How does eutrophication work?
- Fertilisers containing nitrogen are washed from fields to rivers and ponds. 2. This effectively fertilises the algae in the pond causing an 'algal bloom'. 3. The layer of algae on the surface stops sunlight from getting to the plants below. This means they cannot photosynthesize to produce oxgen.4. The plants die which further depletes the oxgen in the water as the bacteria decomposing them use oxygen. 5. The low oxygen levels cause fish and other organims in the water to die.
