
Roles and types of aquatic macroinvertebrates
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Habitats, feeding, life histories, and tolerance

Biological integrity and its application in southern MN

photosynthesis
substrate temperature light
Physical current pH macrophytes
Biological Chemical
DO
[nutrients] macroinvertebrates fish alkalinity

•
Macroinvertebrates are an essential component of freshwater ecosystems
• They serve as food for other organisms (fish, amphibians and waterfowl)
• Are essential to the breakdown and cycling of organic matter and nutrients
• Macroinvertebrate diversity is vital to a properly functioning ecosystem

• Macroinvertebrates are used to assess the health of freshwater environments
• Some macroinvertebrates are sensitive to stress produced by pollution, habitat modification, or severe natural events
• Sampling and identifying macroinvertebrates can reveal whether a body of water is healthy or unhealthy and may reveal the cause of the problem


Spend up to one year (or more) in the stream

Have little mobility

Generally abundant

Primary food source for many fish

Good indicators of local conditions

Diversity = healthy stream

Easy to sample
Adult Caddisfly

Stream Benthic Macroinvertebrates:
Standard Habitat Samples from Iowa Streams

Mayflies (Ephemeroptera)
Ephemerellidae Heptageniidae Isonychiidae
Baetidae (Adult)

Stoneflies (Plecoptera)
Pteronarcydiae
Perlidae
Perlodidae
(Adult)

Caddisflies
(Trichoptera)
Brachycentridae Phryganeidae Hydropsychidae
Philopotamidae Case (Adult)

Damselflies and
Dragonflies (Odonata)
True Bugs (Hemiptera)
Dobsonflies, Alderflies and
Fishflies (Megaloptera)
Beetles (Coleoptera)

True Flies (Diptera)
Midge (Chironomidae)
Blackfly (Simuliidae)
Midge adult Cranefly (Tipulidae)

Crayfish and
Amphipods(Crustacea)
Snails/Mussels (Mollusca)
Worms and
Leeches(Oligochaeta)
Planarians (Platyhelminthes)

Habitat
Movement
Feeding
Life History
Stress Tolerance
Use in Biomonitoring

The place where an organism lives
Running waters – lotic – seeps, springs, brooks, branches, creeks, streams, rivers
Standing waters – lentic – bogs, marshes, swamps, ponds, lakes erosional (riffles, wave action) or depositional areas (point bars, pools)
Mineral bedrock, boulders, cobbles, pebble, gravel, sand, silt, clay
Organic live plants, detritus

Locomotion, habits, or mode of existence
Clingers – maintain a relatively fixed position on firm substrates in current
Climbers – dwell on live aquatic plants or plant debris
Crawlers – have elongate bodies with thin legs, slowly move using legs
Sprawlers – live on the bottom consisting of fine sediments
Burrowers – dig down and reside in the soft, fine sediment
Swimmers – adapted for moving through water
Skaters – adapted to remain on the surface of water

Macroinvertebrates are described by how they eat, rather than what they eat
Functional Feeding Groups – categories of macroinvertebrates based on body structures and behavioral mechanisms that they use to acquire their food

Chew on intact or large pieces of plant material
•Material is usually >1 mm, referred to as Coarse Particulate Organic
Matter (CPOM)
Shredder-herbivores feed on living aquatic plants that grow submerged in the water (northern casemaker caddisflies)
Shredder-detritivores feed on detritus, or dead plant material in a state of decay (giant stoneflies)

Acquire and ingest very small particles (<1 mm) of detritus, often referred to as fine particulate organic matter (FPOM)
Collector-gatherers
– eat fine detritus that has fallen out of suspension that is lying on the bottom or mixed with bottom sediments
Collector-filterers
use special straining mechanisms to feed on fine detritus that is suspended in the water

mouthparts, or sometimes their entire head, protrude as modifications to puncture food and bring out the fluids contained inside
Piercer-herbivores – penetrate the tissues of vascular or aquatic plants or individual cells of filamentous algae and suck the liquid contents (crawling water beetles, microcaddisflies)
Piercer-predators – subdue and kill other animals by removing their body fluids

Adapted to remove and consume the thin layer of algae and bacteria that grows tightly attached to solid substrates in shallow waters
• Jaws of scrapers have sharp, angular edges
(function like using a putty knife or paint scraper)
(flathead mayflies, water pennies, snails)

Feed upon living animals, either by swallowing the entire body of small prey orby tearing large prey into pieces that are small enough to consume
(common stoneflies and hellgrammites)

FFG Examples Diet
Predators Dragonflies, damselflies, stoneflies
Shredders Stoneflies, beetles, caddisflies
Grazers /
Scrapers
Other insects
CPOM, leaves, woody debris
Mayflies, caddisflies, true flies, beetles
Periphyton, diatoms
Characteristics
Toothy jaws, larger in size
Streamlined, flat
Scraping mandibles
Gathering
Collectors
Filtering
Collectors
Mayflies, worms, midges, crayfish
FPOM, settled particles, bacteria
Black flies, netspinning caddisflies, mayflies
FPOM, phytoplankton, floating particles
Filtering hairs, hemoglobin
Some build cases
(caddisflies)

Autochthonous – biomass produced within the system (in stream)
- algae, periphyton, macrophytes
Allochthonous – biomass produced outside the system (riparian and upland)
- tree and shrub leaves and needles
Light is a primary determinant of whether the food base for a given community is live green plants growing within the aquatic environment or decaying plant material that originated in the terrestrial environment

Functional Feeding
Groups: The River
Continuum
(Vannote et al., 1980)
HEADWATERS:
•
Shredders abundant
• Coarse POM
MID-REACHES:
•
Grazers abundant
• Higher 1 ° production
A
M
O
R
D
S
T
R
E
E
R
LARGE RIVERS:
•
Collectors abundant
• Fine-Ultra fine POM
FPOM
CPOM
FPOM
Relative Channel Width

Reproduction, growth, and development of an organism
Hermaphroditic organisms – contain both male and female reproductive organs (flatworms, aquatic earthworms, leeches, snails)
Oviparous – females lay their eggs outside of their body
Ovoviviparous – females retain their eggs and allow them to hatch within their body and release free-living offspring
Growth is relatively simple in flatworms, aquatic earthworms and leeches because they are not restricted by any type of external protective structures
Exoskeleton of arthropods does not grow once it has been produced, so growth of the organism is restricted. As a result, arthropods must shed their skin (molt) in order to increase in size (3-45 times).
Mollusks are enclosed in non-living protective shells produced by the organism; shells are made of protein and calcium carbonate; made larger by adding material, like a tree growth ring


Metamorphosis -
 biological process involving a conspicuous and relatively abrupt change in the insect's body structure through cell growth and differentiation.

Complete metamorphosis is egg > larva (nymph) > pupa > adult
Incomplete metamorphosis

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Many (but not all) of the aquatic macroinvertebrates are in the larval or nymphal stage while in a stream, and will eventually leave the water when they are adults that can fly.

Adult insects often have very short life spans, maybe only 24 hours or a few days. These insects may not live very long once removed from their stream habitat.


Many invertebrates can pass through only a single generation each year (or less), while others are capable of 2 or more generations
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Univoltine – one brood or generation per year (most mayflies, caddisflies)
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Bivoltine - two broods or generations per year
(baetid mayflies)
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Multivoltine - more than two broods or generations per year (some mayflies like Tricorythodes)

Semivoltine - generation time is more than one year
(many stoneflies, dragonflies)

Natural volcanoes, forest fires, floods, landslides
Anthropogenic pollution, removal of water by irrigation, dams, deforestation, removal of riparian vegetation
Freshwater invertebrates vary in their ability to cope with environmental stress
Biomonitoring takes advantage of this situation by identifying whether an aquatic environment is inhabited predominantly by stress tolerant or stress intolerant organisms

Kingdom: Animalia
Phylum: Arthropoda (Arthropods)
Annelida (Segmented Worms)
Mollusca (Mollusks)

Pollution Sensitive Organisms Found In
Good Quality Water
Stoneflies
Mayflies
Water Pennies
Dobsonflies
Riffle Beetles
Mussels

Pollution Sensitive (“Clean Water”)
Benthos
Stonefly Water Penny Beetle Mayfly Dobsonfly
Alderfly Mussel Snipe Fly Riffle Beetle

Can Exist Under a Wide Range of Water
Quality Conditions
Generally of Moderate Quality Water
Caddisflies
Damselflies
Dragonflies
Blackflies
Craneflies
Water Boatman
Backswimmers
Crayfish
Amphipods

Somewhat Pollution Tolerant
Benthos
Damselfly Dragonfly Crayfish Amphipod
Blackfly Caddisfly Isopod Cranefly

Can Exist Under a Wide Range of Water
Quality Conditions, Generally are Highly
Tolerant of Poor Quality Water
Midgeflies/Chironomids
Worms
Leeches
Pouch Snails

Pollution Tolerant (“Polluted Water”) Benthos
Pouch Snail Midgefly Worm Leech

The Tolerance Index
0 - 10
0 most pollution sensitive e.g. Stoneflies
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

from Joel Chirhart
Ophiogomphus
0
Hesperophylax
2.67
Hexatoma
8.07
Lepidostoma
0.12
Perlodidae
2.68
Stenelmis
8.30
Ephemerella
0.26
Glossosoma
1.14
Baetidae
7.18
Hyalella
7.30
Caenis
8.79
Orconectes
9.41
Acroneuria
2.40
Hydropsychidae
7.55
Physa
10

EPT Tolerance Values Family (Species range)
Ephemerellidae
1 (0-2)
Taeniopterygidae
2 (2-3)
Leptophlebiidae
2 (1-6)
Isonychiidae
2 (2-2)
Baetiscidae
3
Heptageniidae
4 (0-7)
Caenidae
7 (3-7)
Capniidae
1 (1-3)
Leuctridae
0 (0-0)
Perlidae
1 (0-4)
Rhyacophilidae
0 (0-1)
Brachycentridae
1 (0-2)
Limnephilidae
4 (0-4)
Hydropsychidae
4 (0-6)

Other taxa tolerance values, Family (species)
Corydalidae
0 (4)
Gomphidae
1 (1-5)
Aeshnidae
3 (2-6)
Calopterygidae
5 (5-6)
From: Benthic Macroinvertebrates in Freshwaters-
Taxa Tolerance Values, Metric and Protocols (Mandaville 2002)
Elmidae
4 (2-6)
Psephenidae
4 (4-5)
Tipulidae
3 (2-7)
Chironomidae
Tanypodinae (4-10)
Podonominae (1-8)
Simulidae
6 (1-7)

“…the capability of supporting and maintaining a balanced, integrated, adaptive community of organisms having a composition, diversity and functional organization comparable to that of natural habitats of the region”
(Karr and Dudley 1981)


First developed biotic index for fish

Became multi-metric index

IBIs are now used world-wide for many different taxa

Must be regionally calibrated with reference sites









It is an ensemble of biological information
It objectively defines benchmark conditions
It can assess change due to human causes
It uses standardized methods
It scores sites numerically, describes in narrative form
It defines multiple condition classes
It has a strong theoretical basis
It does not require fine resolution of taxa

Heptageniidae sp.
(Mayfly larva)
Hydropsyche sp.
(Caddisfly larva)
Great candidates for biological monitoring…
Perlodidae sp.
(Stonefly larva)


Limited migration patterns – good indicators of localized conditions and site-specific impacts
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Integrate effects of human impacts**
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Easy to sample and identify
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Broad range of habitat requirements and sensitivities to pollution

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Build a comprehensive bioassessment data base
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Test and validate metrics, or indices, to ensure they are reliable indicators of human disturbance and are able to discern between changes due to natural variability and human activity

Adopt numeric biocriteria for specific waterbody types sequentially into water quality standards as
EPA publishes technical guidance for those waters


1) Does metric respond to stream impairment?

Significant difference in metric between reference and impaired sites?

2) How many metrics “work”?

3) Determine scoring for each metric (continuous or categorical, 0-10?)

4) Combine scores for each metric: total score

5) Determine impairment threshold (standard)

(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 e.g. Taxa richness, relative abundance of certain taxa, feeding groups
Generalized Plot of B-IBI
Scores vs. Human Impact
Human Impact e.g. Pollution, habitat degradation, flow alteration


Invertebrate Class 2 – Prairie Forest Rivers

Watershed > 500 mi 2 (Cannon, Root, Zumbro)

Invertebrate Class 5 – Southern Streams
(Riffle/Run Habitats)

Watershed < 500 mi 2 (Root, Zumbro)

Invertebrate Class 6 – Southern Forest
Streams (Glide/Pool Habitats)

Watershed < 500 mi 2 (Money, Root, Rush)

Invertebrate Class 9 – Southern Coldwater
Streams
 Size? (Beaver, Pine, Trout, Whitewater, S.Br/S.F. Root)

Composition (3 metrics)
Habitat (2 metrics)
Trophic (1 metric)
Tolerance (6 metrics)
Richness (8 metrics)

Class 5 – Southern Streams (Run/Riffle Habitats)
Biocriteria Threshold 35.9 (23.3 – 48.5)
Metric Category Response Description
ClimberCh Habitat
ClingerChTx
Pct
DomFiveCh
Pct
HBI_MN
Habitat
Composition
Tolerance
InsectTxPct Composition
Odonata Richness
Plecoptera Richness
PredatorCh Richness
Tolerant2Ch
TxPct
Tolerance
Trichoptera Richness
Decrease Taxa richness of climbers
Decrease Relative % of taxa adapted to cling to substrate in swift flowing water
Increase
Increase Average tolerance value of individuals in sample (Chirhart)
Decrease Relative % of insect taxa
Decrease Taxa richness of Odonata
Decrease Taxa richness of Plecoptera
Decrease Taxa richness of predators
Increase Relative % of taxa with tolerance values
= or > 6, using MN TVs
Decrease
Realtive abundance (%) of dominant 5 taxa in subsample (Chir genera separate)
Taxa richness of Trichoptera