Recirculating aquaculture systems (RAS): Environmental solution and climate change adaptation

Considering environmental sustainability and vulnerability to the effects of climate change on fish production, one of the potential adaptation strategies is “Recirculating Aquaculture Systems (RAS)”. RAS are eco-friendly, water efficient, highly productive intensive farming system, which are not associated with adverse environmental impacts, such as habitat destruction, water pollution and eutrophication, biotic depletion, ecological effects on biodiversity due to captive fish and exotic species escape, disease outbreaks, and parasite transmission. Moreover, RAS operate in indoor controlled environment, and thus, only minimally affected by climatic factors, including rainfall variation, flood, drought, global warming, cyclone, salinity fluctuation, ocean acidification, and sea level rise. However, energy consumption and greenhouse gas (GHG) emissions are the two most stringent limiting factors for RAS. Despite these potentials and promises, RAS have not yet been widely practiced, particularly in developing countries, due to complex and costly system designs. Further research with technological innovations are needed to establish low-cost, energy efficient RAS for intensifying seafood production, reducing GHG emissions, and adaptation to climate change.