20080868 Ver 2_I-20 2017 Huddles Sweep Downstream Biotic Index Table_20180629

Table 1-20. Estuarine Biotic Index (EBI) calculations for benthic sweep samples at the Huddles Cut downstream station in
May 2017.
Species/taxona
Number of
individualsb
Sensitivity
value (SV)'
Abundance
value n
Product of
(SV)(n)
Annelida
Oligochaeta
Enchytraeidae sp.
1
1.0
1
1.0
Naididae sp. w/o hair
2
1.0
1
1.0
Tubificoides heterochaetus
1
1.1
1
1.1
Polychaeta
Amphicteis floridus
38
2.0
30
60.0
Eteone heteropoda
7
1.6
3
4.8
Heteromastus filiformis
1
1.1
1
1.1
Marenzelleria viridis
7
2.6
3
7.8
Polydora cornuta
21
1.2
10
12.0
Streblospio benedicti
2
1.1
1
1.1
Arthropoda
Insecta
Diptera
Bezzia/Palpomyia complex
1
2.3
1
2.3
Chironomus decorus
4
1.0
3
3.0
Tanytarsus sp.
1
2.3
1
2.3
Hemiptera
Ranatra nigra
1
2.6
1
2.6
Malacostraca
Amphipoda
Apocorophium lacustre
146
2.2
100
220.0
Apocorophium louisianum
2
2.2
1
2.2
Apocorophium sp.
213
2.2
100
220.0
Gammarus mucronatus
98
2.3
30
69.0
Gammarus tigrinus
214
2.0
100
200.0
Decapoda
Callinectes sapidus
1
2.3
1
2.3
Palaemonetes pugio
7
2.5
3
7.5
Rhithropanopeus harrisii
2
2.5
1
2.5
Isopoda
Cyathura polita
3
2.0
3
6.0
Edotia montosa
19
2.6
10
26.0
Hargeria rapax
22
1.6
10
16.0
Mysida
Americamysis almyra
1
2.2
1
2.2
Mollusca
Bivalvia
Macoma balthica
1
1.5
1
1.5
Macoma tenta
1
2.0
1
2.0
Mytilopsis leucophaeata
1
1.5
1
1.5
Rangia cuneata
4
1.0
3
3.0
Gastropoda
Littoridinops sp.
131
2.0
100
200.0
Total
523
1,081.8
Estuarine Biotic Index = 2.07
Total taxa = 33
Total taxa with sensitivitv values = 28
aOnly those taxa for which a sensitivity value is available are displayed
bTotal number of individuals caught in all three sweep replicates.
`Sensitivity values provided by NCDWR.
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