We know that fish are dense than air. And that fish can stay aloft for quite some significan amount of time.

That updrafts and mixing and keep something suspended is literally a no-brainer. It is also irrelevant to the discussion.

Sulfur can be lofted into the atmosphere. And it will, based on density, be removed. But its removal via rain and absorbtion onto particulates will be far more significant as almost any sulfur compound that could be put into the atmosphere would be polar.

DA Morgan