Toure, a Gambian salt harvester, holds his shovel filled with the salt collected from the crust of the bottom of the Lake Retba (Pink Lake) in Senegal on March 16, 2021. - Lake Retba, divided from the Atlantic Ocean by a narrow corridor of dunes, owes its name to the pink waters caused by the Dunaliella salina algae and is known for its high salt content, up to 40% in some areas. (Photo by MARCO LONGARI / AFP)