One of 4 founders of blün - Gregor Hoffmann. Coypright by blün.

The Clarias gariepinus as a climate saviour?

What does an African catfish do in the Vienna Glasshouse? Correct: the fertiliser. And the aquaponics pioneers at blün want to use it to revolutionise agriculture and solve the climate crisis. Can that work?

On the edge of Marchfeld, where the land is flat, the nearest metro station is far away and most cars are delivery vans, that is also where the greenhouses of the blün company are located. At first glance, the facility resembles the glass houses in the neighbourhood. At blün, too, tomatoes grow under the glass roof. But next door in the dark hall, fish with long barbels chill in their tanks. The fish are swimming next to the vegetables for a reason. Fish tanks and plants are connected by pipes. So the water in which the catfish swim can fertilise the tomatoes.

One man's "dirt", another man's nutrient!

Austria's aquaponics pioneers want to revolutionise agriculture with the help of the African catfish and make a contribution to the fight against the climate crisis. The blün founders have one goal: to use the traditional technique of circular farming to grow fish and vegetables in a resource- and climate-friendly way for the big city of Vienna.

Wandelklima video video about the aquaponics pioneers of blün:

This video was made possible by a thematic sponsorship of the Federal Ministry for Climate Action (BMK) & the Association for Non-Profit Foundations. Credit: Wandelklima.

What is aquaponics and why is this technology good for the climate?

Aquaponics is the name given to the mixed form of aquaculture and agriculture where fish and vegetables are grown in a recirculating system. This type of food production saves water, energy and resources and thus also greenhouse gases. In addition to lower resource consumption, modern aquaponics facilities require little land and can be set up almost anywhere. This strengthens the local economy, shortens transport distances and thus reduces CO2 emissions. In addition, aquaponics helps to protect the oceans from overfishing and pollution caused by aquacultures.

Circularity at blün. Copyright by blün.
Circularity at blün. Copyright by blün.

Eating sustainably - also in Ecolabel top gastronomy.

blün products are now used in the pots and pans of several renowned Viennese top chefs. Sustainably produced fish and vegetables are available, for example, at the Labstelle restaurant at Lugeck in Vienna's 1st district, certified with the Ecolabel.

The whole report can be read at

Cooperation & Theme Sponsorship

The focus on environmental protection is underrepresented as far as engagement from the legal form of the foundation is concerned. The Association for Charitable Foundations (VgS) has therefore been trying to counteract this since 2019 together with the Ministry of Climate Protection (BMK). How is this being done?
Together, the focus is on those environmental issues that are particularly relevant for philanthropic actors. Ideally, a foundation itself is a central actor. Together with a theme ambassador, innovative best practice and pioneer projects are discussed. In cooperation with the non-profit association "Wandelklima", multimedia stories on selected environmental topics are published - such as the one about the company blün in the context of the focus on the circular economy. The theme ambassador also sponsors a multi-stakeholder future workshop in the form of a 2-hour webinar at the end of a thematic block. The next topics in preparation are "Biodiversity" and "Sustainable Mobility". If you are interested in the future workshops on these two topics, simply call + 43 664 544 10 90 or send an email.

An article about the cooperation between the Association for Non-Profit Foundations and the Ministry of Climate Protection was published in the magazine BUSINESSART 4/2021 with the title: "Money for environmental research and innovation: What Wanze and Wels have to do with foundations".