The killer whale (Orcinus orca), or orca, is found in all oceans. These whales can adapt to almost any conditions, and appear to be at home in both open seas and coastal waters. Orcas are toothed whales, related to sperm and pilot whales, and are apex predators vulnerable only to large sharks. They have the most varied diet of all cetaceans, and can tackle prey of all shapes and sizes. They often use a coordinated hunting strategy, working as a team like a pack of wolves.

Orcas can grow to 32 feet in length and weigh as much as 18,000 pounds. Killer whales have a lifespan of 25 to 90 years, with females living longer than males. They form family groups called pods. The typical pod often numbers between three and 25 individuals, but can reach a maximum of about fifty.

Killer whales are threatened by pollution and other human activities in many parts of their range. Since orcas are at the top of the food chain, much of their food is likely to carry high contamination from water pollution.

The Southern Resident killer whales are the significant population in the Northwest Region. These whales are the "resident" type, spending specific periods each year in the San Juan Islands and Puget Sound. The Southern Residents feed mostly on salmon. For an update on the status of these orcas, see the Northwest Fisheries Science Center paper, Summary information on 2008 Southern Resident Killer Whale births and deaths. (PDF 108KB)

"Transient" orcas occasionally visit Puget Sound. These whales feed mostly on pinnipeds and don't have known schedules and locations as resident whales do.