Rethinking fish farming: sea bass from the Münsterland region

Farming has always been practised on the Niehues family farm in Sendenhorst. But Carl Niehues knew that simply continuing to run his parents' farm, keeping even more pigs or cattle - that was not his path. He was looking for a real alternative, a sustainable niche that combined agriculture, animal welfare and climate protection.

In the middle of Münsterland, Carl and his wife Louise finally built a modern saltwater system for fish farming - powered by solar energy and embedded in a closed cycle that also includes a biogas plant. Louise manages the fish farm and organises the entire production process. With her commitment, she ensures that the highest quality and smooth processes are guaranteed every day.

At the same time, Johannes Wolf was looking for a place where his passion for fish and his conviction for sustainable food production could come together. He is a trained fish farmer, experienced in marketing and trade, but always wanted to do something different. He wanted to organise fish farming fairly, regionally and transparently.

Johannes became aware of the Niehues family's farm through an Instagram advert. It quickly became clear that something extraordinary was happening on the site. While the technical infrastructure was already at the highest level, there was a lack of a well thought-out strategy for marketing and scaling. Johannes recognised the potential and brought extensive expertise and a clear vision to the table. The first visit developed into a sustainable partnership. The joint idea gave rise to Geflossenschaft - an innovative initiative for sustainable saltwater aquaculture inland.

The saltwater system for fish farming was developed by the manufacturer Seawater Cubes GmbH on the basis of many years of research work at the Saarland University of Applied Sciences. The systems produce around seven to eight tonnes of fish per year in an area of around 120 square metres. Shoaling fish such as sea bream and sea bass are bred, as they are particularly suitable for breeding. These species require little free swimming space and can therefore be kept efficiently in closed circuits. Keeping them in shoals corresponds to the natural behaviour of the animals and contributes significantly to their well-being and low stress levels.

Sensors were used to record both the fish's perception of stress and the relevant environmental factors in order to optimise animal health and well-being. The water is crystal clear and the use of medication or antibiotics is taboo. The daily water exchange rate of the systems is less than one per cent - an extremely low value that is made possible by technical treatment.

Another plus: the fields are fertilised with the nutrient-rich wastewater from the fish farm, which is enriched with nitrogen and phosphorus from feed residues and excrement - a real building block of the circular economy, in which nothing is lost but everything continues to work. The combination of photovoltaics, biogas and battery storage creates a completely self-sufficient, climate-friendly fish farm in the centre of the region.

In addition to fish farming, the Geflossenschaft offers various formats relating to the topic of sustainable nutrition: These include school visits, cookery events and information events for consumers. In this way, interested parties can gain an insight into the practice of modern aquaculture and better understand the origin of their food.

The vision is clear: over the next three years, ten more facilities are to be built across Germany, always with the same goal: to rethink fish production - sustainably, regionally and collectively.