What happens in the process of eutrophication?

1. Fertilisers are washed into waterways by rain or irrigation.

2. The increased availability of nutrients causes aquatic plant life to grow rapidly.

3. An algal bloom occurs, obscuring light from the plants.

4. Plants cease photosynthesising due to lack of light, depleting oxygen levels.

5. Plants die and are decomposed by bacteria which deplete the oxygen further.

6. The oxygen levels deplete to such an extent that other aquatic life, such as fish, die and the ecosystem collapses.