20061780 Ver 2_Report_20080102

~oDS 1 `1 ~6~
Benthic macroinvertebrates collected at Floogie Mitigation Site, Bertie County, NC
DWQ Qua14 method, WK Dickson, January 2008.
Site: 3 (Upstream) 2 (Reach 2) 1 (Reach 4)
Taxon
TRICHOPTERA
Ptilostomis sp
COLEOPTERA
Enochrus sp
Agabus sp (Larvae)
Peltodytes sp
DIPTERA: CHIRONOMIDAE
Hydrobaenus sp
Limnophyes sp
Psectrotanypus dyari
Zaverlimyia sp
OLIGOCHAETA
Megadriles
Limnodrilus hofineisteri
Ilyodrilus templetoni
Nais sp
Ecclipidrilus sp
CRUSTACEA
Procambarus sp
Crangonyx sp
Caecidotea forbesi
C. racovitzai
Taxa Richnesss
EPT Taxa Richness
NC Biotic Index
3 - -
1 - -
1 - -
- - 1
- 4 19
- - 1
- 1 -
1 - -
1
1 9 2
- - 1
- - 1
- - 5
1 3 1
16 10 4
6 - -
10 - -
9 5 10
1 0 0
7.0 8.6 8.8

-Streams in Bertie County are in NC DWQ Swamp Region B. Streams in this area have
been severely affected by drought condition in late 2007, and I would not expect any sites
to have the expected invertebrate community for "natural" swamp streams, including
NCBI values less than 7.0 and EPT taxa richness >4. Under these difficult conditions, it
is best to look at patterns, rather than to strictly apply DWQ criteria.
-Only the upstream control site was dominated by the usual swamp taxa, especially
amphipods (Crangonyx) and isopods (Caecidotea spp). The downstream area were
dominate by smaller and more tolerant species, especially midges (Hydrobaenus) and
worms. This produces a change in biotic index from 7.0 (almost "Natural") to 8.6-8.8
("Severe Stress").
-I would suggest bringing back some of the collections for sorting in the lab, to see if
some smaller-bodied organisms (esp. midges) are being missed by field picking.