How has spirulina been used traditionally?

Records show that spirulina was used traditionally as a food by the Aztecs in Mexico and has been used by the Kanembu people of North Africa since at least the 16th century. In Africa, spirulina — locally called dihé — is harvested from various alkaline lakes surrounding Lake Chad. Similarly, in Mexico before the Spanish conquest, spirulina — locally called tecuitlatl — was harvested from Lake Texcoco, where it grew abundantly. In both cases, the spirulina is gathered from the lakes and left to try in the sun, after which it can be broken into small pieces to be sold as food.^[1][2][3]