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?
Correct Answer: Option B
Recirculating Aquaculture Systems (RAS) are engineered ecosystems designed to minimize environmental pollution by reducing nutrient discharge. They are indoor, tank-based systems for growing fish at high density under controlled conditions.
Biofilters play a crucial role in purifying water within RAS by removing or detoxifying harmful waste products and uneaten feed. They utilize microorganisms attached to a medium to break down pollutants.
Statement 1 is correct: Biofilters do provide waste treatment by removing uneaten fish feed.
Statement 2 is correct: Biofilters facilitate the nitrogen cycle, converting ammonia (toxic to fish) into nitrite, and subsequently nitrite into nitrate. This process involves nitrifying bacteria growing on the biofilter substrate.
Statement 3 is not correct: Biofilters are used to remove phosphorus waste by-products, not increase phosphorus levels in the water.
Hence, only two statements are correct.