UZAIR NIAZ
IHSAN ULLAH
Pollution
Pollution
Indicators
Pollution indicator species
Question answers
The change in the environment caused
by natural or artificial input of harmful
contaminants into the environment, that cause
instability, disruption or harmful effects to the
ecosystem.
A pollution indicator is anything
that show us if pollution has
happened .
Pollution indicators are plants and animals
that, by their presence, abundance, or
chemical composition, demonstrate some
distinctive aspect of the character or quality
of the environment.
Indicator species
Living organisms can be used as
indicators of pollution:
Lichens can be used as air pollution
indicators.
Invertebrate animals can be used as water
pollution indicators.
Lichens
Unlike trees, grasses and flowers, lichens
are not a single plant
They are actually composed of two
organisms living together in a symbiotic
relationship…
A blue-green algae which photosynthesises
to make food, and a fungus which creates a
“body” in which both partners live
Lichens (cont….)
Lichens are very sensitive to sulphur dioxide
(SO2) pollution in the air – from industry and
burning fossil fuels, especially coal
Different species lichens give clues about air
pollution.
Lichens grow slowly, they indicate long-term
purity of the air.
Types
There are about 30,000 species of lichen worldwide,
covering 8% of the land surface. There are 3 main
types…
Crusty
Leafy
Shrubby/bushy
low
Shrubby lichen
high
Leafy lichen
Crusty lichen
Lichens (cont….)
Clean air - shrubby, hairy
and leafy lichens become
abundant.
Some pollution - more
tolerant crusty lichens are
present
In extreme cases of high
pollution- no lichens at all
Animals as pollution indicators
Invertebrate animals are good indicators
of water pollution. Some can live in very
polluted water others can only live in
clean water.
We can determine if the water is polluted by
collecting a sample of suspected water and
analysis the type of animals that are in the
sample.
Clean water
Stone fly nymph
Freshwater shrimp
Sludge worm
Very polluted
water
Mayfly nymph
Pond skater
Rat-tailed maggot
Fish as a good pollution indication
Fish need oxygen to live in the water. Water pollution
effects the oxygen level in the water. If the water is
so polluted the oxygen levels will fall and fish will die.
This is how fish are a good indicator or pollution.