Viewing a single comment thread. View all comments

breckenridgeback t1_ja9o92e wrote on February 27, 2023 at 9:32 PM

Reply to comment by Psychological-Dog994 in ELI5: Why is it that when fertilizers make their way into waterways, all the oxygen disappears, killing the fish? by Psychological-Dog994

Ultimately, yes: all of Earth's atmospheric oxygen is from photosynthesis. But in the more local sense, it's just dissolved into the water from the air around it.