Module 4 Stream Invertebrate Survey Interpretation
Acadia Creek, Aug 16, 2013 | Survey ID: 20
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 206
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 1
(total # counted 206) / (# of 30cm x 30cm samples x.09m2 1 / (Area: 0.09)) : 2,288.89
B) PREDOMINANT TAXON: Blackfly Larva, (96)
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) = 9
2 x (# of category 2) = 4
(# of category 3) = 5
Pollution Tolerant Index = 18
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 61 / total 206 = 0.30
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 12
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:
96 / 206 = 0.4660
SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 3
EPT Index: 2
EPT to Total Ratio: 2
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
55 2 Mayfly
2 1 Riffle Beetle
Stonefly
Water Penny
Sub Total: 63 4
Category 2 - Somewhat Pollution Tolerant Alderfly larva
Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
7 1 Scud
4 1 Watersnipe Larva
Sub Total: 11 2
Category 3 - Pollution Tolerant 4 2 Aquatic Worm
96 1 Blackfly Larva
Leech
1 1 Midge Larva (chironomid)
3 1 Planarian
Pouch Snail
Truebug Adult
28 1 Water Mite
Sub Total: 132 6