Changes In Great Slave Lake, NWT

Environmental & Science Education, STEM, Earth & Space Science, Earth Systems, Global Change, Climate Change, Sustainability

Ed Hessler

Writing for EOS, Cheryl Katz discusses a recently published paper on changes in Great Slave Lake, NWT.

It is large, "spanning an area the size of Belgium" and deep, "of up to 614 meters (~2000 feet)... the 10th largest freshwater lake in the world and North America's deepest." So far it has been afforded the protection of "its huge mass of cold water...from the climate impacts that have upended the ecosystems of shallower lakes in high northern latitudes."

"But no longer."

Katz continues, "spurred by accelerating Arctic warming, the microscopic algae" which are the basis "of this massive lake’s food web have made a radical regime shift since the turn of the century.... the hefty, chain-forming diatoms that had long ruled Great Slave Lake have now been supplanted by tiny, pancake-shaped counterparts." This could affect the lake’s productivity and carbon dynamics...."

She goes on to describe possible "cascading consequences" of such a "profound change, the correspondence with changes in arctic temperatures, declining temperatures and slowing winds."

Katz concludes by noting that the researchers are now turning their attention to the Northwest Territories’ Great Bear Lake which is farther north, colder, and even bigger than Great Slave Lake. Preliminary data on this lake, the eighth largest in the world, suggest a similar upheaval is underway there too.

Katz let's John Smol," a co-author of the study have the last word. “We think of the Arctic as the miners’ canaries of the planet, and the lakes are recording it. And within the lake, the canaries are probably the algae.” (His website deserves a look.

You should read her reporting which includes relevant links, a striking aerial photograph of the lake and important details on this research, two photographs of the algae in question as well as the significance of the study. The data show that this began in the mid-1990s. And there is also a link to the original paper.