Module 4 Stream Invertebrate Survey Interpretation
Maple Creek, Jul 11, 2015 | Survey ID: 87
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 126
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 2
(total # counted 126) / (# of 30cm x 30cm samples x.09m2 2 / (Area: 0.18)) : 700.00
B) PREDOMINANT TAXON: Aquatic Worm, (73)
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 = 6
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 18 / total 126 = 0.14
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 15
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:
73 / 126 = 0.5794
SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 3
EPT Index: 3
EPT to Total Ratio: 1
Predominant Taxon Ratio: 3
Total: 2.5

Field Data as Collected
Polution Tolerance
Number Counted
Number of Taxa
Common Name
Category 1 - Polution Intolerant 2 2 Caddisfly
Dobsonfly
Gilled Snail
10 1 Mayfly
Riffle Beetle
6 3 Stonefly
Water Penny
Sub Total: 18 6
Category 2 - Somewhat Pollution Tolerant Alderfly larva
Aquatic Beetle
4 1 Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
14 1 Scud
Watersnipe Larva
Sub Total: 18 2
Category 3 - Pollution Tolerant 73 2 Aquatic Worm
1 1 Blackfly Larva
Leech
10 2 Midge Larva (chironomid)
2 1 Planarian
4 1 Pouch Snail
Truebug Adult
Water Mite
Sub Total: 90 7