Este é “Pequenos Pontos Apertados nas costas de um homem morto” (1992) por Joe R. Lansdale.
They did it — they launched the damned nukes and the world went pretty much straight to hell. Not many survived, but some of those who did emerged twenty years later, to a world where mutant whales heaved themselves across the blackened, dry seabed of the Pacific, and the roses… oh God, the roses.
Acho que a antologia é Wastelands 2 de John Joseph Adams.