Question

Explain the impact of eutrophication on the environment.

Answer 1

The primary environmental impacts of eutrophication include:

1. Algal Blooms: Excess nutrients trigger a massive, rapid proliferation of phytoplankton and algae, commonly known as an algal bloom. This forms a thick, green, or discolored layer over the water’s surface. 
2. Depletion of Sunlight: The dense surface layer of algae acts as a barrier that blocks sunlight from penetrating the deeper layers of the water body. This halts photosynthesis for submerged aquatic plants, causing them to die.
3. Severe Oxygen Depletion (Hypoxia): As the abundant algae and submerged vegetation die, they sink to the bottom, where they are decomposed by aerobic bacteria. These bacteria consume vast amounts of dissolved oxygen in the process, drastically lowering oxygen levels in the water.
4. Death of Aquatic Life (Fish Kills): The sharp drop in dissolved oxygen creates hypoxic or “dead zones” where fish, shellfish, and other aerobic aquatic organisms suffocate and die en masse.
5. Deterioration of Water Quality: Affected water becomes turbid, foul-smelling, and aesthetically unpleasant, making it unfit for recreation, navigation, or safe consumption without intensive water treatment.