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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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Lower Base FlowsLower Base Flows

SedimentationSedimentation

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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

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AcknowledgementsAcknowledgements

USDA CSREES New England USDA CSREES New England Water Quality ProgramWater Quality ProgramDr. Art GoldDr. Art GoldDr. Patrick LoganDr. Patrick LoganMaria Maria AlibertiAlibertiSara Sara daSilvadaSilva

THANKS!

BENTHOS ARE COOL