Bull sharks are voracious predators and will eat anything they come across that they're able to overpower. They are opportunistic feeders, meaning they'll eat whatever smaller animals are available, including smaller sharks, fish, turtles, stingrays, invertebrates like crustaceans and molluscs, and even birds. They might even eat smaller bull sharks if they're hungry enough.
Although bull sharks are not typically considered apex predators, they do occupy a high trophic level and play an important role in maintaining a healthy marine ecosystem. Their broad diet helps control the populations of their prey species, and their own mortality helps support other predatory species further up the food chain.