14-16yrs - indicator species - classroom presentation

8/19/2019 14-16yrs - Indicator Species - Classroom Presentation

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Indicator Species


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What is an indicator species? A species whose presence, absence or abundance

reflects a specific environmental condition, habitat or

community.

Indicator species may:

• Provide information on the overall health of an ecosystem.

• Reflect a particular environmental condition, such aspollution.

• Be indicative of a particular habitat type or biological

community.


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Why use indicator species?

• Indicator species can provide an early warning of

environmental changes.

• hey can be used to assess the health of an

environment or ecosystem ! they are often termed

"bioindicators#.

• hey can be a useful management tool.


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How might indicator species show

changes in the environment?

Increase or decrease in abundance

Presence or absence

$hange in behaviour

$hange physiologically or chemically

%ote: Indicator species may be used passively or actively


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Considerations

$are must be ta&en when using indicator species as there are somepotential pitfalls:

• 'udging an ecosystem based on the response of a single indicator

species may not be enough to properly assess it.

• %eed to be sure any correlation shown is real.

• he indicator species must be lin&ed to the environmental condition

studied in a scientifically sound manner to (ustify its use.

• he species may be difficult or time)consuming to survey.

It can be hard work to identify a suitable indicator species!


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E"#$ES


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ir pollution % $ichens

*ichens are formed from a symbiotic relationship between a fungusand an alga.

hey often grow on e+posed roc&s and trees, and need to beefficient at absorbing water.

Air pollutants dissolved in rainwater, especially sulphur dio+ide, candamage lichens and prevent them from growing.


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• ifferent lichens show different levels of

tolerance to pollution.

• -hrubby and bushy lichens are usually

the most sensitive to pollution and areoften absent from polluted areas.

• $rusty lichens are usually more tolerantof pollution and can grow in more polluted

areas.

• By loo&ing at the species present in aparticular area, scientists can assess thelevel of air pollution.

ir pollution % $ichens


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Water pollution

ypes of water pollution can include:

• %itrates e.g. from fertilisers/

• Acid rain• 0eavy metals

• Pesticides

• 1il

• 1ther chemicals

2any a3uatic animals can#t survive in

polluted water, so their presence 4

absence can indicate the level of

pollution in a water body.


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Water pollution % Invertebrates

ifferent invertebrate species are able to tolerate

different levels of water pollution.

he composition of species within a study area can

indicate the level of pollution.


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• -pecies such as the rat)tailedmaggot and sludgeworm cantolerate very high levels of

pollution

• he water louse can tolerate highlevels of pollution

• 5reshwater shrimp can toleratelow levels of pollution

• 2ayfly and stonefly larvae preferclean water


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• 2ussels are suspension feeders and accumulate heavy metals and

to+ins in their tissues.

• 2ussels are often used as indicator species for monitoring the health

of coastal environments.

• here is a "2ussel 6atch# programme that runs in 7.-. coastal and

8reat *a&es waters to assess chemical and biological contamination.



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A ma(or form of water pollution comes from e+cess

nitrates and other nutrients being washed into rivers and

la&es.

he nitrates in the water result in the rapid growth of

algae, which is &nown as an algal bloom.

As a result of the increase in algae, less sunlight can

reach other a3uatic plants, many of which then die.

Water pollution % lgae


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Bacteria begin to brea& down the dead plant material,using up o+ygen as they do so, resulting in the death offish and other organisms.

his process is &nown as eutrophication.

he composition and total amount of algae species canindicate the amount of organic pollution.

Water pollution % lgae


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• Amphibians breathe through their s&in so are easily affected by

changes in water 3uality.

• 5or e+ample, some chemicals may potentially cause physical

abnormalities and malformations.

• Amphibians live both on land and in water.

Water pollution % mphibians


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Climate change & "ontane species

• *ives in a very specific habitat type

• 0as a very low reproductive rate

• -hows very limited dispersal ability

• Is e+tremely sensitive to warm

temperatures

2ontane species species which live in the mountains/ can be

good indicators of climate change, as they often have specific

habitat re3uirements and cannot easily disperse elsewhere.

5or e+ample, the American pi&a is a good indicator of the effects

of climate change, as it:


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• As temperatures rise, the American

pi&a would be forced to see& higher

elevations to find suitable cool, moist

habitat.

• 0owever, as this species already

occupies high elevations, it has

nowhere to go.

• $limate change may already be a

factor in the e+tinction of local pi&a

populations, and the range of the

species is already moving uphill.

Climate change & "ontane species


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'ther e(amples

• op predators ) food chains

• Plants ) soil conditions

• Bioaccumulation ) to+ins


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Summary

• -ome organisms are very sensitive to changes in the

environment and can be used to measure the impact of

human activities.

• Indicator species can be useful in helping to assess

different environmental conditions, such as pollution andclimate change.

• -cientists, industrial companies and landowners may

wish to use indicator species to monitor the health of a

particular ecosystem.• $are must be ta&en when choosing an indicator species

to ensure that the results of a study accurately reflect the

environmental conditions.

14-16yrs - indicator species - classroom presentation

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