Module 4 Stream Invertebrate Survey Interpretation
Noons Creek, Jun 07, 2014 | Survey ID: 62
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 623
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 2
(total # counted 623) / (# of 30cm x 30cm samples x.09m2 2 / (Area: 0.18)) : 3,461.11
B) PREDOMINANT TAXON: Mayfly, (496)
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) = 2
(# of category 3) = 5
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 = 12
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 530 / total 623 = 0.85
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 19
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:
496 / 623 = 0.7961
SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 2
EPT Index: 4
EPT to Total Ratio: 4
Predominant Taxon Ratio:
Total: 2.5

Field Data as Collected
Polution Tolerance
Number Counted
Number of Taxa
Common Name
Category 1 - Polution Intolerant 15 5 Caddisfly
Dobsonfly
Gilled Snail
496 4 Mayfly
Riffle Beetle
19 3 Stonefly
Water Penny
Sub Total: 530 12
Category 2 - Somewhat Pollution Tolerant Alderfly larva
Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
Scud
1 1 Watersnipe Larva
Sub Total: 1 1
Category 3 - Pollution Tolerant 25 2 Aquatic Worm
2 1 Blackfly Larva
Leech
2 1 Midge Larva (chironomid)
2 1 Planarian
Pouch Snail
Truebug Adult
61 1 Water Mite
Sub Total: 92 6