Species

Blue Whale

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  • Blue Whale
  • Blue Whale
  • Blue Whale
  • Blue Whale
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  • Blue Whale in the St. Lawrence Gulf during winter

It is a seasonal summer resident of the Gulf and Estuary, where its abundance peaks in August and September. It can sometimes be observed very close to shore.

Some individuals return to their feeding site regularly (nearly every year), others more sporadically.

Blue whales are present in all the world’s oceans. They frequent coastal waters and the high sea (or international waters).

The blue whales of the St. Lawrence belong to the North Atlantic population, which is estimated at between 600 and 1500 individuals.

The blue whale appears in the List of threatened or vulnerable species in Quebec.

The Atlantic population is listed as “endangered” by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).

The International Union for Conservation of Nature’s” (IUCN) List has designated the blue whale as “endangered”.

The blue whale is a gulper, feeding essentially on small planktonic crustaceans called krill.

It consumes up to four tonnes a day, which corresponds to about 4% of its weight.


Illustrated species: krill.


Rather solitary and nomadic, blue whales travel in pairs or in small temporary groups.

In the St. Lawrence, it has been observed that stable pairs – lasting a day or even several weeks – are formed beginning in July. These pairs are most often male/female duos.

This pairing is believed to be a precursor to reproduction, which takes place in winter.

These vocalizations are composed of low-frequency sounds and infrasounds.

They travel hundreds of kilometers in the deep waters and can serve either as a means of communication for widely dispersed animals in the ocean, or may help whales “read” the seascape and underwater relief to orient themselves during their long journeys.

They may play a role in their mating rituals.

Blue whales sometimes feed on the surface by means of characteristic manoeuvres, namely rolling onto their sides.

Dives generally last 10 to 15 minutes, and occasionally up to 30 minutes.

They can reach depths of 200 m, with most being made between the surface and about 100 m, the depth at which their prey are found during the day.


Photo credit: Jean Lemire

Since 1979, MICS, which fine-tuned the individual identification method based on skin pigmentation patterns, has managed a catalogue of 420 blue whales for the St. Lawrence.

Other projects are being pursued by other research teams in the Estuary and Gulf, notably in the areas of acoustics, population dynamics and diving behaviour.

To discover all the studies dedicated to this specie, consult the research projects on the blue whale on Whales online .