From freshwater to marine aquaponic: new opportunities for marine fish species production

Due to the increasing world population, by 2050 food production should be increased of about 70% to 100%. Tanks to the lowest “carbon footprint”, aquaculture seems to be the most sustainable system for producing food (protein) of animal origin. Despite that, progress can be done for further improving aquaculture sustainability through the “aquaponic” system (IAS). A IAS is based on the bacteria nitrogen cycle which convert fish waste (faeces and uneaten feed) into nitrite and nitrate, this latter absorbed by plants grown in the hydroponic section of the aquaponic system; as a results, water is “depurated” and recycled into the fish tanks. Advantages of this system are the high productivity, the reduced water requirement, the neglectable waste production, the reduced plant disease incidence and pesticides utilization, the modularity of the system which allow its uses for a wide range of purposes (urban agriculture, people resilience in developing countries, marginal land exploitation, etc.); for a contrary, disadvantages are the relevant initial investments, the required high education level of the employees, the “sensitivity” of the systems and some minor others. A relevant future challenge for scientists is to develop “marine aquaponic system” for producing more valuable fish and crops, interesting also for the EU and ‘developed countries’ market.