UPSC Previous Year Question | Prelims GS | 2023

With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements: 1. Biofilters provide waste treatment by removing uneaten fish feed. 2. Biofilters convert ammonia present in fish waste to nitrate. 3. Biofilters increase phosphorus as nutrient for fish in water. How many of the statements given above are correct?

  1. Only one
  2. Only two
  3. All three
  4. None

Answer

Correct Answer

Only two

Explanation

Biofilters in RAS remove waste by filtering out uneaten feed (statement 1) and convert toxic ammonia to less harmful nitrate through nitrification (statement 2). They do not increase phosphorus as a beneficial nutrient—excess phosphorus is actually a pollutant to be managed, so statement 3 is incorrect.

Topics: aquaculture, biofilters, recirculating aquaculture systems, science and technology