Who are the St. Lawrence blue whales?

The St. Lawrence is the seasonal residence of one of the largest concentrations of blue whales of the Northern Hemisphere. What is their relationship with the other blue whales of the Atlantic? It is crucial that we find out more about this endangered population.


  • Who are the St. Lawrence blue whales?
  • Photo credit : © GREMM

To go through the looking glass

Since 1979, research scientists have photo-identified 389 blue whales in the Northwest Atlantic. Richard Sears has biopsied close to half of these whales in order to get their genetic profile and to evaluate the level of contaminants in their body. In other areas of the North Atlantic, he has photo-identified or obtained pictures of close to 80 individuals (approximately 60 in Iceland, of which 25 have been biopsied; the remaining animals were from Greenland, Azores, Canary Islands, Newfoundland, Nova Scotia and in the Gulf of Maine, in the United States).

In short…

The proportion of new individuals identified in the St. Lawrence over the past few years is between 2 and 3 percent. This population is therefore well known. Of the 389 photo-identified animals, 26 were photographed elsewhere than in the St. Lawrence, such as west of Greenland, off Newfoundland and Nova Scotia as well as in the Gulf of Maine in the United States. Only 12 of these animals were never seen in the St. Lawrence. No St. Lawrence whales have been photographed in Iceland, the Azores or the Canary Islands. His findings suggest that the Northwest Atlantic blue whale population is a distinct stock, separate from of Iceland and East Atlantic stocks. Ongoing genetic analyses should soon confirm this hypothesis.

News from the field

In 2012, blue whales catalogue managed by MICS since 1979, contained 420 different individuals for the St-Lawrence

Project leader

Richard Sears, the Mingan Island Cetacean Society (MICS)


Cetacean Genetic Group, GREMM, Mériscope, Trent University and Woods Hole Oceanographic Institute

I want to know more

MICS website