Describe the process of Eutrophication.

Eutrophication occurs when mineral ions from the soil such as nitrates are leached (washed away by the rain) and they run into rivers, lakes and ponds. This increase in nutrients into the water causes an increase in growth of algae called an algal bloom which covers the surface of pond and blocks sunlight from reaching the plants in the water. This means that these plants cannot photosynthesize and die as a result. Without these plants no oxygen is produced and bacteria decompose the dead plants using up any of the remaining oxygen by aerobic respiration. This lack of oxygen in the water results in any life in the water (fish) to die as they can no longer aerobically respire.