1. Using Aquatic Macroinvertebrates to
Why Biomonitor?
Using Aquatic Macroinvertebrates to
Monitor Stream Health

2. Biological Background on Biomonitoring: What is biomonitoring?
Using living species to determine the health of a system
Examples:
300 BC Aristotle uses fish
Kings’ wine and food tasters
Canaries in the coal mine
1972 Clean Water Act mandate to restore and protect the chemical, physical, and biological integrity of the nation’s waters

3. What are macroinvertebrates?
Large visible, bottom dwelling aquatic organism (insects,
snails, worms, clams, crustaceans) that DO NOT have a internal
skeletal structure

4. Roles of Macroinvertebrates:
Pollinators
Decomposers
Shredders
Filterers
Scrapers
Predators
Foodchain
Pests

5. Reasons to Use Macroinvertebrates as
Biomonitors in the Pacific Northwest

6. Stonefly-intolerant
Blackfly-tolerant
How are macroinvertebrates a reliable indicator of water quality?
Aquatic macroinvertebrates differ in their sensitivity to water pollution
—meaning some are pollution tolerant, while others are pollution
intolerant
Aquatic macro’s provide information about the quality of a stream over
long periods of time (videotape vs snapshot)
Easy to collect
Sedentary, so they stay put which allows them to experience present
water quality conditions

7. Complete Metamorphosis
Examples: Beetle, butterflies, moths, bees, black fly, mosquitos

8. Incomplete Metamorphosis
Examples: Stone flies, caddis flies, dragon flies, grass hoppers

9. When do we monitor?

10. Fall:
Less impact on salmon
Low flows-easier/safer access
Concentrated populations of macros
Degraded sites become apparently degraded while pristine sites remain intact

11. Review
What is meant by biomonitoring?
Discuss the historical use of biomonitoring.
When do you sample and why?
4. How are aquatic macroinvertebrates a reliable
indicator of water quality?
What important roles do macroinvertebrates play
in the ecosystem?
6. Define macroinvertebrates