stream critter drawings by christine elder
part of both AQUATIC (water) and
TERRESTRIAL (land) food webs. They
are a major food source for amphibians
(frogs and salamanders), birds, fish, and
reptiles (lizards, snakes, and turtles).
The healthy function of field, forest,
lake, stream, and wetland
ecosystems depends on
macroinvertebrates.
Some
macroinvertebrates
are quite sensitive to
pollution. They live only in
the cleanest surroundings
or water of highest quality.
Other species are not as
sensitive and can handle or
tolerate living in dirtier or
degraded environments.
Aquatic species, growing
or living in or near water,
quickly react to changes in
temperature, oxygen levels,
how clear or cloudy the water is,
and the amount of plant food (fertilizer
or nutrients like nitrogen, phosphorous,
and potassium) in the water.
BOTTOM-DWELLING "BENTHIC"
MACROINVERTEBRATES (aquatic
worms, clams, crayfish, insects, and
snails, for example) may spend all or only
the early stages of their life cycle
attached to gravel, rocks, or
plants at the BOTTOM of water
bodies. These organisms are
grouped by the ways they feed and
how they attach to surfaces. They
may FILTER food out of
the water, GRAZE on
algae growing on rocks, or
SHRED fallen leaves and
sticks in the water. Some
anchor to rocks and pebbles.
Others hang on to leaves or
twigs or cling to sandy or
muddy streambed materials.
WATER QUALITY
controls the types of life
forms or organisms you
will find in a body of water.
Combinations of Benthic
Aquatic Macroinvertebrate
Species (Bottom-Dwelling
Bug Combos) change with
changes in water quality. These
benthic aquatic animals are sorted by
their tolerance levels or ability to stay
alive in water ranging from clean to
dirty to very polluted. All you have
to do to know if stream water quality
is good or bad is see HOW MANY
KINDS of organisms are present. You do
Beetle
Larvae
Mayfly*
creeping
Water Bug
not have to get a total count of all the
macroinvertebrates you find.
Get out to your local stream or lake
and look for some organisms! You might
be surprised at what you find!
Beetle
40 • April 2021 • www.OfficialKidsMag.com
Name: Kids Mag
4 x 2"
Customer Name: BEAVER WATER DISTRICT
Ad Number: 032821NWR6201
www.bwdh2o.org
