Rethinking fish farming: sea bass from the Münsterland region

Farming has always been practised on the Niehues family’s farm in Sendenhorst. But Carl Niehues knew that simply taking over his parents’ farm and keeping even more pigs or cattle wasn’t the right path for him. He was looking for a genuine alternative – a sustainable niche that combined agriculture, animal welfare and reduced resource consumption.

In the heart of the Münsterland region, Carl and his wife Louise eventually set up a modern saltwater fish farm – powered by solar energy and integrated into a closed-loop system that also includes a biogas plant. Louise manages the fish farm and organises the entire production process. Through her dedication, she ensures that the highest quality and smooth operations are guaranteed every day.

At the same time, Johannes Wolf was looking for a place where his passion for fish and his belief in responsible, regional food production could come together. He is a qualified fish farmer, experienced in marketing and trade, but had always wanted to do things a little differently. He wanted to set up a fish farm that was fair, regional and transparent.

An Instagram advert drew Johannes’s attention to the Niehues family’s farm. It soon became clear that something extraordinary was happening on the site. Whilst the technical infrastructure was already of the highest standard, there was a lack of a well-thought-out strategy for marketing and scaling up. Johannes recognised the potential and brought extensive expertise and a clear vision to the table. That first visit developed into a sustainable partnership. From their shared vision emerged ‘Geflossenschaft’ – an innovative initiative for inland saltwater aquaculture.

The saltwater fish-farming system is manufactured by Seawater Cubes GmbH and was developed on the basis of many years of research at the Saarland University of Applied Sciences. Covering an area of approximately 120 square metres, the systems produce around seven to eight tonnes of fish per year. The fish reared are schooling species such as sea bream and sea bass, as they are particularly well suited to aquaculture. As they naturally swim in close-knit schools, they can be kept efficiently in recirculating systems, which corresponds to their natural group behaviour and can help to keep stress levels low.

Sensors were used to monitor both the fish’s stress levels and the relevant environmental factors in order to ensure animal health and welfare as effectively as possible. The water is crystal clear, and the use of medicines or antibiotics is strictly prohibited. The daily water exchange rate in the systems is less than one per cent – an extremely low figure made possible by technical water treatment. 

Another advantage: the nutrient-rich wastewater from fish farming, which is enriched with nitrogen and phosphorus from feed residues and excrement, is used to fertilise the fields – a key component of the circular economy, where nothing is wasted but everything is put to further use. Thanks to a combination of the farm’s own photovoltaic system, biogas and battery storage, the operation is energy-efficient and largely self-sufficient in electricity from renewable sources.

As well as fish farming, the cooperative offers a range of activities centred on environmentally conscious, regional food education: these include, for example, school visits, cookery events and information sessions for consumers. This enables those interested to gain an insight into the practice of modern aquaculture and to better understand where their food comes from.

The vision is clear: over the next three years, ten further facilities are to be established across Germany, all with the same aim: to rethink fish production – regionally, transparently and collaboratively.