eutrophication

• nitrate fertilisers

  1. increased nitrates in water increase the growth of algae and plants
  2. the algae form a cover on the water surface which prevents sunlight reaching plants
  3. the plants die as the cant carry out photosynthesis due to the lack of sunlight
  4. microbes, such as bacteria, increase as the plants start decomposing. the plants start using up oxygen during respiration reducing the amount in the water
  5. the low oxygen concentration in the water cause fish and aquatic insects to suffocate and die, leaving the body of water to be completely lifeless