Module 4 Stream Invertebrate Survey Interpretation
STILL CREEK | Survey ID: 185
A) Abundance and density
ABUNDANCE: 1125 / NUMBER OF SAMPLES: (3 *.09) = DENSITY: 4,166.67
B) PREDOMINANT TAXON
Mayfly 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) = 3
2 x (# of category 2) = 4
(# of category 3) = 4
= 11
EPT INDEX
Good
Acceptable
Marginal
Poor
greater than 8
5 - 8
2 - 5
0 - 1
Total number of EPT taxa from Column C = 4
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
475 / total
1125 =
0.42
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 475 / 1125 = 0.4222
SITE ASSESMENT RATING
Good
Acceptable
Marginal
Poor
4
3
2
1
Pollution Tolerance Index: 2
EPT Index: 2
EPT to Total Ratio: 2
Predominant Taxon Ratio: 3
Total: 2.25
POLLUTION TOLERANT INDEX | |||
---|---|---|---|
Good | Acceptable | Marginal | Poor |
greater than 22 | 22 - 17 | 16 - 11 | less than 11 |
3 x (# of category 1) = 3
2 x (# of category 2) = 4
(# of category 3) = 4
= 11
2 x (# of category 2) = 4
(# of category 3) = 4
= 11
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
475 / total
1125 =
0.42
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: 2
EPT Index: 2
EPT to Total Ratio: 2
Predominant Taxon Ratio: 3
Total: 2.25
EPT Index: 2
EPT to Total Ratio: 2
Predominant Taxon Ratio: 3
Total: 2.25
Field Data as Collected
Polution Tolerance |
Number Counted | Number of Taxa | Common Name |
Category 1 - Polution Intolerant | Caddisfly | ||
Dobsonfly | |||
Gilled Snail | |||
475 | 4 | Mayfly | |
Riffle Beetle | |||
Stonefly | |||
Water Penny | |||
Sub Total: | 475 | 4 | 1 |
Category 2 - Somewhat Pollution Tolerant | Alderfly larva | ||
Aquatic Beetle | |||
9 | 1 | Aquatic Sowbug | |
Clam, Mussel | |||
Cranefly Larva | |||
Crayfish | |||
Damselfy Larva | |||
Dragonfly Larva | |||
Fishfly Larva | |||
7 | 1 | Scud | |
Watersnipe Larva | |||
Sub Total: | 16 | 2 | 2 |
Category 3 - Pollution Tolerant | 187 | 3 | Aquatic Worm |
Blackfly Larva | |||
Leech | |||
439 | 7 | Midge Larva (chironomid) | |
7 | 1 | Planarian | |
Pouch Snail | |||
Truebug Adult | |||
1 | 1 | Water Mite | |
Sub Total: | 634 | 12 | 4 |
Total: | 1125 | 18 | 7 |