Dolphins are skilled marine predators, though misconceptions exist about their diets. Understanding what dolphins consume provides insights into their ecological roles and adaptations within diverse ocean environments. Their feeding habits are shaped by their species, habitat, and the availability of prey in their surroundings.
Do Dolphins Eat Krill?
Dolphins generally do not consume krill as a primary food source. Unlike baleen whales, which filter feed using baleen plates, dolphins possess teeth. Their dentition is designed for grasping and tearing prey rather than filtering small crustaceans. This anatomical difference means dolphins are active hunters, pursuing individual organisms.
Krill are small, shrimp-like crustaceans that form the base of the food web for many filter-feeding marine animals. While some dolphin species, such as spinner dolphins, have been observed to include krill in their diet, this is typically a minor component and not characteristic of most dolphin species. Dolphins are opportunistic, adapting their diet based on what is readily available.
What Dolphins Really Eat
Dolphins are carnivorous mammals, primarily eating fish and cephalopods. Their diet includes mackerel, herring, cod, mullet, anchovies, squid, and octopus, which are abundant in many oceanic habitats.
Beyond fish and cephalopods, some dolphin species also consume crustaceans like shrimp and crabs. For instance, river dolphins adapt to freshwater environments by eating local fish and freshwater crustaceans. An average adult dolphin can consume between 4% to 9% of its body weight in food daily, amounting to roughly 15 to 30 pounds.
How Dolphins Hunt and Feed
Dolphins employ diverse and sophisticated strategies to secure their food, often cooperatively. Many dolphin species hunt in coordinated groups, known as pods. One common cooperative method involves herding schools of fish into a dense “bait ball” or tight mass, making it easier for individual dolphins to take turns swimming through and feeding. This teamwork allows them to maximize their catch efficiency.
Dolphins also utilize echolocation, a natural sonar system, to locate prey. They emit high-frequency clicks that travel through the water and bounce off objects, returning as echoes. By interpreting these echoes, dolphins can determine the precise size, shape, distance, and movement of potential prey, even in dark or murky waters where visibility is limited. Their agility and speed are also important for pursuing and capturing fast-moving prey. Other specialized hunting techniques include “strand feeding,” where dolphins cooperatively drive fish onto mud banks or shallow shores, and “fish-whacking,” using their tail flukes to stun fish.