A United Nations advisor and seaweed guru has called on Scotland to develop seaweed farming and pioneer a “revolution” which he said could solve “the climate crisis, the social crisis, and the environmental crisis”.

Speaking at an Edinburgh Science Festival event, Vincent Doumeizel described seaweed as the greatest “untapped resource” we have on this planet - and said they should be rebranded 'sea vegetables'.

“If we want to repair the ocean rather than destroying it," he said, "seaweed is the best place to start. It does not need land, does not need to be fed, does not need pesticide, and, guess what, you don’t even need to water it.”

Not only could it, he said, be harnessed “to solve the problem of world hunger”, but it could be used to create a biodegradable bioplastic, replace chemical fertilisers, decarbonise food production, and even decrease the methane burped by cows and sheep.

Designers have even found ways to use it to make fabric, replacing cotton and other unsustainable materials in our clothes. Seaweed is also already being used in pharmaceutical treatments for cancer, Alzheimer’s, and cystic fibrosis.

A study by the University of Stirling showed that seaweed derivatives could be used to combat strains of bacteria that cause acne.

Seaweeds can also provide, he said, “a source of jobs and revenue to coastal communities where fishing resources will disappear and keep declining.”

“Scotland,” he observed, “benefits from very strong pioneers in this industry, very strong research centres, very good sea waters, and a very wide biodiversity of seaweed. So Scotland has to license more farms and to grow bigger and better to be the pioneer in this revolution and show the direction to the entire world.”

The Herald:

Vincent Doumeizel at Edinburgh Science Festival

READ MORE: A cry for kelp. Why Scotland's green future could be blue

Mr Doumeizel, who describes himself as “a seaweed evangelist, began his journey when he was working in the food industry in Africa, where he saw, he said, “the face of world hunger”. It was then he decided to dedicate his life to finding the solution to that problem.

He has now written a book titled The Seaweed Revolution advocating the marine plant as a solution to many of the world's crises, and not just hunger. He said: “The food system we have right now is the main contributor to water scarcity, soil depletion, climate change, biodiversity loss, and social crises like modern slavery.”

Scotland, he said, should shift towards algal aquaculture, inspired by what Asian countries, where 99 percent of the world’s farmed seaweed is produced, have already been pioneering for the past fifty years.

“Back twenty thousand years ago," he said, "we stopped being hunter-gatherers and became farmers, but when it comes to the ocean, we are still hunter-gatherers. And one part of the world, Asia, has learned to domesticate the ocean.”

However, since in Scotland, we have different species and different ecosystems, we will learn to develop our own knowledge. The most common method of seaweed farming is on ropes, a technique akin to that used in Scotland to grow mussels.

Among the ideas mentioned by Mr Doumeizel that could be particularly relevant in Scotland is the creation of farms around wind turbine infrastructure. It could also be used as part of a more complex, integrated aquaculture system including salmon pens, whose pollution it could help absorb.

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A harvester for Mara Seaweed gathers kelp on the East Neuk of Fife: Image, Gordon Terris

In Scotland, the seaweed industry is still in its infancy, but he pointed out there are already exciting pioneers. One of these is Mara seaweed, which currently produces gourmet seasoning from seaweed harvested from the East Neuk coastline: flakes of dulse, kelp, and other seaweeds. The company gathers from a 30km stretch for which it has a Crown Estate license

Fiona Houston, Mara's CEO, said: "We manage the licence area to ensure our activities are regenerative and we also have organic accreditation. We supply seaweed for several different uses. As well as producing a rangeof seasonings for consumers and food service, we also produce a range of ingredients that are used by food manufacturers."

Mara Seaweed is currently awaiting planning permission for a farm off St Andrews Bay, which would be the largest seaweed aquaculture licence in Scotland and is raising investment to scale up the business.

The Herald:

Mara Seaweed harvesting kelp, image Gordon Terris

However, one of the big issues preventing Doumeizel’s seaweed revolution from gathering speed is that in Europe and the United States, licences to farm seaweed are extraordinarily hard to obtain.

“Licensing,” he said, “is a big problem for seaweed farming, it is taking on average 5-10 years. In Europe, it’s easier to get a license to pump oil out of the ocean than to grow seaweed.”

One of the potential barriers to seaweed farming in Scotland could be the newly proposed HPMAs which, under current consultation proposals, are set to ban all aquaculture and seaweed harvesting.

READ MORE: ScotGov's HPMA marine plan declared a 'distraction'

Mara Seaweed has plans not only to harvest seaweed for food but to be an innovation hub - and already has research collaborations underway including one looking at developing a process to take seaweed and turn it ultimately into a biochemical called 1,6-hexanediol, which has multiple uses, in construction polymers, paints, and foodstuffs.



Amongst the challenges the world faces, Mr Doumeizel said, is how to provide protein for a global population with an expanding appetite for it, whilst decreasing meat consumption – and seaweeds that are high in protein could also provide an answer to this.

An algae specialist from Wageningen University and Research calculated that by cultivating seaweed in 2 percent of our oceans the protein requirements of the whole planet could be met.

Ten percent of Asian dishes already contain seaweed and, remarkably, 70 percent of all processed foods already include it– though mostly this is carrageenan, a marine polysaccharide extract used as a thickening agent in cream, yogurts, cottage cheese, sliced and prepared meats, canned soups and frozen pizzas.

But Doumeizel is not only interested in the human food that seaweed can provide, he also advocates for its use in solving other problems, for instance, plastic pollution. One of the most high-profile of these solutions is the bioplastic sachets created by London start-up Notpla, which won the Earthshot prize last year. 

According to Notpla's own calculations, 0.03% of the kelp available on earth could replace all the PET plastic in the world.

READ MORE: Rewilders of our seas – bringing back oysters and seagrass

In the food industry, he noted, there is great interest around seaweed’s potential as a "biostimulant", a replacement for chemical fertilisers high in nitrates and phosphates – and a biofilter absorbing agricultural pollution in our seas. The agrichemicals which pollute our rivers and oceans could be mopped up by strategically placed seaweed farms and the marine algae then be harvested and spread on the land.

Such a system has already been pioneered in China, the largest seaweed-producing country in the world.

This, he said, could also help solve the impending problem of what scientists have called  “phosphogeddon”, global shortages of phosphate, upon which so much of global farming depends, and which is chiefly derived from mining in North Africa. The world is expected to reach peak phosphorous in the next few years.

Seaweed could also, he noted, be a potential carbon sink and research into 23 existing seaweed found that it had a carbon sequestration of 3.5 tonnes per hectare, three times that achieved per hectare of Amazon rainforest.

One of Mr Doumeizel's concerns is that we do not replicate the errors we have made in industrial agriculture and the global food industry. “We must learn from the past," he said, "and not reproduce what happened on land with industrial farming and genetically modified organisms and monoculture.”

In The Seaweed Revolution, the author acknowledges that seaweed cultivation will “cause complex environmental impacts”, but notes that we have already deeply damaged our oceans and marine ecosystems. We have already destroyed vast kelp forests. He writes, “While preserving wilderness areas, we will also need to plant seaweed to clean the oceans and continue the cycle of carbon, phosphate, nitrogen, sulphur, water, and other elements required for life on earth.”

Speaking at the Edinburgh Science Festival, he said: “I am fed up with feeding the young generation with fears. I want to feed them with solutions and hope. Seaweed is the biggest untapped solution we have on the planet. I think if we learn to cultivate the ocean then maybe this will be the first generation who will manage to feed the entire population of this world while repairing biodiversity, mitigating climate change, and eliminating inequality.”

The Seaweed Revolution: How Seaweed Has Shaped Or Past And Can Save Our Future by Vincent Doumeizel and translated by Charlotte Coombe, is published by Hero Press