Module 4 Stream Invertebrate Survey Interpretation
Byrne Creek, Feb 15, 2015 | Survey ID: 94
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 111
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 3
(total # counted 111) / (# of 30cm x 30cm samples x.09m2 3 / (Area: 0.27)) : 411.11
B) PREDOMINANT TAXON: Mayfly, (78)
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) = 3
2 x (# of category 2) = 2
(# of category 3) = 2
Pollution Tolerant Index = 7
EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 2
Total number of EPT taxa from Column C = 2
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 78 / total 111 = 0.70
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 6
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:
78 / 111 = 0.7027
SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 1
EPT Index: 2
EPT to Total Ratio: 3
Predominant Taxon Ratio: 2
Total: 2

Field Data as Collected
Polution Tolerance
Number Counted
Number of Taxa
Common Name
Category 1 - Polution Intolerant Caddisfly
Dobsonfly
Gilled Snail
78 2 Mayfly
Riffle Beetle
Stonefly
Water Penny
Sub Total: 78 2
Category 2 - Somewhat Pollution Tolerant Alderfly larva
Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
1 1 Scud
Watersnipe Larva
Sub Total: 1 1
Category 3 - Pollution Tolerant 24 2 Aquatic Worm
Blackfly Larva
Leech
8 1 Midge Larva (chironomid)
Planarian
Pouch Snail
Truebug Adult
Water Mite
Sub Total: 32 3