What metaphors are used in Song of a Citizen by Czeslaw Milosz?

The first three and a half lines of "Song of a Citizen" form one sentence, with the subject ("I, poor man") placed at the beginning of line three. The poet likens himself to a stone in the depths of the sea that has witnessed a cataclysmic disaster. In the disaster, the seas have dried up and a million white fish, deprived of the element that gives them life, leap in agony. Lines three and four continue the metaphor, applying it to the realm of human history. The poet sees many nations deprived of their freedom. The description of them as "white-bellied" links them to the earlier image of the white fish. Using another image drawn from marine life, the poet sees a crab eating at the flesh of the nations. The image suggests rot and decay in a world in which one living thing feeds on another (crabs eat dead fish).