Ch 5 Human Impact on an Ecosystem 1

1. Ch 5 Human Impact on an Ecosystem 1 Pollution

2. Need to know • Define the term: Pollution. • State areas affected by pollution. • State mechanisms to control pollution. • Explain the difference between the terms pollutant and pollution. • Discuss the ecological impact of one human activity.

3. Human Impact on Ecosystems We are going to look at 3 ways that humans affect ecosystems: • Pollution • Conservation • Waste Management

4. Pollution • Pollution is the addition of harmful substances to the environment. • It is the most harmful human impact and affects air, fresh water, sea, soil and land.

5. Some Types of Pollution • Domestic Pollution • Industrial/Air Pollution • River/Water Pollution • Agricultural Pollution – slurry, if it gets into a river/pond

7. Pollutants are substances that cause harm to the environment. • CO2from burning fossil fuels • SO2 from factory chimney

9. Pollutants • Some pollutants are normally present in an environment, e.g. CO2 • but levels are increased by human activity. • Other pollutants never exist in an environment e.g. oil slick, CFCs

10. Learning Check 1 • Explain the term Pollution. • Name some Types of Pollution. • Explain the term Pollutant.

11. Effect of one pollutant from one area- Agricultural, Industrial or Domestic

12. Eutrophication & Algal bloom • Eutrophication: a condition where lakes become over-enriched with nutrients, resulting from excess artificial fertilisers washed into rivers and lakes. • There is a rapid increase in the growth of alga - algal bloom as they use up the nutrients.

13. Eutrophication & Algal bloom • When all the nutrients are used up the algae die and are broken down by bacteria, which use up the oxygen in the water resulting in the death of aquatic organisms such as fish.

14. Eutrophication animation • Water Pollution • Water pollution - Kate Bush

17. Control of Pollutants in the selected area - Agricultural, Industrial or Domestic

18. Learning Check 2 • Explain the term Eutrophication. • Explain the term Algal bloom. • Give an example of a method used to Control Agricultural Pollutants. • Give an example of a method used to Control Industrial Pollutants. • Give an example of a method used to Control Domestic Pollutants.

19. Ecological impact of one human activity – Industrial PollutionBurning Fossil Fuels

21. Acid rain • Burning of fossil fuels releases acidic oxides into the air - Sulphur dioxide (SO2) and nitrogen oxides. • SO2 dissolves in rainwater to form sulphuric acid (H2SO4) • The resulting rain is very acidic – pH 4.0, normal rain water - pH 5.5.

23. Video on Coal-Combustion-and-Acid-Rain • Air pollution Facts

24. From 1997 to 2006 the EU-27 recorded a 28 % decline in weighted emissions of acidification gases.

26. Effects of Acid Rain • Causes soil to become more acidic. • The lower pH causes minerals e.g. Al, K, Ca and Mg, required for normal plant growth to be washed (leached) from the soil into lakes and water supplies. • Soil becomes impoverished and fish die in highly mineralised water. • Inhibits chlorophyll formation. • Burns the leaves of plants.

27. 6. Erodes limestone buildings 7. Causes breathing difficulties – irritates the delicate lining of the lungs

28. Effects of acid rain & global warning

29. 6. Erodes limestone buildings 7. Causes breathing difficulties – irritates the delicate lining of the lungs

31. Dealing with acid rain • Reducing the quantity of fossil fuels burned. • Using catalysts to treat chimney gases (scrubbers are fitted to the insides of chimneys). • Catalytic converters fitted to modern cars. • Developing alternative ‘clean’ energy sources.

32. Learning Check 3 • What is acid rain? • How is acid rain formed? • List some of the effects of acid rain. • How can the probloms dealing with acid rain be controlled?

33. END