20080868 Ver 2_I-12 2014 Little Sweep Downstream Biotic Index Table_20150717

Table 1 -12. Estuarine Biotic Index (EBI) calculations for benthic sweep samples at the Little Creek downstream station in
May 2014.
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Number of
Sensitivity
Abundance
Product of
Species /taxona
individualsb
value (SV)°
value (n)
(SV)(n)
Annelida
Oligochaeta
Tubificidae sp. w/o hair
7
1.0
3
3.0
Polychaeta
Amphicteis floridus
46
2.0
30
60.0
Eteone heteropoda
1
1.6
1
1.6
Laeonereis culveri
3
1.0
3
3.0
Marenzelleria viridis
1
2.6
1
2.6
Polydora cornuta
19
1.2
10
12.0
Arthropoda
Insecta
Diptera
Bezzia/Palpomyia complex
1
2.3
1
2.3
Chironomus decorus
118
1.0
100
100.0
Dicrotendipes nervosus
2
1.0
1
1.0
Goeldichironomus devineyae
41
2.0
30
60.0
Parachironomus sp.
5
1.1
3
3.3
Tanytarsus sp.
5
2.3
3
6.9
Hemiptera
Corixidae sp.
1
1.3
1
1.3
Trichcorixa sexinta
3
1.0
3
3.0
Malacostraca
Apocorophium lacustre
3
2.2
3
6.6
Apocorophium louisianum
42
2.2
30
66.0
Apocorophium sp.
179
2.2
100
220.0
Gammarus mucronatus
39
2.3
30
69.0
Gammarus tigrinus
55
2.0
30
60.0
Lepidactylus dytiscus
2
3.5
1
3.5
Decapoda
Palaemonetes pugio
18
2.5
10
25.0
Rhithropanopeus harrisii
3
2.5
3
7.5
Isopoda
Cassidinidea lunifrons
9
2.0
3
6.0
Cyathura polita
3
2.0
3
6.0
Edotia montosa
5
2.6
3
7.8
Tanaidacea
Hargeria rapax
67
1.6
30
48.0
Maxillopoda
Sessilia
Balanus improvisus
2
2.0
1
2.0
Mollusca
Gastropoda
Littoridinops tenuipes
300
2.0
100
200.0
Total
537
987.4
Estuarine Biotic Index = 1.84
Total taxa = 32
Total taxa with sensitivity values = 28
aOnly those taxa for which a sensitivity value is available are displayed.
TTotal number of individuals caught in all three sweep replicates.
Sensitivity values provided by NCDWR.
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