The production of sea salt is one of the oldest forms of human intervention in natural spaces. Sea salt comes from natural evaporation of seawater out of artificial created ponds. The color of the water indicates the salinity of the ponds. Micro-organisms change their hues as the salinity of the pond increases. The colors can vary from lighter shades of green the vibrant red. Although the sea salt industry covers large areas around the world, the salt ponds and marshes are an important habitat for many species like birds, shellfishes or micro-organisms.