[katieHaylor (OP)]

Donald asks:

"Whale fall" delivers material and energy resources to the ocean floor. I am certain it is not just whales, but most  organisms that are not eaten.
Most organisms on the ocean floor do not float into the upper ocean, and tend to stay close to the floor if not fixed to it.
So after billions of years, why aren't all those nutrients built up into a very thick layer of remnants, hoarding all the carbon, nitrogen, phosphates, etc. Or is it cycled out somehow? How is it recycled out?

What do you think?

[Bored chemist]

They get eaten
https://en.wikipedia.org/wiki/Bottom_feeder
https://en.wikipedia.org/wiki/Detritivore

[evan_au]

Bone worms even eat the whale bones, if the carcass isn't promptly buried in silt.
See: https://en.wikipedia.org/wiki/Osedax

There is relatively little biomass over the deep ocean, so it wouldn't build up very rapidly on the ocean floor.
The ocean floor (and any sediment lying on it) is recycled at subduction zones, preventing it from building up forever.
See: https://en.wikipedia.org/wiki/Subduction

[mrsmith2211]