WHY SEAWEED?

Seaweed is more than just something washed up on the beach.

Around the UK’s coastline, seaweed plays a vital role in the health of our seas, our climate, our economy, and our food system. As interest grows in sustainable industries and nature-based solutions, seaweed is becoming increasingly important for the UK’s future.

Seaweed Around the UK

The UK has a rich and diverse seaweed resource. Over 650 different species of seaweed (known as macroalgae) are found around UK coasts.

This includes seven different species of kelp , which form large underwater forests in cooler, nutrient-rich waters.

Seaweeds grow along rocky shores and beneath the surface in coastal waters all around the UK. Unlike land crops, seaweeds do not need soil, freshwater, fertilisers, or pesticides to grow.

Supporting Healthy Seas

Seaweeds provide essential habitat for marine life. Kelp forests and seaweed beds can:

Offer shelter and food for many marine species
Provide important nursery areas for juvenile fish, crustaceans, and other marine life
Support healthy fisheries and wider marine ecosystems
Help reduce wave energy, contributing to natural coastal protection

Healthy seaweed ecosystems are a key part of resilient and productive UK seas.

Helping Tackle Climate Change

Seaweed can play a role in addressing climate change:

It absorbs carbon dioxide as it grows
It grows quickly and efficiently
It does not require land or freshwater

Research is ongoing into the role seaweed may play in long-term carbon sequestration, as well as how it can help reduce emissions when used in place of more carbon-intensive products. While seaweed is not a single solution, it is increasingly recognised as part of a broader climate and nature strategy.

Reducing Pressure on Land and Resources

As the UK looks for more sustainable ways to produce food and materials, seaweed offers clear advantages:

No competition with farmland
No need for irrigation
Lower environmental impact compared to many land-based crops,

This makes seaweed an attractive option in a world facing climate change, biodiversity loss, and growing demand for resources.

Food, Health, and Nutrition

Seaweed is nutritious and versatile, with nutrient content varying by species, location, season, and processing method. Across different types of seaweed, nutrients can include:

Vitamins A, C, E, and K
Minerals such as iodine, magnesium, potassium, iron, and sodium
Fibre and complex carbohydrates (polysaccharides)
Polyunsaturated essential fatty acids, including DHA and EPA
Sugar alcohols such as mannitol and sorbitol
Phytochemicals including polyphenols and carotenoids

Seaweed also contains glutamic acid, which converts to glutamate and gives seaweed its distinctive umami flavour, enhancing savoury dishes naturally.

Seaweed has a long history of use in food and agriculture in parts of the UK and is now being rediscovered as a sustainable and healthy ingredient.

Did you know? Seaweed used to be used to fertilise jersey potatoes and helped to give them their distinct flavour!

Commercial Seaweed Species in the UK

These species are used across a range of food, agricultural, and industrial applications. Seaweed cultivation and some seaweed harvesting requires a licence. For guidelines on the regulations and licensing process in England, please see the CEFAS report on the ‘Resources’ page of this website.

Sea Lettuce
(Ulva lactuca)

Knotted Wrack
(Ascophyllum nodosum)

Dulse
(Palmaria palmata)

Sea Spaghetti
(Himanthalia elongata)

Winged Kelp
(Alaria esculenta)

Kelp
(Laminaria digitata)

Sugar Kelp
(Saccharina latissima)

Uses of Seaweed

Seaweed has a wide and growing range of uses, including:

Seaweed-based biostimulants for agriculture and horticulture
Food products, from fresh and dried seaweeds to ingredients and seasonings
Packaging and bio-based materials as alternatives to plastics
Animal feed additives, including research into methane-reducing feeds
Beauty and personal care products

Many face creams, cosmetics, and skincare products already contain seaweed-derived ingredients, valued for their binding, moisturising, and antioxidant properties. Many foods like yoghurt and ice cream also contain seaweed-derived alginate because it acts as a thickener and stabiliser, improving texture, helping ingredients stay evenly mixed, and preventing problems like ice-crystal formation or separation during storage.

Face Cream

Ice Cream

Cosmetics

Skincare

Did you know?

A brief history of the seaweed UK industry

C. 500 CE

The beginning

Archaeological evidence suggests seaweed was used as food, animal fodder, and fertiliser by our prehistoric ancestors, just as we do today. It also played a role in early salt extraction and medicine.

500–1500

The rise of seaweed

By the medieval period, seaweed (particularly various species of wrack) became central to coastal agriculture. Rights to collect seaweed were often regulated by local custom or feudal law. Burning seaweed to produce soda ash (used in glass and soap-making) also began on a small scale.

1500–1850

Industrial expansion

The industry expanded significantly with the rise of kelp burning: seaweed was burned to produce alkali (sodium carbonate), supporting booming industries such as glassmaking, soap, and textiles. At its peak (late 18th-early 19th century), kelp production employed tens of thousands of people.

Mid-late 19th Century

Decline of the traditional industry

The kelp industry collapsed due to cheaper imported alkalis and the rise of alternative, industrial chemical processes. Seaweed use reverted largely to local fertiliser, small-scale food and animal feed and many coastal economies suffered as a result.

20th Century

Scientific & Commercial Revival

New industrial uses emerged with extraction of alginates (used as thickeners and stabilisers) and uses in food processing, pharmaceuticals, and textiles. Scotland became the centre of UK seaweed harvesting and processing.

21st Century

Sustainability & Innovation

This century has seen renewed interest driven by sustainable food systems, climate change mitigation and bioplastics, biofuels, and carbon capture. There has been a growth in seaweed farming trials and high-value food, cosmetic, and nutraceutical products. The industry is being developed with a strong emphasis on environmental regulation and ecosystem protection.

Today’s UK Seaweed Industry

Today, the UK seaweed industry is a diverse mix of traditional wild harvesting and emerging cultivation:

Around 99% of UK seaweed supply currently comes from wild harvesting
Seaweed cultivation is an emerging sector with growing interest
Key seaweed hotspots include Western Scotland, the Hebrides, Cornwall, and Devon

When well-managed, both wild harvesting and cultivation can support coastal jobs and rural economies while maintaining healthy marine ecosystems.

The Importance of Responsible Growth

As the industry develops, responsible growth is essential.

This includes:

Science-based management and regulation
Environmental monitoring and protection
Collaboration with coastal communities, fishers, and other sea users

Done well, seaweed can support nature recovery, climate goals, and sustainable economic development.

Looking Ahead

Seaweed is not a single answer to environmental or economic challenges, but it is a powerful part of the UK’s growing blue economy. By supporting sustainable seaweed harvesting and cultivation, the UK can protect its marine environment, strengthen coastal communities, and build a more resilient future. The UK Seaweed Network aims to support the UK Seaweed industry to do just that.