A system and related apparatus for cultivating and harvesting aquatic biomass. The system has three main elements: a substrate device (56) having outstretched wings (14) upon which aquatic organisms are attached and allowed to grow in a marine environment； a flotation device (36) for suspending one or more substrate devices (56)； and an automated device (48) for harvesting and collecting the aquatic biomass from the substrate devices, said automated device (56) having a number of modular arms (98, 100A, 100B) that transport the substrate through a cylindrical member (70), cutting arms (104) that remove biomass from the substrate devices, and washing arms (112) that dislodge the biomass and clean the substrate devices (56).
