Scientists from WCS (Wildlife Conservation Society), the Universidad Austral de Chile, the Blue Whale Center, the American Museum of Natural History (AMNH), NOAA, and other organizations are examining molecular¹ clues to answer a big question: how many types of blue whales exist in the waters of the southeastern Pacific? The answer seems to be two distinct populations, according to a genetic² study comparing the blue whales off the southern coast of Chile with those swimming in the waters of Antarctica and other nearby regions. One of the populations could be made up of pygmy-type blue whales, a subspecies slightly smaller than the Antarctic blue whale. The findings could help wildlife managers devise more effective conservation plans for this endangered species.

 

The study appears in the online edition of the journal Molecular Ecology. 

 

Reaching nearly 100 feet in length, the blue whale is thought to be the largest animal that ever existed, even larger than the biggest known dinosaurs³. Blue whales were nearly hunted to extinction⁴ by commercial whaling fleets in the 20th Century before the species was granted international protection in 1966.

 

Although whaling records dating back to the 1960s indicate that both Antarctic and pygmy-type blue whales utilized⁵ Chilean waters, it wasn't until 2004--when a blue whale feeding and nursing ground was discovered in the protected bays of southern Chile--that scientists began to question whether multiple populations of blue whales currently utilized the southeastern Pacific. A previous study had even recognized the existence of an as-of-yet unnamed subspecies of blue whale based on size differences in animals in the southeastern Pacific. At the time, however, it was unknown how closely related the whales on this Chilean feeding ground were to those in other areas, and thus what this discovery might mean in terms of the recovery of the animals in the Southern Hemisphere.

 

"The most effective way to protect the region's blue whales depends on a better understanding of how blue whales in the waters of Chile interact with other populations of the same species, as well as knowing which areas are used for activities such as feeding and breeding to facilitate future designation of MPA network," said Dr. Juan Pablo Torres-Florez, researcher for the Universidad Austral de Chile and lead author of the study.

 

"Molecular methods give us the means for uncovering the hidden relationships of blue whales in southeastern Pacific, as well as finding regions of importance to the species," said Dr. Howard Rosenbaum, one of the senior authors of the paper and Director of WCS's Ocean Giants Program.