The beavers who skilfully build dams and create ponds are doing the same in the Arctic, affecting the fragile ecosystem in that region (Pic. Courtesy talkradionews.com)
The engineering skill and perseverance of beavers has drawn admiration and awe from not just wildlife enthusiasts but also engineers and architects. Yet, today that same attribute is threatening one of world’s most fragile ecosystem in the Arctic as per a report in smithsonianmag.com.
These large, semiaquatic rodents have innate skill and capability to change landscapes. They can chew trees and wood, construct dams and inundate areas resulting in ponds, and that is the reason they are called “ecosystem engineers”.
Now it is their migration to the north that is causing alarm among scientists and environmentalists.
Information and news about beaver forms a part of the annual Arctic Report Card prepared by the National Oceanic and Atmospheric Administration (NOAA).
Comparison of aerial images of the region which are decades old with the news ones, showed the scientists that there was doubling of ponds created by the beavers in the last 20 years. At present there are 12,000 ponds in a region which had none in 1955.
Talking to the Guardian, Ken Tape, an ecologist with the University of Alaska, Fairbanks, said: "We didn’t know what we would find and ended up being very surprised. There are areas of Alaska that had no evidence of beavers 50 years ago that are now apparently saturated with them.”
Providing a glimpse of the future, Tape added: “It’s just a matter of time before they head even further north. When you consider this is likely happening across the rest of the Arctic in Canada and Russia, that gives you an idea of the scope of this change."
These rodents are masters of constructing dams which create ponds that are shallow. This in Arctic region has led to rise in the total surface water, raising anxiety about as these pools of water are warmer than the surrounding ice. This causes the permafrost, that is the permanently frozen ground, to defrost. The role of permafrost is critical in the environment as it is a carbon sink and its melting means release of carbon dioxide and methane which have been stored in it for years.
A 66 per cent growth in surface water in the region according to scientists could be traced to the beavers.
Tape informed the Guardian: "Those ponds absorb heat better, they change the hydrology of the area and the permafrost responds to that. It’s accelerating the effects of climate change. When you realize what’s happened in western Alaska is likely to happen to northern Alaska, it does give you pause."
There is a growing apprehension about how this reshaping of the landscape of the region and its waterways, will have consequences for Alaska’s indigenous communities. The dams and blockades created by the beavers can gravely affect fish population and aquatic food webs while are also making access by boats tougher.
Helen Wheeler, ecologist at Anglia Ruskin University in England, in a statement said that further studies are being done to determine the effect of these rodents on indigenous livelihoods and ecosystem.
What continues to be puzzling is why are these beavers moving northwards? Many feel it could be due to warming of climate which has resulted in profusion of vegetation making the area very conducive for the beavers to live and thrive. It may also be that the expanding population of these creatures is moving in that direction as it free of predators. It is possible for that the exodus may be due to both the factors.
Whatever the case may be, what is relevant is that the beavers are playing a critical role in the region. Wheeler remarked: "[It] is not entirely clear, but we do know that beavers are having a significant impact on the ecosystems they are colonizing.”