Aquatic Species at Risk - Killer Whale - Northeast Pacific (offshore)

At a glance

Strikingly beautiful and graceful, the killer whale is easily identified by its distinct black and white patterned body. Three different populations exist in the Northeastern Pacific Ocean: "residents," "transients" and "offshores." The Northeast Pacific offshore population is small and has a low potential rate of increase. This population has been poorly studied, but is believed to consist of at least 250 whales.

About the killer whale

Killer whales are the largest member of the dolphin family. They are highly social animals that live in stable, family-related groups called pods. Led by females, these pods usually consist of 5 to 50 whales, although sometimes they can combine to form groups of 100 or more. Like humans, killer whales are very protective of their young.

With no natural predators, killer whales can live to between 50 and 80 years of age. However, mortality between the ages of birth to six months can be as high as 50 per cent. High levels of mortality among newborn whales leads to average life spans of only 17 years for males and 29 years for females. Sexual maturity of killer whales is reached by approximately 15 years of age. Females give birth, on average, to one calf every five years. Combined, these factors lead to extremely slow potential population growth rates.

What they eat

As a species, killer whales feed on a wide range of prey, including squid, octopus, fish, sea turtles, seabirds, sea and river otters, and other large cetaceans, such as whales, porpoises, dolphins. Different killer whale populations specialize on different kinds of prey, some on marine mammals and other on fishes. The preferred prey of the offshore population of killer whales is not known, but is likely fishes.

How to recognize a killer whale

The killer whale’s size―seven to nine metres long and between four and five tonnes in weight―and distinctive black and white pattern makes its unmistakable. The first sight of a killer whale is often the tall dorsal fin, which may reach up to 1.8 metres in height in mature males. In females and young whales, the fin is smaller and crescent-shaped. Behind the dorsal fin is a grey area called a saddle patch. The shape of the dorsal fin and saddle patch, as well as natural nicks and scars on them, are unique to each killer whale.

Calves are born measuring 2.5 metres but grow to reach lengths of up to 7.7 metres (females) to 9 metres (males).

Killer whales talk to each other through a complex variety of whistles, squeaks and whines made with air trapped in their blowholes. The sounds vary from pod to pod, with each group having its own unique dialect of language. Killer whales can recognize their own pods easily from several miles away based on the distinctive songs. Researchers believe that the more similar the dialects between two pods, the closer they are related. Pods of whales with related dialects are called clans.

Killer whale pods are very vocal when hunting for prey. They use a series of clicking sounds that bounce off fish and other objects in the water. Called echo-location, this natural sonar is useful when searching for food or navigating in murky water, enabling the whales to build an accurate picture of what’s around them.

Where the killer whale lives

Killer whales are found in all three of Canada’s oceans, as well as occasionally in Hudson Bay and the Gulf of St. Lawrence. It is not limited by such habitat considerations as depth, water temperature or salinity. They have been seen in water ranging from shallow (several metres deep) to open ocean depths. The offshore population is small and is poorly studied. Some individuals have been sighted as far south as central California and as far north as Alaska.

Why it’s at risk

Killer whales are potentially at risk from human-induced threats which include toxic chemicals, and the possibility that they must compete with fisheries for prey. The offshore population lives near the major offshore routes for oil tankers putting them at risk for collisions with vessels. Given their low population sizes and low potential rates of population growth, human interactions, such as vessel disturbance, underwater noise, competition over fish resources and exposure to oil spills might have a significant impact.

Read About : Killer Whales Serve as Sentinels for Ocean Pollution

What’s being done

Legislation to protect killer whale populations in BC waters was first introduced in 1970 under the Wildlife Act of British Columbia. In 1982, the whales were included in regulations under the Fisheries Act of Canada. These regulations prohibit hunting without a licence, except for Aboriginal hunting. No licences are currently being issued. The Northeast Pacific offshore population of the killer whale is listed as special concern and is protected under the federal Species at Risk Act (SARA). Whale watching guidelines and other public outreach measures are being taken to minimize potentially negative interactions between boats and whales.

A management plan has been finalized.

What can you do?

Killer whales will get the protection they need only if all Canadians work together to reduce threats. Learn more about the killer whale and be aware of human-induced threats to their survival such as industrial activity and water pollution. Do your best to reduce these threats wherever possible to protect the killer whale’s vital habitat. Get involved with the Habitat Stewardship Program for Species at Risk (HSP) or another conservation organization.

Join a stewardship program such as the B.C. Cetacean Sightings Network. The Network’s main goals are to identify key habitats and help reduce threats. The Network also solicits cetacean sighting reports from mariners along British Columbia’s coast. Find out more >>

Or join the British Columbia Adopt a Killer Whale Program, run in conjunction with the Vancouver Aquarium. Find out more >>

Background information provided by Environment Canada, November, 2004.