sent from Canadian waters during
midwinter.

Many of the migrating individuals were assumed to continue south to
temperate and, less frequently, to tropical water where they calved. It
should be emphasized that though all of the southward and the subsequent
northward migrations were presumed to be along pelagic routes, details
were poorly documented.

Blue whales have been reported in both shallow inshore and deep oceanic
zones.

Despite considerable attention in the popular literature to the plight
of the blue whale populations and frequent statements that they are near
extinction, blue whale stocks in the western North Atlantic appear more
abundant than has been usually reported. While present stocks are far
short of previous population sizes, which may have exceeded 200,000
individuals worldwide, they should be sufficiently large for the
species to continue their increase, barring renewed exploitation.

Stranded Specimens

Stranded blue whales can be readily identified by 1) the large body size
(to 85 feet [25.9 m]); 2) the broad flat head; 3) the all-black baleen
plates (270-395 in number), which are usually barely more than twice as
long as they are wide; and 4) the 55-88 ventral grooves extending to the
navel or beyond (Table 2).

Depending on the state of decay and the position of the stranded
specimen, any of the body characteristics described for living animals
may also be used to positively identify the specimen.

[Illustration: Figure 9.--Closeup views of swimming blue whales off
British Columbia (top) and Baja California (bottom). In both photos note
the broad rounded appearance of the head and the single, prominent
central head ridge. In the animal on the top note also the black baleen
plates, barely visible at the front of the slightly open mouth. In the
animal on the bottom note the pattern of light grayish-white mottling
along the back and the raised areas around the blowholes. These features
clearly mark these animals as blue whales. (_Photos by R. M. Gilmore
(top) and K. C. Balcomb (bottom)._)]

[Illustration: Figure 10.--The dorsal fins of blue whales may vary from
distinctly triangular (top) to broadly rounded (middle and inset) to
smoothly falcate in appearance (bottom). Regardless of its shape,
however, the fin is always located well back on the tail and does not
become visible until long after the animal's blow. (_Photos by Japanese
Whales Research Institute, courtesy of H. Omura, mid-