In the wake of the continual release of vast amounts of carbon dioxide (and other acidic substances) into the environment, the water on Earth, particularly seawater, is gradually faced with acidification. Water acidification is generally characterized by the increase in concentration of H⁺, causing serious ecological hazards, including the dissolution of the exoskeleton of coral and shellfish and low fertility of many marine lives. Fortunately, after reading several literatures, we found the solution. Xenorhodopsin is an inward H⁺ bump expressed on the plasma membrane of Nanosalina spp. . In our project, a genetically engineered E. coli, the AcidOceanus, is planned to be constructed and applied to absorb H⁺ in the surrounding water under the condition of lighting. Integrating the Xenorhodopsin gene, AcidOceanus expresses Xenorhodopsin on its plasma membrane and then constantly transports H⁺ into intracellular space. Furthermore, as an approach to recycling H⁺, we are about to coordinate with some companies to design a device where engineered E. coli releases the H⁺ in dark conditions. Our project is devoted to providing a feasible direction for water acidification in a small range of areas, and at the same time instructing the public, especially teens, to be aware of its harm to marine life and the urgency to resolve it.