Every farm, every price, in the open.
Each grower sets their own rate per metre, because each coastline has its own costs. Our network fee sits on top and pays for verification, coordination and reporting. Farms shown without a price are still in Holdfast Standard assessment.
Mulroy Bay Kelp
Our original site and the source of every number on this website. Five seasons of sugar kelp on a sheltered Atlantic inlet, with harvest going to dairy and tillage farms within thirty miles.
Kelp Crofting
Founded by a marine scientist and run at croft scale on the south coast of Skye. Already publishes its own biodiversity and soil data, which makes it the easiest farm in the network to verify.
Câr-y-Môr
Wales' first commercial-scale seaweed and shellfish farm, owned by more than three hundred local members. The clearest example of a coastline sponsoring itself.
Algapelago Marine
The biggest licensed cultivator in England, with an existing biostimulant buyer and the volume to absorb corporate-scale sponsorship in a single site.
Aird Fada - SWMID
The UK's only community-owned seaweed farm. Six kilometres of line run by the island development trust, with every pound of surplus staying on Mull.
Islander Kelp
Northern Ireland's only commercial seaweed farm, run by a mother and son off Rathlin. Small, award-winning, and the most narratable farm in these islands.
Atlantic Mariculture
The highest confirmed cultivated tonnage in the UK, targeting a hundred tonnes. Where a corporate programme goes when it needs scale rather than a story.
Highland Seaweed
Three licensed sites across Wester Ross with hatchery supply secured. Ready to expand line length the moment there is committed demand behind it.
Jurassic Sea Farms
A two-person integrated operation on our own doorstep in Dorset. Small enough that a few thousand sponsored metres changes the business outright.
Roaringwater Bay Co-op
A grower co-operative in West Cork with existing land-farm relationships across the Mizen peninsula and a short run from harbour to field.
Dingle Bay Seaweed
Licensed and cultivating in Kerry. In Holdfast Standard assessment now, with a land partner still to be confirmed before it can take sponsorship.
SeaGrown
England's first offshore seaweed farm, working the North Sea off Scarborough. Exposure and logistics are the open questions on cost per metre.
Vestland Kelp
Nordic coverage for corporates with Scandinavian operations. Cold, deep and productive, with an established aquaculture regulator behind it.
Côtes d’Armor Algues
Europe's oldest seaweed agriculture tradition, on a coast where farmers have spread cast weed on fields for two centuries. The land side is already solved.
Casco Bay Kelp
Fishermen diversifying out of lobster into winter kelp. The obvious first site for US corporate sponsors wanting a domestic pairing.
Paje Seaweed Collective
A women-led shallow-water collective where sponsorship income is measured against household earnings rather than tonnage. A different Holdfast Standard weighting entirely.
Sixty-four licensed seaweed operations were identified across the UK and Ireland during network scoping in September 2026. The farms above are the subset with the scale, land-farm proximity and reporting capability to take sponsorship in the 2026-27 season. Named farms are illustrative in this build and have not all been approached.
Can’t see your coastline?
If you operate somewhere we do not yet cover, tell us where. Sourcing a farm to a region is the part of this we are good at.