They hunt fishes and sea mammals. Because orcas hunt in a pack, they can bring down the largest sharks and sea mammals. Orcas in the Puget Sound area eat a good deal of salmon and a few seals and sea lions. The transient groups that move through Monterey Bay from time to time probably eat more seals and sea lions, as well as the occasional gray whale calf. Once paralyzed, the squid fall easy prey to the whale.
Most baleen whales swim between two and four miles per hour when cruising.
They may reach speeds four times that for short distances. No one really knows, yet. Some theories are that a whale may beach itself when it is heavily parasitized, or diseased, and too tired to hold itself at the surface to breathe. Or parasites may affect the balance organs of the inner ear, and the whale gets confused and beaches itself by accident. These species rarely venture off as single individuals and show great loyalty to group members that are in trouble.