Stream Ecologyand

Macroinvertebrate Biology

Background Information for Developing your Research Project

Ecology• Definition: The study of interactions between

individuals and individuals and their environment

• Simplified Food Chains:– Plants Herbivores Predators

– Dead organic matter Detritivores Predators

• Much green material in temporal areas is not eaten by herbivores, but is delivered to the detrital pool

• Detritus Dead, decaying, particulate organic matter

Sun

Leaves AlgaeMicrobes

(fungi, bacteria)

Smaller leaf particles

Shredders

(crane flies, some caddisflies and stoneflies, sowbugs, and scuds)

Collectors/ Gatherers

(black flies, net-spinning caddisflies, mayflies, midges)

Predators

(Dobson flies, dragonflies/ ”hellgrammites”)

Grazers/ Scrapers

(caddisflies, water pennies,

midges, and mayflies)

Source: A. Berkowitz, posted by T. Meyers

http://www.stroudcenter.org/lpn/LPNmanual/2_BackgroundInformation.pdf

Functional Feeding Groups of Macroinvertebrates

• Shredders– Consume coarse organic matter, such as leaves (Sowbugs)

• Collectors– Consume fine pieces of organic matter, such as leaf fragments

or other material on stream bottom– Filtering Collectors (Clams)– Gathering Collectors (Caddisfly larvae)

• Scrapers– Feed on attached periphyton located on submerged

underwater surfaces (Example: Snails)• Predators

– Feed on other invertebrates (Example: Dragonflies)

Food processing…of this detritus is a major ecosystem function

• Soil formation• Supports predators

– (some predators consumed by humans)• Processed in streams

– If it accumulated, would create anoxic conditions• Influence of processing rates:

– Quality of detritus (P, N, polyphenols, lignins, etc)– Fungi and bacteria colonization– Invertebrate feeding

Ecological Interactions

• Microbes and invertebrates process and get energy from detritus – Microbes often overlooked on many levels

• Different species process materials at different rates– If a species is lost, the entire ecosystem function

will change– Species are being lost at an alarming rate

Adaptations

Variations of anatomy/structure allow for tolerance, feeding capacities, and competition

Trichoptera (Caddisflies) Amphipoda (Scuds) ((Scuds) (Scuds)

Importance

• Impacts on Humans– Aug. 17, 1988, an 85 foot section of Rt. 675 Bridge collapsed over the

Pokomoke (Eastern Shore)– Reduction in cross section area of piles 18-35%

• Due to: Bacteria and fungal decay, Caddisfly decay, water currents– In 1977, MDE estimated Caddisflies occupied 30-100% of the underwater pile

surfaces– From 1976-1986, Caddisflies per 1.5 sq feet in the area averaged 543.5

• (High 1977=1837; Low 1986=50)

– Since 1977, 3 underwater inspections, pile measurements were inconsistent– If use “Chemically Treated Wood,” less fungal and bacterial growth, therefore,

less caddisflies

Trichoptera Biology

• Taxonomy:– Phylum Arthropoda– Class Insecta– Order Trichoptera– Family Lepidostomatidae– Genus Lepidostoma

• Larvae feed on detritus (shredders)• Protective cases• You will identify these to Order at the stream, and to Family in the lab

Amphipoda Biology• Scuds; Detritivores (Shredders)• Taxonomy:

– Phyllum Arthopoda– Class Malacostraca– Superorder Peracarida– Order Amphipoda– Family Gammaridae

Trichoperta Life Cycles

CompleteMetamorphosis

Amphipoda Life Cycle

Incomplete Metamorphosis

Tolerance/Sensitivity of Macroinvertebrates

• Macroinvertebrates can also be categorized by their level of tolerance or sensitivity to stream conditions– Dissolved oxygen– Nutrients– Pollutants– Chemical quality

• Some species can live in “lower” quality water, and are said to be:– More tolerant– Less sensitive

Shredders Roles• Ecological/Trophic

– Leaf litter breakdown• CPOMFPOM

– Course Particulate Organic Matter– Fine Particulate Organic Matter

• Human Impact• Predators (Trout, etc)• Bio-indicator– 0 - 3.75 = No Impairment Evident– 3.75 - 6.50 = Moderate Impairment– >6.5 = Severe Impairment

Selected Major Taxa Order/Family TV Density T x D

Mayflies Ephemeroptera 2 16 32Stoneflies Plecoptera 1 14 14

Caddisflies Tricoptera 3 142 426

Midges - WhiteChironomidae,

Diptera 6 2 12

Midges - RedChironomidae,

Diptera 8 0 0Beetles Coleoptera 4 6 24

Aquatic Worms Oligochaeta 8 2 16

Crane Flies Tipulidae, Diptera 3 3 9

Black Flies Simuliidae, Diptera 6 5 30

Snipeflies Anthericidae, Diptera 2 3 6

Other Flies Diptera 6 0 0Dragon/

Damselflies Odonnata 5 0 0

Hellgramites Megaloptera 0 0 0Alderflies Megaloptera 4 0 0

Scuds Amphipoda 8 8 64Sowbugs Isopoda 8 2 16Crayfish Decapoda 6 0 0

Snails/Limpets Gastropoda 7 1 7

Clams/Mussels Pelecypoda 7 11 77Leeches Hirudinea 10 0 0

Density Total 215 T x D Total 733

Biotic Index (T x D) ÷

Density 3.41

Source: A. Berkowitz, posted by T. Meyers

E=Ephemeroptera (Mayflies)P=Plecoptera (Stoneflies)T=Trichoptera (Caddisflies)

Stream Water Chemistry

• pH• Temperature• Nitrates• Phosphates• Chloride• Dissolved Oxygen

What Is a Watershed?

A watershed is the area of land that drains to a particular point along a stream

Center for Watershed Protection

What is a Watershed?

Definition: the area of land that drains to a particular point along a stream

Each stream has its own watershed

Topography is the key element affecting this area of land

The boundary of a watershed is defined by the highest elevations surrounding the stream

OK, now I know that I live in a watershed …what types of things

can affect the health of my watershed?

Center for Watershed Protection

High levels of paved surfaces, High levels of paved surfaces, or impervious cover, and land or impervious cover, and land use changes can have many use changes can have many

impacts on a watershed.impacts on a watershed.

Harmful Pollutants in Runoff

• Bacteria• Nutrients• Pesticides• Oil and Grease• Turbid (muddy) water• Heavy Metals (zinc, lead, copper)

ImperviousSurfaces

Riparian Zone

• Definition: The interface between land and a stream

• Riparian vegetation is often planted as part of stream restoration efforts because it can:– Remove nutrients from runoff (from fertilizers, etc)– Biofilter pollutants– Trap sediment (less turbid water, improve stream banks)– Improve wildlife habitat– Shade water, mitigating water temperature changes– Reduce soil erosion, reduce flood damage

What is the best way to evaluate stream health?

• Water chemistry is more transient than biotic index of macroinvertebrates due to:– Point-source pollution– Rain events– Seasonal road salting– Inconsistent littering/dumping

Physical Regions of a StreamRiffle: Rapidly moving water,

turbulentPool: Deep, slowly moving water

Run: Smooth flowing water, medium water speed

How do you think these different habitat types will effect water chemistry and

macroinvertebrate populations?

Your Research Project

Objective is to utilize a learned understanding of stream ecology and macroinvertebrate biology to investigate the effects of habitat preference, possibly due to available nutrients and dissolved oxygen, on macroinvertebrate species diversity and abundance in Hereford High School’s stream

How can we do this??

Leaf Packs

Natural Artificial