Sharks, killer whales and humans are the primary eaters of dolphins. Dolphins are near the top of the food chain and employ many defensive strategies, so they are not often eaten by predators.
Dolphins, which travel in groups called pods, are mostly threatened by larger species of sharks. When a member of the pod sees a predator, the able-bodied adults form a ring around the older and younger members of the pod and attack the predators. Adult dolphins are so aggressive while attacking that they have been known to kill sharks.
Dolphins have been found in the bellies of killer whales. It is unknown if the whales attack the dolphin as prey or simply scavenge dolphins that die of natural causes.
Humans are also a threat to dolphins, and in some cases, people consume them. In Japan, dolphin meat is considered a delicacy and sells for as much as $25 per pound, as of 2014. People of some nations, such as the Faroe Islands, consider eating dolphins a tradition. In some South American countries, fishing stocks have been almost completely depleted, and fishermen have turned to dolphins as a food source. In other areas, fishermen kill dolphins to prevent the dolphins from preying on the fish the fishermen are trying to catch.