CANBERRA, April 28 (Xinhua) -- Bowhead whale populations are recovering only in stocks where large areas of hazardous sea ice conditions limited devastating hunting centuries ago, a study finds.
Researchers led by Australia's Adelaide University analyzed historical logbooks from more than 700 whaling voyages, reconstructing their daily positions and hunting successes across the Arctic, said a university statement released Tuesday.
The study found that by the late 1700s, whaling had spread rapidly across the Arctic, reaching most bowhead habitats except those shielded by hazardous sea ice.
Sea ice barriers delayed access to some of the most profitable whaling grounds in the Arctic, providing important natural sanctuaries for bowhead whales, according to the findings, published in the U.S.-based Proceedings of the National Academy of Sciences.
"Bowhead whale populations with ancestors who found refuge in these protective zones, hidden behind hazardous sea ice barriers, are recovering more quickly today," said the study's senior author, Professor Damien Fordham from Adelaide University's Environment Institute.
Bowhead whales were intensively hunted for their blubber, used in oil for lighting and machinery, with whaling becoming widespread after British and American whalers entered the Arctic in the 1700s, the researchers said, adding that commercial whaling ceased in the early 20th century.
"The profits accrued by whaling came at an expense to population numbers of bowhead whales, which plummeted in response to increases of commercial exploitation," said lead author Nicholas Freymueller from Adelaide University.
"Today, only two of the four stocks of bowhead whales are recovering -- populations off the coast of Alaska and West Greenland," said Freymueller, adding that populations off East Greenland and in the Sea of Okhotsk, which were more accessible to whalers, remain depleted. ■
