Coral in Crisis: Can Replanting Efforts Halt Reefs’ Death Spiral?
By Erica Cirino
Visit a coral reef off the coast of Miami or the Maldives and you may see fields of bleached white instead of a burst of colors.
Coral reefs are in a death spiral. Many of the world's major reefs — which give the oceans life, support fisheries, prevent storm damage, provide medicine and create ocean-based tourism opportunities — are expected to disappear by 2100. Experts say coral decline has numerous causes, including chemical runoff, plastic pollution, disease and overfishing.
But the main culprit is climate change, a crisis with no quick fixes.
As the late Ruth Gates — one of the world's foremost coral experts and former director of the Hawaii Institute for Marine Biology — told me two years ago, shortly before her death: "A significant cut in greenhouse gas emissions is required to save corals … not to mention, us. Such an endeavor will require government and public cooperation, and it will take time."
Coral reefs don't have much time, so experts around the world have used whatever tactics were in their reach to try to give corals a fighting chance. Much of their focus has been on top-down, policy-driven approaches like creating marine protected areas, banning toxic sunscreens, and cracking down on the illegal capture of reef fish.
But a growing number of experts, building on efforts by Gates and others, have taken a more bottom-up approach: coral reef restoration, or the process of repopulating deteriorating reefs with healthy coral. And they're tapping citizen scientists to help with the effort — people participating in scientific projects organized by experts.
There's evidence that this type of restoration could solidly support the full range of reef-conservation efforts underway. But given the extent of the crisis and what's at stake, is repeatedly putting new crops of corals into harm's way the answer?
Climate Change Threats
A major coral bleaching event on part of the Great Barrier Reef in Australia.
Oregon State University / CC BY-SA 2.0
Though reefs cover less than 1 percent of Earth's surface, they support more than a million different species, including many types of algae — like sea grasses and sea lettuces — and a broad range of animals from starfish to shrimp to sharks, as well as people. Experts estimate that corals pull $375 billion into the global economy every year, mainly by fostering tourism, supporting fisheries, and contributing to medicine and storm protection.
Despite their value corals have been in decline for decades. Scientists responded by initiating the first reef-restoration efforts about 50 years ago. Since then restoration efforts have been tailored to meet the needs of corals prioritized at specific times and places. In the 1970s, as coastal development boomed, scientists focused on expanding corals' habitat by strategically placing shipwrecks, concrete pipes, tires and other manmade structures underwater on which corals could grow. By the early 2000s, scientists had become more interested in addressing other localized risks to reefs — such as overfishing, irresponsible tourism and invasive species.
But climate change poses an even more far-reaching threat.
Bleaching — a precursor to coral death caused by stressors including warming waters — has left nary a reef unscathed around the world. Most corals thrive in temperatures between 73-84 degrees Fahrenheit. Oceans naturally undergo seasonal warming, which leads to temperature fluctuations high enough to bleach some corals. In the past corals could recover from bleaching events once waters cooled. Scientists say it takes 15 to 25 years for a reef to recover from serious bleaching and become healthy enough to support a rich host of marine life. But today, with the relentless and extreme warming our oceans now face, corals are running out of possible recovery time. It's becoming much harder for them to make a comeback.
Not only does climate change raise the temperature of the oceans, resulting in inhospitable conditions for corals, it deposits excess carbon dioxide into the water — increasing seawater's acidity. More acidic waters can erode hard corals' skeletons and make it more difficult for corals to grow. The cumulative effects have been seen around the planet. According to the National Oceanic and Atmospheric Administration, more than 27 percent of the world's coral population has died over the past three decades.
According to UNESCO, bleaching on coral reefs across the world was first documented in 1983, but since then its frequency and severity has quickly accelerated. In a 2017 report, the organization identified the cause of bleaching on 72% of its so-called "globally significant" reefs from 2014 to 2017 as record-breaking ocean temperatures.
Marine biologist Maria Anderson said a dying coral reef is a painful thing to witness.
"During bleaching, the usual reef hues of browns, purples and greens are replaced by a white ghost town," said Andersen, a resident marine biologist at Ocean Group Maldives who is part of an upstarting coral reef replanting project based at InterContinental Resort, a hotel on Raa Atoll. "Soft corals appear as white blobs that melt off rocks and hard corals turn into fragile skeletons. The only way I can describe it is heartbreaking."
Secret Weapon # 1: The Public
A healthy staghorn coral colony two years after it was planted on a reef in the Florida Keys.
FWC Fish and Wildlife Research Institute / CC BY-NC-ND 2.0
To stem this tide, restoration efforts now mostly involve growing corals in undersea nurseries and transplanting them onto dying reefs that are losing coral. Like saplings being replanted in a fallen forest, young corals can help regenerate an ecosystem that's becoming barren.
But the work can be expensive and labor-intensive. According to researchers it can cost more than $150,000 to restore one reef — a small fortune in low-income coastal communities that may struggle to find funding.
That's why restoration efforts have grown increasingly reliant on the help of citizen scientists. This has significantly reduced the high price tag of restoration by replacing paid labor with volunteers — without any noticeable decline in success. Research shows the growth and survival rate of the corals planted by citizen scientists is almost identical to corals planted by experts. When handled properly, the corals replanted by volunteers survive at a rate of at least 80 percent, and often exceeds 90 percent, said Dalton Hesley, a senior research associate at the University of Miami Benthic Ecology and Coral Restoration Lab, who led that study.
"Replanting is an investment," Hesley said. "These corals should, in theory, live indefinitely, and you should expect to see growth over the years."
But that's only if we also take necessary action to prevent further degradation of, and ultimately remediate, the oceans, he said. Unless the world addresses climate change, runoff, pollution and development, reefs will continue to decline and risk being lost forever.
At this moment in Earth's history, "I don't think it should be a matter of choosing one over the other," said Andersen. Both large-scale efforts to address the climate crisis and labor-intensive replanting efforts are necessary to give reefs a chance of surviving Earth's current extinction crisis. "We have to meet somewhere in the middle, finding renewable resources while also restoring reefs. We can't just sit around and wait, leaving corals in limbo."
Secret Weapon # 2: Genetics
Choosing coral parent colonies to aid reef restoration efforts.
FWC Fish and Wildlife Research Institute / CC BY-NC-ND 2.0
"On first glance replanting may seem like a distraction from mitigating climate change, which is what we have to do if we want to save reefs," said Andersen. But she says restoration can give corals a better chance — especially when they're coupled with recent efforts to supercharge replanting by genetically identifying the most diverse and resilient species.
A well-planned, diverse reef is probably the best remedy to bleaching, Andersen said.
"I've heard of hundreds of restoration projects around the world, but none that have failed," she said. "But if one happened to fail, I would assume its leaders failed to create enough coral diversity."
Hesley agreed: "With high diversity there's strength."
Thousands of species of hard and soft corals have been identified to date, and each of these species has varying levels of resistance to stressors. Even within a species, scientists have identified different gene patterns that can convey different benefits.
"Some corals grow very quickly, some are less prone to disease, some bleach less, some are hardier during storms, for example," Hesley said. "There's not one coral species or individual that excels across the board, so we must focus on creating high levels of coral diversity."
Larger-scale reef restoration projects, like the program Hesley is involved in at the University of Miami, keep track of coral genetics using DNA analysis, ensuring coral diversity. Smaller-scale programs in rather remote places, like Andersen's project in the Maldives, often do not have in-house access to labs and genetics testing, which can be prohibitively expensive.
Andersen said these challenges require her to go through a complex research process and collaboration with coral geneticists on a different atoll to pinpoint the most and least resilient coral species. Then, she must carefully remove fragments of coral from reefs known to have survived past bleaching events so that they can be used to spawn more hardy corals. After that, she monitors the donor reef and fragments to ensure they stay healthy. These preliminary parts of the replanting process, which require permits and extraordinary precision, are left up to the professionals.
Promise and Challenges
When it comes to giving dying corals another shot, Hesley acknowledged that coral reef restoration is not a perfect solution. He said finding adequate funding, staff and volunteer labor, and addressing the root causes of reef decline — climate change and local stressors to reef health — are lingering challenges.
However, Anderson said the benefits of reef restoration, especially those powered by citizen scientists, are strong compared to their drawbacks. This has led to projects cropping up on reefs all around the world, developed by scientists hired by research institutions and hotels alike.
One of the most exciting she's seen is a citizen-science restoration project led by Peter Harrison of Southern Cross University in Australia, who has developed a backpack-sized inflatable coral spawn catcher and nursery pool in which baby corals can grow until they're big enough to be replanted.
Of course, even volunteers can only do so much. Harrison has also pioneered use of robots to swiftly distribute baby corals onto nearly 7.5 acres of damaged reefs, doing a job in just six hours that would take several human hands at least a week. If perfected, it could put volunteer seeding efforts effectively out of business.
But there's always a role for people willing to help. After corals are propagated, whether it's by hand or machine, citizen scientists can help care for them in undersea nurseries.
All of this requires careful planning. Andersen emphasizes the importance of establishing clearly defined goals for restoration, based around a community's needs and available resources. Another aspect of a successful restoration effort, she said, is an effective and accessible training program that primes citizen scientists on how to participate and, ultimately, care about the future of corals.
And that ties into the fundamental reason why citizen science still matters: because restoration buys time for corals. Experts at the Smithsonian Research Institute have found that the more living coral a reef has when exposed to highly acidic waters, the more likely it is to survive, instead of bleaching and dying.
Meanwhile, the efforts help to connect people to something that otherwise might stay out of sight and out of mind beneath the surface of the ocean.
"I don't think a lot of people who get involved in restoration initially have that emotional attachment to coral reefs simply because they haven't had a chance to care about them," Andersen said. "Restoration gives them the opportunity to make a connection, to really understand how dire the situation is, and to do something that can help."
Reposted with permission from The Revelator.
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By Bill Sullivan
Black licorice may look and taste like an innocent treat, but this candy has a dark side. On Sept. 23, 2020, it was reported that black licorice was the culprit in the death of a 54-year-old man in Massachusetts. How could this be? Overdosing on licorice sounds more like a twisted tale than a plausible fact.
The Root of the Problem<p>The unfortunate man who recently succumbed to excessive black licorice consumption is not alone. There are a smattering of similar case reports in medical journals, in which patients experience <a href="https://pubmed.ncbi.nlm.nih.gov/26380428/" target="_blank" rel="noopener noreferrer">hypertension crisis</a>, <a href="https://doi.org/10.5414/cn107011" target="_blank" rel="noopener noreferrer">muscle breakdown</a> or even death. Adverse reactions are most frequently seen in people over the age of 40 who are eating far more black licorice than the average person. In addition, they are usually consuming the product for prolonged periods of time. <a href="https://doi.org/10.1056/NEJMcpc2002420" target="_blank" rel="noopener noreferrer">In the most recent case</a>, the Massachusetts man had been eating a bag and a half of black licorice every day for three weeks.</p><p>Licorice is a flowering plant native to parts of Europe and Asia. Its scientific name, <em>Glycyrrhiza</em>, is derived from the Greek words "glykos" (sweet) and "rhiza" (root). The aromatic and sweet extract from its root has long been used as an herbal remedy for a wide variety of health maladies, from heartburn and stomach issues to sore throats and cough. However, there is <a href="https://www.fda.gov/consumers/consumer-updates/black-licorice-trick-or-treat" target="_blank">insufficient evidence to support that licorice is effective in treating any medical condition</a>.</p><p>Glycyrrhizin (also called glycyrrhizic acid) is the chemical in black licorice that gives the candy its signature flavor, but it also leads to its toxic effects.</p><p>Glycyrrhizin mimics the hormone <a href="https://www.yourhormones.info/hormones/aldosterone/" target="_blank">aldosterone</a>, which is made by the adrenal glands when the body needs to retain sodium and excrete potassium. Sodium and potassium work together as a kind of cellular battery that drives communication between nerves and the contraction of muscles. Too much glycyrrhizin upsets the balance of these electrolytes, which can raise blood pressure and disturb the heart's rhythm. Other symptoms of excessive licorice intake include swelling, muscle pain, numbness and headache. Examination of the man who died from consuming too much licorice revealed that he had <a href="https://doi.org/10.1056/NEJMcpc2002420" target="_blank" rel="noopener noreferrer">dangerously low levels of potassium, consistent with glycyrrhizin toxicity.</a></p><p><a href="https://doi.org/10.1056/NEJMcpc2002420" target="_blank" rel="noopener noreferrer"></a>It should be noted that a number of licorice-based foods do not contain real licorice, but use a flavoring substitute called anise oil, which does not pose the dangers discussed here. In addition, despite its name, <a href="https://www.livestrong.com/article/537724-black-licorice-vs-red-licorice/" target="_blank">red licorice rarely contains licorice extract</a>. Instead, red licorice is infused with chemicals that impart its cherry or strawberry flavor.</p><p>Products that contain real licorice are usually labeled as such, and list licorice extract or glycyrrhizic acid among the ingredients. Be advised that some products, such as black jelly beans or Good & Plenty, are mixtures of different candies that contain both anise oil and licorice extract.</p>
Hidden Dangers That Increase Risk<p>Glycyrrhizin has the distinct licorice flavor and is <a href="https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=19&contentid=Licorice" target="_blank">50 times sweeter than sugar</a> and has been used in other types of candy, soft drinks, tea, Belgian beers, throat lozenges and tobacco. This can make it challenging to keep track of how much glycyrrhizin has been consumed, and a combination of these products could trigger adverse effects.</p><p>Some people take dietary or health supplements that already contain licorice, which increases the risk of toxic effects from eating black licorice candy. Certain medications such as <a href="https://doi.org/10.5414/cn107011" target="_blank">hydrochlorothiazide</a> are diuretics that cause increased urination, which can lower potassium levels in the body. Glycyrrhizin also lowers potassium levels, further disrupting the balance of electrolytes, which can produce muscle cramps and irregular heart rhythms.</p><p>People with certain preexisting conditions are more susceptible to black licorice overdose.</p><p>For example, patients who already have low potassium levels (hypokalemia), high blood pressure or heart arrhythmia are likely to have greater sensitivity to the effects of excessive licorice. Those with liver or kidney deficiencies will also retain glycyrrhizin in their bloodstream for longer times, increasing their risk of experiencing its adverse effects.</p>
What to Do?<p>If you're a fan of black licorice, there is no need to ban it from your pantry. Eaten in small quantities from time to time, licorice poses no significant threat to otherwise healthy adults and children. But it is advisable to monitor your intake.</p><p>With Halloween approaching, be sure to remind your kids that candy is a "<a href="https://www.heart.org/idc/groups/heart-public/@wcm/@global/documents/downloadable/ucm_305557.pdf" target="_blank">sometimes food</a>," especially the black licorice. The <a href="https://www.fda.gov/consumers/consumer-updates/black-licorice-trick-or-treat" target="_blank" rel="noopener noreferrer">FDA has issued warnings</a> about the rare but serious effects of too much black licorice, advising that people avoid eating more than two ounces of black licorice a day for two weeks or longer. The agency states that if you have been eating a lot of black licorice and experience an irregular heart rhythm or muscle weakness, stop eating it immediately and contact your health care provider.</p><p>Some scientists have further cautioned against the routine use of licorice in the form of a dietary supplement or tea for its alleged health benefits. A <a href="https://doi.org/10.1177/2042018812454322" target="_blank" rel="noopener noreferrer">review article from 2012</a> warned that "the daily consumption of licorice is never justified because its benefits are minor compared to the adverse outcomes of chronic consumption."</p>
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Material Revolutions: Shirts Made from Shellfish, Biodegradable Rum Bottles and Reusable Fast Food Containers
In the age of consumption, sustainability innovations can help shift cultural habits and protect dwindling natural resources. Improvements in source materials, product durability and end-of-life disposal procedures can create consumer products that are better for the Earth throughout their lifecycles. Three recent advancements hope to make a difference.
1. Allbirds Shirts Made From Shellfish<p>Sustainable sneaker start-up <a href="https://www.allbirds.com/pages/apparel" target="_blank">Allbirds</a> is known for its thoughtfulness for consumers and the environment. The four-year-old shoe company has become hugely popular by creating comfortable shoes made from responsibly sourced materials like tencel and wool, reported <a href="https://www.fastcompany.com/90565358/allbirds-new-clothing-line-includes-t-shirts-made-from-discarded-crab-shells" target="_blank">Fast Company</a>.</p><p>Recently, Allbirds launched its debut apparel line with garments for men and women made with eco-friendly materials that have a low carbon footprint, the report said.</p><p>Introduced along with the line is a new t-shirt material called "TrinoXO," which is made from wool and discarded snow crab shells from Canada's seafood industry, reported <a href="https://www.cnbc.com/2020/10/20/sustainable-sneaker-start-up-allbirds-is-selling-sweaters-t-shirts.html" target="_blank">CNBC</a> and <a href="https://www.cnn.com/2020/10/20/business/allbirds-sustainable-apparel/index.html" rel="noopener noreferrer" target="_blank">CNN</a>. The shells are the "number two discarded resource on earth," Allbirds claims, reported <a href="https://www.menshealth.com/style/a34427585/allbirds-apparel-clothing-line-review/" rel="noopener noreferrer" target="_blank">Men's Health</a>.</p><p>"Discarded material is the holy grail when it comes to sustainable fibers," Jad Finck, Allbirds head of innovation and sustainability, told Fast Company. "It's far better for the environment than getting raw materials from scratch."</p><p>The shells have antimicrobial properties that keep clothes fresh even after hours of wear, without the need to add "extractive" materials like zinc or silver, Men's Health reported. This allows for longer periods of wear between washes, reducing clothes' environmental footprint.</p><p>"We knew we wanted to be a real brand, and had this vision that we'd be an innovation company first, and a product company second," co-founder Joey Zwillinger told <a href="https://www.vogue.com/article/allbirds-launches-clothing" rel="noopener noreferrer" target="_blank">Vogue</a>. "And our products would solve problems for people in a natural way, and show the world that you don't have to compromise on the planet for amazing products."</p>
2. Bacardi Biodegradable Rum Bottles<p>By 2023, <a href="https://www.bacardi.com/us/en/" target="_blank">Bacardi</a> rum will be sold in 100% biodegradable bottles, <a href="https://www.businesswire.com/news/home/20201021005281/en/Bacardi-First-in-Fight-Against-Plastic-Pollution-With-100-Biodegradable-Spirits-Bottle" target="_blank">Business Wire</a> reported.</p><p>The alcohol giant is collaborating with Danimer Scientific, a leading developer of biodegradable products, to create the new bottles using the natural oils of plant seeds such as palm, canola and soy, the report said.</p><p>According to <a href="https://sports.yahoo.com/bacardi-to-make-100-biodegradable-spirits-bottle-124436841.html?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuZ29vZ2xlLmNvbS8&guce_referrer_sig=AQAAAE1Wl8ONNdph3ID8reylzGM8dbX575Mk96Jw6z3kHZaGjKCz_UgQgxH0Q1n3RNCzhOMBEZ7fAIf8iiOXLRtY9VVHNZsmb-w1VOJnGlzIbuwhmoBo_KOV4dba8FoWrkgmmwwCyQZnRoTL0Uda6HQ4pE5ewGWh2pwQzjS3gKAe1ynm" target="_blank">Yahoo Finance UK</a>, the new bottle will biodegrade in a wide range of environments, including compost, soil, freshwater and seawater. After 18 months, the bottle will disappear completely without leaving microplastics.</p><p>"Nodax PHA is one of the most promising eco-friendly materials in the world today because it delivers the biodegradability that consumers demand without losing the quality feel they receive from traditional plastic," said Danimer Scientific chief marketing & sustainability officer Scott Tuten, reported <a href="https://www.thrillist.com/news/nation/bacardi-biodegradable-spirits-bottle-plastic-free-packaging" target="_blank" rel="noopener noreferrer">Thrillist</a>. "The material provides the best of both worlds, and we look forward to working with Bacardí and incorporating PHA into their iconic packaging."</p><p>Bacardi is also creating a sustainably sourced paper bottle, Yahoo reported.</p><p>The manufacturing of both new bottle types will save energy over petroleum-based plastic ones. Bacardi plans to share the technology with competitors to help in the global fight against <a href="https://www.ecowatch.com/tag/plastic-pollution" target="_self">plastic pollution</a>, and aims to be 100% plastic-free by 2030, reported Thrillist.</p>
3. Burger King Reusable Fast Food Containers<p>Fast food giant <a href="https://www.bk.com/" target="_blank">Burger King</a> plans to launch reusable Whopper boxes and soda cups by next year. Partnering with TerraCycle's zero-waste packaging division Loop, Burger King will nudge customers to return the specialized packaging for hygienic washing and reuse, similar to how milk bottles used to be returned, reported <a href="https://www.marketwatch.com/story/can-burger-kings-reusable-packaging-change-fast-food-forever-11603392581" target="_blank">MarketWatch</a>.</p><p>"During COVID, we have seen the environmental impact of <a href="https://www.ecowatch.com/air-pollution-food-delivery-plastic-waste-2648454324.html" target="_self">increased takeaway ordering</a>, which makes this initiative by Burger King all the more important," said Tom Szaky, TerraCycle and Loop CEO, according to MarketWatch.</p><p>Customers who don't feel comfortable can opt-out of the service, <a href="https://www.abc10.com/article/entertainment/television/programs/the-buzz-burger-king-to-test-reusable-packaging-in-2021/77-f01f1b70-05b7-436d-9971-a7dd6081249b" target="_blank">ABC News</a> reported. Those who are willing to try will be charged a small deposit upon purchase, and when the packaging is returned, they will receive a refund, reported <a href="https://www.cnn.com/2020/10/22/business/burger-king-reusable-packaging-sustainability/index.html" rel="noopener noreferrer" target="_blank">CNN</a>.</p><p>Burger King and TerraCycle are aiming for a container that can be used at least 100 times, reported <a href="https://www.fastcompany.com/90566995/burger-kings-new-whopper-packaging-isnt-greasy-cardboard-its-reusable" rel="noopener noreferrer" target="_blank">Fast Company</a>.</p><p>"The benefit is, you're able to serve your guests without having to create that single-use item in the first place," Matt Banton, global head of innovation and sustainability at Burger King, told <a href="https://www.fastcompany.com/90566995/burger-kings-new-whopper-packaging-isnt-greasy-cardboard-its-reusable" rel="noopener noreferrer" target="_blank">Fast Company</a>. "This product is durable enough to go through the system multiple times, so it's ultimately reducing our environmental impact, and minimizing the amount of single-use packaging that we have to produce as well."</p><p>Burger King has also committed to sourcing 100% of its customer packaging from renewable, recycled or certified outlets, and recycling all customer packaging at its restaurants in the United States and Canada by 2025, reported CNN.</p>
There are many different CBD oil brands in today's market. But, figuring out which brand is the best and which brand has the strongest oil might feel challenging and confusing. Our simple guide to the strongest CBD oils will point you in the right direction.
The ghoulishly named ogre-faced spider can "hear" with its legs and use that ability to catch insects flying behind it, the study published in Current Biology Thursday concluded.
"Spiders are sensitive to airborne sound," Cornell professor emeritus Dr. Charles Walcott, who was not involved with the study, told the Cornell Chronicle. "That's the big message really."
The net-casting, ogre-faced spider (Deinopis spinosa) has a unique hunting strategy, as study coauthor Cornell University postdoctoral researcher Jay Stafstrom explained in a video.
They hunt only at night using a special kind of web: an A-shaped frame made from non-sticky silk that supports a fuzzy rectangle that they hold with their front forelegs and use to trap prey.
They do this in two ways. In a maneuver called a "forward strike," they pounce down on prey moving beneath them on the ground. This is enabled by their large eyes — the biggest of any spider. These eyes give them 2,000 times the night vision that we have, Science explained.
But the spiders can also perform a move called the "backward strike," Stafstrom explained, in which they reach their legs behind them and catch insects flying through the air.
"So here comes a flying bug and somehow the spider gets information on the sound direction and its distance. The spiders time the 200-millisecond leap if the fly is within its capture zone – much like an over-the-shoulder catch. The spider gets its prey. They're accurate," coauthor Ronald Hoy, the D & D Joslovitz Merksamer Professor in the Department of Neurobiology and Behavior in the College of Arts and Sciences, told the Cornell Chronicle.
What the researchers wanted to understand was how the spiders could tell what was moving behind them when they have no ears.
It isn't a question of peripheral vision. In a 2016 study, the same team blindfolded the spiders and sent them out to hunt, Science explained. This prevented the spiders from making their forward strikes, but they were still able to catch prey using the backwards strike. The researchers thought the spiders were "hearing" their prey with the sensors on the tips of their legs. All spiders have these sensors, but scientists had previously thought they were only able to detect vibrations through surfaces, not sounds in the air.
To test how well the ogre-faced spiders could actually hear, the researchers conducted a two-part experiment.
First, they inserted electrodes into removed spider legs and into the brains of intact spiders. They put the spiders and the legs into a vibration-proof booth and played sounds from two meters (approximately 6.5 feet) away. The spiders and the legs responded to sounds from 100 hertz to 10,000 hertz.
Next, they played the five sounds that had triggered the biggest response to 25 spiders in the wild and 51 spiders in the lab. More than half the spiders did the "backward strike" move when they heard sounds that have a lower frequency similar to insect wing beats. When the higher frequency sounds were played, the spiders did not move. This suggests the higher frequencies may mimic the sounds of predators like birds.
University of Cincinnati spider behavioral ecologist George Uetz told Science that the results were a "surprise" that indicated science has much to learn about spiders as a whole. Because all spiders have these receptors on their legs, it is possible that all spiders can hear. This theory was first put forward by Walcott 60 years ago, but was dismissed at the time, according to the Cornell Chronicle. But studies of other spiders have turned up further evidence since. A 2016 study found that a kind of jumping spider can pick up sonic vibrations in the air.
"We don't know diddly about spiders," Uetz told Science. "They are much more complex than people ever thought they were."
Learning more provides scientists with an opportunity to study their sensory abilities in order to improve technology like bio-sensors, directional microphones and visual processing algorithms, Stafstrom told CNN.
"The point is any understudied, underappreciated group has fascinating lives, even a yucky spider, and we can learn something from it," he told CNN.
In 'Road Map for a More Sustainable Future,' NY Regulator Tells Banks to Consider Climate Risks in Planning
By Brett Wilkins
Regulators in New York state announced Thursday that banks and other financial services companies are expected to plan and prepare for risks posed by the climate crisis.