Are Nova Scotia and St. Lawrence fin whales the same animals?

Although Fin whales are present throughout most of the North Atlantic, their movements and population structures are not very well known. In summer, western North Atlantic fin whales are frequently observed in the Gulf of Maine, in the Bay of Fundy, in the Gulf and Estuary of the St. Lawrence and off Nova Scotia. Do the same animals travel from one area to another?

BPJ070724_1096

  • Group of Fin whales
  • Photo credit: © GREMM

To go through the looking glass

When fin whales were particularly abundant off Halifax in the summer of 1997, 57 individual animals were photo-identified from aboard a whale-watching vessel. Photos of these animals were compared with various western North Atlantic fin whale photo-identification catalogues.

In short

Of the 57 fin whales identified off Halifax, nine had already been photographed in the northern portion of the Gulf of Maine and in the Bay of Fundy. Three had been photographed in the Gulf of St. Lawrence. Of these three, one had also been photographed in the St. Lawrence Estuary. One individual was matched with both the Gulf of Maine catalogue and the Gulf of St. Lawrence catalogue. Fin whales were exceptionally plentiful near Halifax in 1997, a phenomenon that could be explained by an abundance of prey. There were in fact reports that large amounts of herring, sand lance and euphausids were present in this sector that year. By contrast, fin whale observations in the St. Lawrence Estuary were rare in 1997. This study therefore suggests that in the summer of 1997, certain fin whales that usually visited the St. Lawrence Estuary chose to stake advantage of abundant prey off Nova Scotia, and remained there. It appears that North Atlantic fin whale movements could be more variable than previously believed.

Project collaborators

Amanda Coakes1, Shannon Gowans2, Peter Simard3, Janie Giard4, Courtney Vashro5 and Richard Sears6

1. Dalhousie University 2. Eckerd College 3. Blind Bay Cetacean Studies 4. GREMM 5. Allied Whale 5. Station de recherche des Îles Mingan (MICS)


Scientific papers

AGLER, B. A., J. A. BEARD, R. S. BOWMAN, H. D. CORBETT, S. W. FROCHOCK, M. P. HOWVERMALE, S. K. KATONA, S. S. SADOVE and I. E. SEIPT. 1990. Fin whale (Balaenoptera physalus) photographic identification: methodology and preliminary results from the western North Atlantic. Reports of the International Whaling Commission (special issue) 12:349-356.

COAKES, A., S. GOWANS, P. SIAMRD, J. GIARD, C. VASHRO and R. SEARS. 2005. Photographic identification of fin whales (Balaenoptera physalus) off the Atlantic coast of Nova Scotia, Canada. Marine Mammal Science, 21(2):323–326

EDDS, P. L. and J. A. F. MACFARLANE. 1987. Occurrence and general behaviour of balaenopterid cetaceans summering in the St. Lawrence Estuary, Canada. Canadian Journal of Zoology 65:1363-1376.

GIARD, J., S. THOMPSON, C. FOLEY et R. MICHAUD. 2001. Les rorquals communs de l’estuaire du Saint-Laurent ; un catalogue des individus identifiés entre 1986 et 2000. Groupe de recherche et d’éducation sur les mammifères marins. 79 p.

KINGSLEY, M. C. S. and R. R. REEVES. 1998. Aerial surveys of cetaceans in the Gulf of St. Lawrence in 1995 and 1996. Canadian Journal of Zoology 76:1529-1550.