Trials are underway into an innovative form of production that combines aquaculture with soilless hydroponics. Known as aquaponics, it enables nutrients, water, energy and space to be utilised twice over, thus going further to optimise resources. Produce Business UK learns more
Researchers in Berlin, Germany, have developed new technology based on this concept and sample crops of tomatoes and fish are already being produced under the scheme.
The research is being carried out under the auspices of the European Union (EU)-backed INAPRO project, which is based at the Leibniz Institute of Freshwater Ecology and Inland Fisheries in Berlin.
Scientists at the Leibniz Institute have been investigating for some time methods of combining aquaculture and hydroponics. Their initial aim was to find a way of providing ideal growth conditions for both fish and vegetables and the result was the development of ASTAF-PRO technology.
Dr Werner Kloas, one of the team behind the investigations, says: “ASTAF-PRO (the aquaponics system for (nearly) emission-free tomato and fish production in greenhouses) provides ideal growth conditions for both fish and vegetables at the same time – a challenge that traditional aquaponics systems cannot overcome. ASTAF-PRO offers sustainable value-added chains, with a significantly reduced water and carbon footprint compared to traditional systems.
“We want to prove the economic viability of the system and develop modular solutions of the system scalable and adaptable to local conditions. INAPRO will open new market opportunities for innovative aquaponics both inside and outside Europe, for producers and technology suppliers from the manufacturing industries as well as the end-users.”
Four large-scale demonstration facilities in Spain, Belgium, Germany and China are being created. Construction has begun on the Spanish facility in Murcia, and at Waren, in Western Pomerania, Germany. Each unit will occupy around 500m2 and the progress of the crops and the success of the production method will be constantly evaluated throughout the next four years.
How it works
Fresh water is brought into the facility and fed into fish tanks. It is removed from there and taken through a series of biological and mechanical filters, a secondary clarifier and a mixing tank, where extra fertilisers are added, before passing through to a tomato-growing hydroponics section.
All of the plants are grown in trenches filled with water. Condenser tubes remove evaporated water and return it to the fish tanks. In total, the daily need for fresh water is less than 3% of the total volume of water involved in the project. The fish water is nitrate-rich, and the carbon dioxide produced by the fish is also directed to plants. The filters enable the nitrates and carbon dioxide to be turned into fertiliser.
Who it’s for
“Together with our international, highly-qualified and experienced project partners from science and industry, we aim at covering the whole value chain from research to market, from modelling and experimental research at pilot scale to communication and knowledge transfer to policymaking, business and the public at large,” says Dr Georg Staaks, project coordinator for INAPRO.
The intention is to identify how this aquaponic system can be adapted to a variety of local conditions, from rural, large-scale agricultural facilities to small, urban farming operations. Although the large-scale facilities are still under construction or in the planning phase, a test and research unit has been underway for some time at Abtshagen in Germany. It has proved successful at producing tilapia (a type of fish) and tomatoes.
The €6 million (£4.7m) INAPRO project involves 18 partners from eight countries, including: China, Norway, Belgium, Italy and the Netherlands. The range of partners is extensive – covering marine and horticultural researchers, Sea Fisheries, universities and technology manufacturers. Participants include PAL-Anlagenbau GmbH Abtshagen, Beijing CAUIOT Co. Ltd, Tilamur, Inagro, Fytagoras, Stichting Dienst Landbouwkundig Onderzoek, and the Yellow Sea Fisheries Research Institute in China. See the full list of consortium partners here.
Other water-based research
The INAPRO project is also linked to a separate EU scheme called WIRE (Water and Irrigated agriculture Resilient Europe), which is looking at the development of water resources in an era of climate change.
A slightly different slant on combining plant and fish culture has also just begun in Abu Dhabi where the world’s first ever aquaponics production facility to combine the creation of food and biofuel is being developed. Operated by the Masdar Institute, the project is the brainchild of the Sustainable Bioenergy Research Consortium, a group seeking ways of reducing carbon emissions by the aviation industry. What is particularly innovative about this project is that it uses seawater rather than freshwater.
Within the new facility, seawater is pumped into ponds producing fish and shrimp for food consumption. The water then moves into a hydroponics area where halophyte plants are cultivated. These plants are unusual in that they can tolerate the saltiness of seawater. Given that 97% of the earth is saline, recent years have seen many researchers paying more attention to halophyte plants. There are around 2,600 species that can absorb seawater. Halophytes can also survive in arid, desert conditions making them perfect for the Abu Dhabi project. Perhaps surprisingly, the halophyte plants are also rich in oils.
Researchers in Abu Dhabi plan to cultivate halophyte crops for the oils and turn these into aviation biofuel. Any remaining wastewater will be passed through a cultivated area of mangroves, which will filter remaining nutrients before it is discharged into the sea.
The initial scheme is a small one, but it is anticipated that if it proves successful then a 200 hectare site will be created for a larger trial.
Thani al Zeyoudi, the UAE’s minister for climate change, says: “This product will not only sustainably produce bioenergy but also offer a pathway to grow our aquaculture industry, which supports food independence.”
A future solution?
Aquaculture is steadily developing as a food source, with production worldwide increasing at around 6% annually. The main concern for environmentalists has been the damage that can be caused by the nutrient rich effluent that is discharged by the food stocks. Combining aquaculture with hydroponics is a logical answer. INAPRO and the Abu Dhabi scheme are set to discover just how far and how successful such combinations can be. If successful, it will have long-term implications for producers whether seeking to produce food or biofuel.