Burgeoning seaweed industry on the North Sea

Last April, two very promising research project were launched that study the production of seaweed on the North Sea. ECN is involved as knowledge supplier and leader of large consortia in which businesses and research institutes are represented. Both projects are financed by the Seventh Framework Programme of the European Union.

Fish farming

How can businesses efficiently combine the cultivation of fish and shellfish with seaweed? This is the main question of the Mermaid project. In fish farming, many nutrients end up in the sea in the shape of droppings. They can serve as nutrient in the cultivation of seaweed. Seaweed cultivation may constitute an interesting additional source of income for entrepreneurial fish farmers, especially if seaweed can be successfully converted into high-protein fish food or if it can be used as source of energy. The manufacturing costs can be significantly lowered this way. Together with ECN, Hortimare and the Danish company DHI, Norwegian and Danish fish farmers are exploring integrated systems for aquaculture and energy generation.

Source: Hortimare


A second consortium focuses on seaweed cultivation on textile as opposed to ropes or nets, which is currently the common technique. Textile appears to offer excellent opportunities: not only is it relatively low-cost; it is also strong and flexible and therefore highly suitable for use at sea. Moreover, textile is very suitable for making inflatable elements. These make for strong yet supple floating devices for the horizontal canvasses on which the seaweed can grow.


In the At~Sea project, industrial textile manufacturers are collaborating intensively with seaweed cultivators and with the research partners ECN, the Scottish Association for Marine Science and MarinTek, which is part of the Norwegian company Sintef. Sioen, a large, innovative textile company in Flanders, is the consortium leader together with Centexbel, the Belgian textile umbrella organisation. In this project, Hortimare is again one of the participating seaweed companies.
ECN will integrate all separate elements into one cultivation system. The innovative substrates from textile that is used for growing seaweed need to be combined with floating devices and anchors to make for a system that is easy to manage by the grower. Planting young seaweed plants and harvesting the seaweed should be easy to do. That may seem simple, but each action that people need to perform at sea is expensive; the process therefore needs to be automated as much as possible.

Sellable product

At~Sea is a 3-year project. At the end of the project, a pilot system needs to be ready that can be used to cultivate seaweed in an innovative way in Europe and elsewhere, for example to produce alginate (a polymer that is used in dentistry and to thicken ink), mannitol (a sweetener), proteins or energy in the shape of biofuel or methane. At~Sea will yield a product that can be sold and that can bring benefits to the textile industry as well as the burgeoning seaweed industry.

Would you like to get more information about this project or other seaweed projects?

Please contact Jip Lenstra.