SEABIOPLAS proposes seaweeds as alternative source for the production of biodegradable polymers, offering advantages over traditional plant sources, including higher productivities, no competition for land use, minimal water consumption while having similar sugar contents and contributing to the reduction of CO2 emissions. SEABIOPLAS offers a complete integrated solution to the plastic SMEs and large enterprises stakeholders involved through the scientific knowledge provided by the RTDs, from the production of the feedstock in sustainable Integrated Multi Trophic Aquaculture systems, to the development of the bio-polymers using innovative technologies of reduced environmental impact until the validation test of the seaweed based-polymers in greener plastic products (shrinkable and stretchable films, adhesives, plastic additives and coatings). As a complement, the viability of valorizing the seaweed by-products as benefic ingredients for European seabass (Dicentrarchus labrax) feeds will be essayed controlled rearing units and IMTA (Integrated multi-trophic aquaculture) sites.