Ephemeral salt lakes in semi-arid and arid regions are shallow, with extreme variation in salinity during wet-dry cycles that limits life to a low diversity of specialised salt-tolerant species. The lakes are dry and salt-encrusted most of the time, but episodic inundation dilutes salt, allowing high growth of algae and larger plants which support crustaceans, insect larvae, fish and specialist waterbirds. These species use dormant life stages to survive drying, or disperse rapidly to other habitats when the lake dries.