20080868 Ver 2_I-50 2015 Little Ponar Downstream Biotic Index Table_20160708

Table 1-50. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Little Creek
downstream station in May 2015.
Species/taxona
Number of
individualsb
Sensitivity
value (SV)`
Abundance
value (n)
Product of
(SV)(n)
Annelida
Oligochaeta
Tubificidae sp. w/o hair
150
1.0
100
100.0
Polychaeta
Amphicteis floridus
230
2.0
100
200.0
Eteone heteropda
30
1.6
30
48.0
Marenzelleria viridis
14
2.6
10
26.0
Mediomastus ambiseta
20
2.0
10
20.0
Polydora cornuta
12
1.2
10
12.0
Streblospio benedicti
396
1.1
100
110.0
Arthropoda
Insecta
Diptera
Bezzia/Palmonyia complex
14
2.3
10
23.0
Chironomus decorus
302
1.0
100
100.0
Dicrotendipes nervosus
10
1.0
10
10.0
Goeldichironomus devineyae
6
2.0
3
6.0
Parachironomus sp.
2
1.1
1
1.1
Tanypus neopunctipennis
4
1.0
3
3.0
Tanytarsus sp.
22
2.3
10
23.0
Malacostraca
Amphipoda
Apocorophium lacustre
126
2.2
100
220.0
Apocorophium louisianum
12
2.2
10
22.0
Apocorophium sp.
320
2.2
100
220.0
Gammarus tigrinus
202
2.0
100
200.0
Isopoda
Cyathura polita
6
2.0
3
6.0
Mollusca
Bivalvia
Macoma balthica
14
1.5
10
15.0
Macoma tenta
6
2.0
3
6.0
Rangia cuneata
8
1.0
3
3.0
Gastropoda
Littoridinops sp.
38
2.0
30
60.0
Total
856
1,434.1
Estuarine Biotic Index = 1.68
Total taxa = 25
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.
W-1