Learnings from Sotenäs Symbioscentrum - From local partnerships to a circular blue economy

At Arctic Food Arena, we investigate how circular food systems can strengthen regional resilience. A powerful example is Sotenäs Symbioscentrum in Kungshamn, Sweden- where the municipality, seafood companies, energy producers, farmers, and innovators collaborate to transform marine by-products into value.

Founded in 2015 and driven by Sotenäs Municipality, Sotenäs Symbioscentrum has become one of Sweden’s most active hubs for industrial, social, and marine symbiosis, showing how coastal regions can build thriving circular blue economies.

What is Sotenäs Symbioscentrum?

Sotenäs Symbioscentrum is a municipal initiative located in Kungshamn that coordinates circular collaboration between seafood processors, biogas producers, agriculture, recycling companies, and clean-tech innovators.

The center emerged from over a decade of local collaboration on waste reduction and resource efficiency. Inspired by a 2013 study trip to Kalundborg, the municipality formalized the Symbioscentrum to drive industrial symbiosis and support sustainable local business development.

Today, it connects key actors such as:

Seafood companies: Marenor, Leröj, Orkla, Smögenlax (under development)
Energy & waste: Renahav (biogas & water treatment)
Agriculture: Klevs Gård
Circular material innovators: Swedish Algae Factory
Local producers: Smögenbryggar’n brewery
Recycling & marine cleanup: Sotenäs Marina Återvinningscentral

What’s happening on the ground?

Sotenäs has created a closed-loop ecosystem where marine resources are continually reused and upgraded:

Wild-caught and farmed fish is processed into food products (Marenor, Leröj, Orkla). Algae and related advanced materials (Swedish Algae Factory) are produced from the nutrient rich wastewater from food processing, returning purified water to the industry. Algae and food waste are used to brew a local beer (Smögenbryggar´n). Fish waste is used as feed ingredients and the remaining wastewater goes into the treatment plant (Renahav), producing clean water and supplying the other cluster companies with hot water, biogas and electricity. The remaining electricity is supplied to the public grid. Fishing gear, marine waste and plastic is collected and recycled in Sotenäs Marina Återvinningscentral.

Renahav as a circular engine

Renahav’s biogas and water treatment facility converts mixed seafood and food-processing wastewater into:

176,000 m³ clean water

25,000 tons of fertiliser

3.1 million m³ biogas per year

1 MW electricity + 1 MW hot water

A dramatic reduction in TOC emissions (from 154,000 kg in 2013 to just 2,027 kg in 2024)

The result is a multi-industry circular ecosystem where each company becomes both supplier and customer of others’ by-products.

What’s next?

The region is poised for significant expansion:

Smögenlax plans to establish a 6,000 ton/year land based recirculating aquaculture system (RAS) salmon farm with their own feed production.
- Environmental permit received in January 2025.
- Phase 1 of large-scale harvest and sales planned to be launched in 2029, with a goal of 2000 ton/year.
- Phase 2 aims to scale harvest and sales to 4,400 ton/year by 2031 and 6,000 ton/year by 2032.
Renahav wants to increase the energy production by increased food waste inclusion, increase the gas value by upgrading and compressing to compressed biogas (CBG), start production of consumer eco fertilizer and additional value-added products from fish waste to grow a stable cash flow.
Crisis preparedness: Renahav and Smögenlax will be developed to fully function at public electric grid failures of less than 30 days. Freshwater production from desalination will be developed.

Overall, the next phase requires 200 MSEK new investment and is expected to create 150 local jobs (direct + indirect).

Key Insights

Neutral facilitation matters. The municipality plays a critical role in coordinating actors, securing funding, and sustaining collaboration. Companies own the flows, but the municipality enables the system.
Build win-win flows. Successful symbiosis depends on business models that benefit all partners, not just waste reduction.
Trust and continuity are essential. Long-term relationships, transparency, and commitment keep the network stable through change. You can’t leave the negotiation table until everyone is satisfied.
Strategic attraction strengthens the ecosystem. Bringing in new actors, such as RAS aquaculture and algae biotech, expands and reinforces existing resource loops.
Experimentation drives progress. Pilot tests, demos, and a willingness to try new solutions accelerate innovation and reduce risk. Be brave and dare to try new things!

Did you know…

Arctic Food Arena visited Sotenäs Symbioscentrum as our very first study visit of the project. We were joined by our reference group in Kungshamn for two days of site visits, inspiration and idea exchanges. Thank you to all of the actors of Symbioscentrum who have inspired our journey.

We also have a guide exploring warm-water fish species suited for aquaculture in an arctic climate. Check it out here