1. Nutrient Overload

2. DECOMPOSERS Nutrients Nitrogen Phosphorus Potassium Rabbit eats Plant and cycle Starts again Photosynthesis

3. Algae Why are Algae found at the beginning of a food chain? Food chains always start with producers. Algae is a plant and so, it is also a producer.

4. As Algae is a plant, it needs light to photosynthesise, What Nutrients does it need? Like all plants, Algae need nutrients to grow. The important nutrients are: 1.Nitrates 2.Phosphates

5. Algae Water Flea Small Fish Large Fish What will happen if lots of Nutrients get into The Water?

6. Where do you think an excess of nutrients could come from? Excess nutrients can enter our waterways by various methods. # Slurry from farmyards # Detergents from washing machines. (Detergents contain Phosphates) # Chemical fertilizers run off from farmers crop fields. # Sewage treatment works (spillage, leaks or intentionally pumped into rivers)

7. What do you think the effect of these EXCESS nutrients are on The food web of the river? Start by thinking what effect it will have on the Algae? The main factor controlling Algal growth is a balance of nutrients In the water. Once there is an abundance of nutrients, there will be a population explosion of algae.

8. Algae don’t live very long, just a few hours in some cases. Huge quantities of dead algae sink to the bottom of the river. What do you think happens to this dead Algae? They are broken down by Micro-Organisms, The Decomposers.

9. Decomposers use up a lot of oxygen from the water as they breakdown the dead algae. Very quickly after nutrient pollution, the waterway becomes Starved of oxygen, this leads to MASS death of fish and Other animals.

10. Effect of Nutrient Overload on a River Algae die and sink to the bottom of the lake or river. Extra nutrients in the water make the algae grow fast. The lack of Oxygen in the water kills fish and other Water animals Dead algae are broken down by microbes called Decomposers which use up lots of oxygen. 2 1 3 4

11. Air pollution One cause of major environmental problems Is Acid Rain. Acid rain is caused by a chemical called Sulphur Dioxide that is dissolved in the rain drops. Where does Sulphur dioxide come from?

12. The main contribution of Sulphur dioxide to the environment Is the burning of fossil fuels Power Stations and Combustion engines from all the Vehicles on the roads are the main producers of this gas. The gas once produced rises into the air, where it dissolves In the clouds to make acid rain. This then falls back to earth contaminating waterways And killing plants.

13. Lichens are plants that are very sensitive to Sulphur Dioxide In the environment. It kills them! Dead Lichens are a living indicator of acid rain pollution.

14. Burning fossil fuels produces the gas Sulphur Dioxide This gas rises into the atmosphere and dissolves in the clouds It then returns to the earth in the rain drops during downfalls. Lichens are very sensitive to Acid rain, it kills them! If the air/water quality is good, lichens with thrive. If Acid rain has polluted the environment, one of the first signs is dead and Dying Lichens 1 2 3 4 5