KfW Entrepreneurs’ Award

KfW Entrepreneurs’ Award

Saltwater fish from Saarbrücken

Problematic conditions caused by open-net pens used in aquaculture and long transport routes have caused many conscientious consumers to lose their appetite for farmed fish. But it is possible to farm saltwater fish sustainably anywhere – even in landlocked places. Something the founders of SEAWATER Cubes have proven. Fish are raised in the best possible conditions in their modern systems. For their idea, the start-up won the KfW Entrepreneurs’ Award for the German state of Saarland.

Video: How SEAWATER Cubes manages its regional fish farm (KfW Group/n-tv).
This video is only available in German.

To buy fresh fish, residents of Saarbrücken could drive four hours to the coast – or go just around the corner, since they can find delicacies such as sea bass and Australian barramundi in the farm store, not at all far from their home in the capital city. The start-up SEAWATER Cubes has developed aquaculture in recycled freight containers on the outskirts of the city, making it possible to raise salt-water fish even inland. The company also sets an example for fair and sustainable production.

“It smells like a holiday by the sea here,” say visitors who pick up the fish they ordered online. It is warm, the air is slightly salty, only the soundscape is more reminiscent of a waterfall than waves. Carolin Ackermann likes to show off the facility: “There are 21,000 fish swimming in the pools. The young fish, which come from a farm in France, are sold when they reach around four grams. After one year, they weigh 400 grams, which is the ideal size for a dinner plate. The fish are prepared for sale here on site.”

The founders of Seawater Cubes (from left to right): Christian Steinbach, Carolin Ackermann and Kai Wagner

Christian Steinbach, Carolin Ackermann and Kai Wagner (left to right) raise saltwater fish in recycled freight containers.

From university studies to start-up

Co-founders Christian Steinbach and Kai Wagner, both in their early 30s, were already in charge of a saltwater recirculation system for fish farming during and after their university studies at the University of Applied Sciences in Saarbrücken. At the time, the city invested a considerable amount in the large-scale project and worked together with the university. But the project went bankrupt and after a buyer was found, that buyer terminated the partnership. The two scientists became unemployed.

But the experience they gained would not be for naught. It led to the idea to develop a compact system suitable for serial production and thus scalable, while also being suitable for farmers seeking an alternative source of income. They applied for EXIST funding from the German Federal Government for their project. Thanks to a recommendation from one of their professors, they joined with Carolin Ackermann, who brought a background in business administration. She had always wanted to start a company “and when you throw engineers and business graduates together, good things come out of it,” she says with a laugh.

It took two years to set up the start-up, which was also supported by Business Angels and by the venture capital company Saarländische Wagnisfinanzierungsgesellschaft mbH. Parallel to the construction of the first facility, the company was spun off as a limited liability company (GmbH), and one year after operations got underway, the sale of the fish began.

Read more under the image gallery.

 The two founders of Seawater Cubes Carolin Ackermann and Christian Steinbach in conversation at the fish tank

Carolin Ackermann and Christian Steinbach at one of the breeding tanks. The system forms a closed circuit, with the salt water constantly recycled.

Sophisticated technology

There are only a handful of competitors and most of them focus on freshwater fish, because the water for them comes from the tap. Anyone who wants to farm sea bass or the exotic and very tasty barramundi has to go the extra mile. The water is salinated with a mineral mixture similar to the composition of the ocean, and it is important to minimise losses of this water. For this reason, the water is subject to continuous treatment.

Carolin Ackermann explains the process: “The basin contains 55,000 litres of water, and the movements of the fish, in addition to the pump, create a good flow. The fish excrement and food waste are collected by a sieve. Biological filters process the ammonium contained in the fish urine. Bacteria convert it to nitrate and then to harmless nitrogen, which is released into the air. The water is completely recirculated three times an hour. We recycle 99 per cent of the water and only need to add 500 litres of water every day.”

An average of one hour per day is enough to operate the fully automated facility. It can even be remotely operated from home. The modular design makes it easy to scale the system.

Kai Wagner, one of the three co-founders of Seawater Cubes, at the delivery of the fish

System operation is fully automatic, but as soon as the fish are big enough to be sold, manual work is required.

Antibiotics are taboo

The fish are given protein-rich feed made from food production residues and plants such as peas or wheat. Antibiotics or other pharmaceuticals, as those used in many environmentally harmful aquaculture facilities in the ocean, are taboo here.

Three different age groups are raised in the separate tanks. This means that there is always a sufficient number of fish ready for sale after the initial phase. The quantities farmed are based on the specific demand. Distributing the fish throughout the region, SEAWATER has become widely known for its high-quality products. Contact with end consumers is important to the founders. They want their customers to know how the fish they buy were raised.

Distribution challenges

The company had initially set its sights on farmers as system buyers. They had a lot of questions, ranging from the necessary permits – which are different in every federal state – to the marketing concept for selling the products. This target group is understandably not very risk-averse because often their entire livelihood depends on success. On the other hand, farmers have suitable locations, staff and experience with animals. To make getting started easier, SEAWATER Cubes is thus planning a franchise model. A training concept has already been developed.

Also targeted are companies that want to set up urban farming projects or urban local supply chains, as well as investors who are committed to sustainable food production. To do this, the start-up needs to collect more references. The plan is to add three new sites before the end of 2021 to prove the system’s readiness for market. There are also plans to expand the facility in Saarbrücken. For financing, the founders want to explore new avenues and are launching a crowdfunding campaign in February 2021.

Of course, the fact that SEAWATER Cubes won the KfW Entrepreneurs’ Award also helps to raise awareness and put the plans into practice. However, one goal cannot be measured in terms of numbers: “Many people don’t know how much work it takes to produce good food. We would like to play a role in raising awareness – especially of the animals that end up on our plates. Our generation can and must change this situation!” says Carolin Ackermann.

Published on KfW Stories: 13 January 2021.