Blue Whale Fact Sheet

Species at Risk Status: Endangered

Where do they live?

Blue whales live in all of the world's oceans. There are three subspecies. Those found in Canada belong to the northern hemisphere subspecies—of which there are both north Atlantic and north Pacific populations. The Atlantic population of blue whales frequents waters off eastern Canada: along the north shore of the Gulf of St. Lawrence; off eastern Nova Scotia; off the south coast of the island of Newfoundland, in the Davis Strait between Baffin Island and Greenland. While they usually go south in winter, some do linger in the St. Lawrence and off southern Newfoundland during years of light ice cover.

What do they look like?

The blue whale is the largest animal on Earth today—and the largest known to have ever existed. The blue whale is a rorqual whale—one of a group that has pleats in the skin of the neck which allow it to expand its mouth to take in huge volumes of water while feeding. One quarter of its entire length is made up by its head. It has a smallish dorsal fin and pointed pectoral flippers. Despite its name, the blue whale is actually a mottled grey colour; every whale has a unique pattern of mottling that makes it identifiable.

The blue whale isn't just big; it's also loud. It can emit sounds at up to 186 decibels—louder than a large ship at 100 meters distance. These sounds are so low in pitch they are below the normal range of human hearing. To date, researchers have not been able to determine why the whales make these calls, although it is likely for communication.

What do they eat?

Blue whales eat mostly krill (shrimp-like crustaceans about two centimetres long). A single blue whale can consume as much as four tons in a day. To eat, these massive animals take large quantities of water into their mouths. Forcing the water back out, they use their baleen as filters to catch the krill and planktonic organisms that were in the water; these are then swallowed.

What is their life cycle?

Living between 70 and 80 years, blue whales reproduce every two or three years. Calves at birth measure seven metres and weigh two tonnes. The largest adult on record measured 29.5 metres; like other rorquals whales, females are larger than males. The total number of blue whales in the Atlantic population is unknown, but as many as 105 are spotted annually in the Gulf of St. Lawrence. Overall, 382 individuals have been recorded in the Gulf since 1979; just under half return regularly.

Blue whales travel singly or in small groups, migrating between temperate waters in summer and more tropical waters in winter. They can swim at speeds of up to 36 km/h, but typically cruise between two and eight km/h.

Why is it at risk?

At least 11,000 blue whales were hunted and killed in the north Atlantic prior to 1960. Approximately 1,500 of these were taken in eastern Canadian waters. Despite the end of commercial hunting in Canada, blue whales remain threatened by human activity in this country. Collisions with ships, entanglement in fishing gear, and the effects of pollution all have the potential to harm these giant creatures.

What is being done?

The blue whale is listed as endangered and protected under the Species at Risk Act (SARA). It is also protected under the Marine Mammals Regulations, which fall under the Fisheries Act.

Internationally, blue whales are protected by the International Whaling Commission; the blue whale is also listed by both the World Conservation Union (IUCN) and the Convention on the International Trade of Endangered Species (CITES).

A recovery plan is in development for the blue whale.

This species will get the protection it needs only if all Canadians work together to reduce threats. Find out more and do your best to reduce these threats wherever possible to better protect its critical habitat. Get involved with the Habitat Stewardship Program for Species at Risk (HSP), or other conservation organizations.