Lake Retba (known to most locals as Lac Rose) its  separated only by some narrow dunes from the Atlantic Ocean and, as expected its salt content is very high. Its salinity content compares to that of the Dead Sea and during the dry season it exceeds it.

Its distinct pink colour is due to the Dunaliella salina bacteria, which is attracted by the lake’s salt content. The bacteria produces a red pigment in order to absorb the sunlight, therefore, giving the lake its unique colour. Its colour is especially visible during the dry season (which lasts from November to June) and less during the rainy season (July- to early October).

This salt is extracted by locals from the bottom of the lake using their hands, then placed into baskets it is transported to the shore where it is used mainly to preserve fish.