Hybrid Minke Whale Species Found in Arctic Waters
28.01.2011 - Water & Oceans, Flora & Fauna, Bi-polar
According to a study recently published in the online journal PLoS ONE, some Antarctic Minke whales have made their way into Arctic waters. It also appears that they have been interbreeding with indigenous Arctic Minke whales, creating a new hybrid species of Minke whale.
Individuals of the Arctic and Antarctic species of Minke whale usually spend the summer in the high latitudes of their respective hemispheres and head towards the equator during the winter. Since summer in the Arctic corresponds to winter in the Antarctic and vice versa, it was believed that the two species would never meet.
However shortly after Norway resumed whaling in 1993, the country established a DNA registry to analyze its catches and help ensure that the industry’s products come from legal sources. This testing has shown that a whale caught by a Norwegian vessel in the northeastern Atlantic in 2007 was found to have genetic blueprint of a hybrid, with an Antarctic Minke mother. Further DNA testing on remains of a whale caught in 1996 - which a scientific observer aboard the vessel had remarked as having unusual colouration for an Arctic Minke – showed that it was in fact a pure Antarctic Minke whale. This provides evidence that Antarctic Minke whales have migrating northwards and have even been mating with their northern relatives.
The explanation for Antarctic Minkes making their way north may have to do with a drop in food supply in the Southern Hemisphere. Japanese studies show that during the 1980s and 90s, Antarctic Minke whale populations declined significantly, while other studies have showed a significant drop in the population of krill – a tiny crustacean that is major food source for whales and other marine mammals in the Antarctic – also declined.