Module 4 Stream Invertebrate Survey Interpretation

MACDONALD CREEK | Survey ID: 11

A) Abundance and density

ABUNDANCE: 39 / NUMBER OF SAMPLES: (1 *.09) = DENSITY: 433.33

B) PREDOMINANT TAXON

Mayfly Larva

C) WATER QUALITY ASSESSMENTS

POLLUTION TOLERANT INDEX
Good Acceptable Marginal Poor
greater than 22 22 - 17 16 - 11 less than 11
3 x (# of category 1) = 6
2 x (# of category 2) = 0
(# of category 3) = 3
= 9

EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 1
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 26 / total 39 = 0.67

D) DIVERSITY ASSESSMENT

TOTAL NUMBER OF TAXA: 7

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: Predominant Taxa 17 / 39 = 0.4359

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: 3
Total: 2.25

Field Data as Collected

Polution Tolerance

Number Counted

Number of Taxa

Common Name

Category 1 - Polution Intolerant Caddisfly
Dobsonfly
Gilled Snail
17 1 Mayfly
Riffle Beetle
9 1 Stonefly
Water Penny
Sub Total: 26 2 2
Category 2 - Somewhat Pollution Tolerant Alderfly larva
Aquatic Beetle
Aquatic Sowbug
Clam, Mussel
Cranefly Larva
Crayfish
Damselfy Larva
Dragonfly Larva
Fishfly Larva
Scud
Watersnipe Larva
Sub Total: 0 0 0
Category 3 - Pollution Tolerant 6 2 Aquatic Worm
5 2 Blackfly Larva
Leech
Midge Larva (chironomid)
Planarian
Pouch Snail
Truebug Adult
2 1 Water Mite
Sub Total: 13 5 3
Total: 39 7 5