TABLE 5. Macroinvertebrate Bioassessment Data for Blue River 1995. Reference: Mitchell River, North Carolina
|
Site No. |
3 |
Score |
6 |
Score |
7 |
Score |
Reference |
|
Site Location |
White Cloud |
|
Rothrock’s Dam |
|
Milltown |
|
Mitchell River |
|
Taxa Richness, Families |
20
|
100%=6
|
14
|
4
|
13
|
4
|
21 Families |
|
FBI |
4.121 |
100%=6 |
3.82 |
6 |
4.84 |
6 |
4.59 |
|
EPT/Chironomidae |
1.62 |
17%=0 |
6.18 |
2 |
2.64 |
2 |
9.286 |
|
CPOM Community Shredders/ Total |
0.12
|
0
|
.01
|
4
|
3
|
4
|
6
|
|
EPT index |
7 |
>100%=6 |
4 |
0 |
7 |
2 |
8 |
|
% Contribution Dom. Family |
18% |
6 |
28%
|
6
|
25% Blackflies |
4
|
34%=3
|
|
Community Loss |
Used as Reference |
6 |
0.65 |
4 |
.84 |
4 |
6 |
|
Ratio of Scrapers to Filterers |
1.35 |
90%=6 |
12.71 |
6 |
.62 |
4 |
1.50 |
|
Total Score |
|
36 |
|
30 |
|
32 |
45 |
Analysis: Site 3--36/45=80% Non-impaired. Best situation to be expected
within an ecoregion. Balanced trophic structure. Optimum community structure for
stream size and habitat quality. Analysis: Site 6 --30/45=66.67% Slightly
impaired. Community structure less than expected. Composition (taxa richness)
lower than expected due to loss of some intolerant forms. Percent contribution
of tolerant forms increases.
Analysis: Site 7--32/45=71.11%. Slightly impaired. Community structure less than
expected. Composition (taxa richness) lower than expected due to loss of some
intolerant forms. Percent contribution of tolerant forms increases.
Taxa Richness=Site TR/RefTR x 100 >80%=6; 60-80=4; 40-60=2; <40=0
FBI=Site FBI/Ref FBI x 100 >85%=6; 70-85=4; 50-70=2; <50%=0
EPT/Chironomidae=Site Ratio/Ref Ratio x 100 >75%=6; 50-75=4; 50-70=2; <50=0
Shredder Community/Total=>50%=6; 35-50%=4; 20-35%=2; <20%=0.
EPT Index=Site/8 x 100 >90%=6; 80-90%=4; 70-80=2; <70=0
% Contribution of Dominant Family 0-35%=6; 35-50%=4; 50-75%=2; >75%=0
Scrapers/Filterers=Ratio of Site/ Ref Ratio x 100 >50%=6; 35-50=4; 20-35=2;
<20%=0
Community Loss (Comparing Site 3 to other sites=<0.5=6; 0.5-1.5=4; 1.5-4=2; >4=0