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
Correct answer
C
All three
D
None
Explanation
In a recirculating aquaculture system, the biofilter is a medium colonised by bacteria. Heterotrophic bacteria break down organic waste such as uneaten feed and faeces (statement 1), and nitrifying bacteria convert toxic ammonia from fish waste into nitrite and then into far less harmful nitrate (statement 2), so both are correct. Biofilters do not add phosphorus to the water; phosphorus build-up is a waste problem in such systems, not a nutrient the filter supplies. So two statements are correct.
Aquaculture TechnologyRecirculating Aquaculture Systems (RAS) & BiofiltrationBiofiltersRecirculating Aquaculture SystemRASfish wasteammonianitratephosphorus