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?
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•
•
•
•
•
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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?
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•
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Bottom of a Stream
Attached to rocks
Attached to plants
In fast moving water, need oxygen
http://www.epa.gov/owow/nps/kids/master
bugtheater.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 watersthese 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…
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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1. Living at the bottom of a stream
2. Living on land, near a stream
3. Living by floating in a stream
Macroinvertebrates tell if a stream
is healthy or not.
1. True
2. False
3. Unsure
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A sample of a Macroinvertebrate
is…
1.
2.
3.
4.
Small bird
Mayfly larva
Butterfly larva
Turtle
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Macroinvertebrates that tell if water
is clean need only a little bit of
oxygen
1. True
2. False
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Macroinvertebrates that survive in
low oxygen water tell scientists
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1. The water is polluted
2. The water is clean
3. That it is water
Large amounts of caddisfly larva,
mayfly larva, and stone fly larva are
found in…
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
1. Polluted water
2. Moderately clean
water
3. Healthy, good
quality water
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0%
2
0%
3
Stoneflies are not present at all,
more leeches, and fly larvae are
found in this stream
1. Polluted
water
2. Moderately
clean water
3. Healthy,
good quality
water
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