The arctic conjures images of windswept, barren landscapes, unspoiled until broached by Europeans. Recent evidence, however, indicates that this idyllic picture may not be entirely accurate. A Canadian team of experts has unearthed new and fascinating evidence that aboriginal whalers changed the ecosystem in the region of at least one prominent settlement in the high Arctic.
Led by Dr. Marianne Douglass of U of T’s geology department, the group of investigators uncovered how the Thule, ancestors of present-day Inuit, impacted the environment through their whaling activities 400 to 800 years ago. The team, which included paleolimnologist Dr. John Smol from Queen’s University, archaeologist Dr. James Savelle of McGill University, and biologist Dr. Jules Blais of the University of Ottawa, published their findings in the January 16 issue Proceedings of the National Academy of Sciences.
“The primary goal of our study was…to determine whether Thule Inuit whalers, who butchered, consumed, and discarded the products of whales, used whale bones as architectural materials, had significantly altered local freshwater ecosystems. If so, these sites provide examples of long-term human-induced changes in Arctic aquatic ecosystems, a region widely believed to have been unaffected by local human impacts until very recently.” The team found nutrient-enriched ponds on Sommerset Island (northwest of Baffin Island) supporting very lush growths of mosses and algae where the Thule dumped whale carcasses. Whale bones from semi-subterranean Thule shelters still litter the site.
Dr. Smol explains the techniques that can detect traces of mammal nutrients from several centuries ago. “Slow sediment accumulation creates a depth-time profile of past changes…like a history book. The two main indicators we used are fossil diatoms [types of uni-algae with glass cell walls]. Some diatom species can only live in nutrient-poor water; others live in nutrient-rich water.” Dr. Blais continues, “…their species abundances reflect the available nutrients. The diatoms show a dramatic shift around 1200 AD. This provides a tool for people to reconstruct human history in places where people did not keep records.”
Other techniques, such as looking at the ratio of nitrogen-15 isotopes to nitrogen-14 isotopes shows a sharp increase in the heavy nitrogen 15 about 800 years ago, “…indicating that whales were brought into the pond around that time” according to Dr. Smol.
Asked if the ecosystem has been permanently altered, Blais indicated that it appears to be: “…nutrients still leach from bone.” Smol concurs: “…because Arctic sites are frozen nine months of the year, decomposition happens very slowly…given slow rates of change…it may take a few more centuries to get back to ‘normal.'”
Although Sommerset Island is the first whaling spot where this kind of sediment analysis study was done, Smol notes that other whaling sites he and Douglass have visited demonstrate similar altered water chemistry and vegetation.
When queried as to whether Thule impacts harmed or helped the Arctic ecosystem, Dr. Smol elaborated on their repercussions. “The high arctic is a very nutrient-poor region. The Thule whalers brought in ocean nutrients [in the whales] and fertilized the terrestrial system [unintentionally]. It caused local terrestrial systems to flourish with mosses. The Thule needed mosses to insulate their whalebone houses. So it could have been a positive feedback system…But I would not classify this as ‘pollution,’ just as I would not classify, say, a wolf killing a muskox and the carcass fertilizing the land. They changed the ecosystem, but not necessarily in a bad way.”
Dr. Blais agrees. “I think that all life alters their environment by being here-and there is no shame in it unless we abuse it.”
