Beavers are proving to be quite the helpful little creatures: First, they proved themselves to be awesome engineers in the California drought. Now, they’ve found a new vocation as biochemists. A recent study has shown that beaver populations are helping to remove nitrogen from waters in northeastern America.
It's estimated there are between 6 and 12 million North American beavers (Castor canadensis) alive today, which is pretty amazing since they almost became extinct in the early 1900s in the United States due to trapping. This rise in beaver populations caused natural resource scientists from the University of Rhode Island to investigate the effect they were having on the surrounding water ecology. Upon investigation, they noticed that the ponds and wetlands that had beavers living upstream tended to have less nitrogen in them.
The use of nitrogen fertilizers has been rising for years as part of a farmer's armory to increase yields, fill pockets and feed mouths. However, when the nitrogen seeps into nearby streams, it causes an algae bloom. The nitrogen fuels the massive growth of these microbes, which use all of the oxygen and subsequently starve the fish and other water-dwelling species of their share.
However, beavers can help counterbalance this. The study, published in the Journal of Environmental Quality, found that the process of beavers building ponds increased the interaction of water with soil and plant matter. The soil and organic matter contained denitrifying bacteria that turned nitrates into nitrogen gas, hence removing it from the system. The study found that this process can reduce the nitrogen levels in the water by 5-45%.
Despite the ecological importance of beavers, they still face threats from fur trading and the stigma of being viewed as a pest by salmon farmers.
Arthur Gold, a natural resources scientist who worked on the project, said in a statement, "It's noteworthy that the beavers have such an impact on improving nitrogen downstream. We have a species whose population crashed from wide-spread trapping 150 years ago. With their return they help solve one of the major problems of the 21st century. I don't want to minimize that. We have to remember that those ponds wouldn't be there without the beavers."
Image credit: Stewart Ho/Flickr. (CC BY-NC-ND 2.0)