Death
One of the most distinctive aspects of this poem is the fact that, though the speaker is addressing another being, that other being is dead. Though the tuna's death lends a certain somberness to the interaction, it doesn't prevent the speaker from developing feelings about it and speaking to it. In other words, the two develop a dynamic relationship, and the notable fact that one party is dead doesn't refute that. It does, however, cause the speaker to view the tuna with a blend of sorrow and admiration. On the one hand, he seems reduced in the eyes of the speaker. Yet, the poem suggests, the fish's fate is to explore the unknown—whether that means the depths of the ocean or the unknown condition of death.
Consumption
In this work, consumption, violence, and power are intertwined forces. The speaker is unpleasantly struck by the sight of the tuna lying in a vegetable market to be sold as food: his status as an object to be consumed is somewhat insulting and robs him of the power he had in the sea. This state, in which the fish turns into food, is juxtaposed with the tuna's earlier life. The speaker compares the living fish to a variety of weapons—a harpoon, a missile, and more. This suggests that, while alive, the tuna was capable of exerting violence. In death, the tuna is now the recipient of violence, as exemplified through his status as a food item.
The Animal World
One intriguing aspect of this poem is the way the speaker attaches human views of the natural world to the tuna. He admires the fish for its ability to penetrate the mysterious, abyssal sea. Meanwhile, he finds the sight of the tuna on land, surrounded by vegetables, to be mundane and a bit sad. Of course, to a fish, the sea isn't mysterious or impenetrable: a human marketplace on land is a more unexpected and strange location. In other words, no matter how closely the speaker looks at the tuna, he's not able to see it entirely clearly. Instead, he brings his own human notions and preconceptions to the experience, perceiving the other species through the lens of his humanness.
