20080868 Ver 2_I-12 2017 Little Sweep Downstream Biotic Index Table_20180629

Table 1-12. Estuarine Biotic Index (EBI) calculations for benthic sweep samples at the Little Creek downstream station in
Mav 2017.
Species/taxon a
Number of
individualsb
Sensitivity
value (SV)'
Abundance
value n
Product of
(SV)(n)
Annelida
Oligochaeta
Tubificoides heterochaetus
2
1.1
1
1.1
Polychaeta
Amphicteis floridus
53
2.0
30
60.0
Eteone heteropoda
1
1.6
1
1.6
Polydora cornuta
2
1.2
1
1.2
Arthropoda
Insecta
Diptera
Bezzia/Palpomyia complex
1
2.3
1
2.3
Chironomus decorus
33
1.0
30
30.0
Dicrotendipes nervosus
126
1.0
100
100.0
Parachironomus sp.
6
1.1
3
3.3
Tanytarsus sp.
20
2.3
10
23.0
Hemiptera
Abedus/Belostoma complex
2
1.0
1
1.0
Corixidae sp.
98
1.3
30
39.0
Trichocorixa sexcintca
10
1.0
10
10.0
Odonata
Enallagma sp.
3
1.5
3
4.5
Ischnura sp.
3
1.0
3
3.0
Malacostraca
Apocorophium lacustre
97
2.2
30
66.0
Apocorophium louisianum
2
2.2
1
2.2
Apocorophium sp.
189
2.2
100
220.0
Gammarus mucronatus
1
2.3
1
2.3
Gammarus tigrinus
196
2.0
100
200.0
Lepidactylus dytiscus
2
3.5
1
3.5
Decapoda
Palaemonetes pugio
83
2.5
30
75.0
Isopoda
Cassidinidea lunifrons
12
2.0
10
20.0
Cyathura polity
3
2.0
3
6.0
Edotia montosa
1
2.6
1
2.6
Hargeria rapax
2
1.6
1
1.6
Maxillopoda
Sessilia
Balanus subalbidus
5
2.0
3
6.0
Mollusca
Bivalvia
Mytilopsis leucophaeata
8
1.5
3
4.5
Gastropoda
Littoridinops sp.
300
2.0
100
200.0
Physidae sp. (physa/physella)
1
1.3
1
1.3
Total
1
609
1,091.0
Estuarine Biotic Index = 1.79
Total taxa = 32
Total taxa with sensitivitv values = 27
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.
MET