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

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

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

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

IDENTIFICATION

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)

Body shape

Case

Legs and prolegs Caddis removed from case Prolegs on midge

Gills Mayfly (Speckle-Winged Quill, Callibaetis)

Cerci (tails) Baetis has center tail that is ½ length of outer tails

Head capsule

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

Stonefly nymph (Golden stone)

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

Stonefly adult (Little Yellow Stone)

Mayflies (Ephemeroptera) Sensitive Nymphs: Three tails, occasionally two Gills usually visible on abdomen Typical movement = crawl, swim (up- down) Small - Total length < 1 inch

Mayfly nymph (Pale Evening Dun) Head is widest part of body

Mayfly nymph (Small Yellow May) Nymph with only two tails Head is widest part of body

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

Mayfly adult

Mayfly adult (Hexagenia)

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

Caddisfly larvae w/ case October caddis

“Free-living” Caddisfly Spotted sedge Branched gills on abdomen

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

Caddisfly adult (October caddis)

Water Pennies (Coleoptera) Sensitive Circular-shaped Attach firmly to rocks Sensitive – need high oxygen and fast flowing water

Megaloptera Sensitive Dobsonfly/ hellgrammites (Corydalidae) Large mandibles 2 short “tails” Predator Alderfly (Sialidae) Long, single “tail” Predator

Odonata Wide range Damselfly 3 fan-shaped caudal gills Dragonfly Robust body Well-developed “jaws”

Crayfish (Decapoda) Wide Range 4 pairs of walking legs Large pair of pinchers Up to 6 inches

Scuds (Amphipoda) Wide Range “Shrimp-like” 14 feet Prefer muddy substrate with rooted vegetation

Cranefly (Diptera) Wide Range Worm-like Head capsule, usually retracted into “accordion- like” body Shredders

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

Snails (Gastropoda) Tolerant Cylindrical shell May be right or left handed

Others Tolerant Worms (Oligochaeta) Segmented bodies Leeches (Hirundinea) Suckers at both ends

Identification

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

Riffle Beetle (Coleoptera) Hard shelled, tube- shaped larvae Found in riffles No tails or anal hooks Gills concealed in chamber at rear of abdomen

Midge Larvae (Diptera) Head capsule No jointed legs Variety of colors Prolegs on 1 st thoracic and last abdominal segments Prolegs

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

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

Example PTI calculation Organism#PTI Midge (Diptera)111 Scud (Amphipoda)572 Periwinkle (Tricoptera)33 Snails (Gastropoda)141 Waterboatman51 PTI = (1x3)+(1x2)+(3x1) = 8 (POOR)

Hilsenhof Biotic Index (HBI) Considers organic pollution ID to Family or lower 10-point scale where: 0 = most sensitive 10 = most tolerant # organisms is considered Sometimes included as 1 metric in a multi-metric analysis, such as IBI

Hilsenhof Biotic Index (HBI) HBI =  (Taxa count) (HBI score) (Total count) Rating: Clean Slightly Enriched EnrichedPolluted

Example HBI calculation Organism#HBI Midge (Diptera)118 Scud (Amphipoda)574 Periwinkle (Tricoptera)34 Snails (Gastropoda)147 Waterboatman58 HBI = (11x8)+(57x4)+(3x4)+(14x7)+(5x8) 90 HBI = 5.18 (POOR/Enriched)

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

Family-level metrics Taxa Richness (# diff taxa identified) Mayfly Taxa Stonefly Taxa Caddisfly Taxa % Diptera HBI

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