Module 4 Stream Invertebrate Survey Interpretation
Peach Creek, Oct 17, 2018 | Survey ID: 214
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 46
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 3
(total # counted 46) / (# of 30cm x 30cm samples x.09m2 3 / (Area: 0.27)) : 170.37
B) PREDOMINANT TAXON: Mayfly, (33)
C) WATER QUALITY ASSESSMENTS
POLLUTION TOLERANT INDEX
Good Acceptable Marginal Poor
greater than 22 22 - 17 17 -11 less than 11
3 x (# of category 1) = 6
2 x (# of category 2) = 2
(# of category 3) = 3
Pollution Tolerant Index = 11
EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 2
Total number of EPT taxa from Column C = 5
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 37 / total 46 = 0.80
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 9
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:
33 / 46 = 0.7174
SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 2
EPT Index: 2
EPT to Total Ratio: 4
Predominant Taxon Ratio: 2
Total: 2.5

Field Data as Collected
Polution Tolerance
Number Counted
Number of Taxa
Common Name
Category 1 - Polution Intolerant Caddisfly
Dobsonfly
Gilled Snail
33 3 Mayfly
Riffle Beetle
4 2 Stonefly
Water Penny
Sub Total: 37 5
Category 2 - Somewhat Pollution Tolerant5 1 Alderfly larva
Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
Scud
Watersnipe Larva
Sub Total: 5 1
Category 3 - Pollution Tolerant 1 1 Aquatic Worm
1 1 Blackfly Larva
1 Leech
Midge Larva (chironomid)
Planarian
1 1 Pouch Snail
Truebug Adult
Water Mite
Sub Total: 4 3
Category 1 - Polution Intolerant Caddisfly
Dobsonfly
Gilled Snail
33 3 Mayfly
Riffle Beetle
4 2 Stonefly
Water Penny
Sub Total: 37 5
Category 2 - Somewhat Pollution Tolerant5 1 Alderfly larva
Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
Scud
Watersnipe Larva
Sub Total: 5 1
Category 3 - Pollution Tolerant 1 1 Aquatic Worm
1 1 Blackfly Larva
1 Leech
Midge Larva (chironomid)
Planarian
1 1 Pouch Snail
Truebug Adult
Water Mite
Sub Total: 4 3