20080868 Ver 2_I-20 2014 Huddles Sweep Downstream Biotic Index Table_20150717

Table 1 -20. Estuarine Biotic Index (EBI) calculations for benthic sweep samples at the Huddles Cut downstream station in
May 2014.
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Number of
Sensitivity
Abundance
Product of
Species /taxona
individuals"
value (SV)°
value (n)
(SV)(n)
Annelida
Oligochaeta
Peloscolex heterochaetus
2
1.1
1
1.1
Tubificidae sp. w/o hair
6
1.0
3
3.0
Polychaeta
Marenzelleria viridis
1
2.6
1
2.6
Polydora cornuta
4
1.2
3
3.6
Arthropoda
Insecta
Diptera
Chironomus decorus
3
1.0
3
3.0
Chironomus sp.
2
1.0
1
1.0
Dicrotendipes nervosus
1
1.0
1
1.0
Goeldichironomus devineyae
22
2.0
10
20.0
Parachironomous sp.
2
1.1
1
1.1
Tanytarsus sp.
1
2.3
1
2.3
Malacostraca
Amphipoda
Ampithoe valida
1
3.0
1
3.0
Apocorophium louisianum
8
2.2
3
6.6
Apocorophium sp.
12
2.2
10
22.0
Gammarus mucronatus
1
2.3
1
2.3
Gammarus tigrinus
251
2.0
100
200.0
Decapoda
Palaemonetes pugio
28
2.5
10
25.0
Isopoda
Edotia montosa
1
2.6
1
2.6
Tanaidacea
Hargeria rapax
2
1.6
1
1.6
Maxillopoda
Sessilia
Balanus improvisus
2
2.0
1
2.0
Mollusca
Gastropoda
Littoridinops tenuipes
10
2.0
10
20.0
Total
163
323.8
Estuarine Biotic Index = 1.99
Total taxa = 24
Total taxa with sensitivity values = 20
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.
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