Submergence
Novella 20,825 words Recommended by 4 award/anthology sources
"As the people began to die, desperation drove us to the depths of the sea for cures. We mined mineral-rich vents until the tube worms went extinct, stripped polymetallic nodule fields bare, squeezed sludge out of sea sponges to treat the new diseases, these monstrous incurable plagues, born from our new climate, that spread through our air. But the people still died. So we dug even deeper..."
Content warnings 2
deathillness-and-pandemic
Quasar links out; the story lives on Clarkesworld, where the author gets the click.