Whence comes the oxygen in the air they breathe?

[+Oltux72]

If they taught you in school that the oxygen you breathe generally comes from trees, they were not telling the whole truth. Over half of it comes from cyanobacteria and algae in the oceans. And there is an obvious problems if you do not have oceans in the conventional sense.

What could replace them?

• land plants - they require abundant rain. Where does the water come from?
• the spores being photosynthetic - that is possible. But - unless they generate their water by magical means, it must rain for that. The actual oxygen atoms in the air come from water consumed in photosynthesis
• something utterly alien - then why so terrestial a fauna?
• nothing - that is disturbingly plausible. The aethers may be a recent - meaning on the order of centuries - arrival and are killing the planet. That world is running out of oxygen, they just don't know it yet.

[Frustration]

I've got a few more possibilities.

• Algae and Cyanobacteria have larger concentrations on, inland bodies of water.
• Ocean life has developed a way to use the investiture from spores as a replacement for water in Photosynthesis, or as a replacement for Photosynthesis( i.e. XSpores -> C6H12O6 + 602)
• Brandon didn't think about it.

Edited March 7, 2022 by Frustration

[Halyo_Alex]

My mentality right now is "We don't have enough knowledge on the rest of the world to deduce anything with reasonable certainty." We've seen one salty island the size of a town in the midst of the Verdant Sea, that really isn't enough information.