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Giant whale sharks have teeth on their eyeballs
The ocean's largest shark relies on vision more than previously believed.
01 July, 2020
Photo by Koichi Kamoshida/Getty Images
- Japanese researchers discovered that the whale shark has "tiny teeth"—dermal denticles—protecting its eyes from abrasion.
- They also found the shark is able to retract its eyeball into the eye socket.
- Their research confirms that this giant fish relies on vision more than previously believed.
<p><br></p>
<p>Cape Cod residents and tourists received a stark warning ahead of the July 4th weekend: <a href="https://www.theguardian.com/environment/2020/jun/30/cape-cod-issues-great-white-shark-warning-ahead-of-4-july-holiday" target="_blank">beware of great white sharks</a>. This isn't a complete outlier, given that the danger of these sharks has increased in recent years. Sharks are having difficulty finding food sources further out at sea, and so every year they've been encroaching upon the Cape's borders in search of seals.</p><p>That sobering story is nowhere near the top of shark news this week, however. In yet another indication that the planet is tiring of us humans, it has been discovered that the world's biggest shark has teeth all over its eyeballs. </p><p>In the exceptionally named research article, "<a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235342" target="_blank">Armored eyes of the whale shark</a>," a team of researchers from Japan's Okinawa Churashima Research Center discovered that these beastly predators evolved a unique defense mechanism for their vision: dermal denticles. </p><p>These denticles are nothing new. Similar v-shaped scales cover shark skin. Structurally, they're akin to tiny teeth. This feature helps sharks decrease turbulence and drag while gliding through the ocean, making them an even more fearsome fish—a tall order for a shark that grows up to 62 feet in length. </p><p>Whale shark mouths are formidable, featuring over 300 rows of tiny teeth. Their teeth play no role in feeding, however: whale sharks are one of three shark species that filter-feed. Their diet is predominantly plankton, krill, jellyfish, sardines, and anchovies. They'll consume small tuna and squids that cross their path. Otherwise, these mammoth swimmers are content taking in what comes. </p>
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzQzMDE4Mi9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYxNjg0ODEzM30.a1qOGXcFkKnvngtfAj7Kd1-rOxcxJEf1pRbbn-ARuv4/img.png?width=980" id="074e3" class="rm-shortcode" data-rm-shortcode-id="0f6ef3da1068593b4fad1879916bc7b9" data-rm-shortcode-name="rebelmouse-image" alt="image of whale shark and whale shark eye" />
<p class=""><br></p>A. Anterior view of the whale shark, showing the locations of the eye (arrows). Note that whale shark eye is well projected from the orbit. Photo was taken in the sea near Saint Helena Island. B. Close-up view of the left eye of a captive whale shark (Specimen A).
<p>Considering their dietary habits, vision was not thought be that important for whale sharks. This species is unique for not having any sort of eyelid or protective mechanism—until now, that is. Not only do dermal denticles protect their vision, the team, led by Taketeru Tomita, discovered that whale sharks have another trick:</p><p style="margin-left: 20px;">"We also demonstrate that the whale shark has a strong ability to retract the eyeball into the eye socket."</p><p>The researchers studied these massive sharks in an aquarium, offering them a rare look at one of the ocean's largest fish (They also studied deceased sharks). The eye denticle is different from the rest of the scales covering their body: they are designed for abrasion resistance, not ocean stealth. </p><p style="margin-left: 20px;">"The covering of the eye surface with denticles in the whale shark is probably useful in reducing the risk of mechanical damage to the eye surface." </p><p>Despite their massive size, whale sharks have relatively small eyes, measuring less than 1 percent of their total length. Their brain's visual center is also relatively small. With this discovery, the researchers realized vision plays a more important role than previously assumed. </p><p style="margin-left: 20px;">"The highly protected features of the whale shark eye, in contrast to the traditional view, seems to suggest the importance of vision in this species. Interestingly, Martin showed that whale shark eyes actively track divers swimming 3–5 m away from the animal, suggesting that vision of the whale shark plays an important role in short-range perception." </p><p>While you likely won't bump into a whale shark while swimming just off the coast, this is yet another reminder of how species adapt to their environment. </p><p><span></span>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
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The great white shark has surprising dining habits
Scientists are befuddled by where the shark gets most of its food.
15 June, 2020
Photo by Gerald Schömbs / Unsplash
- A University of Sydney research team found that the great white shark spends an unexpectedly large amount of time feeding close to the sea bed.
- The group examined the contents in the stomachs of 40 juvenile white sharks and found the remains of a variety of fish species that typically inhabit the sea floor or are buried in the sand.
- The scientists hope that the information gained from this research will assist conservation and management efforts for the species.
<p>In the <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00422/full" target="_blank">first-ever study</a> detailing the eating habits of great white sharks, researchers found that the predator spends an unexpectedly large amount of time feeding close to the sea bed. </p>
Fresh findings
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzM5MjMyNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNjY5NDExM30.3JLqvvn4iB0F29jWuRMnEdmSwY6avTsmo6AP3LgXMxQ/img.jpg?width=1245&coordinates=0%2C333%2C0%2C334&height=700" id="362cb" class="rm-shortcode" data-rm-shortcode-id="f21b84cc3825bf4ac53454c6c4bbb09f" data-rm-shortcode-name="rebelmouse-image" />black shark in blue waterPhoto by Gerald Schömbs on Unsplash<p>A research team from the University of Sydney looked at sharks off the east coast of Australia and found that in their stomachs were remains from a variety of fish species that typically inhabit the sea floor or are buried in the sand. Specifically, the group examined the contents in the stomachs of 40 juvenile white sharks, scientifically known as <em>Carcharodon carcharias</em>, who were caught in the NSW Shark Meshing Program. </p><p>"This indicates the sharks must spend a good portion of their time foraging just above the seabed," explained lead author Richard Grainger, a Ph.D. candidate at the Charles Perkins Centre and School of Life and Environmental Sciences at the University of Sydney, <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">in a press release</a>. "The stereotype of a shark's dorsal fin above the surface as it hunts is probably not a very accurate picture." </p><p>The study was published on June 8, World Oceans Day, in the journal Frontiers in Marine Science<em>. </em>It's an important step forward for scientists trying to better understand the great white's diet and migratory behavior. </p><p>"We discovered that although mid-water fish, especially eastern Australian salmon, were the predominant prey for juvenile white sharks in NSW, stomach contents highlighted that these sharks also feed at or near the seabed," <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">said Vic Peddemors</a>, Ph.D., a co-author from the NSW Department of Primary Industries (Fisheries). </p><p>The research team compared this new dietary information with published data on great white feeding habits from other parts of the world where the sharks make home, mostly South Africa. From there they were able to establish a nutritional framework for the species. </p>What's in a great white's diet?
<p><a href="https://www.frontiersin.org/files/Articles/532445/fmars-07-00422-HTML/image_m/fmars-07-00422-t001.jpg" target="_blank">According to the research</a>, the juvenile great white sharks' diets relied primarily on pelagic — mid-water ocean swimming — fish, such as Australian salmon. This made up 32.2 percent of the shark's diet. Bottom-dwelling fish like stargazers, sole or flathead made up 17.4 percent; batoid fish such as stingrays 14.9 percent; and reef fish, like eastern blue gropers, 5 percent.</p><p>The remaining species eaten by the sharks were unidentified fish or less abundant prey. Grainger pointed out that other marine mammals, sharks, and cephalopods — squid and cuttlefish — were eaten at lower rates. </p><p>"The hunting of bigger prey, including other sharks and marine mammals such as dolphins, is not likely to happen until the sharks reach about 2.2 meters in length," <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">Grainger said</a>.</p><p>Another discovery was that bigger sharks tended to have diets that were higher in fat. Similarly to other animals, this is likely an adaptation to their higher energy needs for migration. Great white's migrate seasonally along Australia's east coast, traveling from southern Queensland to northern Tasmania. The range of distance covered increases with age. </p><p>"This fits with a lot of other research we've done showing that wild animals, including predators, select diets precisely balanced to meet their nutrient needs," said co-author Professor David Raubenheimer, Chair of Nutritional Ecology in the School of Life and Environmental Sciences.</p>Species conservation and management
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="7bb54774f7a5b923690ad15c2e979aca"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/O2FInaOCqoo?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Ultimately, the scientists hope that the information gained from this research will assist conservation and management efforts for the sharks, who are considered a vulnerable and declining species due to overfishing and accidental catching in gill nets.</p>Of particular interest to scientists is better management of relations between humans and great whites. According to <a href="https://www.nationalgeographic.com/animals/fish/g/great-white-shark/" target="_blank">National Geographic</a>, of the over 100 annual shark attacks that happen worldwide, a whopping one-third to half can be attributed to great whites. Yet, research has found that the sharks, who tend to have a curious disposition, are often just taking sample nibble before releasing their human prey. So, at least we know humans aren't a great white delicacy.
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Chemists develop fast-degrading plastic for cleaner oceans
The researchers hope to develop a no-trace plastic to curtail marine pollution and ghost fishing.
24 April, 2020
(Photo: NOAA)
- Cornell University chemists have developed a polymer with the strength of industrial-grade plastics but degrades quickly in sunlight.
- They hope the plastic will one day be used to make fishing nets that leave no environmental trace.
- Their research joins other programs and initiatives aimed at restoring our oceans.
<p>In popular imagination, <a href="https://oceanservice.noaa.gov/facts/garbagepatch.html" target="_blank">the Great Pacific Garbage Patch</a> is a concentration of trash adrift lazily on the ocean. It's an entire continent of tightly packed tires, Styrofoam, syringes, water bottles, trash bags, fishing nets, Tupperware, lost toys, missing sandals, and other detritus that looks like <em><a href="https://bigthink.com/surprising-science/earth-was-a-waterworld" target="_self">Waterworld</a></em> as envisioned by <em>Mad Max</em> director George Miller.</p><p>But there's a more insidious reality to the Pacific Garbage Patch. It doesn't concentrate our garbage in a central, easy-to-find location. Rather, the oceanic gyres disperse it across <a href="https://www.cnn.com/2018/03/23/world/plastic-great-pacific-garbage-patch-intl/index.html" target="_blank">millions of square kilometers</a>, whirling it wherever the winds and waves take it. </p><p>This reality makes the challenge of cleaning the Pacific Ocean daunting, to say the least. As Dianna Parker, from the NOAA Marine Debris Program, said on the <a href="https://oceanservice.noaa.gov/podcast/mar18/nop14-ocean-garbage-patches.html" target="_blank">NOAA Ocean Podcast</a>: "We did some quick calculations that if you tried to clean up less than one percent of the North Pacific Ocean it would take 67 ships one year to clean up that portion."</p><p>One major source of this pollution is lost or abandoned fishing gear. Because these nets, traps, and trawls are made of industrial-grade plastics, they will take hundreds of years to degrade. During the interim, they will continue to scour the oceans in large tangled masses, chocking the waters and killing marine life as they go.</p><p>To reduce this source of marine pollution, Cornell University chemists have gone in a counter-intuitive direction: They've created a new plastic. </p>
A lot of hard work for (hopefully) nothing
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE2MjMyNi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwMTE0NzI2N30.3aiSf1wiYX3TRcLZKVEJbCQrKjbuTLbhtTp4Dw6mRmY/img.jpg?width=1245&coordinates=0%2C96%2C0%2C0&height=700" id="47e3a" class="rm-shortcode" data-rm-shortcode-id="33853c60e6f3be3fecdb198dd5351282" data-rm-shortcode-name="rebelmouse-image" />Commercial fishing nets are made of polymers that are strong but take hundreds of years to degrade.
<p>The polymer is called isotactic polypropylene oxide, or <em>i</em>PPO for short. It was originally discovered in 1949, but for the past fifteen years, Bryce Lipinski, professor of chemistry and chemical biology at Cornell University, and his team have been iterating on the plastic and discovered a new polymer chain with some unique properties.</p><p>Their <em>i</em>PPO has a comparable ultimate tensile strength to <a href="https://en.wikipedia.org/wiki/Nylon_66" target="_blank">nylon-6,6</a>, a sturdy and strong polymer that can maintain stability under adverse conditions. For this reason, nylon-6,6 is used in zip ties, engine parts, industrial applications, and, yes, fishing nets and ropes. </p><p>Unlike nylon-6,6 and other industrial-strength polymers, however, <em>i</em>PPO can readily degrade under the right conditions—those conditions being any wit sunlight.</p><p>"We have created a new plastic that has the mechanical properties required by commercial fishing gear. If it eventually gets lost in the aquatic environment, this material can degrade on a realistic time scale," Lipinski said in <a href="https://news.cornell.edu/stories/2020/04/chemists-create-faster-degrading-plastic-marine-uses" target="_blank">a release</a>. "This material could reduce persistent plastic accumulation in the environment."</p><p>To test their hypothesis, the researchers placed a 93 kilodalton (kDa) sample of their iPPO beneath an LED floodlight. The light exposed the sample to a stream of ultraviolet light with a wavelength of 365 nanometers—a wavelength range within the band of <a href="https://www.who.int/uv/uv_and_health/en/" target="_blank">solar ultraviolet light</a> that passes through the atmosphere to reach Earth's surface.</p><p>After 30 days of constant exposure, the sample reduced to 21 kDa, or roughly a quarter of its original size. Control samples not exposed to ultraviolet light remained unchanged. </p><p>The team <a href="https://pubs.acs.org/doi/10.1021/jacs.0c01768" target="_blank">published their findings</a> last month in the <em>Journal of the American Chemical Society</em>.</p>The deadliest catch
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE2MjMyOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNzQ5MzY2MX0.6_DlCIrKzb7CIqE2-ZDPXYYsV7ao2xtko0ME9odJOj4/img.jpg?width=1245&coordinates=0%2C763%2C0%2C519&height=700" id="0cbe4" class="rm-shortcode" data-rm-shortcode-id="d49eebe85430d3668ed4483c7ef5ecfb" data-rm-shortcode-name="rebelmouse-image" />A sea turtle caught in ghost gear.
<p>Fishing nets and ropes produced with such a biodegradable polymer could moderate a major hazard of today's marine environments: <a href="https://oceanservice.noaa.gov/facts/ghostfishing.html" target="_blank">ghost fishing</a>.</p><p>Ghost fishing begins with lost or abandoned fishing gear. No longer under the control of fishermen, this gear, now known as "ghost gear" or "derelict fishing gear," drifts as flotsam or settles on coastal floors where it continues to serve its function of ensnaring fish and other marine animals.</p><p>A <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/faf.12407" target="_blank">meta-analysis published in <em>Fish and Fisheries</em></a> estimates 5.7 percent of all fishing nets, 8.6 percent of all traps, and 29 percent of all lines become ghost gear each year. The Global Ghost Gear Initiative estimates the annual poundage to be <a href="https://www.bbc.com/news/uk-scotland-highlands-islands-50510666" target="_blank">640,000 metric tons</a>.</p><p>While fishing gear is designed to target certain species, without a fisherman to control it, ghost gear captures animals indiscriminately. Non-target species can often be caught, including protected species of turtles, seabirds, and whales. </p><p>Once caught, they often succumb to starvation, predation, or even cannibalism. Their bodies then attract other animals hoping for an easy meal, who in turn become enmeshed, creating a deadly and self-perpetuating cycle so long as the gear remains unrecovered.</p><p>Ghost fishing wrests an economic toll, too. Beyond the costs of replacing lost gear, ghost gear also culls the populations of species fishermen depend on for their livelihood.</p><p>As Lipinski notes in the release, the goal of his research is to develop a polymer that leaves no trace in the environment. Such a breakthrough may not end the dangers of ghost fishing. Nets and traps would still seize animals before they biodegrade into nothing. But such a polymer would drastically lessen the time such gear could hunt on its wayward path. </p><p>If <em>i</em>PPO could one day reach that goal, it could vastly improve environmental conditions in our oceans.</p>Not too late
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE2MjMyMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1MTA3MDcxNn0.bzbtBMEFpS7L-2E5g2K4IdLc0qnxgVrJdf1ajZRlWnc/img.jpg?width=1245&coordinates=0%2C0%2C0%2C579&height=700" id="03101" class="rm-shortcode" data-rm-shortcode-id="fce6646a76e0266715a4bc334e11d44c" data-rm-shortcode-name="rebelmouse-image" />Volunteers collect rubbish from the Aegean sea to protect biodiversity.
<p><em>i</em>PPO may one day improve the situation, but it is hardly a silver bullet. The gyre that creates Great Pacific Garbage Patch also sweeps up vast amounts of tiny microplastics—most too small to be seen with the naked eye yet will still last hundreds of years. These join fishing nets and everyday plastic items that wash out into the sea.</p><p>"[T]he bottom line is that until we prevent debris from entering the ocean at the source, it's just going to keep congregating in these areas. We could go out and clean it all up and then still have the same problem on our hands as long as there's debris entering the ocean," Dianna Parker said.</p><p>Again, the challenge is daunting. Yet many countries, institutions, and individuals are taking it head-on.</p><p>Last year, the <a href="https://theoceancleanup.com/updates/the-ocean-cleanup-successfully-catches-plastic-in-the-great-pacific-garbage-patch/" target="_blank">Ocean Cleanup Project announced</a> that its latest boom design was successfully capturing and collecting plastics from the Great Pacific Garbage Patch. The system uses the ocean's natural currents to sweep debris into the boom. Once fully operational, the system will be able to return plastics to land for recycling.</p><p>The United Nations has set its <a href="https://www.un.org/sustainabledevelopment/oceans/" target="_blank">Sustainable Development Goal #14</a> to target marine conservation. One of its goals is to significantly reduce all marine pollution by 2025, with an emphasis on preventing land-based sources. </p><p>And a <a href="https://www.nature.com/articles/s41586-020-2146-7" target="_blank">recent study in <em>Nature</em></a> found that the situation isn't hopeless. The researchers projected the recovery of damaged marine habitats by looking at past conservation interventions. They found that we could restore our oceans, resurrect dead zones, and reinvigorate marine species within 30 years. It would take a concentrated effort costing billions of dollars, but the potential rewards would be worth 10 times as much.</p><p>"Overfishing and climate change are tightening their grip, but there is hope in the science of restoration," Callum Roberts, study author and marine conservation biologist at the University of York, <a href="https://www.theguardian.com/environment/2020/apr/01/oceans-can-be-restored-to-former-glory-within-30-years-say-scientists" target="_blank">told the <em>Guardian</em></a>. "One of the overarching messages of the review is, if you stop killing sea life and protect it, then it does come back. We can turn the oceans around and we know it makes sense economically, for human well being and, of course, for the environment."</p>
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Atomic bomb tests help scientists finally date sharks
Nuclear weapons, whale sharks, and how to use both to make eco-tourism more sustainable.
08 April, 2020
SCOTT TUASON/AFP via Getty Images
- Scientists have finally determined the age of whale sharks using radioactive elements from bomb tests.
- Using the new data, the age range of the animals' bones has now been determined.
- The findings will help conservationists better maintain whale shark populations.
There are some things that you presume science already knows and may be surprised to learn it doesn't. One seemingly simple thing was resolved this week, as scientists finally put an age range on whale sharks by dating the slightly radioactive carbon-14 isotope their bones collected after Cold War atomic bomb tests.
Majestic whale sharks, the gentle giants of the shark family.
<p>Weighing in at 9 tons (20,000 pounds) and typically growing to around 10 meters (32 feet) long, the <a href="https://en.wikipedia.org/wiki/Whale_shark" target="_blank">whale shark</a> is the largest living species of fish. Despite the name, it is not a whale, though it is the size of one. Like many kinds of whales, it filter feeds on plankton.</p><p>Many things about the whale shark have remained unknown to science; how long they can live, their mortality rate, and how exactly to determine the age of a specimen from its remains was chief among them. However, these questions are now a little closer to being settled. In a <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00188/full" target="_blank">study</a> recently published in <em>Frontiers in Marine Science,</em> scientists explain how they were able to date the bones of two whale sharks who met their fate earlier than they may have expected. </p><p>Like trees, whale sharks' bones have growth rings. Scientists have known about these rings for a while, but how quickly the rings grow has been unknown. It is difficult to use them to estimate the age of a shark if you aren't sure how much time each ring represents.</p><p><br></p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkyMzQwMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTIxNTczNn0.YIma6eMrPOpf6dpUF08KKfHYTWtcIPibWSQ0Qe6ZK_k/img.jpg?width=980" id="7827f" class="rm-shortcode" data-rm-shortcode-id="37b6174bf3f4d03c75c617427eb0d768" data-rm-shortcode-name="rebelmouse-image" alt="whale shark vertebra" />
A whale shark vertebra from Pakistan, in cross section, showing 50 growth bands
Image: © Paul Fanning, Pakistan node of the UN Food and Agricultural Organisation
<p>This is where carbon-14 comes in. As a result of nuclear bomb tests during the Cold War, large quantities of carbon-14 were put into the oceans. The isotope slowly made its way up the food web and into the bodies of larger animals. Knowing the yearly changes in the amount of carbon-14 in the oceans due to bomb testing, scientists merely had to compare that data with the changes seen in the sharks' bones.</p><p>"We found that one growth ring was definitely deposited every year," <a href="https://www.eurekalert.org/pub_releases/2020-04/aiom-cwn033020.php" target="_blank">said Dr. Mark Meekan</a> of the Australian Institute of Marine Science in Perth, a co-lead on the study. "This is very important, because if you over- or under-estimate growth rates you will inevitably end up with a management strategy that doesn't work, and you'll see the population crash." This means the sharks used in this study were around 35 and 50 years old at the time of their deaths.</p><p>Working forward from there, the scientists were able conclude that the animals may have an age range of 100-150 years. "Earlier modelling studies have suggested that the largest whale sharks may live as long as 100 years," Dr. Meekan explained in <a href="https://www.eurekalert.org/pub_releases/2020-04/aiom-cwn033020.php" target="_blank">a statement</a>. "However, although our understanding of the movements, behaviour, connectivity and distribution of whale sharks have improved dramatically over the last 10 years, basic life history traits such as age, longevity and mortality remain largely unknown. Our study shows that adult sharks can indeed attain great age and that long lifespans are probably a feature of the species. Now we have another piece of the jigsaw added."</p>
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<p>Whale sharks are an interesting species that many eco-tourists want to see. Conservation efforts for them rely on having accurate data on their longevity, mortality rate, and the age of specific animals. This information will help those managing ocean preserves keep the population stable for future generations to enjoy.</p>
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Eating fish may have given Neanderthals brainpower
A new finding suggests Neanderthals were far from the big dumb brutes we make them out to be.
02 April, 2020
Photo by Walt Disney Television via Getty Images
- Scientists have found evidence that the Neanderthals were eating large amounts of fish long before modern humans got to Europe.
- Previously, it was thought that only modern humans were fishing on a large scale.
- The findings show that the Neanderthals were more like us than most people think.
New evidence from a cave in Portugal suggests the Neanderthals were eating fish before modern humans settled Europe. This finding not only changes our understanding of Neanderthals and how they lived but gives further evidence that they were more like us than we tend to imagine.
Nothing fishy about this
<p>An international team explored a cave, known as <a href="https://www.sciencenews.org/article/neandertals-extensive-seafood-menu-rivals-ancient-humans" target="_blank">Figueira Brava</a>, and used uranium-thorium dating to determine the age of excavation layers. The use of the technique allowed the scientists to discover that the layer is between 86,000-106,000 years old, dating back to before modern humans came to Europe.</p><p>Since archaeologists have already found hundreds of fish bones alongside the remains of waterfowl, clams, and dolphins in the cave, the dating suggests that Neanderthals were eating a diverse aquatic diet long before fishing was thought to have been introduced to Europe. While previous investigations had shown that Neanderthals collected shells, including those of edible animals, and used them for making jewelry, this is the first strong evidence that they were actually eating marine animals. </p><p>Filipa Rodrigues, an author of the paper published in <a href="https://www.sciencedaily.com/releases/2020/03/200326144433.htm" target="_blank">Science</a> on the subject, told the <a href="https://www.nytimes.com/2020/03/26/science/neanderthals-fishing-ocean.html" target="_blank">New York Times</a>: "We all have that image of the primitive Neanderthal that eats lots of meat… Now, we have this new perspective that they explored the marine resources like Homo sapiens did."</p>What does eating fish have to do with anything?
<div class="rm-shortcode" data-media_id="YTuKFGRC" data-player_id="FvQKszTI" data-rm-shortcode-id="dccbb5cf80e221bfddb16cb846e8d013"> <div id="botr_YTuKFGRC_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/YTuKFGRC-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/YTuKFGRC-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/YTuKFGRC-FvQKszTI.js"></script> </div> <p>Fish and other types of seafood contain Omega-3 fatty acids, which promotes the growth and development of brain tissue. It has been speculated that the eating of fish may have played a part in the development of early modern humans, giving them the boost in brainpower needed to create symbolic ideas and complex organization.</p><p>Just as eating fish is thought to have helped our immediate ancestors develop their capacity for abstract thought, this finding could explain how Neanderthals were able to function at a similar level. Contrary to popular opinion, Neanderthals were reasonably intelligent. They were able to create fire, had social structures, made cave paintings, built boats, turned seashells into jewelry, used language, and did many other things that anatomically modern humans did.</p><p>Perhaps a diet featuring fish made all of this possible. </p><p> Neanderthals were more human than most people think. This finding shows yet another activity previously thought to be done only by homo-sapiens was also done with regularity by others before our evolutionary cousins died out. While more research is needed to know if this was a widespread behavior or if the cultivation of this much seafood was limited to certain areas, the discovery changes what we thought we knew about our long gone and much maligned cousins. </p>
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