Coast-4c raises $2.5M seed round to scale regenerative seaweed farming platform
What's the deal? Coast-4cDealroom has a profile for this one. Try Dealroom → has raised a $2.5 million seed round to scale its platform connecting smallholder seaweed farmers to global processors.
The round was co-led by Hatch BlueDealroom has a profile for this one. Try Dealroom →'s Blue Revolution Fund, a €92 million sustainable aquaculture fund, and brought in Conservation InternationalDealroom has a profile for this one. Try Dealroom → Ventures, eleaDealroom has a profile for this one. Try Dealroom →, RS GroupDealroom has a profile for this one. Try Dealroom →, Minderoo FoundationDealroom has a profile for this one. Try Dealroom →, and others.
Coast-4c links smallholders to buyers through a traceable supply chain, providing technical support, inputs, and market access to produce high-quality red seaweed.
Why now? Southeast Asia produces most of the world's carrageenan, a seaweed-derived ingredient used in food, cosmetics, and pharmaceuticals.
But supply stays fragmented across informal networks, limiting product quality and farmer incomes. Coast-4c aims to fix that at the source.
The startup will use the funding to reach breakeven ahead of a Series A, scaling first in Southeast Asia before expanding to other regions.
What could go wrong? The model relies on lifting incomes for marginalised coastal communities while restoring marine ecosystems — a dual mandate that is hard to balance.
"Smallholder farmers have long been treated as grant recipients rather than equity-backed producers," said Sol Park, a principal at the Blue Revolution Fund.
Coast-4c must also prove its digital farm management and traceability platform can roll out across scattered coastal networks.
The signal: Coast-4c, an early-stage company aiming to build the world's largest supply chain for regenerative seaweed, was an Earthshot Prize finalist in 2024 and announced this round at the Earthshot Prize Impact Assembly during London Climate Week 2026. The investor mix — spanning the €92 million Blue Revolution Fund, the non-profit Minderoo Foundation, and the elea ethics-in-globalisation fund — shows how blended capital is converging on a model that links coastal community livelihoods to marine ecosystem health.
Read more: The Fish Site
Image credit: "Eucheuma farming, Philippines" by Derek Keats is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/.
