New study harpoons Antarctic minke population boom
27 January 2010
Researchers used genetics to determine pre-whaling numbers for Antarctic minke whales and concluded that the current population is not unusually abundant. In the ongoing debate about whale management, it has been suggested that commercial whaling of larger animals led to a population explosion in the number of smaller minke whales that is currently inhibiting the recovery of depleted species. Now, there is good reason to dismiss the argument that minkes need to be killed in order to save blue, sei, fin and humpback whales as specious.
Working from 52 samples of Antarctic minke whale meat purchased from Japanese markets, scientists used genetic diversity to estimate the long-term population of minkes at 670,000 individuals. The number falls well within the range of recent estimates from sighting surveys conducted under the supervision of the International Whaling Commission and provides evidence that the current population is not artificially high. The study casts doubt on the notion that the industrial slaughter of some two million whales in the Southern Ocean led to a krill surplus that allowed minke numbers to soar and stifle the recovery of the over-harvested whales.
Possibly the loss of top-level krill-eaters did not affect the minke population because of the sheer number of krill. Alternatively, the different whales may not feed on the same krill; they might eat different sizes or hunt at different depths. It is also possible that minke numbers were abnormally low just prior to whaling and a krill surplus allowed them to recover to their long-term average although, the researchers explicitly note, “there is no data to suggest that this was the case.”