Describe the process of eutrophication and its impact on the environment.

A farmer will apply fertiliser to their crops and the fertiliser leaks into a nearby lake, then...
The fertiliser contains nutrients which causes algae on the waters surface to rapidly grow- algal bloom.The algae grows so much that it blocks light to the plants below, so they cannot photosynthesise and die.As less plants are photosynthesising, less oxygen is produced and dissolved into the water.Bacteria (decomposers) decompose the dead plants, they rapidly grow and divide.A large population of bacteria is established and they use a lot of oxygen for respiration, using up the oxygen that is dissolved in the water.As very little oxygen is left dissolved in the water, plants and fish die as they cannot respire- loss of biodiversity.