20080868 Ver 2_I-46 2015 Drinkwater Ponar Downstream Biotic Index Table_20160708

Table 1-46. Estuarine Biotic Index (EBI) calculations for benthic ponar samples at the Drinkwater
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
2
1.0
1
1.0
Tubificoides heterochaetus
1
1.1
1
1.1
Polychaeta
Amphicteis floridus
5
2.0
3
6.0
Eteone heteropoda
12
1.6
10
16.0
Marenzelleria viridis
25
2.6
10
26.0
Mediomastus ambiseta
6
2.0
3
6.0
Streblospio benedicti
18
1.1
10
11.0
Arthropoda
Insecta
Diptera
Chironomus decorus
38
1.0
30
30.0
Malacostraca
Amphipoda
Gammarus tigrinus
2
2.0
1
2.0
Mysida
Americamysis sp.
1
2.2
1
2.2
Mollusca
Bivalvia
Macoma balthica
4
1.5
3
4.5
Macoma tenta
29
2.0
10
20.0
Gastropoda
Littoridinops sp.
13
2.0
10
20.0
Total
1
93
145.8
Estuarine Biotic Index = 1.57
Total taxa = 13
Total taxa with sensitivitv values = 12
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.
1-54