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JAPAN: Killer Whales Strand in Pack Ice |
| February 18, 2005 |
 | The carcasses of some of the stranded whales were brought ashore for post-mortem examination by Japanese experts.
Photo: Yuki Ogino |
On the morning of February 7, 2005, twelve killer whales were spotted trapped in pack ice near a port on the Japanese island of Hokkaido, 1,500 km north of Tokyo and near the Russian border. One adult female and two adult males are believed to have freed themselves and returned to the ocean, but the remaining nine whales died despite frantic efforts to rescue them.
"Mass strandings of killer whales are generally rare," said Dr. Lance Barrett-Lennard, Senior Marine Mammal Scientist at the Vancouver Aquarium. "It’s been 60 years since we’ve had a mass stranding on the B.C. coast, so it seems likely that this stranding was the result of an unusual set of circumstances."
A change in the weather may be to blame for the incident; a low-pressure system bringing about northern winds abruptly blew drifting sea ice toward the shore. According to Dr. Barrett-Lennard, killer whales are usually reluctant to pass under wide areas of ice. The whales appear to have reacted by swimming closer to the coast, where they became trapped.
Scientists conducted post-mortem necropsies on one adult male (765 cm), five adult females (ranging from 563 to 686 cm), and three female calves. Dr. Michiru Ogino, Director of Japan’s Marine Mammal Center, is in the process of testing some samples and having others shipped for testing.
Scientists are working to determine whether the group belonged to a Russian or Japanese killer whale population; there are few killer whales left in Japanese waters, but over 150 killer whales have been identified in far-eastern Russian waters.
Scientists are also keen to find out whether the whales were fish-eating resident killer whales or mammal-eating transients. Resident killer whales are more likely to contribute to the repopulating of killer whales in the area, and the loss of so many at once could severely hamper ongoing conservation efforts.
Source: Whales Online, Vancouver Aquarium Marine Science Centre
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