Could aquafarming be Britain’s next great industry?

Britain spends £61 billion annually importing food — more than £1,000 per household per year. Meanwhile, a maritime territory larger than France’s lies almost completely untapped. This is not a resource problem. This is a policy problem. Aquafarming — the cultivation of seaweed and shellfish — could be Britain’s next great industry, delivering food security, economic growth, and significant carbon sequestration. Yet we have done virtually nothing to develop it.

The potential is staggering. The UK’s Exclusive Economic Zone covers 1.7 million square kilometers — an area larger than France, larger than Spain, nearly the size of Germany. Scotland leads with proven salmon farming expertise generating 3,400 jobs and 87 per cent of UK aquaculture production. But even Scotland’s substantial success represents only a fraction of what is possible. The real opportunity lies in seaweed — a crop that grows with minimal input, requires no feed, requires no fertilizer, and can be used across pharmaceuticals, cosmetics, biofuel, and food production.

The food import problem

Britain’s food deficit shapes everything. We import £61 billion of food annually against £20 billion in exports, creating a £36 billion trade deficit on food. This is despite having one of the world’s largest maritime zones. The imbalance reflects historical choices: to focus agriculture on land-based production, to rely on international supply chains, to treat the seas as fishing grounds rather than farms.

The risks of this dependency became apparent during the pandemic and are becoming clearer as global supply chains fragment. A nation that imports 40 per cent of its food is exposed to price volatility, geopolitical disruption, and supply shocks. The cost of food security is not borne by economics alone; it is borne by inflation, by household budgets, by political stability.

The aquaculture opportunity begins with a simple fact: Britain has the right geography, the right climate, and proven technical expertise. Scotland’s salmon farming sector demonstrates this capability. The missing piece is scale and strategic direction. If Britain converted just 1 per cent of its exclusive economic zone to aquaculture — an area roughly equivalent to Greater London — seaweed production could reach 7.5 to 15 million tonnes per year. That would be four to seven times larger than China’s current seaweed production.

The seaweed opportunity

Seaweed is a remarkable crop. It grows vertically in ocean columns, occupying three-dimensional space rather than competing for land. It requires no freshwater input — it is grown in seawater. It requires no chemical fertilizers or pesticides. It grows at a rate of 0.5 to 1.5 metres per day, making it the fastest-growing plant on Earth. And it has extraordinary commercial potential.

Current seaweed uses include food (nori for sushi, carrageenan as a thickener), animal feed, agricultural soil amendments, and pharmaceuticals. The emerging market is biofuel. Seaweed contains compounds that can be converted into bioethanol and biogas. The biofuel market is projected to grow from $134 billion in 2023 to $204 billion by 2030, representing a compound annual growth rate of 6.3 per cent. European biofuel demand is growing at 6.07 per cent annually, with the market valued at $58 billion in 2025. This is not speculative; this is documented market growth happening right now.

The technology for seaweed cultivation is proven. Integrated Multi-Trophic Aquaculture (IMTA) combines seaweed with fish and shellfish farming in the same ecosystem. Fish waste becomes nutrient input for seaweed. The seaweed then treats the water by absorbing excess nitrogen and phosphorus, cleaning the environment for continued fish production. It is a closed-loop system requiring minimal external input.

Aquaculture is the fastest-growing food production sector globally. Marine agriculture will be as transformative as terrestrial agriculture was three centuries ago.

Food and Agriculture Organization, 2024

The carbon capture potential is substantial. Kelp and other macroalgae sequester 2 to 8 tonnes of CO2 per hectare per year through photosynthesis. Some estimates suggest as much as 20 tonnes per hectare per year for optimized systems. Converting 1 per cent of the UK’s EEZ to aquafarming — roughly 17,000 square kilometers — could sequester millions of tonnes of CO2 annually. This is legitimate carbon removal, not abstract carbon credit trading.

Economic impact and jobs

The economic case is compelling. Direct farm returns from seaweed cultivation are estimated at £8 to £14 billion per year at scale. Adding value through processing — converting seaweed into biofuel, pharmaceuticals, cosmetics, livestock feed — could generate additional GDP impact of £2 to £3.5 billion per year. Scotland’s current salmon farming generates £600 million per year and 3,400 jobs. That is one sector in one region. Scaled to the UK and expanded to include seaweed, shellfish, and fish, aquaculture could become one of the largest agricultural sectors by value.

The jobs are concentrated in deprived coastal communities. A seaweed farming operation requires farming, harvesting, processing, and distribution. Unlike many agricultural jobs, these are not replaceable by automation. A person cleaning and preparing seaweed requires skill and attention. A person monitoring fish health in offshore farms requires training. A person managing a processing facility requires technical knowledge. These are real, local jobs in regions that desperately need them.

Shellfish farming adds another dimension. UK shellfish catch could increase by 50 per cent — generating £550 million in additional catch value — through better management and aquaculture expansion. Aquaculture of oysters, mussels, and scallops could generate an additional £3.5 billion per year. Unlike fish farming, which requires feeding, shellfish farming is filter-feeding — it actually improves water quality while producing food.

The technology landscape

British companies are already developing the necessary technology. Three British firms now produce roof-integrated photovoltaic tiles — a technology relevant to both onshore facilities and future energy needs. The Netherlands is pioneering offshore seaweed farming with North Sea Farm 1, a project demonstrating commercial viability at scale. Rolls Royce is developing Small Modular Reactors (SMRs) at roughly £2 billion per reactor, capable of powering aquaculture facilities and approximately 1.1 million homes each. The UK has the engineering capability; it lacks only strategic direction.

The infrastructure required is modest compared to traditional agriculture. An offshore seaweed farm requires buoys, lines, and harvesting vessels — all proven technology. A processing facility requires standard industrial equipment. The supply chain for seaweed cultivation products is global and mature. The bottleneck is not technology or capability; it is licensing, financing, and regulatory approval.

International precedent

Norway, Iceland, and Ireland have all developed aquaculture industries ahead of Britain. Chile has grown to dominate salmon farming globally. Asia has led in seaweed production. Yet none of these regions have geographic advantages comparable to Britain’s. Our waters are productive, our territory is vast, and our scientific base is world-leading. The only question is whether we act.

The regulatory framework exists. The Marine Management Organisation oversees UK marine policy. Licensing for aquaculture operations is established. The missing piece is political will and strategic investment. A comprehensive aquaculture policy would include: targeted financing for startup operations; regulatory streamlining for proven technologies; research funding for innovation; and trade agreements ensuring market access for British-produced seaweed and seafood.

The next great frontier for agricultural production is not land; it is the sea. Nations that move first will establish competitive advantage that lasts generations.

World Bank, Blue Growth Initiative 2023

The cost is manageable. A transformation program requiring £500 million in research and infrastructure investment over five years would be modest against the potential returns. That investment would create an industry generating £8 to £14 billion per year. The return on investment is 16 to 28 times the initial outlay. Few government investments offer such compelling returns.

Food security and climate

The ultimate value lies not in £billions but in resilience. Britain would reduce its food import dependency. Coastal communities would gain sustainable employment. Carbon sequestration would contribute to climate targets. Food production would be moved closer to consumption, reducing transport emissions. And we would move from being a resource-importing nation toward being a resource-producing nation.

This is not sentimentality. This is strategic security. Nations that depend on others for essential resources are vulnerable to disruption. Britain’s aquaculture potential offers a path toward food independence, economic growth, and environmental stewardship simultaneously. The technology is proven. The demand is real. The investment is available. The only question is whether policymakers have the vision to act.