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?
Show answer
Answer: B. Statement 1 is accepted as correct: biofilters treat waste by breaking down organic matter from uneaten feed and fish waste. Statement 2 is correct: bacteria in the biofilter convert toxic ammonia to nitrite and then to less harmful nitrate. Statement 3 is wrong: biofilters do not add phosphorus as a nutrient. So only two.
Watch for: Removing solid feed is mainly done by mechanical filters, which makes statement 1 feel doubtful.
Why the other options are wrong
- A. Wrong because both statements 1 and 2 are treated as correct.
- C. Wrong because biofilters do not increase phosphorus for fish.
- D. Wrong because ammonia to nitrate conversion is the main job of a biofilter.
Source to check: FAO Fisheries and Aquaculture Technical Paper 589, 'A guide to recirculation aquaculture' (2015)
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.