Seaweed farming refers to the cultivation of seaweed for industrial and commercial purposes. This area concerns both micro-algae and macro-algae. In recent years, global production of marine algae has more than tripled, from 10.6 million tons in 2000 to 32.4 million tons in 2018. Seaweed cultivation is practiced in a relatively small number of countries, and the main producers are in East and Southeast Asia. The rapid development of cultivation of tropical marine algae species (Eucheuma sp. and Kappaphycus alvarezii) as raw material for carrageenan extraction has been the main driving factor behind the increase in marine algae production in recent years. In the countries supported by ARES-CCD, the main producing countries are the Philippines, Tanzania, Vietnam and Madagascar. In Madagascar, after a first trial in 1989, seaweed farming took off in 2010 involving fishing communities and using the species K. alvarezii. Three cultivation techniques are commonly practiced, namely (i) “long-line” or cultivation on a long line, (ii) “off bottom” or cultivation on stakes and (iii) cultivation in tubular nets. As for the production model, commercial actors use two types: (i) the “company farm” model where a private company is in charge of all algae production processes and where the producers (farmers) are employees and (ii) the “village farming” model where producers (farmers) are paid according to their production.