Aquaculture Test Facility

Innovative research facility

The importance of aquaculture is growing steadily. In 2014, human consumption of aquaculture products exceeded that of wild fish for the first time. In order to be able to implement the 2030 Sustainable Development Goals of the Food and Agriculture Organization of the United Nations (FAO), capacities in aquaculture production must be significantly increased while conserving the required resources as much as possible. Against this background, the development of sustainable production processes is of particular importance. In recirculating aquaculture systems (RAS), the aquaculture of fish, algae or crustaceans takes place in tanks. The holding water is purified in an integrated water treatment system and then returned to the holding tanks (recirculation). The use of recirculation technology allows a significant reduction in water requirements compared to conventional flow-through systems. However, the low water exchange rates also lead to a potential enrichment of the water with organic substances such as feed and related additives, which are continuously added to the recirculation system. This requires efficient water treatment to ensure optimal husbandry conditions for the fish. Biological filter systems contribute the degradation of dissolved organic compounds from feed residues and fish excreta with the help of bacteria, which are offered the largest possible colonization area in special filters. Effective disinfection processes (e.g. UV irradiation or ozone treatment) are also available to reduce germ pressure and the pollutant load in the holding water.

Since recirculation systems have individual cleaning dynamics, the comparison of several units is necessary in the context of recirculation management studies. The test units commissioned in Schmallenberg consist of 7 identical individual circuits, which allow the comparison of treatment and control groups, each with several replicates. To minimize the effort required to conduct the studies, the size of the individual circuits (production tank size of 250 l per circuit) was kept to a minimum. The individual circuits are made of stainless steel, which allows the use of ¹⁴C-labeled substances. This allows valuable information to be obtained on the fate of feed-related and biogenic substances in the production chain. The new RAS system can be operated in freshwater modes. Different fish species such as rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus) can be used for the feeding experiments.

The totality of all non-genetic, endogenous as well as exogenous environmental influences in the aquaculture system represents the „exposome“ of the facility to which the animals are exposed during the production process. Modern analytical instruments available at the site can be used to quantify organic matter in water and fish tissue samples collected during the studies. The combination of highly specific analytics and isotope-labeled compounds enables the identification of metabolites of organic substances.

With the innovative aquaculture test facility and the modern chemical-analytical, microbiological and molecular biological laboratories at the Schmallenberg site, Fraunhofer IME has the possibility to offer its customers a comprehensive evaluation concept for aquaculture. Furthermore, the studies can all be carried out under GLP (Good Laboratory Practice).