Recirculating aquaculture system (RAS) is an alternative technique to handle the crucial environmental issues associated with traditional intensive aquaculture systems. The development of an RAS is based on certain principals. As we provide feed to fish in culture tank, the uneaten feed and faecal matter produces waste which may be inorganic or organic in nature. The inorganic and organic matters are removed by mechanical and chemical filtration techniques. Coarse solids (10-100 μ m) are removed by mechanical filtration and fine solids (5-10μ m) are removed by chemical filtration. Further, organic matter is decomposed and toxic nitrogenous compounds are generated. These nitrogenous compounds are due to the protein content available in feed. The mechanical and chemical filters reduce the biochemical oxygen demand of the effluent, whereas, the biological filters convert toxic nitrogenous wastes to elementary nitrogen gas. Moreover, RAS is fast growing and adoptable technique due to the fact it fetches a huge amount of profit. However, RAS is environment friendly is a doubt as the system is purely/partially controlled by some source of energy. Use of Energy may enhance the Global warming, Natural resource depletion and Eutrophication etc. Hence, in the present paper an approach of impact of these factors on Human health and Ecosystem quality has been discussed.
Key words: Global warming, Natural resource depletion, Eutrophication, Human health and Ecosystem quality