The only times when Aschenbach is able to find peace in Death in Venice is during brief moments when he is contemplating the sea. Since it has no permanent form, the sea may represent transcendence of life and death.
While the sea brings rest, the waters of the lagoon smell foul. This was swamp, around which, perhaps, people should not have built their homes. But even worse are the canals. They are stagnant, and carry disease along with boats. When the sea is channeled and controlled, it loses its healing power and can even become deadly. At the end of the novella, when Aschenbach thinks Tadzio is beckoning him to the sea, he dies of cholera. An awareness of ecological relationships can help us to understand the symbolism of water in Death in Venice.
While it is not really necessary for this paper, some students may care to read up about how the sea has been regarded from the early mythologies to the present time. How was the view of the sea changing when Mann wrote Death in Venice? What, exactly, was the significance of the sea for Aschenbach? How is it similar or different for us today?