How Beavers Could Help Clean Up Polluted Waters Around the World

iStock.com/milehightraveler
iStock.com/milehightraveler

Beavers are a lot more impressive than you might think. These semiaquatic rodents can build dams as large as 2800 feet deep, thanks in part to their super sharp teeth and sturdy tails that keep them from tipping over while hauling heavy materials into the water. According to research from scientists at the UK-based University of Exeter, the animals could also potentially help clean up polluted waterways.

Professor Richard Brazier and his colleagues studied the water quality at the site of a fenced-in area in southwest England, where a family of captive beavers has been living since 2011. The water flowed from nearby fields to a local river, where it deposited sediment while passing through 13 dams that had been built by the beavers.

The reduced water flow—and the deep ponds that formed as a result of the dams—had a filtering effect. The beavers’ dams captured more than 100 tons of soil and other sediment that contained high levels of nitrogen and phosphorus, both of which are bad for wildlife and human consumption.

The runoff problem is also twofold: The erosion of soil on agricultural land has both economic and environmental consequences. Scientists suggest that the reintroduction of the Eurasian beaver to rivers could help curb some of this damage. These “ecosystem engineers,” as the animals are called in the University of Exeter study, were believed to have been hunted to extinction in Britain by the 1500s. However, a colony was found in Scotland a decade ago, and there have been some efforts since then to release beaver populations into the wild.

"It is of serious concern that we observe such high rates of soil loss from agricultural land, which are well in excess of soil formation rates,” Brazier said in a statement. “However, we are heartened to discover that beaver dams can go a long way to mitigate this soil loss and also trap pollutants which lead to the degradation of our water bodies. Were beaver dams to be commonplace in the landscape we would no doubt see these effects delivering multiple benefits across whole ecosystems, as they do elsewhere around the world."

In a separate study from 2015, scientists at the University of Rhode Island determined that larger beaver ponds were able to remove up to 45 percent of nitrogen in the water that passed through them, while smaller ponds removed roughly 5 percent. The North American beaver was also on the brink of extinction in the 1800s, but these populations have since rebounded in Rhode Island and other parts of the continent.

10 Products for a Better Night's Sleep

Amazon/Comfort Spaces
Amazon/Comfort Spaces

Getting a full eight hours of sleep can be tough these days. If you’re having trouble catching enough Zzzs, consider giving these highly rated and recommended products a try.

1. Everlasting Comfort Pure Memory Foam Knee Pillow; $25

Everlasting Comfort Knee Pillow
Everlasting Comfort/Amazon

For side sleepers, keeping the spine, hips, and legs aligned is key to a good night’s rest—and a pain-free morning after. Everlasting Comfort’s memory foam knee pillow is ergonomically designed to fit between the knees or thighs to ensure proper alignment. One simple but game-changing feature is the removable strap, which you can fasten around one leg; this keeps the pillow in place even as you roll at night, meaning you don’t have to wake up to adjust it (or pick it up from your floor). Reviewers call the pillow “life-changing” and “the best knee pillow I’ve found.” Plus, it comes with two pairs of ear plugs.

Buy it: Amazon

2. Letsfit White Noise Machine; $21

Letsfit White Noise Machine
Letsfit/Amazon

White noise machines: They’re not just for babies! This Letsfit model—which is rated 4.7 out of five with nearly 3500 reviews—has 14 potential sleep soundtracks, including three white noise tracks, to better block out everything from sirens to birds that chirp enthusiastically at dawn (although there’s also a birds track, if that’s your thing). It also has a timer function and a night light.

Buy it: Amazon

3. ECLIPSE Blackout Curtains; $16

Eclipse Black Out Curtains
Eclipse/Amazon

According to the National Sleep Foundation, too much light in a room when you’re trying to snooze is a recipe for sleep disaster. These understated polyester curtains from ECLIPSE block 99 percent of light and reduce noise—plus, they’ll help you save on energy costs. "Our neighbor leaves their backyard light on all night with what I can only guess is the same kind of bulb they use on a train headlight. It shines across their yard, through ours, straight at our bedroom window," one Amazon reviewer who purchased the curtains in black wrote. "These drapes block the light completely."

Buy it: Amazon

4. JALL Wake Up Light Sunrise Alarm Clock; $38

JALL Wake Up Light Sunrise Alarm Clock
JALL/Amazon

Being jarred awake by a blaring alarm clock can set the wrong mood for the rest of your day. Wake up in a more pleasant way with this clock, which gradually lights up between 10 percent and 100 percent in the 30 minutes before your alarm. You can choose between seven different colors and several natural sounds as well as a regular alarm beep, but why would you ever use that? “Since getting this clock my sleep has been much better,” one reviewer reported. “I wake up not feeling tired but refreshed.”

Buy it: Amazon

5. Philips SmartSleep Wake-Up Light; $200

Philips SmartSleep Wake-Up Light
Philips/Amazon

If you’re looking for an alarm clock with even more features, Philips’s SmartSleep Wake-Up Light is smartphone-enabled and equipped with an AmbiTrack sensor, which tracks things like bedroom temperature, humidity, and light levels, then gives recommendations for how you can get a better night’s rest.

Buy it: Amazon

6. Slumber Cloud Stratus Sheet Set; $159

Stratus sheets from Slumber Cloud.
Slumber Cloud

Being too hot or too cold can kill a good night’s sleep. The Good Housekeeping Institute rated these sheets—which are made with Outlast fibers engineered by NASA—as 2020’s best temperature-regulating sheets.

Buy it: SlumberCloud

7. Comfort Space Coolmax Sheet Set; $29-$40

Comfort Spaces Coolmax Sheets
Comfort Spaces/Amazon

If $159 sheets are out of your price range, the GHI recommends these sheets from Comfort Spaces, which are made with moisture-wicking Coolmax microfiber. Depending on the size you need, they range in price from $29 to $40.

Buy it: Amazon

8. Coop Home Goods Eden Memory Foam Pillow; $80

Coop Eden Pillow
Coop Home Goods/Amazon

This pillow—which has a 4.5-star rating on Amazon—is filled with memory foam scraps and microfiber, and comes with an extra half-pound of fill so you can add, or subtract, the amount in the pillow for ultimate comfort. As a bonus, the pillows are hypoallergenic, mite-resistant, and washable.

Buy it: Amazon

9. Baloo Weighted Blanket; $149-$169

Baloo Weighted Blanket
Baloo/Amazon

Though the science is still out on weighted blankets, some people swear by them. Wirecutter named this Baloo blanket the best, not in small part because, unlike many weighted blankets, it’s machine-washable and -dryable. It’s currently available in 12-pound ($149) twin size and 20-pound ($169) queen size. It’s rated 4.7 out of five stars on Amazon, with one reviewer reporting that “when it's spread out over you it just feels like a comfy, snuggly hug for your whole body … I've found it super relaxing for falling asleep the last few nights, and it looks nice on the end of the bed, too.” 

Buy it: Amazon 

10. Philips Smartsleep Snoring Relief Band; $200

Philips SmartSleep Snoring Relief Band
Philips/Amazon

Few things can disturb your slumber—and that of the ones you love—like loudly sawing logs. Philips’s Smartsleep Snoring Relief Band is designed for people who snore when they’re sleeping on their backs, and according to the company, 86 percent of people who used the band reported reduced snoring after a month. The device wraps around the torso and is equipped with a sensor that delivers vibrations if it detects you moving to sleep on your back; those vibrations stop when you roll onto your side. The next day, you can see how many hours you spent in bed, how many of those hours you spent on your back, and your response rate to the vibrations. The sensor has an algorithm that notes your response rate and tweaks the intensity of vibrations based on that. “This device works exactly as advertised,” one Amazon reviewer wrote. “I’d say it’s perfect.”

Buy it: Amazon

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31 Facts About Sharks

Photo by Jakob Owens on Unsplash
Photo by Jakob Owens on Unsplash

Whether you're a Jaws fanatic or just want to live every week like it's Shark Week, you'll want to read up on these fascinating facts about sharks, adapted from an episode of The List Show on YouTube.

1. There are more than 500 types of sharks.

They range in size from 8 inches to 40 feet long.

2. The cookie cutter shark grows to up to 22 inches.

The cookie cutter shark uses its suction-cup-like lips to attach itself to prey. Once it’s firmly stuck on there, the shark spins its body, using its bottom row of serrated teeth to take out a cone-shaped chunk of flesh. Typically, cookie cutters feed off of sea creatures much bigger than them, but they’ve also taken bites out of a couple of humans … and they’ve been known to leave their mark on submarines, too.

3. Peter Benchley’s 1974 novel Jaws was inspired by a fisherman who caught a 4500-pound behemoth in Montauk in 1964.

The novel wasn’t always going to be called Jaws: Alternate titles included “The Stillness in the Water,” “The Silence of the Deep,” “Leviathan Rising,” and “The Jaws of Death."

4. Peter Benchley later became a shark conservationist.

He used his pen to tackle misconceptions about the fish. In 2006, he said, “I could never write that book today. Sharks don’t target human beings and they certainly don’t hold grudges.” Fun fact: Benchley makes a cameo in Steven Spielberg’s 1975 movie adaptation of his novel. He plays a TV news reporter.

5. Shark attacks are very rare.

In 2018, there were 66 confirmed unprovoked attacks. In America, the risk of dying from a shark attack is 1 in 3,748,067. You’re more likely to be killed by fireworks, a train crash, or MRSA—that antibiotic-resistant bacteria—than you are by sharks. Worldwide, the risk is even lower.

6. Sharks have been around for a while.

Thanks to fossils, we know that they’ve been swimming the seas for at least 400 million years.

7. Some species of shark can live to be incredibly old.

Researchers in 2016 used radiocarbon dating on the eyes of 28 Greenland sharks and determined that one female might have been around 400 years old.

8. Greenland shark meat is a delicacy in Iceland called hákarl.

The shark’s meat is toxic when fresh, so it has to go through a fermentation process that involves burying the shark’s body in sand under rocks for six to 12 weeks. The meat is then cut up and hung to dry. The finished product has a strong scent of ammonia. Anthony Bourdain called it "the single worst, most disgusting and terrible tasting thing" he’d ever eaten.

9. Great white sharks have a man-eating reputation, but they’re much more interested in seals and sea lions.

Great whites have a 40 to 55 percent accuracy rate in catching their seal prey, according to research. The hunting process also often involves the sharks coming fully out of the water, which is called breaching.

10. Great whites are fast.

They can swim at 35mph for short bursts.

11. Many shark researchers think the old tale of “great whites attack humans because they think we’re seals” is a myth.

Great white shark attacks on humans are much less vicious than the way sharks attack prey like seals and sea lions—one study reported that in 76 percent of attacks on surfers the force would not have stunned a pinniped. In most cases they’re probably just curious—though still potentially deadly. One expert told Discovery that if you do see a shark, the safest thing to do is to remain calm and try to slowly and calmly get back to safety.

12. Great white sharks typically aren’t found in aquariums—though not for lack of trying.

Since the 1970s, aquarium workers who have tried to keep the sharks in captivity have been having basically the same tragic experience: finding a captive great white shark sick, then dead, within a week. While in enclosures, the sharks can't swim at the high speeds or over the distances they're supposed to, so they bump into the glass and get hurt or just stop swimming and die. Younger sharks have tended to do better: The Monterey Bay Aquarium was able to keep a young great white for 198 days, but released her after she started going after other sharks.

13. Tiger sharks and sand tiger sharks aren't the same.

Another shark you probably won’t see in captivity these days is the tiger shark—not to be confused with the sand tiger shark, which is a completely different species found in aquariums around the world.

14. Female tiger sharks have many, many pups.

After 13 to 16 months of pregnancy, a female might give birth to between 10 and 82 little shark babies. The average is around 30.

15. It’s not unusual for a female shark to give birth to her pups in the place where she herself was born.

One study, which began in 1995 and concluded in 2012, found this to be the case with lemon sharks in the Bahamas.

16. Female mako sharks stay away from male makos.

In research that lasted for four months, a biologist and his team recorded 264 male and 132 female mako sharks in the Easter Island area. They found that there was a clear divide between where males resided versus females. They were baffled as to why. One of them suggested that it might have to do with the fact that males often bite their intended mate, so maybe the females were trying to avoid that whole situation. Fun fact: Biting is often a part of shark copulation, because the males have to hang on to something.

17. It’s not just biologists who have taken an interest in sharks.

In 2002, software programmer Jason Holmberg went scuba diving on vacation and spotted the rare whale shark. He wanted to make the spotted sharks less mysterious, so he teamed up with an astrophysicist and a marine biologist. They were able to adapt an algorithm that had been created for the Hubble Space Telescope program and use it to start identifying sharks. The algorithm was initially for star mapping, so it made sense as an algorithm for shark spot mapping. They’ve since created a database with 32,000 pictures of whale sharks. The database has helped them track the animals’ locations, which means they can learn more about the whale shark lifestyle.

18. The shape of hammerhead sharks' heads might help with hunting.

Sharks are able to sense electric fields in water, which allows them to determine if they’re in the vicinity of prey. One theory is that hammerhead sharks have more of those sensory organs in their heads, so they can find prey better. Their eyes being so far apart helps too—they have better binocular vision.

19. Shark embryos can sense predators.

In addition to using electric fields to sense prey, sharks also use them to sense predators. Even shark embryos have that ability. In a study published in 2013, a group studying brownbanded bamboo shark embryos found that when the embryos were in the electric field of a predator, their gills would stop moving.

20. Sharks sometimes like to rest in groups.

Nurse sharks and whitetip reef sharks have been observed gathering in groups of 2 to 40, usually in a safe place like a crevice, often just napping.

21. A basking shark looks very weird when it decomposes.

It quickly loses parts of its jaw and tail. So it’s not unusual for people who spot a decomposing basking shark on the shore to believe that they’ve found a sea monster. This happened in 1970 in Massachusetts.

22. A tiger shark once puked up evidence of a murder.

During the 1930s, a tiger shark at Coogee Aquarium in Australia vomited a human arm, evidence that became part of a murder trial. Thanks to a tattoo on the arm, the person it belonged to, James Smith, was identified. It turned out that he was missing—and the shark hadn’t bitten the arm off, it was cut off with a knife. There was a suspect, Patrick Brady, and a man willing to testify that Brady was responsible. But that witness was shot before the trial. Brady’s lawyer claimed that for a homicide, there needed to be a body and all they had was an arm. Brady went free. The shark unfortunately died.

23. The goblin shark eats using "slingshot feeding."

The deep-sea-dwelling goblin shark has a jaw that shoots outward to grab prey in what scientists have dubbed “slingshot feeding,” so it’s no wonder they often get compared to monsters. The goblin shark can deploy its jaw at 10.1 feet per second—roughly twice the speed that New York City pedestrians walk.

24. The goblin shark is named after a Japanese demon.

Japanese fishermen named the sharks tengu-zame. Tengu is a demon with a long nose that sometimes steals children. And zame means “shark.” That’s how we got our English translation: goblin shark.

25. Not all sharks are ferocious carnivores.

The bonnethead shark has long been observed to eat seagrass—up to 62.1 percent of gut content mass. Until recently it was unclear if they were digesting it. But in 2018 it was confirmed through stable isotope analysis that they actually were, making them the first known omnivorous shark.

26. There are multiple types of lantern sharks, including a dwarf lantern shark that doesn’t grow larger than 8 inches.

These sharks have bellies and fins that glow. So it’s thought that when there’s a predator swimming beneath them, the predator doesn’t know the difference between the shark and the light coming into the ocean from the sun.

27. Not all sharks are strictly ocean dwellers.

Bull sharks are unusual in that they can tolerate fresh water. Most sharks have to be in salt water because that’s what their bodies can handle—put them in fresh water and they’ll lose too much salt. But bull sharks are better able to retain salt in their bodies, so they can travel in fresh water. And in fact, in 1937, one was caught in Alton, Illinois, 1000 miles up the Mississippi River from the Gulf of Mexico, where you wouldn’t typically expect to encounter a shark.

28. Megalodon sharks were huge—maybe about 50 feet long.

But there are now theories that the measly great white shark, at less than half that size, may have caused them to go extinct. It was previously believed that megalodons went extinct around 2.6 million years ago, but when a group of paleontologists and geologists went back through the fossils and data, they pegged it at 3.6 million years ago—which just so happened to be the time that great white sharks were emerging. They were probably able to go head-to-head with younger megalodons and out-compete them for food.

29. Megalodon shark teeth could be around 7 inches long.

And in fact, you might want to be on the lookout for them. In 2018, a couple found a fossilized megalodon tooth on a beach in North Carolina.

30. An American president had a megalodon tooth.

Thomas Jefferson loved fossils and even kept some on display at the entrance of Monticello. Today, his megalodon tooth is at the Academy of Natural Sciences in Philadelphia. Of course, he signed it.

31. The song "Baby Shark" used to be sung by kids at camps.

Before Pinkfong’s version of “Baby Shark” became one of the most viewed YouTube videos of all time, it was a common song for kids to sing at camps. But when Johnny Only turned it into the bop that we all get stuck in our heads today, he did change some things. In the original lyrics, the sharks attack people and even kill them. Peter Benchley would not approve.