* Diffusion from the atmosphere: Oxygen from the air dissolves into the surface waters of the ocean. This is similar to how soda gets carbonated - the CO2 in the air dissolves into the liquid.
* Photosynthesis by marine organisms: Phytoplankton, microscopic algae, produce oxygen as a byproduct of photosynthesis. This oxygen is then released into the surrounding water.
While the amount of dissolved oxygen in seawater varies depending on factors like temperature, salinity, and depth, it's essential for marine life to survive. Many marine organisms rely on dissolved oxygen for respiration, the process of converting food into energy.
