Microalgae represent the basis of the food chain in aquatic systems and bind nutrients and CO2 to build up their biomass. Today, microalgae are cultivated for the production of various products (e.g. for human and animal nutrition, for cosmetics, as raw material for energy or the chemical industry).
In this project a novel idea is developed. The tendency of selected algae species to anchor to a solid object is used for immobilization on a textile carrier, supported by biological surface functionalization. Thus, a high growth density of microalgae can be achieved while simultaneously ensuring a high or growth-promoting nutrient supply in indoor aquaculture systems through the constant flow around the textiles and thus the algae in a biofilm reactor.
Integrating algae production into a shrimp (prawn) aquaculture system recycles nitrogen excreted by the animals and derived from feed residues through the algae into a very valuable and highly usable feed or protein source for shrimp growth. When the shrimp are fully grown, they are harvested and sold as high-quality food. The newly developed algae production modules have been integrated into an indoor shrimp facility in Germany and are currently being tested.
Indoor aquaculture in recirculating systems is still a niche market in Germany and tries to present itself as a positive example of a responsible and sustainable method of aquaculture, in contrast to the often critically portrayed aquaculture with well-known negative headlines about environmentally damaging forms, especially in pond cultures in the tropics. In 2016, the Food and Agriculture Organization (FAO) in its report on the status of fisheries and aquaculture for Europe predicted an annual growth of aquaculture of about 3 % until 2025.
