#MonitoringMonday – The Guérande Salt Marshes

It is a fine interplay of ocean, sun, wind and the traditional know-how of local salt workers to produce the popular “Fleur de Sel”. For over a thousand years, Guérande salt has been grown and harvested by hand in the Pays de la Loire, south of Brittany, in France.

The peninsula’s marshlands are connected to the Atlantic Ocean and thus receive a regular supply of seawater from the tides. Sun and wind cause the water in the shallow pools to evaporate and the salt concentration to rise.

The Healthy Vegetation Index (HVI) is shown in this satellite image from April 01, 2020. The HVI is a band combination to visualise the (health) status of the vegetation. The salt ponds are coloured in a deep blue, due to the flooding with seawater at the time, so no measurable vegetation is visible.