Aquaculture & Fisheries

Biography

Biography: Werner Kloas

Abstract

Aquaculture is globally the fastest growing sector of agriculture that needs to be sustainable and to meet also bioeconomical demands concerning productivity and environmental impacts. In principle, aquaponics, the combination of aquaculture and horticulture within a single aquaponic recirculation system provides a sustainable approach but the productivity of both, fish and vegetables, is lower compared to separate production sites. The aim of our new concept for aquaponic systems is to improve sustainability and productivity and to reduce environmental impacts in comparison with conventional aquaculture. ASTAF-PRO (aquaponic system for the (nearly) emission-free tomato and fish production in greenhouses) is a new combination of systemic parts and constitutes of two independent recirculating units, a recirculating aquaculture system (RAS) for rearing fish and a recirculating hydroponic unit producing vegetables. Both systems are connected by a one-way-valve to launch nutrient containing fish water into the hydroponic reservoir for optimization as fertilizer. Additionally the air-conditioning of the greenhouse is regaining evaporated water by condensation. The first experimental trial of the ASTAF-PRO prototype demonstrates successfully the proof of principle using a combination of tilapia and tomato production. The tilapia production revealed an optimum productivity and feed conversion ratio as in single RAS while the tomato production at least demonstrates the potential for similar efficiency as by conventional hydroponics. Thus ASTAF-PRO as a new concept reveals an improvement of sustainability, productivity, and resource efficiency with reduction of environmental impacts and might promote future application of aquaponics for food security.