A Salt Marsh is made up of shallow basins and salt tables where the salt is harvested.
This white gold is obtained by evaporation of water using the combined forces of the sun and wind.
Sea water entry into the salt marshes :
Sea water enters into the salt marshes as from March. At this stage, it contains 29g of salt per litre.
Water circulation in the ponds:
From March to August, water circulates through the basins (some of which are more than 300 hectares). Salt workers make the water circulate from one pond to another.
The sea water loses approximately 90% of its fresh water. So, the resulting brine, or very salty water, contains 260 g of salt per litre, in order to keep the salt marshes going.
When the brine is saturated, salt workers send it to the crystallisers or salt tables (shallow rectangular basins). Thanks to the wind and the sun, the evaporation continues and the salt crystallises.
After a few months, a layer of salt, 10cm thick is formed at the bottom of the tables. The salt is harvested once a year, in September.