A new concept for aquaponic systems to improve sustainability, increase productivity, and reduce environmental impacts

W Kloas,B Wittstock,B Rennert,J Graupner,S Wuertz,R Groß,U Schmidt,D Baganz,G Staaks,A Zikova,H Monsees,J Suhl,M Tschirner

doi:10.3354/aei00146

Abstract

Aquaculture is globally the fastest growing sector of agriculture that needs to be sus- tainable and must also meet bioeconomic demands. In principle, aquaponics, the combination of aquaculture and horticulture within a single recirculating aquaponic system (SRAPS), provides a sustainable approach; however, it has lower productivity of both fish and plants in comparison to separate recirculating systems. The aim of our new concept for aquaponics is to improve sustain- ability and productivity concomitant with lowering environmental emissions. The aquaponic system for (nearly) emission free tomato and fish production in greenhouses (ASTAF-PRO) is a new combination of systemic parts, consisting of 2 independent recirculating units: an aquaculture sys- tem (RAS) for fish and a hydroponic unit for plants. Both systems are connected by a 1-way valve to deliver fish water containing nutrients into the hydroponic reservoir, where the fish water can be optimized as fertilizer in order to meet specific demands of the plant species. Thus, our double recir- culation aquaponic system (DRAPS) can provide optimum conditions for both parts to increase pro- ductivity and to prevent any adverse interactions between plant and fish units. Water use is mini- mized by condensing the plant evapo-transpired water via air conditioning and returning it into the RAS. Testing of the ASTAF-PRO prototype successfully demonstrated the principle using a combi- nation of tilapia and tomato production. Tilapia productivity was similar to single RAS, while tomato production at least indicated the potential for similar efficiency to conventional hydroponics. Thus, ASTAF-PRO improves sustainability and productivity while lowering environmental emissions, and might promote future application of aquaponics for food security.

Highlights

The growth of the world’s population is expected to nearly stabilize at just above 10 billion people after 2062 (UN 2014b) and poses challenges concerningPublisher: Inter-Research · www.int-res.comAquacult Environ Interact 7: 179–192, 2015 duce food, and to process and transport agricultural goods
Tilapia productivity was similar to single recirculating units: an aquaculture system (RAS), while tomato production at least indicated the potential for similar efficiency to conventional hydroponics
For the first practical rearing trial in 2009, we selected a combination of Nile tilapia Oreochromis niloticus and tomatoes Solanum lycopersicum

Summary

Introduction

Aquacult Environ Interact 7: 179–192, 2015 duce food, and to process and transport agricultural goods. Agriculture is the largest global user of water, accounting for 70% of total withdrawal, and the food production and supply chain consumes ~30% of energy produced globally (UN 2014a). Water, food, and energy are inextricably linked by interacting with each other, and the water−food−energy nexus must be managed in a sustainable way concomitant with the protection of the environment to maintain biodiversity. In order to fulfill global needs for valuable animal protein, aquaculture is by far the fastest-growing sector of agriculture to supply humans with fish (FAO 2014). There is an urgent need to integrate aquaculture within the water−food−energy nexus into agricultural production systems using value-added chains concomitant with lowering adverse environmental impacts

Methods

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Discussion

Conclusion