Category: Beavers and Nitrates

AIN’T THAT THE BEAVER-DAMMED TRUTH

Headline in Sierra Club magazine today, just really takes the matter and lays it out for everyone to see. This is what I think to myself most mornings.

We Don’t Deserve Beavers

Tar Creek doesn’t seem like an inviting home for wildlife. For more than 70 years, miners blasted open the earth underneath the Oklahoma waterway in search of lead and zinc. Today, mountains of waste material from the mines tower above what is now classified by the EPA as a Superfund site. Groundwater that flows through the abandoned mines flushes toxic heavy metals, including cadmium and lead—both potent neurotoxins even at low concentrations—into the creek. The water runs bright orange.

One family of toothy critters didn’t seem to care. In 2014, the beavers set up shop in a nearby tributary. “At first, they were a nuisance,” said Nick Shepherd, an environmental consultant and research assistant at the University of Oklahoma. At the time, Shepherd was conducting research at Tar Creek, and the beaver’s dam-building was messing with his data. “We couldn’t get measurements because the beavers had totally transformed the stream from a three-foot-wide channel to an 80-foot-wide meandering wetland,” Shepherd said.

Wait. I can guess what happens next. Can you?

Shepherd and his colleagues kept collecting data when they could. Then, two years after the beavers moved in, a team visiting the site noticed something interesting—the water that spilled over the beaver dams was running clear. Water-quality measurements seemed to confirm what they were seeing: just above one of the beaver dams, cadmium concentrations were 57 percent lower than they were upstream, where the polluted stream flowed into the beaver-created wetland, according to results they recently published in the journal Science of the Total Environment. Iron concentrations were 63 percent lower. The beavers were cleaning up Tar Creek.

Yes it’s true. You make the messes. We clean the messes. That’s just the way it is. Any questions?

Beavers build dams because they’re safer in the water. On land, with their unwieldy tails and awkward waddle, they make easy pickings for coyotes and bobcats. These beaver refuges flood the landscape around waterways, turning tiny tributaries into sprawling wetlands, flush with life. “When we have beavers, there’s deep pools and shallow spots; fast water and slow water all mixed together,” said Emily Fairfax, an ecohydrologist at California State University Channel Islands. This variation in aquatic habitat not only creates habitat for a diversity of species, but it also supports a diversity of chemical processes—including those that can remove toxic contaminants from a Superfund site.

A stream without beaver dams “is like a firehose,” said Sarah Koeningburg, a researcher and filmmaker at conservation nonprofit the Beaver Coalition. Water rushes through, pulling any contaminants along with it. But as water slows down above a beaver dam, it interfaces with the air above it and the groundwater seeping in from below. “You can just watch the chemical reactions happening in front of you as the stream is flowing,” said Rachel Gabor, a watershed hydrologist at the Ohio State University. At the ponds created by the beavers of the Tar Creek Superfund site, oxygen mixed and mingled into the water column. As it did so, it reacted with the iron turning the water orange and created ferrous oxide—rust. In its pure elemental form, iron dissolves into water, but rust forms heavy particulates, which sank to the bottom of the pond. Cadmium likes to bind onto rust, and so it too wound up at the bottom of the beaver pond.

In the study they published, Shepherd and his colleagues didn’t measure a difference in lead concentrations. However, the beaver dams might still work their magic with lead levels too. The mucky bottoms of beaver ponds create the perfect conditions for anaerobic bacteria, which thrive without oxygen. Instead, these microbes breathe sulfate, kickstarting a complex series of chemical reactions that eventually transform dissolved elemental lead into iron ore. Like rust, iron ore sinks to the bottom of beaver ponds. As the beavers continue to engineer the riparian ecosystem, Shepherd hopes that bacteria will pull lead and zinc out of the water. Right now, the beaver pond is young, so the bottom of the pond hasn’t yet developed into the thick sludge of a mature wetland.” That happens with time, as plants and other organic matter sink to the bottom of the wetland and break down. “Right now, there isn’t much organic matter to create those anaerobic conditions,” Shepherd said. Plus, not much water makes its way through dense beaver-pond muck, which makes it a slow filter, Shepherd said. “But given a bigger wetland and more time, it’s possible.”

The Tar Creek beavers aren’t the only crew doing remediation work. At The Wilds, an Ohio site heavily polluted by coal mining, beavers succeeded in bringing dangerously acidic water, a common side-effect of mining, back to a healthy pH, Gabor said. It’s not entirely clear how the beavers are doing this, but Gabor thinks it has something to do with the interface between surface water and groundwater, which might dilute acidic surface water as it washes into the beaver-engineered wetland. That explanation doesn’t work for sites like Tar Creek, though, where groundwater is the source of pollution.

Well sure. And do we EVER say thank you? No of course not. We just kill them and trap them and call them names.

Beavers are doing us a favor by cleaning up these toxic sites. But doesn’t the pollution hurt them? “Would beavers prefer not to live in pollution? Sure!” Fairfax said. “But their habitat is really pinched, and they are going to build wherever they can. If they can live and thrive and create a colony in a polluted stream, they will.”

In the future, Shepherd and his colleagues plan to collect samples from the beavers from the Tar Creek site in order to analyze the heavy metal concentrations in their tissues. But the colony seems to be healthy and thriving; “It doesn’t seem to slow them down,” Shepherd said.

Introducing beavers to a toxic ecosystem would be an entirely different matter, Fairfax said. “If they don’t want to move in, it’s ethically questionable to put an animal into a known contamination site.” But, she said, scientists can get habitats ready for beavers by building human-made structures that resemble beaver dams, called beaver dam analogs (BDAs). These structures slow down water much like a beaver would, kickstarting the biochemical reactions that clean up waterways, and hopefully encouraging move in and take over the maintenance of those BDAs. “If beavers choose to come into those areas, that’s their prerogative as a creature that can make decisions,” Fairfax said. And who are we to object?

Tissue samples? That’s our reward for getting you out of this terrible jam? Nobody ever just says “thank you” anymore, do they?

WE DON’T NEED BEAVERS. WE CAN DO IT OURSELVES!

heidi08 Beavers, Beavers and Nitrates, Beavers and Nitrogen removal April 5, 2022

I’m sure you remember the exciting news that came a few years ago about beaver ponds removing nitrogen from soil, right? Well I’m not sure how I feel after comparing this recent article comparing it to Arthur Gold’s great study in 2017. I guess farmers will be more happy to make their own wetlands if they’re almost as effective as beaver ponds at removing nitrogen?

Small wetlands can have big impacts

In a new study, researchers have shown that wetlands built next to farmlands can dramatically reduce the amount of excess nutrients reaching aquatic environments.

“Even very small wetlands can be effective,” says Maria Lemke, lead researcher of the study at The Nature Conservancy.

The study was conducted over 12 years on a 272-acre farm in McLean County in central Illinois. Many farms in this part of the United States use tile drainage systems—a network of interconnected underground pipes that drain water from the farms.

“Our findings show that constructed wetlands can be very effective at reducing excess nitrogen losses from agricultural tile systems,” says Lemke. “We also show that these wetlands can capture dissolved phosphorus efficiently.”

Lemke and colleagues showed that wetlands as small as 3% of the tiled area draining into them can be effective. These wetlands catch excess nutrients draining from surrounding farmlands. This means less nutrients end up in streams and rivers, and ultimately, the ocean.

Really small. Say like “pond sized”. Like ohh say something a beaver might make. Though not an ACTUAL beaver because they’re icky.

Constructed wetlands can be a useful conservation practice that mitigates nutrient export from farms to aquatic ecosystems. Nitrogen runoff that enters wetlands comes in the form of dissolved compounds called nitrates. Microbes in wetlands can use these dissolved nitrates as energy sources.

These microbes convert the nitrates into harmless nitrogen gas, which is released into the atmosphere. Conversion from dissolved nitrate to nitrogen gas results in less nitrogen exiting the wetlands into aquatic ecosystems. “Wetlands provide the perfect habitats for microbes to perform this process,” says Lemke.

Phosphorus removal from farm drainage is a more complex process. Soil chemistry and clay content play important roles in removing dissolved phosphorus. “It’s important to analyze soils at potential wetland sites to characterize their long-term retention capacity for phosphorus,” says Lemke.

Even the smallest wetlands reduced nitrogen loss from farm tiles by 15 to 38%. As drainage water moved through a series of connected wetlands, nitrogen loss was increased up to 57%.

Sure beaver ponds do it BETTER and when the pond is damaged the beavers fix it for free but they’re so icky and unpredictable. No one wants them around. People just want beaver benefits without beavers. That’s possible right?

Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States

Using the annual range of denitrification observed in our three ponds, we estimate that denitrification in beaver ponds that average 0.26 ha can annually remove 49 to 118 kg nitrate N km⁻² of catchment area. In beaver ponds that average 1 ha, denitrification can account for 187 to 454 kg nitrate N km⁻² of catchment area. Moore et al. (2004), using the SPARROW model, predicted total N catchment yields between 200 and 1000 kg km⁻² for undeveloped land uses (i.e., rural) in southern New England. Based on the beaver pond/watershed area ratios (0.18–0.7%), and interpond variability in denitrification, we estimate that beaver ponds in southern New England can remove 5 to 45% of watershed nitrate loading from rural watersheds with high N loading (i.e., 1000 kg km⁻²). Thus, beaver ponds represent an important sink for watershed nitrate if current beaver populations persist.

Well, okay, beavers are better, but to refer to my previous point. they’re icky. And so unpredictable.It’s much easier to do it without them.

“The idea is that if we combine in-field practices with edge-of-field wetlands, we may be able to decrease further the wetland sizes needed for desired nutrient reductions,” says Lemke.

WETLAND-CREATION ASSISTANTS NEEDED

heidi08 Beaver ecological impact, Beavers and Nitrates, Beavers and Nitrogen removal January 26, 2022

You know what they say. Not everything is about money unless you don’t have any and then EVERYTHING is. Let’s hope this new study out of Ontario will turn some heads. Thank you Bob Kobres of Georgia for alerting me to it.

New economic model finds wetlands provide billions in filtration value

Southern Ontario wetlands provide $4.2 billion worth of sediment filtration and phosphorus removal services each year, keeping our drinking water sources clean and helping to mitigate harmful and nuisance algal blooms in our lakes and rivers.

A new study from the University of Waterloo uses economic valuation to help us understand the importance of Southern Ontario’s wetlands for water filtration—particularly as these sensitive ecosystems continue to be lost by conversion to agriculture or urban development.

“Wetlands naturally filter out phosphorus and sediments from water, but their value is often greatly overlooked,” said Tariq Aziz, who carried out the study during his Ph.D. and postdoctoral work in Waterloo’s Department of Earth and Environmental Science. “By calculating the economic value of wetland filtration and comparing it to the costs of engineered interventions, we hope to reinforce the importance of protecting our wetlands.” (more…)

“IT MAY BE A DESTROYED POND, BUT AT LEAST THE TRAINS RUN ON TIME”

heidi08 Beaver ecological impact, Beavers and Birds, beavers and community, Beavers and Nitrates, What's killing beavers now? May 24, 2021

It’s the old story. Girl meets beaver pond. Girl loses beaver pond. You know the rest. This time it’s told from New York with trains.

Dammed pond dries out after state removes beaver dam

SARANAC LAKE — When the state removed train tracks for its rail trail project earlier this month it also removed a beaver dam that was creating a pond near where McKenzie Brook flows into Lake Flower.

Locals in the neighborhood who frequently walk along the tracks were shocked and upset. They say draining the pond of water is harming the wildlife living there. The state departments of Transportation and Environmental Conservation say the dam removal was permitted to prevent it from flooding and eroding the corridor, and that impacts to wildlife will be minimal.

“Two beaver dams were partially blocking water flow at a culvert and action was taken to mitigate potential for flooding,” DEC spokesperson JoMo Miller wrote in an email. “This is a common and necessary action for mitigating what can be a significant, costly and sometimes dangerous failure of infrastructure.

Stop me if you’ve heard this one before. You know the railway explaining that it had to tie beavers to the tracks to prevent THE FLOODING. Everyone does it. You know how it is.

Barbara Kent has lived within a mile of the pond her entire life. Every day, several times a day, she walks her two dogs “Maisie” and “Marigold” on the train-track trails passing the pond, where she takes in the sylvan sights.

Turtles sun themselves on logs, herons swoop low to stand in the water, loons and mergansers feed on the water and frogs belch noisily. Kent said the beavers dammed up the water generations ago and their work has lasted decades.

“It was always there, always,” Kent said. “Everybody just loved it up there.”

Well you know how it is. You and some turtles live your life near a beaver pond. And the beavers get killed them the pond gets destroyed. It’s a dog’s life.

The water body on McKenzie Brook is known colloquially as “Toxic Pond” because the old landfill, now greened over, can be seen through the trees.

Kent was “mortified” when on May 7 she walked down and saw excavator tracks leading off the rails to the dam. The middle of the dam was torn out. Water that used to trickle through the dam underneath now poured over the top. The water level in the pond was dropping and mud could be seen all along the perimeter.

On May 18 the water had dropped low enough to expose tires, logs and beaver huts out in the pond.

The water flowed over the busted dam and through a culvert, to a pond between the Sara Placid Inn and Suites and the Best Western hotel, under another culvert on state Route 86 and into Lake Flower.

“I fell apart over it,” Kent said with a sad chuckle. “I’m 73 years old. It doesn’t take much to rattle me.”

Well, you gotta break eggs to make an omelette and destroy some ponds to keep the trains tracks nice and dry. You know how it is.

Kent said she has no problem with the rail trail project, a controversial topic in town. She just hopes it will be accessible to people of all abilities. But she also said work has been done on the train tracks before without needing to rip the dam out and she doesn’t think it was necessary now.

“Am I being unreasonable?” Kent asked. “This was breeding grounds for so much wildlife.”

The DEC claims the environmental impact will be small.

“While there may be local and short-lived impacts to wildlife, these impacts are not expected to be significant,” Miller wrote. “Some local wildlife species using this wetland may move to other wetland areas and riparian corridors within the immediate area, whereas other species may continue to use the area.”

Adirondack Park Agency Spokesperson Keith McKeever said his agency would defer to the DEC’s judgement in commenting on this issue, because it has jurisdiction.

Kent said she’s worried the now-dry edges of the pond pose a wildfire risk.

Come on, it’s just a little destruction. The turtles and the frogs and the fish gotta be used to that by now. Be reasonable. It’s for the trains!

Kent wondered if the beavers would rebuild their dam and if the state would return to remove it again.

Some don’t want to leave it to beavers. Kent said she’s seen other frequenters of the trail throwing branches back into the water to dam it up again. She’s not sure if this is illegal or will just be ripped out again.

Kent said this feels like it’s a “losing battle.”

She was even hesitant to tell the Enterprise at first.

“But I kind of felt I owed it to the turtles,” she said.

Kent loves the area and has many happy memories there. Her dogs know the trail by heart. Kent was ecstatic on Tuesday when she saw a heron — whom she’s named “Harry” — still flying around. But she’s concerned for the turtles, ducks, eagles and geese. She was worried that she didn’t see any loons.

She hopes they’ll all find another place to live and expects some of the turtles have taken up residence downstream in Lake Flower.

Sure the wildlife has had their home destroyed and the beavers are gone, but just look the tracks are super dry, isn’t that great? The problem with you is that you don’t appreciate the right things.

IOWA WONDERS IF BEAVERS CAN ACTUALLY HELP

heidi08 Beavers and Nitrates, Beavers and Nitrogen removal January 27, 2021

The role beavers play in the ecosystem has been examined and re-examined so many times over and over again that sometimes I imagine beavers sitting nervously backstage, waiting with suspense for their name to be called, like the academy awards or something. Will this time be the one? Will they finally say I’m good? Will they like me?

Well now Iowa is joining the consideration.

Beavers and the Dams They Build Can Improve Water Quality

A bit of a trouble maker, beavers do help improve ecosystems and they potentially play a key role in water quality improvement.

A new partnership between Iowa State University Extension and Outreach, the Department of Natural Resource Ecology and Management at Iowa State, and the Iowa Nutrient Research Center will study the water quality and quantity impacts of beaver dams in central Iowa, and how effective these dams are at reducing nitrogen and phosphorus concentrations in Midwest agricultural watersheds.

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You don’t say. Color me surprised. I thought they only did that in Rhode Island and New England, and Cornwall and Washington. I didn’t know they did it in Iowa too!

“Beaver dams have been studied heavily for fish and wildlife habitat, but there’s been limited research on how these dams impact nutrients and flooding in the Midwest,” said Billy Beck, assistant professor and extension forestry specialist at Iowa State University.

Beck is studying the nutrient reduction potential of dams in central Iowa, and results will be provided to the Iowa Nutrient Reduction Strategy science team. The data will be used to help clarify the influence within the stream channel and the processes associated with in-stream nutrient loss on watershed-scale nutrient loads.

Oooh I have a guess about what you’re going to find. Call on me!

Shelby Sterner, an Iowa State graduate student studying environmental science, is tasked with leading the study, which entails elements of forestry, hydrology, biogeochemistry and fluvial geomorphology (how water shapes the earth).

The overall goals of the project are to identify and quantify key nutrient removal processes associated with beaver dams in central Iowa, and estimate the potential impact of dams on watershed-scale nutrient loading within the agricultural Midwest.

Beck said he understands the frustration landowners often have with beaver dams. He’s not looking to promote them – per se – but he believes with some balance, they can be beneficial.

HAHAHA. Sure they might do good things, but that doesn’t mean we should LET them for god’s sake, Be reasonable. I’m not a monster.

Baby steps. Iowa. Baby steps.