The ocean ecosystems affect the biosphere by . I) producing a substantial amount of the biosphere's oxygen II) adding carbon dioxide to the atmosphere III) being the source of most of Earth's rainfall IV) regulating the pH of freshwater biomes and terrestrial groundwater The ocean ecosystems affect the biosphere by . I) producing a substantial amount of the biosphere's oxygen II) adding carbon dioxide to the atmosphere III) being the source of most of Earth's rainfall IV) regulating the pH of freshwater biomes and terrestrial groundwater only II and IV only I and III only I, II, and III only I, II, and IV