A halocline is a layer in a body of water where there is a rapid change in salinity with depth. This phenomenon often occurs in oceans, seas, and large lakes, where the mixing of freshwater and saltwater creates distinct layers. The halocline can affect marine life and water circulation, as organisms may be adapted to specific salinity levels. In addition to salinity, the halocline can also influence temperature and density in the water column. It is commonly found in areas where freshwater from rivers meets saltwater from the ocean, such as estuaries. Understanding haloclines is important for studying aquatic ecosystems and their responses to environmental changes.