Uses for Seaweed content

Uses for Seaweed

There are numerous edible species that grow around the British Isles, including Shetland. Brown seaweeds are the most abundant. Diagrams, identification tips and lots more useful information can be found in our Fuelling the Future leaflet. 

Food and drink

Seaweed has been a food source for thousands of years, forming a staple part of the diet in countries like Japan, Korea and China. In European countries, seaweed has often been used as an alternative food source during hard times while Welsh ‘laver’ and ‘dulse’ are considered delicacies by many. Recently, there has been increased interest in seaweed as a food source due to its high antioxidant and mineral content.

Agar is made from certain red seaweeds and used in food production.

Carrageenans are extracted from red seaweed and are widely used in the food industry, for their gelling, thickening and stabilising properties. Their main application is in dairy and meat products, due to their binding to food proteins.

Liquid seaweed extracts from brown seaweeds are used as mineral and vitamin supplements in agriculture, horticulture, animal husbandry and, more recently, in human health products.

A Seaweed Harvesting Workshop was delivered by the Shetland Seaweed Growers in 2015. The workshop gave guidance on how to sustainably harvest bladderwrack from the shores.

Cosmetics, medicine, science

Alginates are extracted from brown seaweed and used to create gels for foams, stabilisers, emulsifiers and industrial gums. They are also used by the cosmetic and health industries for body wraps, facial masks, soaps, shampoo and conditioners, make-up gels/creams, indigestion remedies, encapsulating particles and absorbent wound-dressings, along with a range of other products.

More recently, the anti-bacterial and anti-cancer properties of seaweed derivatives such as fucoidan and laminarin are being investigated by the pharmaceutical and medical professions.

Agar is made from certain red seaweeds and is universally used in laboratories as a substrate for bacteria cultures. There is currently no satisfactory substitute for laboratory agar.


Historically, kelp was burned on a massive scale (including in Orkney and Shetland) to produce ‘potash’ (potassium salts) for fertiliser. This practice has now been replaced by world-wide mining of potash ores.