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Macroinvertebrates and Bioassessment: Using Biological Indicators to Measure Stream Health
Caitlin Chaffee URI Cooperative Extension
Macroinvertebrates and Bioassessment: Using Biological Indicators to Measure Stream Health
Caitlin Chaffee URI Cooperative Extension
Presentation OutlinePresentation Outline
Measuring Human ImpactsBiological MonitoringMacroinvertebrates as IndicatorsBenthic Index of Biotic IntegrityMacroinvertebrate Sampling MethodsCommon Macroinvertebrates
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Measuring Human ImpactsChanges in land use affect watershed resources:
•Changes in hydrology•Changes in water quality •Changes in stream morphology•Changes in stream ecology
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Measuring Human Impacts
Increased development
= Increased Impervious Surface
40% evapotranspiration 38% evapotranspiration
10% runoff
20% runoff
25% shallow infiltration
21% shallow infiltration
25% deep infiltration
21% deep infiltration
Natural Ground Cover 10 – 20% Impervious Surface
Effects of Development on site Hydrology
*Percentages are estimates*Percentages are estimates
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35% evapotranspiration 30% evapotranspiration
30% runoff
55% runoff
20% shallow
infiltration10%
shallow infiltration15% deep
infiltration5% deep infiltration
35–50% Impervious Surface 75—100% Impervious Surface
Effects of Development on site Hydrology
*Percentages are estimates*Percentages are estimates
WHAT DOES THIS WHAT DOES THIS MEAN???MEAN???
More runoff in a shorter More runoff in a shorter amount of timeamount of time
DEVELOPED
Higher overall and peak volumeShorter time to peak flow
UNDEVELOPED
Smaller volume, lower peakLonger time to peak flow
Hydrologic Response: Developed vs. Undeveloped Conditions
Runoff Volume
(Q)
Time
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The Results
• Flooding• Stream bank erosion• Stream channel widening and deepening• Lower base flows • Sedimentation• More pollutant inputs
Flooding Flooding
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Stream Bank Erosion Stream Bank Erosion
Channel Widening Channel Widening and Deepening and Deepening
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Increased Pollutant Increased Pollutant InputsInputs
Changes to Water Quality• Temperature• pH• Dissolved Oxygen• BOD • Nutrients (nitrogen and phosphorus)• Turbidity• Pathogens• Heavy metals• Petroleum based compounds
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biological indicator: groups or types of biological resources that can be used to assess environmental condition.
biological monitoring: the study of organisms and their responses to environmental condition
biological assessment: an evaluation of the biological condition of a water body using biological monitoring data and other direct measurements of resident biota in surface waters
Measuring Human Impacts
Biological IntegrityBiological Integrity
“the ability to support and maintain a balanced, integrated, and adaptive community of organisms having a species composition, diversity and functional organization comparable to those of natural habitats within a region" †
†(Karr,1981)
“the ability to support and maintain a balanced, integrated, and adaptive community of organisms having a species composition, diversity and functional organization comparable to those of natural habitats within a region" †
†(Karr,1981)
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Wood River
Great candidates for biological monitoringGreat candidates for biological monitoring……
Benthic MacroinvertebratesBenthic Macroinvertebrates
Heptageniidae sp.(Mayfly larva)
Hydropsyche sp.(Caddisfly larva)
Perlodidae sp.(Stonefly larva)
(bottom(bottom--dwelling)dwelling) (animals w/o backbones visible to naked eye)(animals w/o backbones visible to naked eye)
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Macroinvertebrates as Indicators
• Limited migration patterns–good indicators of localized conditions and site-specific impacts
• Integrate effects of human impacts
• Easy to sample and identify
• Broad range of habitat requirements and sensitivities to pollution
Human Impacts on Macroinvertebrate Communities
• Changes to water chemistry / water quality parameters
• Changes to habitat type
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Characterizing Macroinvertebrates
• Feeding habits (“functional feeding groups”)
• Tolerance to Pollution
Some build cases (caddisflies)
FPOM, phytoplankton, floating particles
Black flies, net-spinning caddisflies, mayflies
Filtering Filtering CollectorsCollectors
Filtering hairs, hemoglobin
FPOM, settled particles, bacteria
Mayflies, worms, midges, crayfish
Gathering Gathering CollectorsCollectors
Scraping mandiblesPeriphyton, diatoms
Mayflies, caddisflies, true flies, beetles
Grazers / Grazers / ScrapersScrapers
Streamlined, flatCPOM, leaves, woody debris
Stoneflies, beetles, caddisflies
ShreddersShredders
Toothy jaws, larger in size
Other insectsDragonflies, damselflies, stoneflies
PredatorsPredators
CharacteristicsCharacteristicsDietDietExamplesExamplesFFGFFG
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Functional Feeding Groups: The River
Continuum(Vannote et al., 1980)
CPOM
FPOM
FPOM
STREAM
ORDER
Relative Channel Width
HEADWATERS:
•Shredders abundant
•Coarse POM
MID-REACHES:
•Grazers abundant
•Higher 1° production
LARGE RIVERS:
•Collectors abundant
•Fine-Ultra fine POM
The Tolerance Index0 - 10
most pollution sensitivee.g. Stoneflies
0 10
most pollution tolerante.g. Midges & Leeches
require high DO, clear water, rocky cobble substrate
contain hemoglobin, tolerate lower DO, prefer soft substrate, less sensitive to toxins
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Stonefly Water Penny Beetle Mayfly Dobsonfly
Alderfly Mussel Snipe Fly Riffle Beetle
Macroinvertebrates as Indicators
Pollution Sensitive (“Clean Water”) Benthos
Macroinvertebrates as Indicators
Blackfly Caddisfly Isopod Cranefly
Damselfly Dragonfly Crayfish Amphipod
Somewhat Pollution Tolerant Benthos
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Macroinvertebrates as Indicators
Pouch Snail Midgefly Worm Leech
Pollution Tolerant (“Polluted Water”) Benthos
Benthic Index of Biotic Integrity(B-IBI)
• Index based on macroinvertebrate samples that integrates several metrics to produce an overall“health score” for a given water body
Result: dose-response curves to human impact
Human Impact
IBI S
core
e.g. Taxa richness, relative abundance of certain taxa, feeding groups
e.g. Taxa richness, relative abundance of certain taxa, feeding groups
e.g. Pollution, habitat degradation, flow alteration
e.g. Pollution, habitat degradation, flow alteration
Generalized Plot of B-IBI Scores vs. Human Impact
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EPA’s Suggestions for IBI Use†
• Nonpoint Source Pollution Assessment• Watershed Protection• TMDL Process• NPDES Permitting• Ecological Risk Assessment• Development of Water Quality Criteria and
Standards
These are suggestions…Can IBICan IBI’’s be s be successfully implemented in these programs?successfully implemented in these programs?
† Barbour et al., 1999
Macroinvertebrate Sampling: The Basics
• Identify the goal – How will the data be used?– Regulatory purposes– Detect trends– Screening purposes– Educational programs
• The goal should guide your sample design and dictate your methods
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Macroinvertebrate Sampling: The Basics• Site selection (including reference site)• Site assessment• Organism collection and preservation
– Standardize habitat type– Standardize sampling method– Dip net or sampler
• Identification– Sample size– Fixed-count subsamples vs.
“whole samples”• Calculation
– Select metrics– Calculate IBI score– Compare to reference score
Example Method: Rapid Bioassessment Protocol
• Sampled three 1m2 sections of stream reach (riffle habitat) with dip net
• Subsample size: 100 organisms• Preserved and identified organisms in
each subsample• Calculated RBP scores for each
subsample
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RBP Metrics
Taxa RichnessEPTtaxa30xpEPT30xFBI30xpDom30xScrapFilt30xpShred30xCLI30xRBP Score
# # TaxaTaxa
# Ephemera, # Ephemera, PlecopteraPlecoptera and and TrichopteraTrichoptera taxataxa
% Ephemera, % Ephemera, PlecopteraPlecoptera and and TrichopteraTrichoptera taxataxaFamily Biotic Index Family Biotic Index –– based on tolerance based on tolerance valuesvalues
% Dominant % Dominant taxontaxon (diversity measure)(diversity measure)
Ratio of scrapers to filterersRatio of scrapers to filterers
% Shredders% Shredders
Community Loss Index Community Loss Index –– comparison to comparison to reference sitereference siteMaximum Score = 48Maximum Score = 48
Score is then expressed as a percentage of Score is then expressed as a percentage of reference site score.reference site score.
Common MacroinvertebratesMayflies (Ephemeroptera)
Baetidae
Ephemerellidae Heptageniidae Isonychiidae
(Adult)
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Common MacroinvertebratesStoneflies (Plecoptera)
Perlidae Peltoperlidae
Perlodidae(Adult)
Common Macroinvertebrates
Brachycentridae Phryganeidae Hydropsychidae
Philopotamidae
Caddisflies (Trichoptera)
Case (Adult)
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Common Macroinvertebrates
Damselflies and Dragonflies (Odonata)
True Bugs (Hemiptera)
Dobsonflies, Alderflies and Fishflies (Megaloptera)
Beetles (Coleoptera)
Field Day: Streamside Biosurvey
• Simple method for macroinvertebratecollection and analysis
• Includes macroinvertebrate collection and habitat characterization procedures
• Practice identifying macroinvertebrateswith keys