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?

The correct answer is (a) because only statement 2 is accurate: biofilters house nitrifying bacteria that convert toxic ammonia excreted by fish into less harmful nitrate. Statement 1 is the most common trap, but it is incorrect because the removal of solid waste like uneaten feed is the function of mechanical filtration, whereas biofilters treat dissolved chemical waste. This question tests the core concept of the nitrogen cycle and the specific functional roles of different filtration components within a Recirculating Aquaculture System (RAS).