20 th Annual Student GREEN Congress “Counting Critters” Workshop

What are Benthic Macroinvertebrates?  Benthic = bottom dwelling  Macro = large enough to see with the naked eye  Invertebrate = without a backbone (could be a clam, a worm, a crab, or an insect, for example) Often refer to them as “stream bugs”

Big Diversity of Benthic Macroinvertebrates Leech Black fly larva Midge Dragonfly Crawdad Cranefly Mosquito Caddisfly Mayfly Stonefly Gilled snail

Why Do We Monitor Stream Bugs? Chemical WQ data offers good, but limited information. Only a “snapshot” view of conditions Only a “snapshot” view of conditions Doesn’t measure “biology” Doesn’t measure “biology” Nitrates pH D.O. Fecal coliform Temperature T.S.S

Biological Assessment  Use living organisms to tell us something about the environment

Why Use “stream bugs” in Bioassessment of Streams  Abundant  Diverse  Sedentary

Plus, They Have the Same Habitat Needs as Salmon  Clean, cold, oxygenated water  Connected migration paths  Habitat features for spawning and rearing Habitat  Dependable stream flows Dependable

Stream Bugs Tell A Story  No “good” or “bad” bugs  Presence or absence can be indicators of good or poor stream health.  Diversity (not total number of bugs) = Healthier sample

How Do They Tell The Story?  B.I.B.I.  “Benthic Index of Biological Integrity”  10 “metrics” indicating stream health

10 Metrics  Taxa richness  # mayfly taxa (Ephemeroptera)  # stonefly taxa (Plecoptera)  # caddisfly taxa (Trichoptera)  # long-lived taxa  # intolerant taxa  % tolerant taxa  % predators  # clinger taxa  % dominance (3 taxa) Mayfly larva Stonefly larva Caddisfly larva Caddisfly case

Taxa Richness Leech Black fly larva Midge Dragonfly Crawdad Cranefly Mosquito Caddisfly Mayfly Stonefly Gilled snail

% Dominance (3 taxa) Ephemeroptera Plecoptera Trichoptera leech bloodworm netspinner caddisfly Intolerant species Tolerant species Plecoptera

Number of Intolerant Taxa lepidostomatidae caddisfly ephemerellidae mayfly nymph capniidae stonefly nymph Gilled snail Dobsonfly larva Riffle beetle Water penny

% Tolerant Taxa leech black fly larva bloodworm netspinner caddisfly baetidae mayflies Midge larva

Number of Clinger Taxa Water penny Stonefly nymph Mayfly nymph Caddisfly larvae –Caddisfly Alderfly Riffle beetle larva

Number of Long-Lived Taxa Dragonfly nymph Alderfly larvaGilled snail Pteronarcys stonefly Dragonfly nymph

Number of Mayfly Taxa (Ephemeroptera)

Number of Caddisfly Taxa (Trichoptera)

Number of Stonefly Taxa (Plecoptera)

% Predators taxa water beetle Dragonfly larva Great diving beetle Stonefly larva Rhycophila caddisfly

Computing the B.I.B.I.  Example: Taxa Richness 0-20 taxa = low (1) 0-20 taxa = low (1) taxa = moderate (3) taxa = moderate (3) 40+ taxa = high (5) 40+ taxa = high (5)

Computing the B.I.B.I.  Taxa richness1 3 5  # mayfly taxa (Ephemeroptera)1 3 5  # stonefly taxa (Plecoptera)1 3 5  # caddisfly taxa (Trichoptera)1 3 5  # long-lived taxa1 3 5  # intolerant taxa1 3 5  % tolerant taxa1 3 5  % predators1 3 5  # clinger taxa1 3 5  % dominance (3 taxa)1 3 5

Computing the B.I.B.I.  Taxa richness 3  # mayfly taxa (Ephemeroptera) 5  # stonefly taxa (Plecoptera) 3  # caddisfly taxa (Trichoptera) 1  # long-lived taxa 1  # intolerant taxa 3  % tolerant taxa 1  % predators 3  # clinger taxa 5  % dominance (3 taxa) 5  TOTAL: 30

Final B.I.B.I. Scores*  10 – 16 = Very Poor  = Poor  28 – 36 = Fair  38 – 44 = Good  = Excellent *10 Metric B-IBI Score used by Mindy Allen Stonefly Caddisfly

When in the Field…. Observe: land use, canopy cover…etc.