Old whalers' journals revealed why some whales survived and others didn't
Scientists have discovered that the fate of bowhead whales still depends on where whalers were able to get to hundreds of years ago. Where dangerous sea ice interfered with the hunt, whale populations are now recovering better.
An international team led by scientists from the University of Adelaide has studied the historical logs of more than 700 whaling voyages. The researchers reconstructed the ships' routes, the whalers' daily positions and the locations of successful hunts in the Arctic.
Details
Greenland whales have been commercially hunted for centuries. Hunting for them began as early as the 16th century off the coast of Newfoundland and Labrador, and later spread to other areas of the Arctic. British and American whalers were particularly active in harvesting these animals from the end of the XVIII century. Whale oil was used to light and lubricate machinery during the early industrialisation era.
But whalers were not able to reach everywhere. In some areas, dangerous ice conditions actually became a barrier to ships. These areas turned out to be natural refuges for some of the bowhead whales.
According to the study, it is those populations whose ancestors took refuge behind such ice barriers that are now recovering faster.
Of the four major bowhead whale populations, only two - off the coast of Alaska and West Greenland - are recovering significantly. The populations off East Greenland and in the Sea of Okhotsk, according to the authors, have been more severely affected by fishing and show few signs of recovery so far.
Why it matters
The work shows that the effects of mass fishing can persist for centuries. Where and how actively whalers hunted in the 18th and 19th centuries still affects the status of populations today.
This is important for the conservation of not only whales, but also other long-lived marine animals. If a species lives a long time and breeds slowly, it can recover from over-hunting very slowly - even a century after fishing has stopped.
The study also shows the value of historical data. Old ship's logbooks that once served as whalers' working records now help us understand where animals were most severely decimated and which populations need special protection.
Background
Greenland whales are Arctic long-lived animals closely associated with sea ice. In recent years, scientists have also warned that their summer feeding grounds could shrink dramatically due to climate change, with separate papers predicting the loss of much of the suitable Arctic habitat by the end of the 21st century.
This poses a double challenge: some populations are still reeling from historic whaling, and now face a rapid decline in sea ice.
Source
A study by Nicholas A. Freymueller and co-authors Historic logbooks reveal spatial footprints of commercial whaling published in Proceedings of the National Academy of Sciences in 2026. The authors analysed the historical logbooks of more than 700 whaling voyages to reconstruct the spatial footprint of commercial whaling.