The physical and chemical properties of the substrates of marine brine ponds are described in relation to the quantity and quality of the salt produced. It is revealed that the production of good quality salt is achieved in those ponds with coarse sediments; it is better sorted and negatively skewed. Low salt production is observed in those ponds with fine sediments and rich in organic carbon. In ponds with fine sediments, a thick, dark‐colored rich organic layer is formed below the salt that causes problems during the harvest High amounts of colloidal Fe hydroxides rich in Cu, Zn, Cr, Cd, Pb, Ni, and V are observed in the brine of evaporation ponds with fine substrate. The high contents of organic carbon encountered in ponds with moderate salt quality is because of high biological activity, including intense vegetation, in the surrounding region. The knowledge resulting from this research can be used for the improvement of the quality and the increase of the quantity of salt produced in crystallization ponds and in the construction of saltworks.