Harvesting seaweed for the dinner table

Globally, there are between 10,000 and 20,000 different described species of seaweed, or macroalgae. In Norwegian waters, there are around 500 species. Most can be classified into three groups based on colour: red algae, green algae, and brown algae.

In Europe, the consumption of macroalgae as food is very low, even though historically it has been part of both diets and animal feed. Seaweed as food is most common in East Asia, but we are now seeing greater interest in harnessing the diversity of the ocean also in Europe," says Dr Hanne Mæhre from NIBIO.

However, it is important to exercise caution when harvesting seaweed for food as it absorbs harmful substances such as iodine and heavy metals from seawater. Generally, it is the brown algae that accumulate the most of these harmful substances. Yet, there are significant variations between species, growing locations, age, and seasons. Oarweed is a good example of a brown algae that should not be harvested for food.

As the use of seaweed has decreased, much of the knowledge about these resources has also been lost. To increase their use in the right way, it is therefore important to increase public knowledge about these raw materials.

“Since macroalgae grow in the ocean, they require neither agricultural land nor freshwater to grow. This makes them more sustainable alternatives for food and feed than many terrestrial plants," says Mæhre.

In the ALGEBRA project, NIBIO, in collaboration with Tuvsjyen AS, has developed prototypes of various products with the aim of facilitating increased use of locally harvested seaweed for the dinner table.