These more or less saline lakes are usually created under the influence of strong rains and rapid run-off in sub-desert landscapes, which leads to the creation of large waterbodies in inland depressions. The most important ones are found in North Africa and the Middle East. They are amongst the largest wetlands in the Mediterranean, apart from deltas.
In a chott, permanent vegetation is very sparse with some green islands wherever water is present. Invertebrates are limited to a handful of species that are adapted to xeric conditions. Waterbirds are rare.
A sebkha is usually more saline than a chott. It is a shallow depression which retains water for a rather long period; it only dries up at the peak of summer. Those that are vegetated are the smallest ones, since they concentrate and retain more water and are consequently less saline.
Dayas look like chotts, but water is brackish and usually more permanent.
A Garaet (a Saharan word) refers to a small waterbody located in a topographic depression.
Traditionally, these wetlands were used mainly after the rains for extensive and wandering animal husbandry: goats, sheep and camels. More recently, some of them have been drained for urbanization, others have been modified to develop commercial palm-tree plantations, still others are used for the rejection of sewage water or industrial waste water. A few have been designated as protected areas.