20080868 Ver 2_I-9 2017 Drinkwater Sweep Upstream Biotic Index Table_20180629

Table 1-9. Estuarine Biotic Index (EBI) calculations for benthic sweep samples at the Drinkwater Creek upstream station in
May 2017.
Species/taxon'
Number of
individualsb
Sensitivity
value (SV)c
Abundance
value n
Product of
(SV)(n)
Annelida
Oligochaeta
Enchytraeidae sp.
1
1.0
1
1.0
Paranais sp.
2
1.1
1
1.1
Polychaeta
Amphicteis floridus
154
2.0
100
200.0
Laeonereis culveri
2
1.0
1
1.0
Arthropoda
Insecta
Coleoptera
Berosus sp.
22
1.5
10
15.0
Diptera
Apedilum sp.
4
4.0
3
12.0
Chironomus decorus
2
1.0
1
1.0
Dicrotendipes nervosus
34
1.0
30
30.0
Goeldichironomus devineyae
1
2.0
1
2.0
Parachironomus sp.
10
1.1
10
11.0
Procladius sp.
4
1.2
3
3.6
Tanytarsus sp.
13
2.3
10
23.0
Ephemeroptera
Callibaetis sp.
10
1.1
10
11.0
Hemiptera
Corixidae sp.
95
1.3
30
39.0
Trichocorixa sexcinta
8
1.0
3
3.0
Odonata
Enallagma sp.
19
1.5
10
15.0
Malacostraca
Amphipoda
Apocorophium lacustre
2
2.2
1
2.2
Apocorophium louisianum
183
2.2
100
220.0
Apocorophium sp.
295
2.2
100
220.0
Gammarus tigrinus
300
2.0
100
200.0
Isopoda
Cassidinidea lunifrons
71
2.0
30
60.0
Cyathura polita
16
2.0
10
20.0
Maxillopoda
Sessilia
Balanus improvisus
2
2.0
1
2.0
Mollusca
Bivalvia
Mytilopsis leucophaeata
2
1.5
1
1.5
Gastropoda
Littoridinops sp.
226
2.0
100
200.0
Total
1
667
1,294.4
Estuarine Biotic Index = 1.94
Total taxa = 26
Total taxa with sensitivity values = 23
'Only 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.
1-13