Module 4 Stream Invertebrate Survey Interpretation
Spanish Bank Creek, Jul 22, 2017 | Survey ID: 181
A) ABUNDANCE AND DENSITY
ABUNDANCE total number of organisms from Column B: 267
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 3
(total # counted 267) / (# of 30cm x 30cm samples x.09m2 3 / (Area: 0.27)) : 988.89
DENSITY invertebrate density per square meter
# of 30cm x 30cm samples: 3
(total # counted 267) / (# of 30cm x 30cm samples x.09m2 3 / (Area: 0.27)) : 988.89
B) PREDOMINANT TAXON: Blackfly Larva, (142)
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) = 4
Pollution Tolerant Index = 21
2 x (# of category 2) = 8
(# of category 3) = 4
Pollution Tolerant Index = 21
| EPT INDEX | |||
| Good | Acceptable | Marginal | Poor |
| greater than 8 | 5 - 8 | 2 - 5 | 0 - 2 |
Total number of EPT taxa from Column C = 8
| 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 93 / total 267 = 0.35
D) DIVERSITY ASSESSMENT
Total Number of Taxa: 17
| 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:
142 / 267 = 0.5318
142 / 267 = 0.5318
| SITE ASSESMENT RATING | |||
| Good | Acceptable | Marginal | Poor |
| 4 | 3 | 2 | 1 |
| Pollution Tolerance Index: | 3 |
| EPT Index: | 3 |
| EPT to Total Ratio: | 2 |
| Predominant Taxon Ratio: | 3 |
| Total: | 2.75 |
Field Data as Collected
Polution Tolerance |
Number Counted | Number of Taxa | Common Name |
| Category 1 - Polution Intolerant | 6 | 2 | Caddisfly |
| Dobsonfly | |||
| Gilled Snail | |||
| 47 | 2 | Mayfly | |
| Riffle Beetle | |||
| 40 | 4 | Stonefly | |
| Water Penny | |||
| Sub Total: | 93 | 8 | |
| Category 2 - Somewhat Pollution Tolerant | Alderfly larva | ||
| 1 | 1 | Aquatic Beetle | |
| Aquatic Sowbug | |||
| Clam, Mussel | |||
| 1 | 1 | Cranefly Larva | |
| Crayfish | |||
| Damselfy Larva | |||
| Dragonfly Larva | |||
| Fishfly Larva | |||
| 13 | 1 | Scud | |
| 4 | 1 | Watersnipe Larva | |
| Sub Total: | 19 | 4 | |
| Category 3 - Pollution Tolerant | 11 | 2 | Aquatic Worm |
| 142 | 1 | Blackfly Larva | |
| Leech | |||
| Midge Larva (chironomid) | |||
| 1 | 1 | Planarian | |
| Pouch Snail | |||
| Truebug Adult | |||
| 1 | 1 | Water Mite | |
| Sub Total: | 155 | 5 |