Question

Eutrophication in water bodies leading to killing of fishes is mainly due to
A) Non availability of oxygen
B) Non availability of light
C) non availability of food
D) non availability of essential nutrients

Answer 1

Eutrophication is when a body of water becomes highly enriched with minerals and nutrients which induce excessive growth of algae in that water body

Complete Answer:
Eutrophication it is also known as hypertrophication or dystrophication, is a condition when water body becomes highly enriched with nutrients this can be a problem in marine habitats such as lakes as it can cause algal blooms and some algae even produce toxins that are harmful to higher forms of life. Furthermore harmful algal blooms, dead zones and fish kills are as a result of this process, which occurs when the environment becomes highly enriched with nutrients that ultimately increase the amount of plant and algae growth two estuaries and coastal waters and thereby it causes the problems along the food chain an effects the animals that feed upon them that is that is it disturbs the complete ecosystem of a water body. This process then result in the depletion of oxygen level of that water body after bacterial degradation of the algae

So, the correct answer is option ‘A’ i.e., non availability of oxygen. **

Note: The major cause of this nutrient enrichment of water bodies nowadays is due to human activities like passage of Savage, industrial effluents and runoff from fertilized fields rich in nitrates and phosphates.