Beavers Could Help Protect United States Rivers: Here’s How

by Sean Griffin
(Photo by: Arterra/Universal Images Group via Getty Images)

Beavers, and their ability to build dams, may come to the rescue to save waterways in the United States.

According to new research, the animals’ dam-building skills actually protect rivers threatened by climate change. The aquatic rodent creates ponds and excavates waterways when its habitat dries up. These movements could work to decrease climate change’s damage by controlling rivers’ flow and improving water quality.

“As we’re getting drier and warmer in the mountain watersheds in the American West, that should lead to water quality degradation,” Stanford University professor Scott Fendorf, a senior author of the beaver study, told SWNS. “Yet unbeknownst to us prior to this study, the outsized influence of beaver activity on water quality is a positive counter to climate change.”

The impact these incredible creatures have had on U.S. waterways makes some call beavers the “working class heroes of their ecosystems,” researchers shared.

Nature Communications published the study, which was based on mountain rivers in Colorado and found that beavers’ dams raise water levels upstream. Water then gets diverted into surrounding soils and secondary waterways. These are known collectively as riparian zones.

Fendorf and colleagues also found that beaver dams had another great effect. They increase nitrate removal by nearly 50 percent, which in turn boosts water for oxygen-breathing aquatic organisms.

The study’s lead author, Dr. Christian Dewey of Oregon State — whose athletic mascot, ironically, is a beaver — had first set out to track seasonal changes in hydrology.

“Completely by luck, a beaver decided to build a dam at our study site,” Dr. Dewey said. “The construction of this beaver dam afforded us the opportunity to run a great natural experiment.”

Researchers Speak on Beavers’ Ability to Improve Water Quality

The team reviewed data on water levels. These were gathered hourly by sensors installed in the river and riparian area. These samples included ones from below the ground’s surface to monitor nutrient and contaminant levels.

They compared the year-long datasets to the area’s water quality during the nearly three-month period. This started in late July 2018, when the beaver dam blocked the river.

Periods of drought caused less water to flow through rivers and streams. This in turn causes the concentrations of contaminants and excess nutrients, such as nitrogen, to rise. Major downpours and seasonal snowmelt also help flush out contaminants and restore water quality.

Researchers found that the beaver dam built near the study’s site significantly increased the removal of nitrate. It created a surprisingly steep drop between the water levels above and below.

“Beavers are countering water quality degradation and improving water quality by producing simulated hydrological extremes that dwarf what the climate is doing,” Fendorf said.

“We would expect climate change to induce hydrological extremes and degradation of water quality during drought periods,” Fendorf added. “In this study, we’re seeing that would have indeed been true if it weren’t for this other ecological change taking place, which is the beavers, their proliferating dams, and their growing populations.”