Assessing the environmental footprint and the water-energy-food nexus of aquaponics systems

Aquaponics is the production of vegetables and fish by integrating hydroponics (soil-less culture) and aquaculture through water recirculation. Among the deployment of urban agriculture (UA) in the developed world, aquaponics... [ view full abstract ]

Aquaponics is the production of vegetables and fish by integrating hydroponics (soil-less culture) and aquaculture through water recirculation. Among the deployment of urban agriculture (UA) in the developed world, aquaponics were employed in rooftop farms, such as the UF002 De Schilde in The Hague (The Netherlands) (https://www.urbanfarmers.nl/en/) or the company ECF-Farm systems in Berlin (Germany) (http://www.ecf-farmsystems.com/en/). Such systems are employed in commercial UA initiatives as a way to create resource-efficient businesses that are competitive in the food market. However, there is little data available on the environmental footprint of this type of urban food system. Furthermore, there is a need to observe the nexus of the water-energy-food flows due to the specific role of water and energy in aquaponics.

This study evaluates the environmental footprint and the water-energy-food nexus of the production of vegetables and fish in aquaponics systems by using the Life cycle assessment (LCA) methodology. To do so, an aquaponics pilot project in the South-Westfalia University of Applied Sciences (Soest, Germany) will be evaluated. The system consists of three fish tanks of 1200L, sedimentation tanks, biofilter and UV disinfection unit on the aquaculture system and four deep water culture grow beds as well as a vertical grow bed system. The fish species reared in the system is European Catfish (Siluris Glanis), a robust endemic carnivore with high yield, while in the hydroponics culture the crop is lettuce (variety Salanova Cook RZ). Other crops are basil, Melissa, purslane and true watercress.

The on-going data collection process highlight the complexity of evaluating integrated food production systems. The environmental footprint and water-energy-food nexus will be completed as a second stage. Results will contribute to the knowledge of the environmental metabolism of aquaponics systems. Environmental hotspots will be identified to propose improvement measures toward a more environmentally friendly aquaponics design. In the context of the SustUrbanFoods project (MSCA-IF-708672), the environmental results will be integrated in a global sustainability assessment, encompassing also the economic and social dimensions. Furthermore, the results of aquaponics production will be compared to other urban food systems in Europe, such as urban allotments, rooftop gardening, indoor farming or periurban food cooperatives.