I would like to focus mostly on the nonhuman entities that are encapsulated within the lower part of the vessel where Pym is hiding. Being that the area causes extreme claustrophobia; it makes a stressful environment for someone to be stuck in for a long period of time. Large crates, piles of heavy lumber, and the complete lack of any form of light, makes it probably the most unpleasant area for a human to be stowed away in for days. With this being said, it truly does not take much to completely break a person, since even before Arthur started running out of food and water, he was already showing signs of deprivation from being stuck in such a cramped and dark space– dark space made up of organic material like wood and metal. These non-human materials, even if they are not living breathing entities, still act as an antagonist to the human and animal characters, because they make life more difficult.
When Tiger the dog attacks Arthur, this shows the human/animal divide. Humans tend to either panic, or use their mental power to try and find a solution when in a bad situation. Animals, even domestic ones, can revert back to their primal instincts and attack when uncomfortable. It is also apparent that the humans in the story use religion as a form of comfort whenever coping with hardships, they tend to verbalize their gratitude by saying “thank god.” While I do not know if animals are religious, I do know that they do not verbalize their thanks in the same way we do as humans.
The sea also acts as an unwelcoming environment to humans, these hardships these characters endure, is because they are stuck out in a lawless ocean, where the mutineers can take over and hold each other hostage. This shows the nature vs human dynamic. Humans are land creatures, and voyaging out into the sea for months at a time is not a natural act; it causes death and misfortune.