The Independent (London)
Global warming has caused an unexpected collapse in the numbers of the
world's most hunted whale, scientists believe.
They think that a
sharp contraction in sea ice in the Antarctic is the likeliest
explanation behind new findings, which suggest that the number of minke
whales in the surrounding seas has fallen by half in less than a decade.
The findings—which were the talk of the annual meeting in London last week of the International Whaling Commission (IWC), the body that regulates whaling—has greatly strengthened the arguments of conservationists who are resisting moves to lift a 15-year-old official ban on the hunt.
It also further underlines the importance of last week's agreement in Bonn on how to implement the Kyoto Protocol, the international treaty to combat climate change.
Commercial whaling has been banned officially since 1986, but Japan and Norway each continue to kill about 500 minke whales a year. Japan does so under the guise of "scientific research," allowed under the WIC's treaty; Norway by exempting itself from the ban, which is also permitted under the agreement.
For years environmentalists have struggled to justify opposing the killing for conservation reasons. The last attempt to count the number of minke whales in the Southern Ocean around Antarctica, between 1985 and 1991, estimated that there were some 760,000 of them—far more than could be endangered by any conceivable catch.
But the latest counts, during the 1990s, suggest that there are now only about 380,000 left. The minkes in the Southern Ocean are a distinct species, far more abundant than their cousins in the northern hemisphere.
Whales are notoriously difficult to count at sea, and no one is certain of the true figures. But the IWC's Scientific Committee is reassessing its official estimate of their numbers as a result of the new evidence that they are sharply declining.
No one knows why their numbers are crashing. But global warming is the main suspect because the krill on which they feed live at the edge of the sea ice, and so their abundance depends on its circumference.
Until recently scientists thought the sea ice in the area had not shrunk much, because satellite measurements have shown little change since they began in 1973. But Australian government research, based on more than 40,000 records from whaling ships since 1931, suggest that it dropped by a quarter between the mid-1950s and early 1970s, when global warming was beginning to take hold.
As minke whales live for 60 years, it could have taken until now for the effects to become clear.
Last week Sidney Holt—who served on the Scientific Committee between 1960 and 1997, and is the world's senior scientist in the field—said he thought global warming was "the likeliest hypothesis" for the crash.
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