1. Control and Management
The Biosphere
SG Biology

2. Learning Outcomes 1
State that pollution affects air, fresh water, sea and land.
State that the main sources of pollution are domestic, agricultural and industrial, giving an example of a pollutant from each.
Give an example of one way in which pollution may be controlled.

3. Pollution is caused by the presence of a substance that is harmful to an animal or a plant, it can affect freshwater, sea, land and air.

4. Sources of Pollution Pollutants come from 3 main sources:
Industrial Pollution
Agricultural pollution
Domestic pollution

5. Agricultural Pollution
Crops sprayed with pesticides
Pesticides wash off and reach the rivers
This damages the river habitat and kills organisms.

6. Industrial Pollution
Most of our electricity comes from power stations which burn fossil fuels.
Fossil fuels release harmful gases into the air when they are burned, e.g.
Sulphur dioxide
Nitrogen dioxide
When there gases dissolve in rainwater they form acid rain.

7. Acid Rain

8. Acid Rain Acid Rain Kills fish and trees
Damages buildings, especially limestone
Falls into lakes and poisons fish and birds

9. Questions – Acid Rain What is acid rain?
Why is 'acid rain' a misleading term?
What two elements are responsible for acid rain?
What human activities cause acid rain?
What effects does acid rain have on humans?
What effects does acid rain have on trees and plants?
What effects does acid rain have on buildings and structures?

10. Domestic Pollution Domestic rubbish Old car parts
Car exhausts release toxic gases to the air.

11. Controlling Pollution
Pollutant
Method of Control
Soot in smoke
Lead in exhaust fumes
Domestic sewage

12. Controlling Pollution
Pollutant
Method of Control
Soot in smoke
Clean Air Act prohibits factories from releasing black smoke.
Lead in exhaust fumes
Domestic sewage

13. Controlling Pollution
Pollutant
Method of Control
Soot in smoke
Clean Air Act prohibits factories from releasing black smoke.
Lead in exhaust fumes
Introduction of lead free petrol
Domestic sewage

14. Controlling Pollution
Pollutant
Method of Control
Soot in smoke
Clean Air Act prohibits factories from releasing black smoke.
Lead in exhaust fumes
Introduction of lead free petrol
Domestic sewage
Treatment at sewage works before waste is discharged

15. Quick Test Name the three main sources of pollution.
Name four parts of the environment that pollutants affect.
Name a gas which causes acid rain.
Name an agricultural chemical that can cause pollution.
How can we reduce the effect of domestic sewage on the environment?

16. Copy and complete the diagram of acid rain

17. Acid Rain
SO2 and NOx react with water to form acid rain clouds containing sulphuric acid and nitric acid.
Older trees die back
Sulphur dioxide, nitrogen oxides
Acid rain in soil, surface run off
Power station, industry, houses, traffic
Acidification in lakes, fish die

18. Learning outcomes 2
State that organic waste is a food source for microorganisms.
Explain the relationship between level of pollution with organic waste, numbers of micro-organisms, oxygen concentration and numbers of species.
Describe the effect of increased numbers of microorganisms on the oxygen available to other organisms.
Explain what is meant by “indicator species”.

19. Sewage
Organic waste (sewage) provides food for bacteria, which allows them to grow and reproduce
Bacteria use up the oxygen in the water.
There is less oxygen for other organisms such as fish and insects.
Animals such as fish, stonefly nymphs and shrimps decrease in number.

20. Domestic Pollution – sewage Describe the trends shown in the graph below.

21. Domestic Pollution – sewage
As the concentration of sewage pollution rises, the population of bacteria rises.
This is because the bacteria feed off the sewage which provides raw materials and energy for growth and reproduction.
At the same time the concentration of oxygen falls.
This is because the bacteria use up the oxygen as they break down the organic waste in the sewage.
Animals such as fish and stonefly nymphs decrease in number.

22. Mayfly nymphs cannot survive in waters low in oxygen
Mayfly nymphs cannot survive in waters low in oxygen. They are an indication that the waters are clean

23. Pollution Indicators
The presence or absence of particular organisms can indicate whether the water is polluted or not.
These are called Indicator Species

24. Freshwater pollution Indicator Species
Animals found in water with low levels of oxygen
Sludge worm
Rat-tailed maggot
Blood worm
Animals found in water with high levels of oxygen
Mayfly nymph
Stonefly nymph
shrimp

26. Air Pollution Indicators
Lichens
Different types of lichen have different sensitivities to sulphur dioxide gas.
3 main types – crusty, leafy and shrubby
Indicator species present
Appearance of lichen
SO2 concentration
Crusty lichens only
High
Crusty and leafy
Medium
Shrubby
low

27. Air Pollution Map
Look at the air pollution map, and explain the distribution of the different types of lichen.

28. Quick Test
What effect does domestic sewage have on the number of bacteria in a river?
How do the bacteria numbers affect the level of dissolved oxygen in the water?
How does the reduction in oxygen level affect the numbers of fish and invertebrate numbers in the river?
What name is given to an organism whose presence or absence gives information about the level of pollution in a river?
Name two organisms that can live in water where the oxygen level is low.
Name two organisms that can only live in water that is unpolluted.
Which organisms are indicators of air pollution?

29. Learning Outcomes 3
Explain an adverse effect of using fossil fuels and nuclear power as energy sources.
Give 2 examples of poor management of natural resources and suggest possible improvements.
Describe how the effect of poor management of natural resources can produce problems.
Explain how components of an ecosystem are controlled in agriculture.

30. Alternative energy
Alternative sources of energy need to be used to reduce the harmful effects of fossil fuels.
Sources of energy include:-
Solar power
Wind power
Tidal power
Nuclear power

31. Solar Power Uses the suns energy to generate electricity. Advantages
No pollution
Disadvantages
Initially expensive
Not useful in areas with limited sunshine

32. Wind Power Uses movement energy from the wind to generate electricity.
Advantages
Renewable
Low-level technology
No atmospheric pollution
Disadvantages
Visual and noise pollution
Limited to windy sites
No wind, no energy

33. Tidal Power Uses movement energy of the tides to generate electricity.
Advantages
Reliable
Low running costs
No air pollution
Renewable
Disadvantages
Possible flooding
High initial costs
Obstacle to water transport.

34. Nuclear Power Nuclear energy is an alternative to fossil fuels but it:
Produces radioactive waste, which can cause cancer.
It is difficult to dispose of safely.
Waste should be sealed in lead containers and dumped on the ocean beds.

35. Management of Resources
Humans obtain resources from the Earth, this has led to the destruction of habitats.
Resources are managed for:
Agriculture
Forestry
Fish stocks
Conservation is important to prevent the loss of resources and wildlife.

36. Poor management of resources
Overfishing in the North Sea
Destruction of rainforests
Overuse of land, leading to desert soils.
Solutions
Have fish quotas, or increase net mesh to allow smaller fish to survive
Produce food more efficiently to limit areas being logged for agriculture.
Set aside areas as national parks.
Use different agricultural practices, such as crop rotation and natural fertilisers.

37. Managing land for agriculture
In agricultural practices it is necessary to control
Nutrient supply
Addition of fertilisers – natural and artificial
The habitat of the plant
Clearing land of competitors
Cultivation
Erects fences

38. Greenhouse Effect
The main greenhouse gases are carbon dioxide and methane. These gases reduce the amount of heat radiated into space.
Only a small rise in temperature may lead to climate changes and a rise in sea level.

39. What is the greenhouse effect?
Explain what is happening at points 1, 2 and 3 in the greenhouse.

40. What is the greenhouse effect?
The glass absorbs the infra-red radiation
Some of the energy is re-radiated into the greenhouse which makes it warmer
The soil becomes warm and radiates long wave infra-red rays.

41. The greenhouse effect The atmosphere gets warmer atmosphere
Greenhouse gases absorb some of the infra-red radiation. They radiate some of it back towards the Earth.
atmosphere
The earth becomes warm and radiates long wavelength infrared rays
earth

42. Effects of Global Warming

43. Deforestation
Deforestation reduces photosynthesis which removes CO2, and also reduces the rate at which carbon dioxide is “locked up” as wood.
Burning of chopped down wood or industrial uses, releases CO2.
Increased microbe activity on the decaying material releases CO2 and methane (CH4)

44. Quick Test
Why do we need to reduce the amount of fossil fuels burned for electricity?
Name two alternatives to fossil fuels as sources of energy
Give one way of reducing the adverse effects of fossil fuels.
Give one way of reducing the adverse effects of nuclear power.
Give two possible solutions to the problem of over fishing in the North Sea.
Which is the main gas responsible for the greenhouse effect?

45. Carbon Dioxide Production
The pie chart shows the percentage of increase in the carbon dioxide content of the atmosphere caused by various activities.
What percentage of the increase in CO2 comes from generating electricity?
Which human activity produces an increase in CO2 of 25%?
Explain two ways in which deforestation causes an increase in the carbon dioxide concentration in the atmosphere.

46. Atmospheric Carbon Dioxide
The graph shows how the amount of carbon dioxide in the atmosphere increased over 20 years.
What was the total increase in the average CO2 concentration?
Each year there is more CO2 in the air when it is winter in the northern half of the Earth. Explain this as fully as you can.