20080868 Ver 2_I-46 2017 Drinkwater Ponar Downstream Biotic Index Table_20180629

Table 1-46. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Drinkwater
Creek downstream station in May 2017.
Species/taxon a
Number of
individualsb
Sensitivity
value (SV)c
Abundance
value (n)
Product of
(SV)(n)
Annelida
Polychaeta
Eteone heteropoda
13
1.6
10
16.0
Marenzelleria viddis
180
2.6
100
260.0
Mediomastus ambiseta
52
2.0
30
60.0
Streblospio benedicti
19
1.1
10
11.0
Arthropoda
Insecta
Diptera
Chironomus decorus
2
1.0
1
1.0
Tanypus neopunctipennis
3
1.0
3
3.0
Hemiptera
Corixidae sp.
42
1.3
30
39.0
Trichocorixa sexcinta
6
1.0
3
3.0
Malacostraca
Amphipoda
Apocorophium louisianum
2
2.2
1
2.2
Apocorophium sp.
3
2.2
3
6.6
Gammarus tigrinus
11
2.0
10
20.0
Isopoda
Cyathura polita
4
2.0
3
6.0
Edotia montosa
2
2.6
1
2.6
Mysida
Americamysis almyra
5
2.2
3
6.6
Mollusca
Bivalvia
Macoma balthica
2
1.5
1
1.5
Macoma tenta
2
2.0
1
2.0
Rangia cuneata
12
1.0
10
10.0
Gastropoda
Littoridinops sp.
108
2.0
100
200.0
Total
1
320
650.5
Estuarine Biotic Index = 2.03
Total taxa = 17
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.
1-52