OCEAN GARDENS: a scalable and modular approach to open-ocean seaweed aquafarming for sustainable products enabling carbon dioxide removal and marine ecosystem co-benefits

To address climate change and protect the oceans, a rapid reduction in greenhouse gas emissions is imperative. Achieving this target requires scalable alternatives to fossil carbon sources. Currently, biofuels rely on land-based biomass, which is inherently limited and competes with food production for land, freshwater, and fertilizers. Ocean-grown seaweeds present a transformative solution as a sustainable feedstock to decarbonize the transportation and chemical industries. Unlocking their potential, at the scale required for meaningful impact, necessitates the development of large-scale offshore seaweed aquaculture farms. Ocean Gardens aims to pioneer this effort by proving the feasibility and viability of innovative methods and suitable locations for cultivating seaweeds in polyculture across the European Union’s offshore waters.

With a robust consortium comprising SME, research institutions, and local stakeholders, this project will demonstrate the feasibility of cultivating native seaweed species using innovative floating techniques in the open ocean. These methods offer a more cost-effective and scalable alternative to traditional line-based seaweed farming. Over the course of the project, environmental impacts and co-benefits—including carbon uptake, nutrient bioremediation, and biodiversity changes—will be monitored through a combination of established and novel tools, such as in situ sensors, drones, and cameras.

Gran Canaria, Spain, will serve as the primary demonstration site, where operational permits are already secured. The project will also evaluate the potential for replicating this model in Galicia and the Mediterranean, exploring the advantages of co-cultivation with mussel and fish aquafarms. This will involve studying the physico-chemical properties of local waters, identifying suitable native seaweed species, and analyzing the regulatory framework and market applications for cultivated biomass in each region.

A strong emphasis will be placed on dissemination and education. Workshops for the general public will be held in Spain, France, and Germany, alongside targeted training for government personnel overseeing permitting processes and hands-on sessions for local fishermen and participants in inclusion projects for immigrants in Gran Canaria. These efforts aim to raise awareness about the diversity of seaweed species that can be cultivated in European waters, their positive impact on marine ecosystems, and their applications in driving a transition toward a just and sustainable future.