20080868 Ver 2_I-21 2015 Porter Sweep Upstream Biotic Index Table_20160708

Table 1-21. Estuarine Biotic Index (EBI) calculations for benthic sweep samples at the Porter Creek upstream 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
38
1.0
30
30.0
Tubificoides heterochaetus
10
1.1
10
11.0
Polychaeta
Amphicteis floridus
236
2.0
100
200.0
Arthropoda
Insecta
Diptera
Bezzia/Palpomyia complex
8
2.3
3
6.9
Dicrotendipes nervosus
4
1.0
3
3.0
Glyptotendipes sp.
4
1.3
3
3.9
Tabanus sp.
4
1.4
3
4.2
Tanypus neopunctipennis
4
1.0
3
3.0
Tanytarsus sp.
2
2.3
1
2.3
Hemiptera
Abedus/Belostoma sp.
18
1.0
10
10.0
Pelocoris femoratus
2
2.3
1
2.3
Malacostraca
Amphipoda
Apocorophium lacustre
2
2.2
1
2.2
Apocorophium sp.
2
2.2
1
2.2
Gammarus tigrinus
300
2.0
100
200.0
Orchestia uhleri
2
2.0
1
2.0
Isopoda
Cassidinidea lunifrons
48
2.0
30
60.0
Cyathura polita
132
2.0
100
200.0
Mollusca
Gastropoda
Littoridinops sp.
90
2.0
30
60.0
Physidae sp. (physa/physella)
2
1.3
1
1.3
Total
431
804.3
Estuarine Biotic Index = 1.87
Total taxa = 21
Total taxa with sensitivity values = 17
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.
1-27