e.g, instigate some large bloom of plant matter or algae, and engineer/find the right conditions for the matter to sink to the bottom of the ocean without decomposing.
At least the first part. There’s an easy profit motive: increasing the base of the food chain feeds the rest of it, and some of those are products we like to eat.
The second part, if you can find a profit motive to compost the ocean floor and actually do it in a profitable way, then it will get done. Else we’re stuck relying on natural processes.
e.g, instigate some large bloom of plant matter or algae, and engineer/find the right conditions for the matter to sink to the bottom of the ocean without decomposing.