95%
of the seaweed used in the UK is imported, rather than grown here.
Regenerative ocean farming · Essex coast
Growing cleaner seas.
Clean Tide is a sugar kelp farm taking shape off the Essex coast, cultivating native kelp that cleans estuary water as it grows, then feeding it back into local soil.
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Why here, why now
Britain grows almost none of its own seaweed.
The UK imports the overwhelming majority of the seaweed it uses, mostly shipped from Asia, while a handful of farms operate around our own coast.
The outer Blackwater is nutrient-rich, sheltered, and close to London's markets. It has the conditions for kelp and the demand on its doorstep, yet there is no commercial seaweed farm in the Essex estuaries. Clean Tide is built to change that: starting small, proving the science, and growing a genuinely local supply.
9
active commercial seaweed farms across the whole United Kingdom, as counted in 2024.
0
commercial seaweed farms operating in the Essex estuaries, despite the conditions.
The environmental case
A crop that gives back to the water.
Sugar kelp needs no land, no freshwater, no feed and no fertiliser. It grows by drawing nutrients straight out of the sea, so the act of farming it actively cleans the estuary.
Cleaner water
Removes excess nutrients
As it grows, kelp absorbs the surplus nitrogen and phosphorus that drive algal blooms in the Thames Estuary, taking the pollution out of the water column with every harvest.
No inputs
Nothing taken from the land
No freshwater, no soil, no feed, no chemical fertiliser. The farm sits on longlines in open water and asks nothing of the landscape around it.
Living habitat
Shelter for marine life
The lines become foraging and nursery habitat for fish and invertebrates, while easing localised ocean acidification across the farm.
Restoration ally
Works with native oysters
Sited beside the native oyster restoration already underway in the Blackwater Marine Conservation Zone. Two efforts that strengthen the same waters.
From sea to soil
A local loop, closed.
1
Grow in the estuary
Native sugar kelp is cultivated on longlines, pulling nutrients from the water as it grows through winter and spring.
2
Harvest & process
Landed and processed in Essex into a liquid biostimulant, which keeps the value, and the jobs, on the coast.
3
Feed local soil
Applied to neighbouring arable farms, improving yields and soil health while cutting reliance on synthetic fertiliser.
4
Cleaner water returns
Less fertiliser runoff means less nutrient pollution flowing back into the estuary, closing the circle.
Independent UK farm trials have recorded crop yield increases of up to +24% from kelp-based biostimulants, alongside better soil health and drought resilience.
Source: published Innovate UK and farmer-led UK trial results. Clean Tide will publish figures for its own product once the pilot harvest is complete.
The site
The outer Blackwater, Essex.
- ConditionsNutrient-rich, sheltered water with established aquaculture heritage along the Dengie coast.
- SpeciesNative sugar kelp, Saccharina latissima, the most widely cultivated kelp in the UK.
- Pilot scaleA small longline farm to prove the site and the science before scaling up.
- NeighboursAlongside native oyster restoration in the Blackwater Marine Conservation Zone.
51.7°N / 1.0°E
Outer Blackwater Estuary. Close to London's markets, far enough offshore for clean, flowing water.
Be part of cleaner seas.
Whether you're an Essex farmer, a partner, an investor, or simply curious, we'd like to hear from you as Clean Tide takes shape.
Start a conversation →or email us directly at hello@cleantideseaweed.com