What is the first step of eutrophication?

  1. Increase in decomposers
  2. Decrease in oxygen
  3. Death of fish
  4. Increased nitrate ions in the water
Answer

D) Increased nitrate ions in the water

Fertilisers or sewage add nitrates first. O Level Biology · Topic 19 Relationships of Organisms with One Another and with the Environment · 19.4 Effects of humans on ecosystems

Biology MCQ · More O Level Biology: Organisms and the Environment MCQs · Practise