Killer whale (Orcinus orca)

The killer whale, or orca, is the largest dolphin in the world and is found in all oceans. Orcas can grow to 32 feet in length and weighing between 3,000 and 12,000 pounds and live up to 90 years, with females living longer than males. Orcas are top 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.

These whales can adapt to almost any conditions, and appear to be at home in both open seas and coastal waters. They form matriarchal family groups called pods. The typical pod often numbers between three and 25 individuals, but can reach a maximum of about 50.

The Southern Resident killer whales (J, K & L pods) 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.

Northern residents live in waters off northern Vancouver Island to southeast Alaska.

Southern resident whales  live most of their lives in the inland waters of Puget Sound and the Georgia Strait; ; and Transient orcas pass through the area as they move to and from Alaska and the open ocean. These whales feed mostly on pinnipeds and don't have known schedules and locations as resident whales do.

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 toxic chemicals. Southern resident populations are also threatened by lack of prey (salmon) and increased vessel traffic.

As of June 2007, Southern resident orcas numbered 87. Southern resident orcas are listed as 'threatened' under the US Endangered Species Act and a  recovery plan was issued in January 2008 by the National Marine Fisheries Service.