Seaweed is used in many countries for very different purposes - directly as food, especially in sushi, as a source of phycocolloids, extraction of compounds with antiviral, antibacterial or antitumor activity and as biofertilizers. About four million tons of seaweed are harvested annually worldwide. Of the various species known, less than 20 account for 90% of the biomass exploited commercially. This book details 147 species of edible seaweed, including scientific name and respective common names, geographic location, nutritional composition, uses and is extensively illustrated.