Some people are excited about beaver because of their role in water storage. Some because they protect frog populations. Some because of salmon/steelhead habitat, water fowl range or sediment removal. There are A LOT of reasons to get excited about beaver.
Looks like we just added another to a very long list.
Beavers take a chunk out of nitrogen in Northeast rivers
Nitrogen levels have been increasing in Northeast waters for years. The use of nitrogen fertilizers has risen and urbanization has brought in influences such as septic systems. This nitrogen is released into small streams and ponds and eventually travels to estuaries, where rivers meet the sea.
High levels of nitrogen in these areas stimulate algal blooms. As these organisms die and decompose, oxygen is consumed from bottom waters, creating low oxygen levels that can generate fish kills. While many know of these dead zones in the Gulf of Mexico, they are also becoming a problem for the plentiful estuaries that comprise the coastline of the Northeast U.S.
Arthur Gold at the University of Rhode Island, along with his colleagues, studies how the presence of beavers affects nitrogen levels in these waters.
“What motivated us initially to study this process was that we were aware of the fact that beaver ponds were increasing across the Northeast,” he said. “We observed in our other studies on nitrogen movement that when a beaver pond was upstream, it would confound our results.”
Oh those darned confounding beavers! It was their sneaky tricks that ‘ruined’ Dr. Glynnis Hood’s dissertation by saving water on the driest year on record in Alberta. She had to completely change her whole paradigm. Remember that? And Dr. Suzanne Fouty’s dissertation too! They were planning one thing and found another, and look at what failures those slacker-researchers turned out to be!
(Sometimes the confusion that comes from finding what you don’t expect IS the dissertation, Julia.)
The researchers realized the water retention time and organic matter build up within beavers’ ponds lead to the creation of ideal conditions for nitrogen removal. They then wanted to see how effectively they can do this.
The researchers tested the transformative power of the soil by taking sample cores and adding nitrogen to them. These samples, about the size of a large soda bottle, were large enough to incorporate the factors that generate chemical and biological processes that take place in the much larger pond. They were also small enough to be replicated, manageable and measured for numerous changes. Researchers then added a special type of nitrogen to the samples that allowed them to be able to tell if the nitrogen was transformed and how.
Bacteria in the organic matter and soil were able to transform nitrogen, specifically a form called nitrate, into nitrogen gas, removing it from the system. This is denitrification. Thanks to the conditions brought about by the beaver ponds, this process can remove approximately 5-45% of the nitrogen in the water, depending on the pond and amount of nitrogen present.
“I think what was impressive to us was that the rates were so high,” Gold explained. “They were high enough and beavers are becoming common enough, so that when we started to scale up we realized that the ponds can make a notable difference in the amount of nitrate that flows from our streams to our estuaries.”
Nitrogen is one of those things, like carbon for instance, which is totally necessary for life. In certain amounts it helps make everything grow – but when you have too much of it messes everything up in horrible ways. Its heavily used in fertilizers so that crops produce the maximum bang for the minimal buck. Ideally nitrogen gets removed by bacteria thru a process called denitrification. But lately the bacteria can’t keep up. Then nitrogen from farmer Joe’s fertilizer washes down stream and mixes with farmer Ted’s and on down river with everyone else’s – until it gets to the ocean causing huge dead zones near river mouths. You’ve read about this, right?
Well, it turns out the nitrogen problem might have an interesting furry solution.
The research has some interesting implications. Julia Lazar, who conducted the work as part of her doctoral dissertation and is now working as an environmental consultant, said it might change the way people think about beavers and their ponds.
“Most of these beavers are in areas with smaller streams, not big rivers,” Lazar said. “These smaller streams are usually the first to be developed, causing a decrease in beaver populations. So, it may be important to keep these areas from being developed so they can have effects on nitrogen levels downstream.”
Smaller streams like Alhambra Creek in Martinez?
Gold hopes to study the ponds over a longer period and to study abandoned ponds to see if the nitrogen retaining qualities remain after the beavers are gone.
“It’s noteworthy that the beavers have such an impact on improving nitrogen downstream,” Gold said. “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.”
GO BEAVERS!
In a rational world, one that was capable of using new information to actually change behavior, farmers would LEAP at the chance to have beaver on their land and control their nitrogen runoff. Everyone would welcome these nitrogen-removing heroes and the world would be one step closer to recognizing that beavers do very important things for us and should be protected as more American than bald eagles.
Yesterday I and much of the beaver world, were really excited about this research.
But today I have come back down to earth and remembered that for nine years now I’ve been thinking THIS is the thing that will tip the scales in favor of beavers: salmon, water, frogs, nitrogen. And it never is. Whatever magic property beavers are found to have next, they will STILL be beavers and people will still see them as pests. Beaver benefits have been a cover story in Phys.org two times in the last 5 days. But it really doesn’t matter. It could be every day, or twice a day. Researchers who depend on industrial dollars will keep saying “Oh, yes they can do good things in some regions, but not here in special-circumstance-land. More research must be done.”
I don’t mean to sound hopeless. But people are VERY robust in their prejudices, whatever they are. They are sure what they believe is entirely justified, and aren’t really interested in having their beliefs challenged.
I guess sometimes, sometimes there are still surprises.
