4.17 understand the biological consequences of eutrophication caused by leached minerals from fertiliser

Eutrophication: environment of an aquatic ecosystem that is boosted by chemical nutrients. 

Biological Consequences of Eutrophication:

1. Excessive nutrients from fertilizers in farms can be washed into rivers and lakes by rain.

2. These excessive nutrients allow the rapid growth of plants such as algae and duckweed. The growth of algae on the river surface blocks sunlight for aquatic plants, therefore they can no longer absorb sunlight via photosynthesis, which causes them to die.

3. When there is less photosynthesis, oxygen levels deplete.

4. Furthermore, decomposers breaking down the dead plants by photosynthesis can cause further depletion of oxygen. 

5. This stresses the survival of marine organisms, which potentially leads to a reduction in biodiversity.