Ten salt production workers stand in a muddy salt field south of Nha Trang

Ten salt production workers stand in a muddy salt field south of Nha Trang

Ten salt production workers wearing conical sunhats stand in a muddy salt field south of Nha Trang, Vietnam. These are likely wage laborers who work for the land-owning salt factory. Mountains, blue sky, and clouds are visible in the distant background.

This type of salt production is a low-cost technology that is known and used in shallow coastal regions throughout Southeast Asia. Sea water enters the fields at high tide. The fields are edged with roughly three-foot high mud dykes, which retain sea water after the tide recedes. Over a period of sunny days, the water evaporates leaving the dry, white salt powder to be collected for sale.

In tropical regions, salt is an especially necessary and highly prized addition to people’s diet, as it helps retain body fluids in the heat. Traditionally salt was traded to interior groups from the coasts or, in some regions, it could be mined from salt layers found within inland mountains.