During World War II the occupying Japanese conducted extensive swamp reclamation to create an air field. It has been adapted as the Funafuti International Airport. As a consequence of the specific topographic characteristics of Fongafale, unlike other atoll islands of a similar size, Fongafale does not have a thick freshwater lens. The narrow fresh water and brackish water sheets in the sub-surface of Fongafale islet results in the taro swamps and the fresh groundwater resources of the islet being highly vulnerable to salinization resulting from the rising sea level.