Respuesta :
Answer:
Because you get most of your oxygen from the ocean. You've probably heard of photosynthetic organisms. There are plants that are photosynthetic in the ocean, that give off oxygen. So most of the oxygen you breathe, comes from those photosynthetic organisms(plants), in the ocean.
more than half of the oxygen you breathe comes from marine photosynthesizers , like phytoplankton and seaweed. Both use carbon dioxide, water and energy from the sun to make food for themselves, releasing oxygen in the process.