IN the salt marshes of Cadiz in southwestern Spain, Juan Carlos Sanchez de Lamadrid surveyed a grid of rectangular pools of milky water, part of a time-honoured tradition to harvest salt from the sea.
Civilisations as old as the Phoenicians who ruled the Mediterranean from around 1,200BC have taken advantage of the constant and strong winds that blow from North Africa, facilitating the evaporation of seawater to produce salt in the region.
