An oysterman empties a mesh bag to measure the oysters at an oyster farm located in the marshes of the Bahia de Cadiz natural park in San Fernando de Cadiz, on August 30, 2021. - In the Bahia de Cadiz Natural Park, located over a large estuary, the action of the sea, wind and river sediments deposited over the centuries have drawn a mosaic of landscapes from beaches, mud flats and marshes. Nowadays most of the salt marshes are dedicated to the cultivation of marine species such as clams, sea basses, soles, mullets, prawns and oysters. (Photo by CRISTINA QUICLER / AFP)