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.

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].)

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-Pacific [top]; S. Leatherwood, southern California (middle and inset); and F. W. True, northern North Atlantic, courtesy of U.S. National Museum [bottom].)