek Up stream Samples 1 2 3 4 5 Average Annelida Clitellata Naididae sp. w/o hair 0 1 0 0 0 0.2 Polychaeta Amphicteis floridus 0 0 1 0 0 0.2 Eteone heteropoda 8 6 2 3 1 4.0 Heteromastus filiformis 1 0 2 0 0 0.6 Mediomastus ambiseta 1 2 6 1 0 2.0 Neanthes succinea 2 2 0 1 0 1.0 Polydora comuta 0 0 1 0 0 0.2 Streblospio benedicti 14 28 5 15 12 14.8 Arthropoda Insecta Coleoptera Berosus sp. 0 0 0 1 0 0.2 Diptera Apedilum sp. 1 0 0 0 0 0.2 Chironomus decorus 1 11 6 9 8 7.0 Cricotopus sp. 1 0 0 0 0 0.2 Goeldichironomus devineyae 1 0 0 1 0 0.4 Parachironomus sp. 0 0 1 4 7 2.4 Tanytarsus sp. 1 5 0 2 1 1.8 Malacostraca Amphipoda Apocorophium louisianum 0 1 0 1 4 1.2 Apocorophium sp. 2 8 1 14 10 7.0 Gammarus mucronatus 8 34 4 20 0 13.2 Gammarus tigrinus 8 14 11 33 64 26.0 Decapoda Palaemonetes pugio 0 0 0 3 0 0.6 Rhithropanopeus harrisii 0 0 0 1 0 0.2 Isopoda Edotia montosa 0 1 0 0 0 0.2 Probopyrus pandalicola 0 0 0 2 0 0.4 Mysida Americamysis almyra 1 3 0 0 0 0.8 Maxillopoda Balanus improvisus 0 2 2 10 15 5.8 Ostracoda Candonidae sp. 0 0 0 0 2 0.4 Cyprideis littoralis 2 4 0 1 1 1.6 Cnidaria Anthozoa Actiniaria sp. 0 2 0 0 0 0.4 Mollusca Bivalvia Macoma balthica 11 23 10 8 15 13.4 Macoma tenta 2 4 0 0 1 1.4 Mulinia lateralis 0 0 0 0 1 0.2 Rangia cuneata 0 1 0 0 0 0.2 Gastropoda Littoridinops sp. 1 4 6 8 1 4.0 Total taxa by sample 66 156 58 138 143 Total abundance = 561 Total taxa present = 32 Shannon -Wiener diversitv = 2.56 1-61 Table 1-52. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Long Creek upstream station in May 2018. S ecies/taxona Number of individualsb Sensitivity value SV ` Abundance value n Product of SV n Annelida Clitellata Naididae sp. w/o hair 1 1.0 1 1.0 Polychaeta Amphicteis floridus 1 2.0 1 2.0 Eteone heteropoda 20 1.6 10 16.0 Heteromastus filiformis 3 1.1 3 3.3 Mediomastus ambiseta 10 2.0 10 20.0 Neanthes succinea 5 1.7 3 5.1 Polydora cornuta 1 1.2 1 1.2 Streblospio benedicti 74 1.1 30 33.0 Arthropoda Insecta Coleoptera Berosus sp. 1 1.5 1 1.5 Diptera Apedilum sp. 1 4.0 1 4.0 Chironomus decorus 35 1.0 30 30.0 Cricotopus sp. 1 1.4 1 1.4 Goeldichironomus devineyae 2 2.0 1 2.0 Parachironomus sp. 12 1.1 10 11.0 Tanytarsus sp. 9 2.3 3 6.9 Malacostraca Amphipoda Apocorophium louisianum 6 2.2 3 6.6 Apocorophium sp. 35 2.2 30 66.0 Gammarus mucronatus 66 2.3 30 69.0 Gammarus tigrinus 130 2.0 100 200.0 Decapoda Palaemonetes pugio 3 2.5 3 7.5 Rhithropanopeus harrisii 1 2.5 1 2.5 Isopoda Edotia montosa 1 2.6 1 2.6 Mysida Americamysis almyra 4 2.2 3 6.6 Maxillopoda Balanus improvisus 29 2.0 10 20.0 Mollusca Bivalvia Macoma balthica 67 1.5 30 45.0 Macoma tenta 7 2.0 3 6.0 Mulinia lateralis 1 2.3 1 2.3 Rangia cuneata 1 1.0 1 1.0 Gastropoda Littoridinops sp. 20 2.0 10 20.0 Total 332 593.5 Estuarine Biotic Index = 1.79 Total taxa = 32 Total taxa with sensitivity values = 28 a Only those taxa for which a sensitivity value is available are displayed. b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-62 Table 1-53. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Long Creek downstream station in May 2018. Species/taxon Long Creek Downstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 1 0 0 0 0 0.2 Eteone heteropoda 1 3 2 0 1 1.4 Heteromastus filiformis 4 3 1 1 1 2.0 Marenzellaria viridis 0 1 1 0 1 0.6 Mediomastus ambiseta 3 6 2 0 6 3.4 Neanthes succinea 1 0 0 1 1 0.6 Polydora cornuta 0 0 1 1 0 0.4 Streblospio benedicti 11 20 1 8 9 9.8 Arthropoda Insecta Diptera Chironomus decorus 0 10 1 8 2 4.2 Parachironomus sp. 0 0 0 1 0 0.2 Tanytarsus sp. 0 1 0 1 0 0.4 Malacostraca Amphipoda Apocorophium louisianum 0 0 1 9 3 2.6 Apocorophium sp. 1 0 2 25 2 6.0 Gammarus mucronatus 1 0 0 22 8 6.2 Gammarus tigrinus 1 4 3 12 0 4.0 Mysida Americamysis almyra 2 0 0 0 0 0.4 Tanaidacea Hargeria rapax 0 0 0 1 0 0.2 Maxillopoda Balanus improvisus 0 1 33 10 2 9.2 Mollusca Bivalvia Macoma balthica 3 11 5 5 2 5.2 Macoma tenta 6 3 13 8 9 7.8 Mulinia lateralis 0 4 0 0 3 1.4 Gastropoda Elysia chlorotica 0 1 0 0 0 0.2 Littoridinops sp. 1 11 2 2 3 3.8 Total taxa by sample 36 1 79 1 68 1 115 1 53 Total abundance = 351 Total taxa present = 22 Shannon -Wiener diversity = 2.66 1-63 Table 1-54. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Long Creek downstream station in May 2018. Species/taxona Number of individuals" Sensitivity value (SV)` Abundance value (n) Product of SV)(n) Annelida Polychaeta Amphicteis floridus 1 2.0 1 2.0 Eteone heteropoda 7 1.6 3 4.8 Heteromastus filiformis 10 1.1 10 11.0 Marenzellaria viridis 3 2.6 3 7.8 Mediomastus ambiseta 17 2.0 10 20.0 Neanthes succinea 3 1.7 3 5.1 Polydora cornuta 2 1.2 1 1.2 Streblospio benedicti 49 1.1 30 33.0 Arthropoda Insecta Diptera Chironomus decorus 21 1.0 10 10.0 Parachironomus sp. 1 1.1 1 1.1 Tanytarsus sp. 2 2.3 1 2.3 Malacostraca Amphipoda Apocorophium louisianum 13 2.2 10 22.0 Apocorophium sp. 30 2.2 30 66.0 Gammarus mucronatus 31 2.3 30 69.0 Gammarus tigrinus 20 2.0 10 20.0 Mysida Americamysis almyra 2 2.2 1 2.2 Tanaidacea Hargeria rapax 1 1.6 1 1.6 Maxillopoda Balanus improvisus 46 2.0 30 60.0 Mollusca Bivalvia Macoma balthica 26 1.5 10 15.0 Macoma tenta 39 2.0 30 60.0 Mulinia lateralis 7 2.3 3 6.9 Gastropoda Littoridinops sp. 19 2.0 10 20.0 Total 238 441.0 Estuarine Biotic Index = 1.85 Total taxa = 22 Total taxa with sensitivitv values = 21 a Only those taxa for which a Sensitivity value is available are displayed. b Total number of individuals caught in all five ponar replicates. Sensitivity values provided by NCDWR. 1-64 Table 1-55. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Tooley Creek upstream station in May 2018. Species/taxon Toole Creek Upstream Samples 1 2 3 4 5 Average Annelida Clitellata Naididae sp. w/o hair 0 3 0 1 0 0.8 Polychaeta Eteone heteropoda 1 1 0 2 0 0.8 Heteromastus filiformis 1 0 0 0 0 0.2 Mediomastus ambiseta 0 1 1 0 0 0.4 Streblospio benedicti 1 3 0 7 1 2.4 Arthropoda Insecta Diptera Bezzia/Palmonyia complex 0 0 1 1 0 0.4 Chironomus decorus 5 30 4 8 2 9.8 Parachironomus sp. 0 0 2 0 0 0.4 Malacostraca Amphipoda Apocorophium louisianum 0 12 0 1 1 2.8 Apocorophium sp. 0 8 0 8 2 3.6 Gammarus mucronatus 0 0 0 1 0 0.2 Gammarus tigrinus 3 8 3 3 2 3.8 Tanaidacea Hargeria rapax 0 1 0 0 0 0.2 Mysida Americamysis almyra 0 0 0 1 0 0.2 Ostracoda Candonidae sp. 3 1 2 1 1 1.6 Cyprideis littoralis 1 0 0 2 0 0.6 Mollusca Bivalvia Macoma balthica 11 11 10 18 1 10.2 Macoma tenta 0 1 0 0 0 0.2 Gastropoda Littoridinops sp. 3 1 1 0 0 1.0 Total taxa by sample 29 81 24 54 10 Total abundance = 198 Total taxa present = 18 Shannon -Wiener diversitv = 2.21 1-65 Table 1-56. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Tooley Creek upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance value (n) Product of (SV)(n) Annelida Clitellata Naididae sp. w/o hair 4 1.0 3 3.0 Polychaeta Eteone heteropoda 4 1.6 3 4.8 Heteromastus filiformis 1 1.1 1 1.1 Mediomastus ambiseta 2 2.0 1 2.0 Streblospio benedicti 12 1.1 10 11.0 Arthropoda Insecta Diptera Bezzia/Palmonyia complex 2 2.3 1 2.3 Chironomus decorus 49 1.0 30 30.0 Parachironomus sp. 2 1.1 1 1.1 Malacostraca Amphipoda Apocorophium louisianum 14 2.2 10 22.0 Apocorophium sp. 18 2.2 10 22.0 Gammarus mucronatus 1 2.3 1 2.3 Gammarus tigrinus 19 2.0 10 20.0 Tanaidacea Hargeria rapax 1 1.6 1 1.6 Mysida Americamysis almyra 1 2.2 1 2.2 Mollusca Bivalvia Macoma balthica 51 1.5 30 45.0 Macoma tenta 1 2.0 1 2.0 Gastropoda Littoridinops sp. 5 2.0 3 6.0 Total 117 178.4 Estuarine Biotic Index = 1.52 Total taxa = 18 Total taxa with sensitivity values = 16 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. Table 1-57. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Tooley Creek downstream station in May 2018. Species/taxon Toole Creek Downstream Samples 1 2 3 4 5 Average Annelida Clitellata Tubificoides heterochaetus 0 0 0 0 2 0.4 Polychaeta Eteone heteropoda 7 7 4 11 5 6.8 Heteromastus filiformis 1 1 0 3 0 1.0 Marenzelleria viddis 0 1 0 1 0 0.4 Mediomastus ambiseta 83 38 48 63 18 50.0 Polydora cornuta 1 0 4 0 0 1.0 Streblospio benedicti 14 12 10 6 3 9.0 Arthropoda Insecta Diptera Chironomus decorus 29 16 18 12 10 17.0 Goeldichironomus devineyae 1 0 0 0 0 0.2 Parachironomus sp. 1 0 0 1 0 0.4 Malacostraca Amphipoda Apocorophium louisianum 2 0 3 3 0 1.6 Apocorophium sp. 9 0 7 6 2 4.8 Gammarus mucronatus 6 2 9 5 1 4.6 Gammarus tigrinus 2 1 4 7 0 2.8 Mysida Americamysis almyra 0 0 0 1 0 0.2 Tanaidacea Hargeria rapax 0 0 1 1 0 0.4 Maxillopoda Balanus improvisus 89 5 100 15 5 42.8 Ostracoda Candonidae sp. 0 0 1 0 0 0.2 Cyprideis littoralis 0 3 0 2 0 1.0 Mollusca Bivalvia Macoma balthica 40 28 37 27 9 28.2 Macoma tenta 27 31 38 32 26 30.8 Mulinia lateralis 0 2 3 0 2 1.4 Gastropoda Littoridinops sp. 6 2 17 1 5 6.2 Total taxa by sample 318 149 304 197 88 Total abundance = 1,056 Total taxa present = 22 Shannon -Wiener diversitv = 2.21 1-67 Table 1-58. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Tooley Creek downstream station in May 2018. Speciesltaxona Number of individualsb Sensitivity value (SV)` Abundance value (n) Product of (SV) n Annelida Clitellata Tubificoides heterochaetus 2 1.1 1 1.1 Polychaeta Eteone heteropoda 34 1.6 30 48.0 Heteromastus filiformis 5 1.1 3 3.3 Marenzelleria viridis 2 2.6 1 2.6 Mediomastus ambiseta 250 2.0 100 200.0 Polydora cornuta 5 1.2 3 3.6 Streblospio benedicti 45 1.1 30 33.0 Arthropoda I nsecta Diptera Chironomus decorus 85 1.0 30 30.0 Goeldichironomus devineyae 1 2.0 1 2.0 Parachironomus sp. 2 1.1 1 1.1 Malacostraca Amphipoda Apocorophium louisianum 8 2.2 3 6.6 Apocorophium sp. 24 2.2 10 22.0 Gammarus mucronatus 23 2.3 10 23.0 Gammarus tigrinus 14 2.0 10 20.0 Mysida Americamysis almyra 1 2.2 1 2.2 Tanaidacea Hargeria rapax 2 1.6 1 1.6 Maxillopoda Balanus improvisus 214 2.0 100 200.0 Mollusca Bivalvia Macoma balthica 141 1.5 100 150.0 Macoma tenta 154 2.0 100 200.0 Mulinia lateralis 7 2.3 3 6.9 Gastropoda Littoridinops sp. 31 2.0 30 60.0 Total 568 1017.0 Estuarine Biotic Index = 1.79 Total taxa = 22 Total taxa with sensitivitv values = 20 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. Sensitivity values provided by NCDWR. .: Table 1-59. Numbers of benthic macro invertebrates collected in each ponar grab sample at the Muddy Creek upstream station in May 2018. Species/taxon Muddy Creek Upstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 0 2 0 0 0 0.4 Eteone heteropoda 3 2 0 0 0 1.0 Streblospio benedecti 3 2 1 0 16 4.4 Arthropoda Insecta Diptera Chironomus decorus 42 22 3 0 18 17.0 Tanypus neopunctipennis 3 0 0 0 0 0.6 Malacostraca Amphipoda Apocorophium sp. 0 0 2 2 0 0.8 Gammarus mucronatus 3 0 2 0 0 1.0 Gammarus tigrinus 21 4 15 5 6 10.2 Ostracoda Candonidae sp. 27 42 7 2 2 16.0 Cyprideis littoralis 0 0 1 0 0 0.2 Mollusca Bivalvia Macoma balthica 6 0 1 1 8 3.2 Gastropoda Littoridinops sp. 6 6 15 1 0 5.6 Total taxa by sample 114 80 47 11 50 Total abundance = 302 Total taxa present = 12 Shannon -Wiener diversitv = 1.87 Table 1-60. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Muddy Creek upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance Product of value (n) (SV)(n) Annelida Polychaeta Amphicteis floridus 2 2.0 1 2.0 Eteone heteropoda 5 1.6 3 4.8 Streblospio benedecti 22 1.1 10 11.0 Arthropoda Insecta Diptera Chironomus decorus 85 1.0 30 30.0 Tanypus neopunctipennis 3 1.0 3 3.0 Malacostraca Amphipoda Apocorophium sp. 4 2.2 3 6.6 Gammarus mucronatus 5 2.3 3 6.9 Gammarus tigrinus 51 2.0 30 60.0 Mollusca Bivalvia Macoma balthica 16 1.5 10 15.0 Gastropoda Littoridinops sp. 28 2.0 10 20.0 Total 103 159.3 Estuarine Biotic Index = 1.55 Total taxa = 12 Total taxa with sensitivity values = 10 a Only those taxa for which a sensitivity value is available are displayed bTotal number of individuals caught in all five ponar replicates. 'Sensitivity values provided by NCDWR. 1-70 Table 1-61. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Muddy Creek downstream station in May 2018. S ecies/taxon Muddy Creek Downstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 0 2 4 0 0 1.2 Eteone heteropoda 1 0 2 2 1 1.2 Heteromastus filiformis 0 1 0 0 2 0.6 Mediomastus ambiseta 11 8 2 3 5 5.8 Neanthes succinea 0 0 2 0 0 0.4 Streblospio benedicti 2 10 14 7 16 9.8 Arthropoda Insecta Diptera Chironomus decorus 2 1 2 0 0 1.0 Hemiptera Corixidae sp. 0 0 2 0 0 0.4 Malacostraca Amphipoda Apocorophium louisianum 2 0 26 0 2 6.0 Apocorophium sp. 0 3 60 0 3 13.2 Gammarus mucronatus 8 3 42 0 6 11.8 Gammarus tigrinus 30 7 56 2 23 23.6 Mysida Americamysis almyra 0 0 2 0 1 0.6 Maxillopoda Balanus improvisus 4 1 6 0 0 2.2 Ostracoda Candonidae sp. 1 0 0 0 0 0.2 Cyprideis littoralis 1 0 6 0 0 1.4 Mollusca Bivalvia Macoma balthica 16 14 12 19 16 15.4 Macoma tenta 5 2 6 1 7 4.2 Mulinia lateralis 0 0 1 1 0 0.4 Mytilopsis leucophaeata 0 0 2 0 0 0.4 Gastropoda Littoridinops sp. 0 1 0 0 0 0.2 Total taxa by sample 83 53 247 35 82 Total abundance = 500 Total taxa present = 20 Shannon -Wiener diversity = 2.31 1-71 Table 1-62. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Muddy Creek downstream station in May 2018. S ecies/taxona Number of individualsb Sensitivity value SV ° Abundance value (n) Product of (SV)(n) Annelida Polychaeta Amphicteis floridus 6 2.0 3 6.0 Eteone heteropoda 6 1.6 3 4.8 Heteromastus filiformis 3 1.1 3 3.3 Mediomastus ambiseta 29 2.0 10 20.0 Neanthes succinea 2 1.7 1 1.7 Streblospio benedicti 49 1.1 30 33.0 Arthropoda Insecta Diptera Chironomus decorus 5 1.0 3 3.0 Hemiptera Corixidae sp. 2 1.3 1 1.3 Malacostraca Amphipoda Apocorophium louisianum 30 2.2 30 66.0 Apocorophium sp. 66 2.2 30 66.0 Gammarus mucronatus 59 2.3 30 69.0 Gammarus tigrinus 118 2.0 100 200.0 Mysida Americamysis almyra 3 2.2 3 6.6 Maxillopoda Balanus improvisus 11 2.0 10 20.0 Mollusca Bivalvia Macoma balthica 77 1.5 30 45.0 Macoma tenta 21 2.0 10 20.0 Mulinia lateralis 2 2.3 1 2.3 Mytilopsis leucophaeata 2 1.5 1 1.5 Gastropoda Littoridinops sp. 1 2.0 1 2.0 Total 1 300 571.5 Estuarine Biotic Index = 1.91 Total taxa = 20 Total taxa with sensitivity values = 18 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-72 Table 1-63. Numbers of benthic macroi nverteb rates collected in each ponar grab sample at the Huddles Cut upstream station in May 2018. Species/taxon Huddles Cut Upstream Samples 1 2 3 4 5 Average Annelida Polychaeta Eteone heteropoda 1 2 0 0 0 0.6 Heteromastus filiformis 1 9 12 4 9 7.0 Mediomastus ambiseta 2 0 1 3 0 1.2 Neanthes succinea 8 14 7 8 13 10.0 Polydora cornuta 1 0 0 0 0 0.2 Streblospio benedicti 0 0 3 0 1 0.8 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 2 0 0 0 1 0.6 Chironomus decorus 1 0 1 1 0 0.6 Cladotanytarsus sp. 0 0 0 0 1 0.2 Goeldichironomus devineyae 2 0 0 1 0 0.6 Parachironomus sp. 1 2 1 0 0 0.8 Tanypus neopunctipennis 0 1 0 0 0 0.2 Tanytarsus sp. 1 4 2 1 0 1.6 Malacostraca Amphipoda Apocorophium lacustre 0 3 1 1 1 1.2 Apocorophium louisianum 0 1 0 4 0 1.0 Apocorophium sp. 2 1 2 6 2 2.6 Gammarus mucronatus 1 0 0 0 0 0.2 Gammarus tigrinus 2 0 0 0 0 0.4 Decapoda Palaemonetes pugio 0 1 5 0 2 1.6 Rhithropanopeus harrisii 0 2 0 3 2 1.4 Isopoda Maxillopoda Balanus improvisus 27 24 46 52 1 30.0 Ostracoda Cyprideis littoralis 3 10 3 2 0 3.6 Mollusca Bivalvia Bivalvia sp. 0 0 1 0 0 0.2 Macoma balthica 2 3 2 3 1 2.2 Macoma tenta 8 4 3 2 2 3.8 Rangia cuneata 1 0 1 0 1 0.6 Gastropoda Littoridinops sp. 2 5 2 2 1 2.4 Total taxa by sample 68 86 93 93 38 Total abundance = 378 Total taxa present = 25 Shannon -Wiener diversity = 2.30 1-73 Table 1-64. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Huddles Cut upstream station in May 2018. Number of Sensitivity Abundance Product of Species/taxona individualsb value (SV)` value (n) (SV)(n) Annelida Polychaeta Eteone heteropoda 3 1.6 3 4.8 Heteromastus filiformis 35 1.1 30 33.0 Mediomastus ambiseta 6 2.0 3 6.0 Neanthes succinea 50 1.7 30 51.0 Polydora cornuta 1 1.2 1 1.2 Streblospio benedicti 4 1.1 3 3.3 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 3 2.3 3 6.9 Chironomus decorus 3 1.0 3 3.0 Cladotanytarsus sp. 1 3.9 1 3.9 Goeldichironomus devineyae 3 2.0 3 6.0 Parachironomus sp. 4 1.1 3 3.3 Tanypus neopunctipennis 1 1.0 1 1.0 Tanytarsus sp. 8 2.3 3 6.9 Malacostraca Amphipoda Apocorophium lacustre 6 2.2 3 6.6 Apocorophium louisianum 5 2.2 3 6.6 Apocorophium sp. 13 2.2 10 22.0 Gammarus mucronatus 1 2.3 1 2.3 Gammarus tigrinus 2 2.0 1 2.0 Decapoda Pa/aemonetes pugio 8 2.5 3 7.5 Rhithropanopeus harrisii 7 2.5 3 7.5 Isopoda Maxillopoda Balanus improvisus 150 2.0 100 200.0 Mollusca Bivalvia Macoma balthica 11 1.5 10 15.0 Macoma tenta 19 2.0 10 20.0 Rangia cuneata 3 1.0 3 3.0 Gastropoda Littoridinops sp. 12 2.0 10 20.0 Total 244 442.8 Estuarine Biotic Index = 1.81 Total taxa = 25 Total taxa with sensitivity values = 24 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. Sensitivity values provided by NCDWR. 1-74 Table 1-65. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Huddles Cut downstream station in May 2018. S ecies/taxon Huddles Cut Downstream Samples 1 2 3 4 5 Avera e Annelida Clitellata Enchytraeidae sp. 3 0 0 0 0 0.6 Naididae sp. 0 0 0 4 0 0.8 Naididae sp. w/o hair 24 4 12 0 0 8.0 Paranais litoralis 0 0 0 0 12 2.4 Polychaeta Eteone heteropoda 3 0 0 0 8 2.2 Heteromastus filiformis 6 8 12 0 0 5.2 Marenzelleria vindis 87 100 100 100 88 95.0 Mediomastus ambiseta 0 0 0 12 4 3.2 Neanthes succinea 3 4 4 4 4 3.8 Leitoscoloplos fragilis 0 0 0 12 0 2.4 Arthropoda Malacostraca Amphipoda Gammarus tigrinus 6 4 20 0 0 6.0 Haustorius sp. 6 28 20 0 8 12.4 Lepidactylus dytiscus 6 8 12 16 0 8.4 Isopoda Cyathura polita 3 0 0 0 0 0.6 Tanaidacea Hargeria rapax 0 0 4 0 0 0.8 Ostracoda Candonidae sp. 0 0 0 4 4 1.6 Cyprideis littoralis 0 4 4 0 4 2.4 Mollusca Bivalvia Geukensia demissa 0 0 0 0 4 0.8 Macoma tenta 0 0 0 0 4 0.8 Gastropoda Littoridinops sp. 3 0 4 0 0 1.4 Total taxa by sample 150 160 192 152 140 Total abundance = 794 Total taxa present = 18 Shannon -Wiener diversity = 1.70 1-75 Table 1-66. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Huddles Cut downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance Product of value (n) (SV)(n) Annelida Clitellata Enchytraeidae sp. 3 1.0 3 3.0 Naididae sp. 4 1 3 3.0 Naididae sp. w/o hair 40 1 30 30.0 Paranais litoralis 12 1.1 10 11.0 Polychaeta Eteone heteropoda 11 1.6 10 16.0 Heteromastus filiformis 26 1.1 10 11.0 Marenzelleria viridis 475 2.6 100 260.0 Mediomastus ambiseta 16 2.0 10 20.0 Neanthes succinea 19 1.7 10 17.0 Leitoscoloplos fragilis 12 1.4 10 14.0 Arthropoda Malacostraca Amphipoda Gammarus tigrinus 30 2.0 30 60.0 Lepidactylus dytiscus 42 3.5 30 105.0 Isopoda Cyathura polita 3 2 3 6.0 Tanaidacea Hargeria rapax 4 1.6 3 4.8 Mollusca Bivalvia Geukensia demissa 4 3.4 3 10.2 Macoma tenta 4 2 3 6.0 Gastropoda Littoridinops sp. 7 2.0 3 6.0 Total 271 583.0 Estuarine Biotic Index = 2.15 Total taxa = 18 Total taxa with sensitivity values = 15 a Only those taxa for which a sensitivity value is available are displayed. b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. 1-76 Table 1-67. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Porter Creek upstream station in May 2018. Species/taxon Porter Creek Upstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 4 8 12 2 2 5.6 Eteone heteropoda 2 0 10 0 4 3.2 Mediomastus ambiseta 4 0 0 0 0 0.8 Streblospio benedicti 8 52 4 12 2 15.6 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 0 4 6 1 0 2.2 Chironomus decorus 10 2 4 3 0 3.8 Dicrotendipes nervosus 0 0 2 0 0 0.4 Tanytarsus sp. 0 10 4 0 0 2.8 Malacostraca Amphipoda Apocorophium lacustre 0 0 16 0 16 6.4 Apocorophium sp. 4 0 0 0 4 1.6 Gammarus tigrinus 88 92 60 100 60 80.0 Ostracoda Candonidae sp. 2 0 0 0 0 0.4 Cyprideis littoralis 0 2 2 1 4 1.8 Mollusca Bivalvia Mytilopsis leucophaeata 0 2 0 2 2 1.2 Rangia cuneata 0 0 2 0 0 0.4 Gastropoda Littoridinops sp. 2 4 14 22 22 12.8 Total taxa by sample 124 1 176 1 136 1 143 1 116 Total abundance = 695 Total taxa present = 15 Shannon -Wiener diversity = 1.61 1-77 Table 1-68. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Porter Creek upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance Product of value (n) (SV)(n) Annelida Polychaeta Amphicteis floridus 28 2.0 10 20.0 Eteone heteropoda 16 1.6 10 16.0 Mediomastus ambiseta 4 2.0 3 6.0 Streblospio benedicti 78 1.1 30 33.0 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 11 2.3 10 23.0 Chironomus decorus 19 1.0 10 10.0 Dicrotendipes nervosus 2 1.0 1 1.0 Tanytarsus sp. 14 2.3 10 23.0 Malacostraca Amphipoda Apocorophium lacustre 32 2.2 30 66.0 Apocorophium sp. 8 2.2 3 6.6 Gammarus tigrinus 400 2.0 100 200.0 Mollusca Bivalvia Mytilopsis leucophaeata 6 1.5 3 4.5 Rangia cuneata 2 1.0 1 1.0 Gastropoda Littoridinops sp. 64 2.0 30 60.0 Total 251 470.1 Estuarine Biotic Index = 1.87 Total taxa = 15 Total taxa with sensitivity values = 13 a Only those taxa for which a sensitivity value is available are displayed. bTotal number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. W. Table 1-69. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Porter Creek downstream station in May 2018. Species/taxon Porter Creek Downstream Samples 1 2 3 4 5 Average Annelida Clitellata Tubificoides heterochaetus 1 0 12 0 8 4.2 Polychaeta Eteone heteropoda 4 2 1 2 0 1.8 Marenzellaria viridis 14 23 8 22 17 16.8 Mediomastus ambiseta 36 23 48 13 92 42.4 Streblospio benedicti 10 11 19 14 20 14.8 Arthropoda Insecta Diptera Chironomus decorus 2 3 2 1 0 1.6 Chironomus sp. 1 0 0 0 0 0.2 Coelotanypus sp. 0 1 0 1 0 0.4 Malacostraca Amphipoda Apocorophium lacustre 1 0 0 0 0 0.2 Apocorophium sp. 0 0 6 0 0 1.2 Gammarus tigrinus 5 8 11 0 3 5.4 Tanaidacea Hargeria rapax 0 0 1 0 0 0.2 Maxillopoda Balanus improvisus 0 1 0 0 0 0.2 Ostracoda Cyprideis littoralis 0 1 0 0 0 0.2 Mollusca Bivalvia Macoma balthica 14 22 10 18 19 16.6 Macoma tenta 21 18 22 19 31 22.2 Mulinia lateralis 1 0 0 0 2 0.6 Gastropoda Littoridinops sp. 0 8 3 1 1 2.6 Total taxa by sample 110 121 143 91 193 Total abundance = 658 Total taxa present = 16 Shannon -Wiener diversitv = 2.00 1-79 Table 1-70. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Porter Creek downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance value (n) Product of (SV)(n) Annelida Clitellata Tubificoides heterochaetus 21 1.1 10 11.0 Polychaeta Eteone heteropoda 9 1.6 3 4.8 Marenzellaria viridis 84 2.6 30 78.0 Mediomastus ambiseta 212 2.0 100 200.0 Streblospio benedicti 74 1.1 30 33.0 Arthropoda Insecta Diptera Chironomus decorus 8 1.0 3 3.0 Chironomus sp. 1 1.0 1 1.0 Coelotanypus sp. 2 1.8 1 1.8 Malacostraca Amphipoda Apocorophium lacustre 1 2.2 1 2.2 Apocorophium sp. 6 2.2 3 6.6 Gammarus tigrinus 27 2.0 10 20.0 Tanaidacea Hargeria rapax 1 1.6 1 1.6 Maxillopoda Balanus improvisus 1 2.0 1 2.0 Mollusca Bivalvia Macoma balthica 83 1.5 30 45.0 Macoma tenta 111 2.0 100 200.0 Mulinia lateralis 3 2.3 3 6.9 Gastropoda Littoridinops sp. 13 2.0 10 20.0 Total 337 636.9 Estuarine Biotic Index = 1.89 Total taxa = 16 Total taxa with sensitivity values = 15 a Only those taxa for which asSensitivity value is available are displayed b Total number of individuals caught in all five pnar replicates. ° Sensitivity values provided by NCDWR. I Table 1-71. Numbers of benthic macro invertebrates collected in each ponar grab sample at the DCUT11 upstream station in May 2018. Species/taxon DCUT11 Upstream Samples 1 2 3 4 5 Average Annelida Clitellata Limnodrilus hoffineisteri 0 2 0 0 0 0.4 Polychaeta Amphicteis floridus 18 50 27 20 33 29.6 Eteone heteropoda 0 0 0 2 0 0.4 Arthropoda I nsecta Coleoptera Berosus sp. 0 4 0 0 0 0.8 Peltodytes sp. 0 0 3 0 0 0.6 Diptera Bezzia/Palpomyia complex 4 2 6 0 9 4.2 Chironomus decorus 0 2 0 0 3 1.0 Dicrotendipes nervosus 0 4 0 0 6 2.0 Goeldichironomus devineyae 0 0 0 0 3 0.6 Tanytarsus sp. 4 4 0 0 3 2.2 Odonata Pachydiplax longipennis 0 2 0 0 0 0.4 Malacostraca Amphipoda Apocorophium sp. 4 0 0 0 0 0.8 Gammarus tigrinus 40 64 100 52 100 71.2 Ostracoda Candonidae sp. 0 2 0 2 12 3.2 Cyprideis littoralis 24 42 6 8 27 21.4 Mollusca Bivalvia Bivalvia sp. 0 2 0 0 0 0.4 Mytilopsis leucophaeta 0 4 0 2 0 1.2 Rangia cuneata 1 0 0 0 0 0.2 Gastropoda Littoridinops sp. 12 34 6 2 27 16.2 Total taxa by sample 107 218 148 88 223 Total abundance = 784 Total taxa present = 18 Shannon -Wiener diversity = 1.71 IN Table 1-72. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the DCUT11 upstream station in May 2018. Species/taxona Number of individualsb Sensitivity Abundance Product of value (SV)` value (n) (SV)(n) Annelida Clitellata Limnodrilus hoffineisteri 2 1.0 1 1.0 Polychaeta Amphicteis floridus 148 2.0 100 200.0 Eteone heteropoda 2 1.6 1 1.6 Arthropoda I nsecta Coleoptera Berosus sp. 4 1.5 3 4.5 Peltodytes sp. 3 1.4 3 4.2 Diptera Bezzia/Palpomyia complex 21 2.3 10 23.0 Chironomus decorus 5 1.0 3 3.0 Dicrotendipes nervosus 10 1.0 10 10.0 Goeldichironomus devineyae 3 2.0 3 6.0 Tanytarsus sp. 11 2.3 10 23.0 Odonata Pachydiplax longipennis 2 1.0 1 1.0 Malacostraca Amphipoda Apocorophium sp. 4 2.2 3 6.6 Gammarus tigrinus 356 2.0 100 200.0 Mollusca Bivalvia Mytilopsis leucophaeta 6 1.5 3 4.5 Rangia cuneata 1 1.0 1 1.0 Gastropoda Littoridinops sp. 81 2.0 30 60.0 Total 282 549.4 Estuarine Biotic Index = 1.95 Total taxa = 18 Total taxa with sensitivity values = 16 a Only those taxa for which a sensitivity value is available are displayed bTotal number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. Table 1-73. Numbers of benthic macro invertebrates collected in each ponar grab sample at the DCUT11 downstream station in May 2018. Species/taxon DCUT11 Downstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 2 0 4 0 0 1.2 Eteone heteropoda 4 4 2 0 0 2.0 Heteromastus filiformis 4 0 6 0 0 2.0 Marenzellaria viridis 0 4 0 4 6 2.8 Mediomastus ambiseta 2 0 0 0 0 0.4 Streblospio benedicti 4 0 0 0 4 1.6 Arthropoda I nsecta Diptera Bezzia/Palpomyia complex 2 4 4 2 6 3.6 Chironomus decorus 2 2 0 0 2 1.2 Dicrotendipes nervosus 26 16 22 12 12 17.6 Parachironomus sp. 0 0 0 0 2 0.4 Tanypus neopunctipennis 2 0 0 0 0 0.4 Tanytarsus sp. 10 32 22 12 26 20.4 Odonata Enallagma sp. 0 2 0 0 0 0.4 Malacostraca Amphipoda Apocorophium lacustre 100 62 64 48 44 63.6 Apocorophium sp. 100 100 100 90 66 91.2 Gammarus tigrinus 100 100 100 62 100 92.4 Ostracoda Candonidae sp. 0 2 0 0 0 0.4 Cyprideis littoralis 0 2 0 0 2 0.8 Mollusca Bivalvia Macoma tenta 0 2 0 0 0 0.4 Mytilopsis leucophaeta 2 4 0 2 0 1.6 Gastropoda Littoridinops sp. 2 2 4 2 16 5.2 Total taxa by sample 362 338 328 234 286 Total abundance = 1,548 Total taxa present = 20 Shannon -Wiener diversity = 1.78 am Table 1-74. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the DCUT11 downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance value (n) Product of (SV)(n) Annelida Polychaeta Amphicteis floridus 6 2.0 3 6.0 Eteone heteropoda 10 1.6 10 16.0 Heteromastus filiformis 10 1.1 10 11.0 Marenzellaria viridis 14 2.6 10 26.0 Mediomastus ambiseta 2 2.0 1 2.0 Streblospio benedicti 8 1.1 3 3.3 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 18 2.3 10 23.0 Chironomus decorus 6 1.0 3 3.0 Dicrotendipes nervosus 88 1.0 30 30.0 Parachironomus sp. 2 1.1 1 1.1 Tanypus neopunctipennis 2 1.0 1 1.0 Tanytarsus sp. 102 2.3 100 230.0 Odonata Enallagma sp. 2 1.5 1 1.5 Malacostraca Amphipoda Apocorophium lacustre 318 2.2 100 220.0 Apocorophium sp. 456 2.2 100 220.0 Gammarus tigrinus 462 2.0 100 200.0 Mollusca Bivalvia Macoma tenta 2 2.0 1 2.0 Mytilopsis leucophaeta 8 1.5 3 4.5 Gastropoda Littoridinops sp. 26 2.0 10 20.0 Total 497 1020.4 Estuarine Biotic Index = 2.05 Total taxa = 20 Total taxa with sensitivitv values = 18 a Only those taxa for which a sensitivity value is available are displayed. b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. Table 1-75. Numbers of benthic macro invertebrates collected in each ponar grab sample at the DCUT19 upstream station in May 2018. Species/taxon DCUT19 Upstream Samples 1 2 3 4 5 Average Annelida Polychaeta Eteone heteropoda 8 6 0 1 6 4.2 Arthropoda I nsecta Coleoptera Berosus sp. 0 0 0 1 0 0.2 Diptera Bezzia/Palpomyia complex 4 4 12 2 4 5.2 Chironomus decorus 0 0 6 1 0 1.4 Goeldichironomus devineyae 0 0 0 1 0 0.2 Glyptotendipes sp. 0 2 0 0 0 0.4 Tanytarsus sp. 2 2 8 2 2 3.2 Malacostraca Amphipoda Apocorophium louisianum 2 0 18 3 14 7.4 Apocorophium sp. 16 10 48 8 54 27.2 Gammarus tigrinus 0 0 12 4 6 4.4 Isopoda Cyathura polity 0 0 2 0 0 0.4 Ostracoda Candonidae sp. 100 100 64 16 10 58.0 Cyprideis littoralis 2 0 0 0 0 0.4 Mollusca Gastropoda Littoridinops sp. 14 18 20 5 10 13.4 Total taxa by sample 148 142 190 44 106 Total abundance = 630 Total taxa present = 13 Shannon -Wiener diversity = 1.67 am Table 1-76. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the DCUT19 upstream station in May 2018. Number of Sensitivity Abundance Product of Species/taxona individualsb value (SV)` value (n) (SV)(n) Annelida Polychaeta Eteone heteropoda 21 1.6 10 16.0 Arthropoda Insecta Coleoptera Berosus sp. 1 1.5 1 1.5 Diptera Bezzia/Palpomyia complex 26 2.3 10 23.0 Chironomus decorus 7 1.0 3 3.0 Goeldichironomus devineyae 1 2.0 1 2.0 Glyptotendipes sp. 2 1.3 1 1.3 Tanytarsus sp. 16 2.3 10 23.0 Malacostraca Amphipoda Apocorophium louisianum 37 2.2 30 66.0 Apocorophium sp. 136 2.2 100 220.0 Gammarus tigrinus 22 2.0 10 20.0 Isopoda Cyathura polita 2 2.0 1 2.0 Mollusca Gastropoda Littoridinops sp. 67 2.0 30 60.0 Total 207 437.8 Estuarine Biotic Index = 2.12 Total taxa = 13 Total taxa with sensitivity values = 11 a Only those taxa for which a sensitivity value is available are displayed bTotal number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. Table 1-77. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the DCUT19 downstream station in May 2018. Species/taxon DCUT19 Downstream Samples 1 2 3 4 5 Average Annelida Clitellata Naididae sp. w/o hair 14 18 27 36 0 19.0 Polychaeta Eteone heteropoda 4 0 0 0 0 0.8 Marenzellaria viridis 0 4 0 0 0 0.8 Mediomastus ambiseta 0 2 0 0 0 0.4 Neanthes succinea 0 4 3 3 0 2.0 Arthropoda I nsecta Diptera Bezzia/Palpomyia complex 2 0 0 3 0 1.0 Malacostraca Amphipoda Apocorophium lacustre 0 0 0 3 0 0.6 Apocorophium sp. 14 2 0 6 9 6.2 Gammarus mucronatus 0 2 0 0 0 0.4 Gammarus tigrinus 100 100 100 100 33 86.6 Isopoda Cassidinidea lunifrons 0 0 0 3 0 0.6 Cyathura polita 0 2 0 0 0 0.4 Edotia montosa 4 2 3 0 0 1.8 Tanaidacea Hargeria rapax 2 4 6 3 0 3.0 Ostracoda Candonidae sp. 2 0 3 6 0 2.2 Cyprideis littoralis 0 2 0 0 0 0.4 Mollusca Bivalvia Rangia cuneata 0 2 0 0 0 0.4 Gastropoda Littoridinops sp. 0 0 3 0 0 0.6 Total taxa by sample 142 144 145 163 42 Total abundance = 636 Total taxa present = 17 Shannon -Wiener diversity = 1.25 1-87 Table 1-78. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the DCUT19 downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance value (n) Product of (SV)(n) Annelida Clitellata Naididae sp. w/o hair 95 1.0 30 30.0 Polychaeta Eteone heteropoda 4 1.6 3 4.8 Marenzellaria viridis 4 2.6 3 7.8 Mediomastus ambiseta 2 2.0 1 2.0 Neanthes succinea 10 1.7 10 17.0 Arthropoda Insecta Diptera Bezzia/Palpomyia complex 5 2.3 3 6.9 Malacostraca Amphipoda Apocorophium lacustre 3 2.2 3 6.6 Apocorophium sp. 31 2.2 30 66.0 Gammarus mucronatus 2 2.3 1 2.3 Gammarus tigrinus 433 2.0 100 200.0 Isopoda Cassidinidea lunifrons 3 2.0 3 6.0 Cyathura polita 2 2.0 1 2.0 Edotia montosa 9 2.6 3 7.8 Tanaidacea Hargeria rapax 15 1.6 10 16.0 Mollusca Bivalvia Rangia cuneata 2 1.0 1 1.0 Gastropoda Littoridinops sp. 3 2.0 3 6.0 Total 205 382.2 Estuarine Biotic Index = 1.86 Total taxa = 17 Total taxa with sensitivity values = 15 a Only those taxa for which a sensitivity value is available are displayed. b Total number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. Table 1-79. Numbers of benthic macro invertebrates collected in each ponar grab sample at the Duck Creek upstream station in May 2018. Species/taxon Duck Creek Upstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 3 0 0 0 0 0.6 Streblospio benedicti 3 0 0 0 0 0.6 Arthropoda I nsecta Diptera Tanytarsus sp. 0 0 0 16 0 3.2 Malacostraca Amphipoda Gammarus tigrinus 15 12 0 8 20 11.0 Ostracoda Candonidae sp. 15 0 12 24 44 19.0 Cyprideis littoralis 6 32 16 20 52 25.2 Mollusca Bivalvia Mytilopsis leucophaeata 0 8 0 4 4 3.2 Gastropoda Littoridinops sp. 3 0 4 28 16 10.2 Total taxa by sample 45 52 32 100 136 Total abundance = 365 Total taxa present = 8 Shannon -Wiener diversity = 1.63 • Table 1-80. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Duck Creek upstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)` Abundance Product of value (n) (SV)(n) Annelida Polychaeta Amphicteis floridus 3 2.0 3 6.0 Streblospio benedicti 3 1.1 3 3.3 Arthropoda Insecta Diptera Tanytarsus sp. 16 2.3 10 23.0 Malacostraca Amphipoda Gammarus tigrinus 55 2.0 30 60.0 Mollusca Bivalvia Mytilopsis /eucophaeata 16 1.5 10 15.0 Gastropoda Littoridinops sp. 51 2.0 30 60.0 Total 86 167.3 Estuarine Biotic Index = 1.95 Total taxa = 8 Total taxa with sensitivity values = 6 a Only those taxa for which a sensitivity value is available are displayed. bTotal number of individuals caught in all five ponar replicates. ° Sensitivity values provided by NCDWR. Table 1-81. Numbers of benthic macroinvertebrates collected in each ponar grab sample at the Duck Creek downstream station in May 2018. S ecies/taxon Duck Creek Downstream Samples 1 2 3 4 5 Average Annelida Polychaeta Amphicteis floridus 0 1 1 0 0 0.4 Mediomastus ambiseta 21 22 13 37 11 20.8 Neanthes succinea 0 1 0 0 0 0.2 Polydora cornuta 1 0 0 0 0 0.2 Streblospio benedicti 5 17 15 3 8 9.6 Arthropoda I nsecta Diptera Chironomus decorus 21 42 42 22 29 31.2 Coelotanypus sp. 5 1 5 4 0 3.0 Cricotopus sp. 0 1 1 11 2 3.0 Dicrotendipes nervosus 1 2 0 1 3 1.4 Tanytarsus sp. 2 0 1 0 0 0.6 Malacostraca Amphipoda Apocorophium lacustre 1 5 5 6 0 3.4 Apocorophium sp. 2 3 3 8 5 4.2 Gammarus mucronatus 0 0 1 1 0 0.4 Gammarus tigrinus 56 100 65 100 63 76.8 Mysida Americamysis almyra 0 5 2 5 0 2.4 Tanaidacea Hargeria rapax 0 0 1 0 0 0.2 Maxillopoda Balanus improvisus 20 13 24 17 27 20.2 Ostracoda Cyprideis littoralis 2 15 2 5 2 5.2 Mollusca Bivalvia Macoma balthica 3 3 1 0 3 2.0 Macoma tenta 4 3 3 5 4 3.8 Rangia cuneata 0 1 0 0 0 0.2 Gastropoda Littoridinops sp. 6 15 16 12 3 10.4 Total taxa by sample 150 250 201 237 160 Total abundance = 998 Total taxa present = 21 Shannon -Wiener diversity = 2.08 1-91 Table 1-82. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Duck Creek downstream station in May 2018. Species/taxona Number of individualsb Sensitivity value (SV)° Abundance value (n) Product of (SV)(n) Annelida Polychaeta Amphicteis floridus 2 2 1 2.0 Mediomastus ambiseta 104 2 100 200.0 Neanthes succinea 1 1.7 1 1.7 Polydora cornuta 1 1.2 1 1.2 Streblospio benedicti 48 1.1 30 33.0 Arthropoda Insecta Diptera Chironomus decorus 156 1 100 100.0 Coelotanypus sp. 15 1.8 10 18.0 Cricotopus sp. 15 1.4 10 14.0 Dicrotendipes nervosus 7 1.0 3 3.0 Tanytarsus sp. 3 2.3 3 6.9 Malacostraca Amphipoda Apocorophium lacustre 17 2.2 10 22.0 Apocorophium sp. 21 2.2 10 22.0 Gammarus mucronatus 2 2.3 1 2.3 Gammarus tigrinus 384 2.0 100 200.0 Mysida Americamysis almyra 12 2.2 10 22.0 Tanaidacea Hargeria rapax 1 1.6 1 1.6 Maxillopoda Balanus improvisus 101 2 100 200.0 Mollusca Bivalvia Macoma balthica 10 1.5 10 15.0 Macoma tenta 19 2.0 10 20.0 Rangia cuneata 1 1.0 1 1.0 Gastropoda Littoridinops sp. 52 2.0 30 60.0 Total 1 542 945.7 Estuarine Biotic Index = 1.74 Total taxa = 21 Total taxa with sensitivitv values = 20 a Only those taxa for which a sensitivity value is available are displayed b Total number of individuals caught in all five ponar replicates. Sensitivity values provided by NCDWR. 1-92