Macroinvertebrates

Little Creatures that tell us

If our natural waterways are healthy

Benthic Macroinvertebrates

• Benthic means: living at the bottom of a body of water (stream, river, pond)

• Macro- large

• Invertebrate- animal without backbone

• Macroinvertebrate- large water dwelling invertebrate able to be seen without a microscope

What are Macroinvertebrates?

• Organisms that have no backbone

• Visible without a microscope

• Found in Fresh Water Streams

• Eats leaves & algae in stream

• Source of Energy for larger animals

What are Macroinvertebrates?

• Snails

• Crayfish

• Worms

• Fly larva

• Mayfly, caddisfly, stone fly larva

• Clams

• Water beetles

Indicator Species

• Indicator Species means…

• They tell scientists when there is a problem in nature- specifically the stream environment

• The problem being pollution

Why are Macroinvertebrates Important?

• Source of Energy for larger animals

• Brook Trout or other fish eats them…

• Then fish are eaten by birds, raccoons, humans

• Helps with the Food Web

Where do Macroinvertebrates live?

• Bottom of a Stream

• Attached to rocks

• Attached to plants

• In fast moving water, need oxygen

• http://www.epa.gov/owow/nps/kids/masterbugtheater.html

Why are Macroinvertebrates Important?

• They are good indicators of the stream’s overall health

• These animals are different sizes, shapes, and have different adaptations that make it easy for scientists to learn if a stream is healthy

Why do they need clean water?

• To survive the macroinvertebrates that show that the water is clean need…– Lots of oxygen to survive– Poor oxygen, they die and provide no food for

the Trout, kingfishers, Salmon, etc.– Those macroinvertebrates that need poor

dirty water to survive- tell scientists that the water is polluted

Macroinvertebrates

What do Macroinvertebrates tell Scientists about a Stream?

• Some macroinvertebrates are only found in Healthy untouched waters- not polluted- these tell scientists that the water is pure and good

• Others are found in moderate or OK waters- these may have some pollutants- they tell the scientists that the water is starting to get worse

• Also other macroinvertebrates only survive in poor water, this tells scientists that the water quality is poor and needs help

Which Macroinvertebrates tell that there is good quality

water?• Different kinds of stoneflies, mayflies, and

caddisflies tell a scientist the stream is healthy.

• Scientists look for a variety of the above

Stonefly Larva

Which macroinvertebrates do you find in a Moderately clean Stream?

• The number of different macroinvertebrates becomes less as pollution rises

• There will be fewer stoneflies, many fewer mayflies, and only some types of caddisflies

• Soft-bodied worms and fly larva also increase• Beetles are probably still in the stream; mollusks

are not.

What macroinvertebrates are in poor quality streams?

• Stoneflies are not present at all

• A few mayflies and caddisflies- maybe there

• Most found are soft-bodied animals: fly larvae, leeches and planaria (round worm, tape worm).

• Amphipod- fast moving shrimp looking creature

Planaria- Flatworm

http://www.watersheds.org/earth/enved.htm

Macroinvertebrate means…

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1. Small creature that you need a microscope to see

2. Small creature that you can see without a microscope

3. Small creature that lives on land

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Benthic means…

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0% 1. Living at the bottom of a stream

2. Living on land, near a stream

3. Living by floating in a stream

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Macroinvertebrates tell if a stream is healthy or not.

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1. True

2. False

3. Unsure

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A sample of a Macroinvertebrate is…

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1. Small bird

2. Mayfly larva

3. Butterfly larva

4. Turtle

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Macroinvertebrates that tell if water is clean need only a little bit of

oxygen

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1. True

2. False

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Macroinvertebrates that survive in low oxygen water tell scientists

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0% 1. The water is polluted

2. The water is clean

3. That it is water

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Large amounts of caddisfly larva, mayfly larva, and stone fly larva are found in…

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1. Polluted water

2. Moderately clean water

3. Healthy, good quality water

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Smaller amounts of caddisfly, mayfly and stone fly larva, along with some worms are in this type of water

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0% 0%0%

1. Polluted water

2. Moderately clean water

3. Healthy, good quality water

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Stoneflies are not present at all, more leeches, and fly larvae are found in this stream

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0% 0%0%

1. Polluted water

2. Moderately clean water

3. Healthy, good quality water

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