We know very, very little about the ocean though. The ocean floor is mapped less than the surfaces of Mars and Venus, and we probably have studied less than 1% of the ocean by volume. Plenty of space for mer-civilisations and less anthropomorphic communities to thrive.the ocean is such a dead end for evolution. you'd think populated with living things the longest ...there would be some sort of mer-civilization ...rather than just ever more varieties of things to get stuck in plastic garbage.
And yet we supply them with free plastic. We should tax them somehow! Or just stop giving it to them.