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Scientists Develop Seawater Battery as an Alternative to Lithium

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Building a battery isn’t terribly complicated: All you need is a cathode, an anode, and an electrolyte that transmits ions between them. In a quest to develop a sustainable alternative to lithium, a team of scientists from South Korea is looking to the sea for some of those components, inhabitat reports.

In their study published in the journal ACS Applied Materials & Interfaces, the nine researchers from Ulsan National Institute of Science and Technology (UNIST) illustrate the science behind their seawater battery. Here the saltwater serves as a catholyte, which acts as both the electron-collecting cathode and the ion-transporting electrolyte simultaneously. Their invention (technically a sodium-air battery) depends on sodium-ion-rich saltwater to function, and with access to the ocean, it’s able to provide a constant charge.

The sustainable nature of seawater makes it the perfect contrast to lithium, which is used in the batteries that power our iPhones and electric cars. Lithium needs to be mined from the earth, which can have damaging effects on entire landscapes. Seawater, on the other hand, is something we have in excess.

The seawater battery still needs some fine-tuning before it’s ready to compete with lithium on the commercial market (UNIST’s battery produces an average of 2.7 volts compared to the average 3.6 to four volts discharged by a lithium-ion battery). But the potential for a day when ocean-powered batteries become mainstream is there.

[h/t inhabitat]

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Animals
Meet the Biologists Who Rescue Whales Trapped in Fishing Gear
NOAA Fisheries Service scientists disentangle a young North Atlantic right whale off the coast Florida.
NOAA Fisheries Service scientists disentangle a young North Atlantic right whale off the coast Florida.

Scott Landry and his team had been searching the waters of Cape Cod Bay for hours without any luck. For several days in September, mariners had reported to the Center for Coastal Studies in Provincetown, Massachusetts, that they'd seen a humpback whale trailing ropes and buoys from its enormous body. Landry, the center's director for marine animal entanglement response, knew time was growing short: Every day a whale spends entangled costs it precious energy and increases its chances of dying.

The crew had checked every reported location and was growing concerned about the fading daylight when a whale-watching boat called to say it had spotted the animal more than 20 miles away.

The five-member team sped out of the bay on their 35-foot, 600-horsepower rigid inflatable boat toward the animal's last known location. Finally spotting it, they worked to get close enough for a clear look at how the ropes and buoys were wrapped around the whale's body.

It wasn't easy. The boat bounced in the wind and rough seas. The whale moved quickly and obscurely, diving for up to seven minutes at a time. No one knew what direction the animal was moving or where it would surface. When it did come up for air, it disappeared again almost immediately. "We need a clear idea of how a whale is entangled to disentangle it properly,” Landry tells Mental Floss. “We had about two seconds when it came up for a breath."

When he finally got a look, the news wasn't good. "It was the worst kind of entanglement—a rope wrapped around its upper jaw," Landry recalls. Because a whale's head is seldom above the surface and ropes there may not trail as far, they prove hardest to remove. "The whale was moving at high speed, we were moving at high speed, and we had to pace alongside it and get within 30 feet to cut it free. The window of time and the target were both small."


A North Atlantic right whale with fishing line embedded in its jaw.
Getty Images

This time of year, many humpback whales travel from feeding grounds off the coast of Canada and New England to winter calving grounds in waters around Florida and the Caribbean, a journey of more than 1000 miles. A surprising number of them are dragging materials along with them—rope, nets, and other gear in which they've become hopelessly entangled. Increased fishing in areas where whales forage has resulted in more entanglements, which can kill them.

Humpback whales reach weights of 80,000 pounds and lengths up to 60 feet. You need a good reason to approach one of these massive creatures in a small craft on the open ocean. The special teams that free the whales believe it's worth risking their lives to save these endangered cetaceans.

These teams exist all over the world. Landry's institute, the Center for Coastal Studies, has freed more than 200 large whales and other marine animals since 1984. It belongs to the Atlantic Large Whale Disentanglement Network, which includes National Oceanic and Atmospheric Administration (NOAA) fisheries offices, state offices, and research institutions from Florida to Canada.

The U.S. had 123 confirmed entangled whale cases in 2016 alone, but the ones we see likely represent only a fraction of the total. Jamison Smith, disentanglement coordinator for NOAA, tells Mental Floss that lack of centralized record-keeping early on means no one knows the actual number, but since the early 1980s, it has hit at least the low thousands. At least 83 percent of North Atlantic right whales became entangled at least once between 1980 and 2009, and more than half of the humpback whales in the Gulf of Maine have had at least one entanglement.

"Right whales and humpbacks have a huge problem," Michael Moore, senior scientist at Woods Hole Oceanographic Institution (WHOI), tells Mental Floss. "Something radical has to happen, or these species are going to go away."

A WORLDWIDE—AND DEADLY—PROBLEM

Marine animals get caught up in just about anything humans put in the water, and we put in a lot of stuff—commercial fishing gear, recreational fishing gear, buoy warning systems, trash. "This problem plagues whales throughout the world," Amy Knowlton, research scientist at the New England Aquarium's Anderson Cabot Center for Ocean Life, tells Mental Floss. "It is one of the biggest conservation issues for marine mammals."

Whales off U.S. coasts most often get tangled in active fishing gear. On the East Coast, it's mostly snow crab and lobster gear. At the height of lobster season, close to a million vertical lines lurk in waters off Maine, and North Atlantic right whales, which are facing extinction in part due to entanglements, may encounter these lines about 2500 times a year. These plankton-grazing whales, which can reach 55 feet long and weigh 128,000 pounds, move slowly through the ocean with open mouths, so most entanglements start there, Knowlton explains. Once ensnared, the whales tend to thrash and roll, which only makes the problem worse, wrapping the ropes through their baleen and around their heads and flippers.

On the West Coast, where NOAA had 71 reports of whale entanglements in 2016, the vast majority in the past two years involved Dungeness crab fishing gear, located along the entire coast. Last year, for example, that gear was responsible for 22 out of 29 entanglements that NOAA definitively associated with specific fisheries or gear types.

Ghost nets—abandoned fishing gear drifting in the ocean—also entangle whales, as does other debris. Junk tends to be more prevalent in certain parts of the ocean, accumulating in gyres and along currents. More debris equals more entanglements.

In a 2012 paper in Conservation Biology, WHOI researcher Julie van der Hoop reported that scientists determined cause of death for 43 percent of 1762 known whale mortalities in the Northwest Atlantic between 1970 and 2009. Of those, 67 percent resulted from human interactions, and entanglement in fishing gear was the primary cause of death.

Entanglement can cause whales to drown or seriously injure and eventually kill them. If they survive, the gear can easily double the drag an animal experiences as it moves through the water. "They can't feed, and they exert a lot more energy just to swim, dragging that gear," Knowlton says. "Their health declines and, if they don't drown at the outset, they experience a slow, painful death."

Expending that extra energy can mean the difference between a female successfully reproducing or not, according to Moore, and with so few right whales remaining, reproduction is critical to survival of the species.

"The calving rate in North Atlantic right whales has been sparse, driven to some degree by lack of food but also wasteful pursuits such as swimming through the water pulling a whole bunch of excess drag," Moore says.

Even whales that free themselves or are freed by humans experience stress, pain, and loss of energy.

THIS IS HOW YOU FREE A WHALE

Aerial view of North Atlantic right whale that a team of state and federal biologists assisted in disentangling off Daytona Beach, Florida.
A team of state and federal biologists help an entangled right whale off Daytona Beach, Florida.

In order to disentangle a whale, you first have to find it. "When you consider the size of the ocean, the odds of that happening are incredibly small," Landry says. In some areas, most reports come from commercial fishing operations. The research community and the public also report whales in need of help.

Once a team reaches the whale, they have to assess the situation before taking any action. "You might think we just get in there and start cutting stuff off the whale," he continues. "But we found through trial and error that doesn't help. You have to understand how the whale is entangled and strategically cut things away. Every situation, every whale differs. Sea conditions differ. No two disentanglements are alike."

Often, the first step is for a crew member to use grappling hooks to attach buoys to the animal to help them track it and slow it down. This tactic is one of many they use that was inspired by historic whaling techniques, Smith says, but there's a key difference: "They were trying to kill the whale and we're trying to save it, which is harder to do."

Meanwhile, another crew member with a camera on a long pole assesses the situation. The team then determines the best approach and attempts to cut the whale free using specially designed knives on long poles.

"You're running on adrenaline, focused on the animal and the gear and how to best access that in a safe manner," Knowlton says. "I've spent a lot of time with right whales, and feel I have a sense of what to expect, but they always throw surprises at you. It is not a comfortable situation to be in. I really wish nobody had to be in it."

Keeping crews safe remains priority one. Whales are large, powerful animals. Entanglement creates stress and—despite a popular misconception that whales understand our motives—they have no idea we are trying to help them, Landry says. "Their response is a fear response. Most deal with it by trying to flee, but others will try to defend themselves."

Even so, only one person has died while disentangling a whale under current protocols. Joe Howlett, a long-time member of the Campobello Whale Rescue Team in Canada, was killed July 10, 2017, off New Brunswick by a just-freed right whale, which may have breached or flipped.

Network members plan a response based on the animal's distance from shore, weather, time of day, and availability of resources such as boats and crew. "The biggest challenge is trying to keep a consistent crew on call day in and day out, year after year," Landry says.

The success rate varies. "If we can get our hands on the whale, figuratively, we have about an 85 percent chance of disentangling a humpback," Landry says. "A 50 to 60 percent chance on a right whale."

Knowlton points out that 25 percent of all entangled animals reported just disappear: "A lot more we see multiple times, but weather and other challenges mean we can't get out there. In short, disentanglement is not the solution."

Eliminating whale entanglement entirely would require keeping all rope and debris out of the ocean—not a likely scenario. But lawmakers and scientists are working on solutions. Seasonal restrictions on fishing and modification of gear could help.

Rope strength plays a role, according to Knowlton. Strength of ropes used by commercial fishing has increased, and with it, the severity of whale injuries. Using rope that breaks at 1700 pounds—more than strong enough for the majority of fishing needs but something a whale likely could break—could reduce probability of mortality by 72 percent.

Developing gear that doesn't use ropes could make an even bigger difference. This has been done in parts of the world, and oceanographic researchers routinely retrieve gear using GPS and tracking technology and not ropes. "With economies of scale, that could be conceivable for fisheries," Moore says. "The argument that you need a plastic float on the surface to know where a trap is set is a little antiquated given the technology we have now." Ropeless methods could even help fishermen, because they lose gear to whale entanglements.

As for the whale Landry's team pursued in September, after an hour of near misses, the team was able to finally get close enough to cut the rope free with a hook-shaped knife on the end of a 30-foot pole. As they always do, they removed the rope and buoys from the water. (The National Marine Fisheries Service archives all removed gear for continued study, with the ultimate aim of better understanding and, ultimately, preventing entanglement.)

Had the tourist boat not happened upon the whale, it almost certainly would have died.

"That's one of our biggest fears," Landry says. "It was just a tiny chance for someone to see that whale before it left the area entirely and went somewhere we would never find it." It's happened before, he notes. "You win some and lose some. It's a big responsibility. On the bright side, more often than not, we're able to get the job done."

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Animals
10 Juicy Facts About Sea Apples

They're both gorgeous and grotesque. Sea apples, a type of marine invertebrate, have dazzling purple, yellow, and blue color schemes streaking across their bodies. But some of their habits are rather R-rated. Here’s what you should know about these weird little creatures.

1. THEY’RE SEA CUCUMBERS.

The world’s oceans are home to more than 1200 species of sea cucumber. Like sand dollars and starfish, sea cucumbers are echinoderms: brainless, spineless marine animals with skin-covered shells and a complex network of internal hydraulics that enables them to get around. Sea cucumbers can thrive in a range of oceanic habitats, from Arctic depths to tropical reefs. They're a fascinating group with colorful popular names, like the “burnt hot dog sea cucumber” (Holothuria edulis) and the sea pig (Scotoplanes globosa), a scavenger that’s been described as a “living vacuum cleaner.”

2. THEY'RE NATIVE TO THE WESTERN PACIFIC OCEAN.

Sea apples have oval-shaped bodies and belong to the genus Pseudocolochirus and genus Paracacumaria. The animals are indigenous to the western Pacific, where they can be found shuffling across the ocean floor in shallow, coastal waters. Many different types are kept in captivity, but two species, Pseudocolochirus violaceus and Pseudocolochirus axiologus, have proven especially popular with aquarium hobbyists. Both species reside along the coastlines of Australia and Southeast Asia.

3. THEY EAT WITH MUCUS-COVERED TENTACLES.

Sea cucumbers, the ocean's sanitation crew, eat by swallowing plankton, algae, and sandy detritus at one end of their bodies and then expelling clean, fresh sand out their other end. Sea apples use a different technique. A ring of mucus-covered tentacles around a sea apple's mouth snares floating bits of food, popping each bit into its mouth one at a time. In the process, the tentacles are covered with a fresh coat of sticky mucus, and the whole cycle repeats.

4. THEY’RE ACTIVE AT NIGHT.

Sea apples' waving appendages can look delicious to predatory fish, so the echinoderms minimize the risk of attracting unwanted attention by doing most of their feeding at night. When those tentacles aren’t in use, they’re retracted into the body.

5. THE MOVE ON TUBULAR FEET.

The rows of yellow protuberances running along the sides of this specimen are its feet. They allow sea apples to latch onto rocks and other hard surfaces while feeding. And if one of these feet gets severed, it can grow back.

6. SOME FISH HANG OUT IN SEA APPLES' BUTTS.

Sea apples are poisonous, but a few marine freeloaders capitalize on this very quality. Some small fish have evolved to live inside the invertebrates' digestive tracts, mooching off the sea apples' meals and using their bodies for shelter. In a gross twist of evolution, fish gain entry through the back door, an orifice called the cloaca. In addition expelling waste, the cloaca absorbs fresh oxygen, meaning that sea apples/cucumbers essentially breathe through their anuses.

7. WHEN THREATENED, SEA APPLES CAN EXPAND.

Most full-grown adult sea apples are around 3 to 8 inches long, but they can make themselves look twice as big if they need to escape a threat. By pulling extra water into their bodies, some can grow to the size of a volleyball, according to Advanced Aquarist. After puffing up, they can float on the current and away from danger. Some aquarists might mistake the robust display as a sign of optimum health, but it's usually a reaction to stress.

8. THEY CAN EXPEL THEIR OWN GUTS.

Sea apples use their vibrant appearance to broadcast that they’re packing a dangerous toxin. But to really scare off predators, they puke up some of their own innards. When an attacker gets too close, sea apples can expel various organs through their orifices, and some simultaneously unleash a cloud of the poison holothurin. In an aquarium, the holothurin doesn’t disperse as widely as it would in the sea, and it's been known to wipe out entire fish tanks.

9. SEA APPLES LAY TOXIC EGGS.

These invertebrates reproduce sexually; females release eggs that are later fertilized by clouds of sperm emitted by the males. As many saltwater aquarium keepers know all too well, sea apple eggs are not suitable fish snacks—because they’re poisonous. Scientists have observed that, in Pseudocolochirus violaceus at least, the eggs develop into small, barrel-shaped larvae within two weeks of fertilization.

10. THEY'RE NOT EASILY CONFUSED WITH THIS TREE SPECIES.

Syzgium grande is a coastal tree native to Southeast Asia whose informal name is "sea apple." When fully grown, they can stand more than 140 feet tall. Once a year, it produces attractive clusters of fuzzy white flowers and round green fruits, perhaps prompting its comparison to an apple tree.

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