The diet varies with the season and region. Their food consists of crustaceans, mollusks, squid, and a variety of fish. Harbor seals do not chew their food; they either tear it into chunks or swallow it whole. Their molars allow them to crush hard objects like shells and crustaceans. Adults consume around 4.5 to 8.2 kg of food per day, which is 5-6% of their body weight.

Animal Foods: fish; mollusks; aquatic crustaceans

Primary Diet: carnivore (Piscivore , Eats non-insect arthropods, Molluscivore )