1. Biomonitoring
the study of biological organisms and their responses to environmental conditions; can be fish, algae or insect communities

2. Benthic macroinvertebrates
Benthic = Live on or in bottom substrate
Macro = Large enough to be seen with unaided eye
Invertebrate = Animal without a backbone

3. Why study macroinvertebrates?
Affected by the physical, chemical and biological conditions of stream
Can’t escape pollution - show the effects of short and long-term pollution events
Can show the cumulative impacts of pollution
May show the impacts of habitat loss

4. Why study macroinvertebrates?
Critical part of the stream’s food web
Relatively easy to sample and identify (easier than algae)
Have greater diversity in stream than fish - sport fishing, stocking of fish and exotic species have altered fish community

5. IDENTIFICATION

6. Key identification features
Overall body shape (NOT SIZE)
Case made of sticks, leaves, stone
Legs
Presence and location of gills
Presence and location of cerci (“tails”)
Head capsule, unusual appendages
Movement (crawl; swim side-to-side, up-down)
These are the “key” features for getting to the order and family level; there are other common features such as wing pads, anal hooks, antennae, etc . Some family and most genus/species identification requires very specific microscope work to identify variations is small features, such as mandibles, toes, “bumps”, etc.
Student Watershed Research Project (SWRP) Macroinvertebrates

7. Body shape
Mayfly example of typical insect body: head, thorax, abdomen
Student Watershed Research Project (SWRP) Macroinvertebrates

8. Case Case 1: Fall caddis (Family Limnephilidae, Genus Dicosmoecus)
Case 2: American Grannom (Family Brachycentridae, Genus Brachycentrus)
Case 3: Periwinkle, Cinnamon Sedge (Family Limnephilidae, 35+ genus in Oregon)
Student Watershed Research Project (SWRP) Macroinvertebrates

9. Legs and prolegs Prolegs on midge Caddis removed from case
Jointed legs are used primarily for movement.
Prolegs are non-jointed appendages – aren’t easily identified as legs
Prolegs on midge
Caddis removed from case
Student Watershed Research Project (SWRP) Macroinvertebrates

10. Gills Mayfly (Speckle-Winged Quill, Callibaetis)
Presence, location and shape of gills is important for ID. Mayflies have abdominal gills, but the shape can vary.
Mayfly (Speckle-Winged Quill,
Callibaetis)
Student Watershed Research Project (SWRP) Macroinvertebrates

11. Cerci (tails) Baetis has center tail that is ½ length of outer tails
The number and length of tails/cerci can help with taxonomy. Keep in mind that fragile tails may break during collection, so number of tails should not be only ID feature used.
Baetis has center tail that is ½ length of outer tails
Student Watershed Research Project (SWRP) Macroinvertebrates

12. Head capsule Midges – head capsule
Color can help, but isn’t a good means for sorting invertebrates
Red midge on bottom is bloodworm, which is an example of where noting color can give information about organism. Bloodworms have hemoglobin – these organisms can obtain oxygen in low DO waters.
Student Watershed Research Project (SWRP) Macroinvertebrates

13. Stoneflies (Plecoptera) Sensitive
Nymphs:
Two distinct "tails" called cerci, which are actually sensory feelers
Usual movement = crawl; swim side-side
Insect nymphs with three pair of jointed legs, each with paired claws.
Two pair of wing pads (developing wings) present on thorax.
No gills along abdomen
Length up to 3 inches
The name Plecoptera, derived from the Greek "pleco" meaning folded and "ptera" meaning wing, refers to the pleated hind wings which fold under the front wings when the insect is at rest.
Student Watershed Research Project (SWRP) Macroinvertebrates

14. Stonefly nymph (Golden stone)
Golden stone (Family Perlidae, Hesperoperla pacifica). This species is an example of sorting by key features and reaching a positive Genus/species identification.
Student Watershed Research Project (SWRP) Macroinvertebrates

15. Stoneflies (Plecoptera) Sensitive
Feeding types:
Predator
Shredder
Omnivore
Adults:
resemble nymphs, but possess a long pair of wings folded down the length of the body.
Eaten by a variety of fish species

16. Stonefly adult (Little Yellow Stone)
Little Yellow Stone (Family Perlodidae, Genus Isoperla). Nymph is a predator which is sensitive to temperature and sediment pollution.
Student Watershed Research Project (SWRP) Macroinvertebrates

17. Mayflies (Ephemeroptera) Sensitive
Nymphs:
Three tails, occasionally two
Gills usually visible on abdomen
Typical movement = crawl, swim (up-down)
Small - Total length < 1 inch
The name Ephemeroptera is derived from the Greek "ephemera" meaning short-lived, and "ptera" meaning wings.   This is a reference to the short lifespan of most adult mayflies.
Student Watershed Research Project (SWRP) Macroinvertebrates

18. Mayfly nymph (Pale Evening Dun)
Head is widest part of body
Pale Evening Dun (Family Heptageniidae, Genus Heptagenia). Dorsal-ventrally flattened; 3 well developed tails; head is widest part of body
Student Watershed Research Project (SWRP) Macroinvertebrates

19. Mayfly nymph (Small Yellow May)
Nymph with only two tails
Small Yellow May (Family Heptageniidae, Genus Epeorus). Dorsal-ventrally flattened; 2 tails; head is widest part of body
Head is widest part of body
Student Watershed Research Project (SWRP) Macroinvertebrates

20. Mayflies (Ephemeroptera) Sensitive
Feeding Types:
Collector-Gatherers
Scrapers
Adults:
Resemble nymphs with two pair of long, lacy wings folded upright
Adults usually have only two tails (cerci)
Food for fish and predatory macroinvertebrates

21. Mayfly adult

22. Mayfly adult (Hexagenia)
The genus Hexagenia (family Ephemeridae) is the exception to the rule that mayflies are usually small – some of these adults can be 2 inches long.
Student Watershed Research Project (SWRP) Macroinvertebrates

23. Caddisflies (Tricoptera) Sensitive
Larvae:
Soft “worm-like”bodies
Head contains a hard covering
Larvae are known for their construction of hollow cases that they either carry with them or attach to rocks
built from twigs or bark, small stones, or rolled leaves
used for protection and pupation
Anal hooks usually present
Large - Length up to 2 inches
The name Trichoptera, derived from the Greek words "trichos" meaning hair and "ptera" meaning wings, refers to the long, silky hairs that cover most of the body and wings.
Student Watershed Research Project (SWRP) Macroinvertebrates

24. Caddisfly larvae w/ case October caddis
Fall caddis (Family Limnephilidae, Genus Dicosmoecus)
Student Watershed Research Project (SWRP) Macroinvertebrates

25. “Free-living” Caddisfly Spotted sedge
Spotted sedge (Family Hydropsychidae, Genus Hydropsyche). All 3 thoracic segments have hardened exoskeleton; large anal hooks;
Branched gills on abdomen
Student Watershed Research Project (SWRP) Macroinvertebrates

26. Caddisflies (Tricoptera) Sensitive
Feeding Types:
Predators
Grazers
Collector-Gatherers
Adults:
“Moth-like”; usually nocturnal
Wings fold into “tent” on back
Eaten by fish and by some macroinvert predators
Collector-Filterers
Scrapers
Shredders

27. Caddisfly adult (October caddis)
Fall caddis (Family Limnephilidae, Genus Dicosmoecus)
Student Watershed Research Project (SWRP) Macroinvertebrates

28. Water Pennies (Coleoptera) Sensitive
Circular-shaped
Attach firmly to rocks
Sensitive – need high oxygen and fast flowing water
The name Coleoptera, derived from the Greek words "koleos" meaning sheath and "ptera" meaning wings, refers to the modified front wings which serve as protective covers for the membranous hind wings.
Student Watershed Research Project (SWRP) Macroinvertebrates

29. Megaloptera Sensitive
Dobsonfly/ hellgrammites (Corydalidae)
Large mandibles
2 short “tails”
Predator
Alderfly (Sialidae)
Long, single “tail”
                                                                                        
Megaloptera have a large wing span (mega = large ptera = wing) - up to 16 cm. Corydalidae are sometimes called hellgrammites or toe biters.
Student Watershed Research Project (SWRP) Macroinvertebrates

30. Odonata Wide range Damselfly Dragonfly 3 fan-shaped caudal gills
Robust body
Well-developed “jaws”
The name Odonata, derived from the Greek "odonto-" meaning tooth, refers to the strong teeth found on the mandibles of most adults.
Student Watershed Research Project (SWRP) Macroinvertebrates

31. Cranefly (Diptera) Wide Range
Worm-like
Head capsule, usually retracted into “accordion-like” body
Shredders
The name Diptera, derived from the Greek words "di" meaning two and "ptera" meaning wings, refers to the fact that true flies have only a single pair of wings.
Student Watershed Research Project (SWRP) Macroinvertebrates

32. Midge Larvae (Diptera) Tolerant
Pear-shaped body, with swollen base where they attach
Filter feeders
                                                                                              

33. Snails (Gastropoda) Tolerant
Cylindrical shell
May be right or left handed
Gastro = stomach, poda = foot
Student Watershed Research Project (SWRP) Macroinvertebrates

34. Others Tolerant Worms (Oligochaeta) Leeches (Hirundinea)
Segmented bodies
Leeches (Hirundinea)
Suckers at both ends
Oligo = little or few, chaeta = hairs
Student Watershed Research Project (SWRP) Macroinvertebrates

35. Identification Are these the same organism? Soft or covered body?
Head or head capsule?
Legs or prolegs?
Do we consider color?
Student Watershed Research Project (SWRP) Macroinvertebrates

36. Green Rock Worm (Tricoptera)
No case
Predator
Found in riffles
Only first thoracic segment has hard shell
Pair of anal hooks

37. Data Analysis Data collection is key
Level of ID determines level of analysis
Score (5) vs. interpretation (“POOR”)
Use the same data analysis tool for comparing data
Local-scale tool most accurate
Requires time
High quality “reference” sites
Collecting and reporting the data is most important. The data can be interpreted many ways, but as long as all crucial data is reported (organisms, taxa, number in sample), a different data analysis tool can be applied to the same data in the future.
Student Watershed Research Project (SWRP) Macroinvertebrates

38. Pollution Tolerance Index
National-level tool
ID to Order
3 groups
Pollution Sensitive (3 pts)
Wide Range (2 pts)
Pollution Tolerant (1 pt)
Data limited since # organisms not considered

39. Biometrics
“Biometric” - a measure of some characteristic of the biological community
Taxa Richness and Composition
EPT
Tolerance and Intolerance
HBI
Feeding Ecology
% or abundance of functional feeding groups
Population Attributes
dominance
“Biometrics” are usually only applied at the family or genus/species level.
Student Watershed Research Project (SWRP) Macroinvertebrates

40. Family-level metrics Taxa Richness (# diff taxa identified)
Mayfly Taxa
Stonefly Taxa
Caddisfly Taxa
% Diptera
HBI
Examples from Guide to Pacific Northwest Aquatic Invertebrates by Rick Hafele and Steve Hinton (available through Oregon Trout)
Student Watershed Research Project (SWRP) Macroinvertebrates

41. Multi-metric indices Include several (usually 5-10) metrics
Combined, they measure various aspects of stream health
Examples:
Index of Biological Integrity (IBI)
State of Oregon Multi-metric Index
Student Watershed Research Project (SWRP) Macroinvertebrates