As for the salt mines of Pedra de Lume, most of the salt was exported to Brazil until 1887 when the Brazilian government decided to banish the importation of salt to improve the national production.
The salt production in Santa Maria suffered a big crisis until 1920 when a Portuguese investor revived it and, in 1927, started the exportation to the Belgian Congo.
In 1961 the salt flats were nationalized and were operative until 1984 when the salt production started to decline and then stopped. After the end of the production, the salt mines were given to the local families of Santa Maria.
Most of the salt mines are now completely covered with hotels and houses built on top, but you can still see some of them on the northeast side of Santa Maria where some local people are still producing salt for in-island use.