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 Impacts Biological Monitoring Macroinvertebrates as

Indicators Benthic Index of Biotic Integrity Macroinvertebrate Sampling

Methods Common Macroinvertebrates

Measuring Human ImpactsChanges in land use affect watershed

resources:•Changes in hydrology•Changes in water quality •Changes in stream morphology•Changes in stream ecology

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

35% evapotranspiration 30% evapotranspiration

30% runoff

55% runoff

20% shallow

infiltration10%

shallow infiltration

15% deep infiltration

5% 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

The Results

• Flooding• Stream bank erosion• Stream channel widening and

deepening• Lower base flows • Sedimentation• More pollutant inputs

Flooding Flooding

Stream Bank Erosion Stream Bank Erosion

Channel Widening Channel Widening and Deepening and Deepening

Lower Base FlowsLower Base Flows

SedimentationSedimentation

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

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)

Wood River

Great candidates for biological Great candidates for biological monitoring…monitoring…

Benthic Benthic MacroinvertebratesMacroinvertebrates

Heptageniidae sp. (Mayfly larva)

Hydropsyche sp. (Caddisfly larva)

Perlodidae sp. (Stonefly larva)

(bottom-dwelling)(bottom-dwelling) (animals w/o backbones visible to naked (animals w/o backbones visible to naked eye)eye)

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

Characterizing Macroinvertebrates

• Feeding habits (“functional feeding

groups”)

• Tolerance to Pollution

FFGFFG ExampleExampless

DietDiet CharacteristiCharacteristicscs

PredatorPredatorss

Dragonflies, damselflies, stoneflies

Other insects Toothy jaws, larger in size

ShredderShredderss

Stoneflies, beetles, caddisflies

CPOM, leaves, woody debris

Streamlined, flat

Grazers / Grazers / ScrapersScrapers

Mayflies, caddisflies, true flies, beetles

Periphyton, diatoms

Scraping mandibles

GatherinGathering g CollectorCollectorss

Mayflies, worms, midges, crayfish

FPOM, settled particles, bacteria

Filtering hairs, hemoglobin

Filtering Filtering CollectorCollectorss

Black flies, net-spinning caddisflies, mayflies

FPOM, phytoplankton, floating particles

Some build cases (caddisflies)

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 sensitive

e.g. Stoneflies

0 10

most pollution tolerant

e.g. Midges & Leeches

require high DO, clear water, rocky cobble substrate

contain hemoglobin, tolerate lower DO, prefer soft substrate, less sensitive to toxins

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

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

Sco

re

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

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 IBI’s be Can IBI’s be successfully implemented in these successfully implemented in these programs?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

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

RBP Metrics

Taxa RichnessEPTtaxa30xpEPT30xFBI30xpDom30xScrapFilt30xpShred30xCLI30xRBP Score

# Taxa# Taxa

# Ephemera, Plecoptera and Trichoptera taxa# Ephemera, Plecoptera and Trichoptera taxa

% Ephemera, Plecoptera and Trichoptera taxa% Ephemera, Plecoptera and Trichoptera taxa

Family Biotic Index – based on tolerance Family Biotic Index – based on tolerance valuesvalues

% Dominant taxon (diversity measure)% Dominant taxon (diversity measure)

Ratio of scrapers to filterersRatio of scrapers to filterers

% Shredders% Shredders

Community Loss Index – comparison to Community Loss Index – comparison to reference sitereference site

Maximum 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 Macroinvertebrates

Mayflies (Ephemeroptera)

Baetidae

Ephemerellidae Heptageniidae Isonychiidae

(Adult)

Common MacroinvertebratesStoneflies (Plecoptera)

Perlidae Peltoperlidae

Perlodidae(Adult)

Common Macroinvertebrates

Brachycentridae

Phryganeidae Hydropsychidae

Philopotamidae

Caddisflies (Trichoptera)

Case (Adult)

Common Macroinvertebrates

Damselflies and Dragonflies (Odonata)

True Bugs (Hemiptera)

Dobsonflies, Alderflies and Fishflies

(Megaloptera)

Beetles (Coleoptera)

Field Day: Streamside Biosurvey

• Simple method for macroinvertebrate collection and analysis

• Includes macroinvertebrate collection and habitat characterization procedures

• Practice identifying macroinvertebrates with keys

AcknowledgementsAcknowledgements

USDA CSREES New England USDA CSREES New England Water Quality ProgramWater Quality Program

Dr. Art GoldDr. Art Gold Dr. Patrick LoganDr. Patrick Logan Maria AlibertiMaria Aliberti Sara daSilvaSara daSilva

THANKS!

BENTHOS ARE COOL