Beavers enter Arctic tundra: Why is that concerning?

A recent report published by the National Oceanic and Atmospheric Administration (NOAA) has revealed that beavers are marching into the Arctic tundra and altering the landscapes of specific regions in Alaska and Canada. 

Titled ‘Beaver Engineering: Tracking a New Disturbance in the Arctic’, the report is part of the Arctic Report Card 2021, which includes satellite pictures to track the movement of the rodents to study their colonisation of different areas, Newsweek has reported.

The number of beaver ponds in western Alaska, for instance, has nearly doubled in the last 20 years, reaching a whopping 12,000. Efforts to map their presence in Canada are also being made. 

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The findings are alarming. An increase in the beaver population can raise greenhouse gas emissions in certain areas, such as the Arctic tundra. Even though they are known to prevent climate change, beaver ponds, in particular, are responsible for increasing the amount of surface water, which causes the frozen ground to thaw. This subsequently leads to the trapped organic material to break down and release methane and carbon dioxide.  

Co-author of the report Helen Wheeler, from the U.K.’s Anglia Ruskin University, has been studying the impact beavers can have on the environment. “There are concerns that beavers will impact fish populations for example, but as well as the dams created by beavers changing hydrologies and impacting fish directly there is also the issue of access to important fishing and hunting grounds, beaver dams can block passage of rivers by boats, and submerged beaver dams can make travel dangerous,” she told Newsweek in an email. 

“Whether their expansion northwards is entirely due to climate change or increased populations following historical reductions in the trapping of beavers for fur and food, or a combination of the two, is not entirely clear, but we do know that beavers are having a significant impact on the ecosystems they are colonizing,” she added.

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According to Newsweek, the report stated, “Fieldwork is underway to characterize the impacts of beaver ponds on aquatic and terrestrial Arctic ecosystems, starting with hydrology and permafrost, and continuing downstream to methane flux, fish populations, and aquatic food webs. As a result of these efforts, most of the questions surrounding beaver engineering in the Arctic are presently being examined but are unanswered.”