Method for the mass production of seedlings of the tropical brown seaweed Sargassum (Phaeophyceae, Ochrophyta).

Farming of Sargassum to produce harvestable crop can be a challenging task to seaweed farmers.•Sexually-produced Sargassum seedlings can be propagated in a hatchery using 140-liter plastic tanks connected with PVC pipes and seawater supply directly pumped from the sea, passing through a filter system.•First step of this method is to collect large amount of fertilized eggs from special branches called receptacles, found at the ends of lateral branches of Sargassum, excised from fertile thalli during its spawning season and collecting their eggs for recruitment into artificial substrate tanks.•Egg collection involves force-releasing the fertilized eggs by vigorous shaking of a small vessel where 100-200 egg-bearing receptacles excised from fertile plants are contained. Each tank can produce up to 2000-3000 seedlings that can supply at least a hectare of farm. Scaling up the production to several hectares of farm is done by simply increasing the number of recruitment tanks and the number of recruitment panels in the hatchery system.