Groups of sea lions, regardless of species, have a number of different names that also identify their physical location and expected seasonal behavior. For example, when found on land, a group of sea lions is called a colony. In the water, a group of sea lions is called a raft.
Additionally, during the breeding season, a colony of sea lions is known as a rookery. When several females are found in a male sea lion's territory in any season, the group of sea lions is known as a harem.
Sea lions, part of a group of animals known as pinnipeds that also include seals and walruses, only live in the Pacific Ocean.