Dr. Brenna McLeod, a recent Ph.D. graduate of the Environmental and Life Sciences program at Trent University, and Dr. Bradley White, chair of Biology, are part of a research team gaining much attention after a new study of ancient whale bones revealed that, although fewer than 450 North Atlantic right whales remain in the western North Atlantic, the demise of the species in this region is not only related to whaling in the 17th - 20th centuries, but might also be due to a pre-whaling event that limited genetic diversity in the species.

The study, recently published in the journal Conservation Genetics, was conducted during Dr. McLeod’s Ph.D. term at Trent under the supervision of Dr. White. Research was conducted in the Natural Resources DNA Profiling & Forensic Centre (NRDPFC) labs in Trent’s state-of-the-art DNA Building. The ancient DNA work was also done in Trent Anthropology professor Dr. Anne Keenleyside's palaeo-DNA lab facility.

“The research conducted by Dr. Mcleod was made possible by the DNA infrastructure obtained with a CFI grant to a group of Biology faculty and MNR scientists. This equipment together with the palaeo-DNA facilities of Trent’s Department of Anthropology provided a unique opportunity to study this highly endangered species,” says Dr. White. “The DNA Centre also holds the archive of DNA from 70 per cent of the species that has been collected over a period of 25 years with the close collaboration of the New England Aquarium in Boston.”

Typically perceived as a species that was once abundant and successful in the North Atlantic Ocean, the North Atlantic right whale in the Western North Atlantic was always assumed to have suffered a large population reduction because of 16th century Basque whalers. The discovery in 1978 of a 16th century Basque whaling galleon by historian Dr. Selma Barkham offered the first chance to test these assumptions.

The new study, which examines genetic characteristics of a single right whale bone recovered from the galleon that had sunk in the harbour of Red bay in 1565, is significant for today because it demonstrates that the right whale has had low levels of genetic diversity for far longer than had been thought.

“We were able to successfully extract DNA from these bones, as well as from bones that had been sitting on shore for over 400 years at long-forgotten 16th century Basque whaling stations scattered along the shores of Quebec and Labrador. We examined 218 whale bones in total to identify their species of origin and found that 217 were bowhead whale and only one was a right whale,” Dr. McLeod says. “There was no evidence of a right whale targeted hunt by the Basques in the Western North Atlantic!”

Today, recovery of the rare and endangered North Atlantic right whale is limited by several intrinsic and extrinsic factors – the combination of which makes it very difficult to predict the future survival of the species, and to assess the degree to which any particular factors are having an impact.

“Overall, our studies suggest that the North Atlantic right whale had a smaller historical (pre-commercial whaling) population size and has had low levels of genetic diversity for longer than has been thought. Both of these characteristics have now been shown to pre-date commercial exploitation of the species. This is a big surprise given what was previously thought,” explains Dr. McLeod, who is now teaching at Saint Mary's University in Nova Scotia. “Humans are certainly responsible for the endangered status of the species - there is no doubt that the right whale was hunted in the eastern and western North Atlantic, and reduced to today's critically low numbers, however the size of the overall population decrease was not as large as was previously thought. The removal of a substantial Basque whaling impact in the western North Atlantic suggests that the overall scale of the population reduction is smaller than was previously suggested.”