Module 4 Stream Invertebrate Survey Interpretation
Windebank Creek, Sep 07, 2014 | Survey ID: 71
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 654
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 3
(total # counted 654) / (# of 30cm x 30cm samples x.09m2 3 / (Area: 0.27)) : 2,422.22
B) PREDOMINANT TAXON: Mayfly, (555)
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) = 3
Pollution Tolerant Index = 16
EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 2
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 557 / total 654 = 0.85
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 10
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:
555 / 654 = 0.8486
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: 1
Total: 2.25

Field Data as Collected
Polution Tolerance
Number Counted
Number of Taxa
Common Name
Category 1 - Polution Intolerant 0 0 Caddisfly
0 0 Dobsonfly
0 0 Gilled Snail
555 3 Mayfly
1 1 Riffle Beetle
2 1 Stonefly
0 0 Water Penny
Sub Total: 558 5
Category 2 - Somewhat Pollution Tolerant0 0 Alderfly larva
0 0 Aquatic Beetle
0 0 Aquatic Sowbug
0 0 Clam, Mussel
1 1 Cranefly Larva
0 0 Crayfish
0 0 Damselfy Larva
0 0 Dragonfly Larva
0 0 Fishfly Larva
8 1 Scud
0 0 Watersnipe Larva
Sub Total: 9 2
Category 3 - Pollution Tolerant 29 1 Aquatic Worm
57 1 Blackfly Larva
0 0 Leech
0 0 Midge Larva (chironomid)
1 1 Planarian
0 0 Pouch Snail
0 0 Truebug Adult
0 0 Water Mite
Sub Total: 87 3