Marennes-Oléron oysters: claires, PGI and traceability

OstraOS was born in 2024 in La Tremblade, at the mouth of the Seudre. Our first features were written with oyster farmers from the Marennes-Oléron basin, and the software still shows it. A claire is a zone type of its own. Affinage is a tracked event. The basin's qualities come pre-configured.

One basin, many claires

Between the Charente and Seudre estuaries, and on the island of Oléron, old salt marshes became claires: shallow clay ponds whose seawater is renewed on spring tides. Oysters move there after growing out at sea. They are finished there. Some turn green from a micro-alga, the blue diatom.

The basin's appellations

• Fine de Claire: cupped oyster finished for a few weeks in a claire.
• Spéciale de Claire: finished at a lower density, meatier.
• Fine de Claire Verte Label Rouge: recognisable by its green gills.
• Pousse en Claire Label Rouge: grown in a claire, at very low density, over several months.
• PGI Huîtres Marennes Oléron: the geographical indication protecting oysters finished in the basin.

Each appellation rests on three proofs: which claire the oyster was finished in, for how long, and at what density. OstraOS records all three for every lot.

What OstraOS tracks for you

• Your claires on the farm map, separate from grow-out beds and purification basins.
• The start and end of each affinage, with the claire, the density and the target quality.
• Compliance when the lot leaves the claire: actual duration is compared with the minimum you set for the quality.
• The measured meat yield, useful to defend a Fine or a Spéciale.
• A sales block on any lot that has not completed its path.