Module 4 Stream Invertebrate Survey Interpretation
Acadia Creek, Jul 22, 2015 | Survey ID: 89
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 325
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 3
(total # counted 325) / (# of 30cm x 30cm samples x.09m2 3 / (Area: 0.27)) : 1,203.70
B) PREDOMINANT TAXON: Mayfly, (178)
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) = 4
Pollution Tolerant Index = 12
EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 2
Total number of EPT taxa from Column C = 3
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 184 / total 325 = 0.57
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 8
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:
178 / 325 = 0.5477
SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 2
EPT Index: 2
EPT to Total Ratio: 3
Predominant Taxon Ratio: 3
Total: 2.5

Field Data as Collected
Polution Tolerance
Number Counted
Number of Taxa
Common Name
Category 1 - Polution Intolerant 6 1 Caddisfly
Dobsonfly
Gilled Snail
178 2 Mayfly
Riffle Beetle
Stonefly
Water Penny
Sub Total: 184 3
Category 2 - Somewhat Pollution Tolerant Alderfly larva
Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
3 1 Scud
Watersnipe Larva
Sub Total: 3 1
Category 3 - Pollution Tolerant 1 1 Aquatic Worm
129 1 Blackfly Larva
Leech
Midge Larva (chironomid)
Planarian
1 1 Pouch Snail
Truebug Adult
7 1 Water Mite
Sub Total: 138 4