Seaweed (macroalgae)

Seaweed is one of the planet’s largely unexploited natural resources and among the fastest growing plants in the world. Norway has a long tradition in harvesting seaweed for alginate production, and there is a growing interest for cultivating seaweed in Norway. More than 400 commercial permits have been granted in over 90 sites along the coast.

Seaweed has several advantages over land-based plants. It only needs seawater and sunlight to grow, it doesn’t require any fertilizer, and it grows rapidly under the cold conditions in Norway. Seaweed also has a positive impact on the environment due to its ability to recycle waste from fish farms and agriculture into valuable sources of nitrogen and phosphorus. Seaweed also binds large amounts of carbon from the water, which helps prevent acidification of the ocean.

Long traditions

Due to its unique features, seaweed can be used in many applications such as human food, animal feed, pharmaceuticals, bioenergy and fertilizer, and thus has a large potential for value creation.

Seaweed has a long tradition as a protein and energy source in food and feed, and as a source of minerals, vitamins and bioactive components that are beneficial to both human and animal health.

The most relevant species of seaweed for feed is brown seaweed such as sugar kelp (Saccharina latissima), winged kelp (Alaria esculenta), and finger kelp (Laminaria digitata) because of its potential for high biomass production. The nutritional value of brown seaweed is, however, limited due to the high content of water, ash, complex carbohydrates and various antinutritional factors, as well as the low content of digestible protein and energy.

Breaking it down

To use seaweed in modern animal feed, it is necessary to use targeted processing to increase its nutritional value or functional properties. A cost-efficient way to process the seaweed biomass is by a cascading biorefinery approach where the entire biomass can be used for a range of products.

Foods of Norway researchers are also using the seaweed biomass as feedstock to produce microbial ingredients such as yeast. These processes include enzymatic or acid hydrolysis of the biomass, producing sugar and other nutrients that we use in the fermentation media to produce yeast.

Seaweed contains valuable bioactive components with documented health effects. Bioactive components extracted from the seaweed biomass are used in functional feeds for salmon and broiler chickens. A major research effort by Foods of Norway and supporting projects is to develop new tools to upgrade the nutrient value or to develop functional feed components from seaweed, including development of a tailormade enzyme toolbox.


Published 28. August 2015 - 14:11 - Updated 4. November 2021 - 12:10