The net mоvement оf cаrbоn dioxide (CO2) is from the аtmosphere into the surfаce ocean. The net movement of oxygen (O2) is in the other direction, from the surface ocean to the atmosphere. Overall, the ocean absorbs excess carbon dioxide from the atmosphere but the ocean releases excess oxygen to the atmosphere. The ocean is a major source of oxygen to the atmosphere. QUESTION: A) Why is there so much oxygen in the surface ocean? Explain what puts it there, and how. B) Explain two ways the water of the surface ocean would change if nothing lived in the top 50 meter layer of the ocean. BONUS for a third way.