Depending on where and how they die, dead fish float briefly because of gas created by bacterial decay, but sink after a rupture, or a few days. Many dead fish

Depending on where and how they die, dead fish float briefly because of gas created by bacterial decay, but sink after a rupture, or a few days. Many dead fish will get eaten as they fall through the water column. Things that sink all that way to the bottom of the ocean do still get recycled by the biosphere - but the biosphere at the bottom, which is only connected tenuously and very slowly with the surface - most of the carbon etc... will stay down there for a very long time. > I'd expect pictures of the ocean floor to look like a weird nightmarish Hieronymus Bosch painting of a thick layer of dead but intact fish. Not intact for long, because the seafloor has lots of scavengers, but yes, this is pretty accurate - see Whalefall: https://en.wikipedia.org/wiki/Whale_fall https://en.wikipedia.org/wiki/Whale_fall and Marine Snow: > About three-quarters of the deep ocean floor is covered in this thick, smooth ooze. The ooze collects as much as six meters every million years. https://oceanservice.noaa.gov/facts/marinesnow.html https://oceanservice.noaa.gov/facts/marinesnow.html