Rationale for hunting Antarctic minke whales doesn’t hold water

Journal Watch Online 15 Jan 10;

Leaky faucetA new study has cast doubt on the idea that Antarctic minke whales are more numerous than usual and should be hunted to make way for other whale species.

Some researchers have suggested that the population of Antarctic minke whales (Balaenoptera bonaerensis) shot up after hunters killed about 2 million large whales during the 20th century. Since large whales eat huge amounts of krill, the reasoning goes, their disappearance would have boosted the food supply for Antarctic minke whales. This species is now so abundant that it is holding back the recovery of other whales, some argue.

To find out if these whales really did undergo a population boom, researchers collected 52 samples of minke whale meat from markets in Japan. By studying the animals’ DNA, they were able to get a better picture of the population’s genetic diversity. That led the team to conclude that the number of Antarctic minke whales has historically been around 670,000 – close to the number thought to exist today.

It’s possible that commercial whaling didn’t affect the population size because there was already plenty of krill in the ocean, the researchers write in Molecular Ecology. Alternatively, Antarctic minke whales may not draw from the same krill supply as larger whales. For instance, they might eat different sizes of krill or hunt at different depths. – Roberta Kwok

Source: Ruegg, K., Anderson, E., Baker, C., Vant, M., Jackson, J., & Palumbi, S. (2010). Are Antarctic minke whales unusually abundant because of 20th century whaling? Molecular Ecology, 19 (2), 281-291 DOI: 10.1111/j.1365-294X.2009.04447.x