Module 4 Stream Invertebrate Survey Interpretation

BUCK CREEK | Survey ID: 245

A) Abundance and density

ABUNDANCE: 251 / NUMBER OF SAMPLES: (1 *.09) = DENSITY: 2,788.89

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) = 21
2 x (# of category 2) = 22
(# of category 3) = 8
= 51

EPT INDEX
Good Acceptable Marginal Poor
greater than 8 5 - 8 2 - 5 0 - 1
Total number of EPT taxa from Column C = 11

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 218 / total 251 = 0.87

D) DIVERSITY ASSESSMENT

TOTAL NUMBER OF TAXA: 18

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 147 / 251 = 0.5857

SITE ASSESMENT RATING
Good Acceptable Marginal Poor
4 3 2 1
Pollution Tolerance Index: 4
EPT Index: 4
EPT to Total Ratio: 4
Predominant Taxon Ratio: 3
Total: 3.75

Field Data as Collected

Polution Tolerance

Number Counted

Number of Taxa

Common Name

Category 1 - Polution Intolerant 12 3 Caddisfly
0 0 Dobsonfly
0 0 Gilled Snail
147 5 Mayfly
0 0 Riffle Beetle
59 3 Stonefly
0 0 Water Penny
Sub Total: 218 11 7
Category 2 - Somewhat Pollution Tolerant 0 0 Alderfly larva
3 1 Aquatic Beetle
0 0 Aquatic Sowbug
0 0 Clam, Mussel
1 1 Cranefly Larva
0 0 Crayfish
0 0 Damselfy Larva
0 0 Dragonfly Larva
0 0 Fishfly Larva
0 0 Scud
0 0 Watersnipe Larva
Sub Total: 4 2 11
Category 3 - Pollution Tolerant 4 1 Aquatic Worm
1 1 Blackfly Larva
0 0 Leech
17 2 Midge Larva (chironomid)
0 0 Planarian
0 0 Pouch Snail
0 0 Truebug Adult
7 1 Water Mite
Sub Total: 29 5 8
Total: 251 18 26