Food for whales is a term used to describe the type of food that whales consume. The two main sources of food for whales are krill and PLANKTON. Krill is a small, shrimp-like crustacean that lives in large swarms in the ocean and is a major food source for many species of whales. PLANKTON is a collective term for a wide variety of microscopic organisms that drift in the ocean and are also a major food source for whales.