Pi finds a tooth on a carnivorous island
A tiger attacks a small goat and drags it though the bars of its cage (offscreen), and we hear the goat cry in pain. The tiger is shown dragging the animal away to eat it.
We see a cargo ship sink, presumably killing many.
In a lifeboat, a hyena attacks and kills an obviously lame zebra, nipping on its flanks as Pi and the zebra both scream. Shown in the dark, mostly in silhouette, no blood.
A hyena bites an orangutan on the neck and drags it out of view to kill it; a few spots of blood are shown on the deck. A tiger quickly kills the hyena, no blood or gore shown (we do hear the hyena's neck snap). The tiger tries to kill Pi but is unable to reach him. The tiger swallows a live rat whole. The tiger later snacks on a meerkat.
The hyena appears to be coughing up / throwing up water.
Sea sickness is mentioned in the survival guide Pi reads and Pi tries to induce sea sickness in the tiger as a means to tame it.
We catch a brief glimpse of what appears to be a hippo being attacked by sharks. A sperm whale briefly tangles with a giant squid.
Pi pounds a fish with the blunt side of an axe to kill it, apologizing profusely to it afterward. Some blood seen.
Pi and the tiger fight, Pi keeps it at bay by putting a boathook in its mouth, which doesn't appear to hurt it. Pi stabs a fish with a spear, no blood.
Pi finds a human tooth inside an acidic plant on an island, and talks about how the island literally eats living things, even animals.