Module 4 Stream Invertebrate Survey Interpretation
Peach Creek, Apr 30, 2016 | Survey ID: 132
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 199
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 3
(total # counted 199) / (# of 30cm x 30cm samples x.09m2 3 / (Area: 0.27)) : 737.04
B) PREDOMINANT TAXON: Mayfly, (74)
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) = 8
(# of category 3) = 3
Pollution Tolerant Index = 20
EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 2
Total number of EPT taxa from Column C = 5
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 134 / total 199 = 0.67
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 14
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:
74 / 199 = 0.3719
SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 3
EPT Index: 2
EPT to Total Ratio: 3
Predominant Taxon Ratio: 4
Total: 3

Field Data as Collected
Polution Tolerance
Number Counted
Number of Taxa
Common Name
Category 1 - Polution Intolerant 43 1 Caddisfly
Dobsonfly
Gilled Snail
74 2 Mayfly
Riffle Beetle
17 2 Stonefly
Water Penny
Sub Total: 134 5
Category 2 - Somewhat Pollution Tolerant1 1 Alderfly larva
3 1 Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
24 1 Damselfy Larva
Dragonfly Larva
1 1 Fishfly Larva
Scud
Watersnipe Larva
Sub Total: 29 4
Category 3 - Pollution Tolerant 30 3 Aquatic Worm
5 1 Blackfly Larva
Leech
Midge Larva (chironomid)
Planarian
Pouch Snail
1 1 Truebug Adult
Water Mite
Sub Total: 36 5