Dolphins live in the Pacific Ocean. Some far out in the ocean, such as the hourglass dolphin, others near the land. The Pacific Ocean is the biggest ocean in the universe. It settles between Asia and North America. Other kinds of dolphins live in the Amazon River. These types of dolphins are called river dolphins. A dolphin is a carnivorous predator so it hunts and eats only meat. A dolphin reduces the number of animals that live in it's biome. This is a dolphin's niche, or role and job, to be a predator. River dolphins are prey for snakes who live near river banks. So dolphins are both prey and predator!