These lakes are usually large and shallow in semi-arid regions, with high concentrations of salts, mediated by inflows of water. Their productivity from growth of algae and plants can support large numbers, but low diversity of organisms equipped with tolerance to high salinity and other solutes. They have relatively simple foodwebs, with high numbers of microbes and plankton, crustaceans, insect larvae, fish and specialised waterbirds such as flamingos.