Research through the Australian Marine Mammal Centre has found evidence that pygmy blue whales (Balaenoptera musculus brevicauda) from two Australian feeding aggregations — one in the Bonney Upwelling region off South Australia and Victoria, and the other in the Perth Canyon off Western Australia — show high genetic similarity. This means that individuals from both aggregations are likely to belong to the same genetic population.
Dr Luciana Möller and her colleagues at Macquarie University say the high level of genetic similarity between Australian blue whales was particularly evident when they compared these whales with Antarctic blue whales — of the subspecies B. m. intermedia. As expected, the two recognised Southern Hemisphere subspecies showed low genetic similarity.
Given the severe decline in blue whale numbers due to whaling in the early 20th century, Dr Möller says the findings are good news as they mean it is more likely that Australian pygmy blue whales are able to maintain their genetic diversity over time.
Dr Möller says the research confirms the potential of genetic analysis to identify blue whale populations and to differentiate blue whale sub-species. It also provides information on the genetic structure of Australian populations, which will be incorporated into models for measuring the recovery and status of blue whales in Australian waters.
Further genetic research is now necessary to determine the identity of blue whales in Geographe Bay — another area off Western Australia where blue whales are frequently sighted. Defining populations of blue whales will be extremely important to future management and conservation efforts of these animals in Australia and elsewhere.
Corporate Communications, AAD
More information: C. Attard, L.B. Beheregaray, C. Jenner et al. Genetic structure of blue whales (Balaenoptera musculus) in Australian feeding aggregations. Conservation Genetics (in review).