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?
(a) Only one
(b) Only two
(c) All three
(d) None

Explanation:

Biofilters are a key component in the filtration portion of a recirculating aquaculture system (RAS). They house the nitrifying bacteria and are the primary site where biological nitrification occurs. The biofilters convert ammonia present in fish waste to nitrate. Therefore, statement 2 is correct.

However, biofilters do not provide waste treatment by removing uneaten fish feed. Therefore, statement 1 is incorrect.

Biofilters do not increase phosphorus as nutrient for fish in water. Therefore, statement 3 is incorrect.

Therefore, only statement 2 is correct.