DESCRIZIONE
An on-site integrated production plant, in which fresh water, sodium, magnesium, calcium, potassium, sodium hydroxide, chlorine, hydrochloric acid, sulfuric acid, hydrogen, oxygen and the like are produced by electrolyzing seawater using an electric power obtained by a wind power on the ocean, a tidal current or the like, and at the same time, malt, sawdust or the like loaded on shore is fermented to make ethanol, carbon dioxide generated in the fermentation is used in photosynthesis to cultivate a vegetable, an oxygen generated in the cultivation is supplied to a fish preserve or a fish reef to farm fish, and further oxygen is returned to seawater with decreased concentration of oxygen to prevent the occurrence of red tides.