Indicate the sources of oxygen and carbon dioxide in the water. Which gas is the limiting factor and why?

The source of oxygen is aquatic plants, which release it through photosynthesis. The sources of carbon dioxide are aquatic organisms and organic residues. Organisms produce carbon dioxide when they breathe and organic matter when they decompose.
The limiting factor is the oxygen content, since its content in water is 20-30 times less than in air. And the deeper, the less oxygen.

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