The project explored new forms of industrial symbiosis, showing how residual resources such as water, heat or nutrients from one process could support RAS operations. Four pilots were implemented to test complementary solutions: treatment of RAS discharge water for reuse in other industries; utilisation of geothermal resources to heat and mineralise RAS water; development of concepts for a fully circular agro‑industrial park with RAS; and a small‑scale demonstration RAS designed to build public awareness and skills.

Now completed, TETRAS delivered a comprehensive Portfolio of Solutions, compiling all project results into practical guidance for decision‑makers, investors, developers and regulators. The portfolio includes investment‑ready business cases, feasibility studies, licensing and permitting guidelines, technical recommendations, LCA insights, communication tools and a set of non‑technical recommendations designed to support innovation and market access for RAS and related symbiotic concepts.

By providing evidence‑based tools and demonstrating real‑world applications, TETRAS equipped public authorities, industry actors and research institutions with the knowledge and practical models needed to integrate RAS into regional development strategies. The project has contributed to more sustainable use of aquatic resources in the Baltic Sea Region and supported the transition towards a circular blue economy.