Lagoons are expanses of shallow coastal salt water, of varying salinity and water volume, wholly or partially separated from the sea by sand banks or shingle, or, less frequently, by rocks. Fully saline coastal lagoons are classified as X02. Flads and gloes, considered a Baltic variety of lagoons, are small, usually shallow, more or less delimited water bodies still connected to the sea or cut off from the sea very recently by land upheaval. Characterised by well-developed reedbeds and luxuriant submerged vegetation and having several morphological and botanical development stages in the process whereby sea becomes land. Mediterranean lagoons may host the Ruppietum community with halophytic vegetation, while at sites with a fresh water supply, plant communities of Juncetum and Phragmitetum can develop. Sarcocornia perennis and Arthrocnemum macrostachyum may occur here.