The killer whale, also known as orca, is the ocean’s top predator. It is the largest member of the Delphinidae family, or dolphins. Members of this family include all dolphin species, as well as other larger species, such as long-finned pilot whales and short-finned pilot whales, whose common names also contain “whale” instead of “dolphin.”

Found in every ocean in the world, they are the most widely distributed of all cetaceans (whales and dolphins). Scientific studies have revealed many different populations with several distinct ecotypes (or forms) of killer whales worldwide—some of which may be different species or subspecies. They are one of the most recognizable marine mammals, with their distinctive black and white bodies. Globally, killer whales occur in a wide range of habitats, in both open seas and coastal waters. Taken as a whole, the species has the most varied diet of all cetaceans, but different populations are usually specialized in their foraging behavior and diet. They often use a coordinated hunting strategy, working as a team like a pack of wolves.

Hunters and fishermen once targeted killer whales. As a result, historical threats to killer whales included commercial hunting and culling to protect fisheries from killer whales. In addition, although live capture of killer whales for aquarium display and marine parks no longer occurs in the United States, it continues to remain a threat globally. Today, some killer whale populations face many other threats, including food limitations, chemical contaminants, and disturbances from vessel traffic and sound. Efforts to establish critical habitat, set protective regulations, and restore prey stocks are essential to conservation, especially for the endangered Southern Resident killer whale population.

All killer whale populations are protected under the Marine Mammal Protection Act. Only two populations receive additional special protections under federal law:

• Southern Resident Distinct Population Segment (DPS) (listed as endangered under the Endangered Species Act
• AT1 Transient stock (designated as depleted under the MMPA)

Southern Resident killer whales are the only endangered population of killer whales in the United States, ranging from central California to southeast Alaska. Long-term commitments across state and international borders are needed to stabilize the Southern Resident population and prevent their extinction. The Southern Resident killer whale is one of NOAA Fisheries’ Species in the Spotlight. This initiative includes animals considered most at risk for extinction and prioritizes recovery efforts.

NOAA Fisheries is committed to the conservation of killer whales and the protection and recovery of endangered populations. Our scientists and partners use a variety of innovative techniques to study and protect them. We also work with our partners to develop regulations and management plans that protect killer whales and their food sources, decrease contaminants in oceans, reduce ocean noise, and raise awareness about the whales and the actions people can take to support their recovery.