Module 4 Stream Invertebrate Survey Interpretation
SPANISH BANK CREEK | Survey ID: 68
A) Abundance and density
ABUNDANCE: 448 / NUMBER OF SAMPLES: (2 *.09) = DENSITY: 2,488.89
B) PREDOMINANT TAXON
Blackfly Larva
C) WATER QUALITY ASSESSMENTS
POLLUTION TOLERANT INDEX
Good
Acceptable
Marginal
Poor
greater than 22
22 - 17
16 - 11
less than 11
3 x (# of category 1) = 9
2 x (# of category 2) = 8
(# of category 3) = 5
= 22
EPT INDEX
Good
Acceptable
Marginal
Poor
greater than 8
5 - 8
2 - 5
0 - 1
Total number of EPT taxa from Column C = 7
EPT TO TOTAL RATIO
Good
Acceptable
Marginal
Poor
0.75 - 1.00
0.50 - 0.75
0.25 - 0.50
0 - 0.25
# of EPT
92 / total
448 =
0.21
D) DIVERSITY ASSESSMENT
TOTAL NUMBER OF TAXA: 18
PREDOMINANT TAXON RATIO
Good
Acceptable
Marginal
Poor
0 - 0.40
0.40 - 0.60
0.60 - 0.80
0.80 - 1.0
PREDOMINANT TAXON RATIO: Predominant Taxa 314 / 448 = 0.7009
SITE ASSESMENT RATING
Good
Acceptable
Marginal
Poor
4
3
2
1
Pollution Tolerance Index: 4
EPT Index: 3
EPT to Total Ratio: 1
Predominant Taxon Ratio: 2
Total: 2.5
| POLLUTION TOLERANT INDEX | |||
|---|---|---|---|
| Good | Acceptable | Marginal | Poor |
| greater than 22 | 22 - 17 | 16 - 11 | less than 11 |
3 x (# of category 1) = 9
2 x (# of category 2) = 8
(# of category 3) = 5
= 22
2 x (# of category 2) = 8
(# of category 3) = 5
= 22
| EPT INDEX | |||
|---|---|---|---|
| Good | Acceptable | Marginal | Poor |
| greater than 8 | 5 - 8 | 2 - 5 | 0 - 1 |
| EPT TO TOTAL RATIO | |||
|---|---|---|---|
| Good | Acceptable | Marginal | Poor |
| 0.75 - 1.00 | 0.50 - 0.75 | 0.25 - 0.50 | 0 - 0.25 |
# of EPT
92 / total
448 =
0.21
| PREDOMINANT TAXON RATIO | |||
|---|---|---|---|
| Good | Acceptable | Marginal | Poor |
| 0 - 0.40 | 0.40 - 0.60 | 0.60 - 0.80 | 0.80 - 1.0 |
| SITE ASSESMENT RATING | |||
|---|---|---|---|
| Good | Acceptable | Marginal | Poor |
| 4 | 3 | 2 | 1 |
Pollution Tolerance Index: 4
EPT Index: 3
EPT to Total Ratio: 1
Predominant Taxon Ratio: 2
Total: 2.5
EPT Index: 3
EPT to Total Ratio: 1
Predominant Taxon Ratio: 2
Total: 2.5
Field Data as Collected
Polution Tolerance |
Number Counted | Number of Taxa | Common Name |
| Category 1 - Polution Intolerant | 8 | 2 | Caddisfly |
| Dobsonfly | |||
| Gilled Snail | |||
| 64 | 3 | Mayfly | |
| Riffle Beetle | |||
| 20 | 2 | Stonefly | |
| Water Penny | |||
| Sub Total: | 92 | 7 | 3 |
| Category 2 - Somewhat Pollution Tolerant | Alderfly larva | ||
| 1 | 1 | Aquatic Beetle | |
| 2 | 1 | Aquatic Sowbug | |
| Clam, Mussel | |||
| 2 | 1 | Cranefly Larva | |
| Crayfish | |||
| Damselfy Larva | |||
| Dragonfly Larva | |||
| Fishfly Larva | |||
| 12 | 1 | Scud | |
| Watersnipe Larva | |||
| Sub Total: | 17 | 4 | 4 |
| Category 3 - Pollution Tolerant | 11 | 2 | Aquatic Worm |
| 314 | 1 | Blackfly Larva | |
| Leech | |||
| 9 | 2 | Midge Larva (chironomid) | |
| 4 | 1 | Planarian | |
| 1 | 1 | Pouch Snail | |
| Truebug Adult | |||
| Water Mite | |||
| Sub Total: | 339 | 7 | 5 |
| Total: | 448 | 18 | 12 |