From the shoreline to the plant: building a sargassum supply chain

A resource that arrives on its own schedule

Sargassum is not farmed and not ordered. It arrives with the currents, in a season that runs mainly from spring to late summer in the Caribbean, in quantities that satellite bulletins can forecast a few weeks ahead but that vary strongly from one year and one coast to the next. A supply chain built on it must therefore cope with peaks and gaps: collect intensively when the mats arrive, store what the process will use later, and plan for years when less strands.

Quality starts on the beach

Freshly stranded sargassum and sargassum that has rotted for a week are different materials. Decomposition begins within a day or two on a warm beach; collection at sea or within hours of landing keeps the biomass fresher and cleaner. Sand, plastic and other debris come with beach collection and wear out equipment. Salt and water content differ between mats collected at sea and mats collected on shore. All of this varies from delivery to delivery, which is why conditioning, the preparation step before conversion, exists: it standardises the feed so the process sees a consistent material.

What one platform needs

One platform at full capacity valorises 0.4 million tonnes of wet sargassum a year, a fraction of the 2 to 10 million tonnes that models estimate strand on Atlantic and Caribbean coasts annually. That modelled regional availability is not contracted supply: collection, quality, storage and logistics remain project-specific, and they are what the supply chain has to secure.

How Salacia is organising it

• Coastal partnerships first. Salacia's second strategic objective is to structure a resilient supply chain spanning collection, cultivation and logistics, anchored in coastal partnerships, starting with the French Departments of the Americas, where the first industrial demonstration is planned.
• A collection partner from the start. The partnership with Sargawatt, a marine biomass collection company developing scalable solutions for mass sargassum harvesting, connects expertise in collection and supply with Salacia's work on conversion. It covers the whole chain: coastal collection and logistics, biomass quality, preparation, transport and industrial valorisation.
• Volumes that follow the roadmap. Laboratory proof needs kilograms; continuous pilots need tonnes; the industrial demonstration in phase 4 integrates sea-to-plant logistics with local collection partners; the first large-scale platform in phase 5 deploys large-scale supply.
• Traceability from day one. Knowing where the biomass comes from, how it was collected and how it moved supports operational performance, environmental assessment and the consistency of the process, and it is required by the sustainability certifications the roadmap targets.
• Cultivation as a complement. Beyond stranded seaweed, supply and cultivation pilots launched in phase 3 explore grown biomass as a second, steadier source.

Why it matters to the coasts

A collection chain that pays for sargassum turns a clean-up cost into a local activity. Collection at sea protects beaches before the seaweed lands; a plant on the coast keeps the value where the problem is. The long-term objective is a model that supports coastal resilience, local resource valorisation and renewable fuel supply chains at the same time.