Transcript Effectiveness of Macroinvertebrate IBI’s as Watershed

Macroinvertebrates and
Bioassessment: Using
Biological Indicators to
Measure Stream Health
Caitlin Chaffee
URI Cooperative Extension
Presentation Outline
Measuring Human Impacts
Biological Monitoring
Macroinvertebrates as Indicators
Benthic Index of Biotic Integrity
Macroinvertebrate Sampling
Methods
 Common Macroinvertebrates
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Measuring Human Impacts
Changes 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
Effects of Development on site
Hydrology
40% evapotranspiration
38% evapotranspiration
10%
runoff
25%
shallow
infiltration
Natural Ground Cover
*Percentages are estimates
20%
runoff
21% shallow
infiltration
25% deep
infiltration
21% deep
infiltration
10 – 20% Impervious Surface
Effects of Development on site
Hydrology
35% evapotranspiration
30% evapotranspiration
55%
runoff
30%
runoff
20%
shallow
infiltration
15% deep
infiltration
35–50% Impervious Surface
*Percentages are estimates
10%
shallow
infiltration
5% deep
infiltration
75—100% Impervious Surface
Hydrologic Response: Developed vs.
Undeveloped Conditions
DEVELOPED
Runoff
Volume
Higher overall and peak volume
WHAT DOES
THIS
Shorter time to peak flow
MEAN???UNDEVELOPED
Smaller volume, lower peak
Longer time to peak flow
(Q)
More runoff in a shorter
amount of time
Time
The Results
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Flooding
Stream bank erosion
Stream channel widening and deepening
Lower base flows
Sedimentation
More pollutant inputs
Flooding
Stream Bank Erosion
Channel Widening
and Deepening
Lower Base Flows
Sedimentation
Increased Pollutant
Inputs
Changes to Water Quality
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Temperature
pH
Dissolved Oxygen
BOD
Nutrients (nitrogen and phosphorus)
Turbidity
Pathogens
Heavy metals
Petroleum based compounds
Measuring Human Impacts
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
Biological 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)
Wood River
Benthic Macroinvertebrates
(bottom-dwelling) (animals w/o backbones visible to naked eye)
Heptageniidae sp.
(Mayfly larva)
Hydropsyche sp.
(Caddisfly larva)
Perlodidae sp.
(Stonefly larva)
Great candidates for biological monitoring…
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
FFG
Examples
Diet
Characteristics
Predators
Dragonflies,
damselflies,
stoneflies
Other insects
Toothy jaws, larger in
size
Shredders
Stoneflies,
beetles,
caddisflies
CPOM, leaves,
woody debris
Streamlined, flat
Grazers /
Scrapers
Mayflies,
Periphyton,
caddisflies, true diatoms
flies, beetles
Scraping mandibles
Gathering
Collectors
Mayflies,
FPOM, settled
worms, midges, particles,
crayfish
bacteria
Filtering hairs,
hemoglobin
Filtering
Collectors
Black flies, netspinning
caddisflies,
mayflies
FPOM,
Some build cases
phytoplankton,
(caddisflies)
floating particles
Functional Feeding
Groups: The River
Continuum
(Vannote et al., 1980)
HEADWATERS:
•Shredders abundant
•Coarse POM
MID-REACHES:
•Grazers abundant
•Higher 1° production
CPOM
S
T
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E
A
M
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D
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FPOM
FPOM
LARGE RIVERS:
•Collectors abundant
•Fine-Ultra fine POM
Relative Channel Width
The Tolerance Index
0 - 10
0
most pollution sensitive
e.g. Stoneflies
require high DO, clear
water, rocky cobble
substrate
10
most pollution tolerant
e.g. Midges & Leeches
contain hemoglobin, tolerate
lower DO, prefer soft
substrate, less sensitive to
toxins
Macroinvertebrates as Indicators
Pollution Sensitive (“Clean Water”) Benthos
Stonefly
Alderfly
Water Penny Beetle
Mussel
Mayfly
Snipe Fly
Dobsonfly
Riffle Beetle
Macroinvertebrates as Indicators
Somewhat Pollution Tolerant Benthos
Damselfly
Blackfly
Dragonfly
Caddisfly
Crayfish
Isopod
Amphipod
Cranefly
Macroinvertebrates as Indicators
Pollution Tolerant (“Polluted Water”) Benthos
Pouch Snail
Midgefly
Worm
Leech
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
Generalized Plot of B-IBI
Scores vs. Human Impact
IBI Score
e.g. Taxa richness,
relative abundance
of certain taxa,
feeding groups
Human Impact
e.g. Pollution,
habitat
degradation, flow
alteration
EPA’s Suggestions for IBI Use†
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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
successfully implemented in these programs?
† Barbour et al., 1999
Macroinvertebrate Sampling: The
Basics
• Identify the goal – How
will the data be used?
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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 Richness
EPTtaxa30x
pEPT30x
FBI30x
pDom30x
ScrapFilt30x
pShred30x
CLI30x
RBP Score
# Taxa
# Ephemera, Plecoptera and Trichoptera taxa
% Ephemera, Plecoptera and Trichoptera taxa
Family Biotic Index – based on tolerance
values
% Dominant taxon (diversity measure)
Ratio of scrapers to filterers
% Shredders
Community Loss Index – comparison to
reference site
Maximum Score = 48
Score is then expressed as a percentage of
reference site score.
Common Macroinvertebrates
Mayflies (Ephemeroptera)
Ephemerellidae
Baetidae
Heptageniidae
Isonychiidae
(Adult)
Common Macroinvertebrates
Stoneflies (Plecoptera)
Perlidae
Perlodidae
Peltoperlidae
(Adult)
Common Macroinvertebrates
Caddisflies (Trichoptera)
Brachycentridae
Philopotamidae
Phryganeidae
Case
Hydropsychidae
(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
Acknowledgements
 USDA CSREES New England
Water Quality Program
 Dr. Art Gold
 Dr. Patrick Logan
 Maria Aliberti
 Sara daSilva