Survey of resource use efficiency and estimation of carbon and water footprints in fish farming systems using life cycle analysis

Resource use efficiency in fish farming systems is a critical area of concern to stakeholders in the seafood industry. Fish farming systems have varying degrees of efficiency of resource use thus have differential impacts on the environment and/or human health. This study addressed the sustainability in fish farming by measuring resource use efficiencies of five fish farms and eight fish hatcheries using life cycle analysis (LCA). Farm input and output data were analyzed using FoodCarbonScope, and results were reported as carbon dioxide emissions (CO2e/kg output), energy consumption (MJ/kg), and water use (L/kg) from farm operations. Comparative analyses were made among fish farms and hatcheries and terrestrial animal food products (chicken, beef and pork) from published literature. CO 2 emissions from five fish farms indicated that cobia cage farm had the highest emissions at 8 kg CO2e/kg fish output. An Asian sea bass recirculation farm had the lowest emissions at 1.7 kg CO2e/kg fish output. The high CO2 emissions from the cobia cage farm were due to feed use (60%). Feeds were delivered to the farm in Panama from Chile and Peru, an average of 5,600 km. Feed for the Asian sea bass farm, on the other hand, came from a distance of 880 km. The cobia cage farm consumed the highest energy with 123 MJ/kg and Asian sea bass recirculating system the lowest, at 21 MJ/kg. Feed transport was the main source of energy consumption. Among the three recirculating fish farms, tilapia farm (VA) had the highest water use with 403 L/kg and a sea bream farm (NY) used 39 L/kg. The table below is a summary of results.* This study confirmed that in fish farming systems, feed production, processing and transport were the main sources of CO2 emissions and energy consumption. Recirculating systems used filtration systems of low water use. Finally, comparing fish and chicken, beef and pork on CO2 emissions we found that chicken was comparable to fish having the lowest emissions followed by pork. On energy consumption fish and chicken were more energy efficient followed by pork and beef. Water use in fish systems is more efficient followed by chicken and pork. Beef used almost 140 times (on average) more water than fish. *Please refer to dissertation for diagram