Eutrophication leads to
depletion of dissolved oxygen in water
death of animals
depletion of ozone
Only 1 & 2
As we have learnt,
Eutrophication refers to the condition in which the growth of aquatic plants take place in excess amount due to nutrient enrichness of water bodies.
It leads to organic loading, depletion of oxygen, death of animals and fouling of water.
Hence, the correct answer is Option (4)