Module 4 Stream Invertebrate Survey Interpretation

SAUL CREEK | Survey ID: 192

A) Abundance and density

ABUNDANCE: 43 / NUMBER OF SAMPLES: (2 *.09) = DENSITY: 238.89

B) PREDOMINANT TAXON

Stonefly 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) = 9
2 x (# of category 2) = 2
(# of category 3) = 4
= 15

EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 1
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 28 / total 43 = 0.65

D) DIVERSITY ASSESSMENT

TOTAL NUMBER OF TAXA: 11

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 21 / 43 = 0.4884

SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 2
EPT Index: 2
EPT to Total Ratio: 3
Predominant Taxon Ratio: 3
Total: 2.5

Field Data as Collected

Polution Tolerance

Number Counted

Number of Taxa

Common Name

Category 1 - Polution Intolerant 4 2 Caddisfly
Dobsonfly
Gilled Snail
3 1 Mayfly
Riffle Beetle
21 2 Stonefly
Water Penny
Sub Total: 28 5 3
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 1
Category 3 - Pollution Tolerant 8 2 Aquatic Worm
Blackfly Larva
Leech
3 1 Midge Larva (chironomid)
1 1 Planarian
Pouch Snail
Truebug Adult
2 1 Water Mite
Sub Total: 14 5 4
Total: 43 11 8