tag:theconversation.com,2011:/uk/topics/sea-otters-29270/articlesSea otters – The Conversation2023-08-18T12:39:21Ztag:theconversation.com,2011:article/2106222023-08-18T12:39:21Z2023-08-18T12:39:21ZMemes about animal resistance are everywhere — here’s why you shouldn’t laugh off rebellious orcas and sea otters too quickly<figure><img src="https://images.theconversation.com/files/543322/original/file-20230817-27-rb0yah.jpg?ixlib=rb-1.1.0&rect=299%2C221%2C3598%2C2428&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's tempting to envision orcas attacking yachts as the forward troops in an animal uprising.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/killer-whale-family-with-yacht-royalty-free-image/1425229306?adppopup=true">Jackson Roberts/iStock via Getty Images Plus</a></span></figcaption></figure><p><a href="https://cheezburger.com/21059333/orca-gangs-are-attacking-yachts-and-the-memes-are-killer">Memes galore</a> centered on the “orca revolution” have inundated the online realm. They gleefully depict orcas launching <a href="https://www.theguardian.com/commentisfree/2023/may/25/orcas-ramming-yachts-spanish-whale-behaviour-trauma-humans">attacks on boats in the Strait of Gibraltar</a> and <a href="https://www.theguardian.com/environment/2023/jun/21/orca-rams-yacht-off-shetland-first-such-incident-northern-waters">off the Shetland coast</a>.</p>
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<p>One particularly ingenious image showcases an orca posed as a sickle crossed with a hammer. The cheeky caption reads, “<a href="https://twitter.com/rhelune/status/1669051456085712907">Eat the rich</a>,” a nod to the orcas’ penchant for sinking lavish yachts.</p>
<p>A <a href="https://www.npr.org/2023/07/13/1187295769/otter-santa-cruz-surfboard-surfers-california">surfboard-snatching sea otter</a> in Santa Cruz, California has also claimed the media spotlight. Headlines dub her an “<a href="https://www.latimes.com/california/newsletter/2023-07-21/otter-841-essential-california-essential-california">adorable outlaw</a>” “<a href="https://www.today.com/video/otter-remains-at-large-after-series-of-surfboard-thefts-188563013674">at large</a>.”</p>
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<a href="https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="black and white image of otter wearing beret next to text 'Accept our existence or expect resistance ... an otter world is possible – Otter 841'" src="https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=567&fit=crop&dpr=1 754w, https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=567&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/543052/original/file-20230816-27-mcay7s.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=567&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Memes position the otter as a renegade revolutionary, modeled on Ché Guevara.</span>
<span class="attribution"><a class="source" href="https://www.instagram.com/p/Cu7L_O4L0GC/">thesurfingotter via Instagram</a></span>
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<p>Memes conjure her in a beret like the one donned by socialist revolutionary Ché Guevara. In one caption, she proclaims, “<a href="https://www.instagram.com/p/Cu7L_O4L0GC/">Accept our existence or expect resistance</a> … an otter world is possible.”</p>
<p><a href="https://literature.ucsd.edu/people/faculty/emeriti/aisfahanihammond.html">My scholarship</a> centers on animal-human relations through the prism of social justice. As I see it, public glee about wrecked surfboards and yachts hints at a certain flavor of <a href="https://www.britannica.com/topic/schadenfreude">schadenfreude</a>. At a time marked by drastic socioeconomic disparities, white supremacy and environmental degradation, casting these marine mammals as revolutionaries seems like a projection of desires for social justice and habitable ecosystems.</p>
<p>A glimpse into the work of some political scientists, philosophers and animal behavior researchers injects weightiness into this jocular public dialogue. The <a href="https://doi.org/10.4324/9780203797631">field of critical animal studies</a> analyzes structures of oppression and power and considers pathways to dismantling them. These scholars’ insights challenge the prevailing view of nonhuman animals as passive victims. They also oppose the widespread assumption that nonhuman animals can’t be political actors.</p>
<p>So while meme lovers project emotions and perspectives onto these particular wild animals, scholars of critical animal studies suggest that nonhuman animals do in fact engage in resistance. </p>
<h2>Nonhuman animal protest is everywhere</h2>
<p>Are nonhuman animals in a constant state of defiance? I’d answer, undoubtedly, that the answer is yes. </p>
<p>The entire architecture of animal agriculture <a href="https://brill.com/display/title/32110?language=en">attests to animals’ unyielding resistance</a> against confinement and death. Cages, corrals, pens and tanks would not exist were it not for animals’ tireless revolt. </p>
<p>Even when hung upside down on conveyor hangars, <a href="https://brill.com/display/title/32110?language=enthe">chickens furiously flap their wings and bite</a>, scratch, peck and defecate on line workers at every stage of the process leading to their deaths.</p>
<p>Until the end, hooked tuna resist, gasping and writhing fiercely on ships’ decks. Hooks, nets and snares would not be necessary <a href="https://doi.org/10.5130/csr.v22i1.4363">if fish allowed themselves to be passively harvested</a>.</p>
<p><a href="https://doi.org/10.1111/j.1527-2001.1991.tb00213.x">If they consented to repeated impregnation</a>, female pigs and cows wouldn’t need to be tethered to “<a href="https://www.forbes.com/sites/jamesmcwilliams/2013/10/25/milk-of-human-kindness-denied-to-dairy-cows/">rape racks</a>” to prevent them from struggling to get away. </p>
<p>If they didn’t mind having their <a href="https://press.uchicago.edu/ucp/books/book/chicago/C/bo28907793.html">infants permanently taken from their sides</a>, dairy cows wouldn’t need to be blinded with hoods so they don’t bite and kick as the calves are removed; they wouldn’t bellow for weeks after each instance. I contend that failure to recognize their bellowing as protest reflects “<a href="https://www.jstor.org/stable/43154308">anthropodenial</a>” – what <a href="https://www.britannica.com/science/ethology">ethologist</a> Frans de Waal calls the rejection of obvious continuities between human and nonhuman animal behavior, cognition and emotion.</p>
<p>The prevalent view of nonhuman animals remains that of René Descartes, the 17th-century philosopher who <a href="https://doi.org/10.1093/oso/9780199375967.003.0013">viewed animals’ actions as purely mechanical</a>, like those of a machine. From this viewpoint, one might dismiss these nonhuman animals’ will to prevail as unintentional or merely instinctual. But political scientist Dinesh Wadiwel argues that “even if their defiance is futile, the <a href="https://brill.com/display/title/32110?language=en">will to prefer life over death is a primary act of resistance</a>, perhaps the only act of dissent available to animals who are subject to extreme forms of control.”</p>
<h2>Creaturely escape artists</h2>
<p>Despite humans’ colossal efforts to repress them, nonhuman animals still manage to <a href="https://yalebooks.yale.edu/book/9780300192483/every-twelve-seconds/">escape from slaughterhouses</a>. They also break out <a href="https://content.time.com/time/specials/packages/completelist/0,29569,2041628,00.html">of zoos</a>, circuses, aquatic parks, <a href="https://www.nj.com/union/2015/07/watch_21_horses_escape_watchung_stables_roam.html">stables</a> and <a href="https://www.sciencealert.com/how-a-team-of-baboons-hitched-a-brilliant-plan-to-escape-a-research-lab-in-texas-texas-biomedical-testing-barrel">biomedical laboratories</a>. Tilikum, a captive orca at Sea World, <a href="https://www.akpress.org/fear-of-the-animal-planet-e-book.html">famously killed his trainer</a> – an act at least one marine mammal behaviorist <a href="https://www.orlandosentinel.com/2010/03/07/how-smart-are-killer-whales-and-can-they-decide-to-kill-a-person/">characterized as intentional</a>.</p>
<p>Philosopher Fahim Amir suggests that depression among captive animals is likewise a form of emotional rebellion against unbearable conditions, <a href="https://btlbooks.com/book/being-and-swine">a revolt of the nerves</a>. Dolphins engage in self-harm like thrashing against the tank’s walls or cease to eat and <a href="https://www.theguardian.com/environment/2014/jun/08/the-dolphin-who-loved-me">retain their breath until death</a>. Sows whose body-sized cages impede them from turning around to make contact with their piglets <a href="https://btlbooks.com/book/being-and-swine">repeatedly ram themselves</a> into the metal struts, <a href="https://doi.org/10.1093/pastj/gtu015">sometimes succumbing to their injuries</a>.</p>
<p>Critical animal studies scholars contend that all these actions arguably demonstrate nonhuman animals’ yearning for freedom and <a href="https://press.uchicago.edu/ucp/books/book/chicago/W/bo6407651.html">their aversion</a> <a href="https://www.press.jhu.edu/books/title/9383/chimpanzee-politics">to inequity</a>.</p>
<p>As for the marine stars of summer 2023’s memes, fishing gear can <a href="https://www.theguardian.com/commentisfree/2023/may/25/orcas-ramming-yachts-spanish-whale-behaviour-trauma-humans">entangle and harm orcas</a>. Sea otters were <a href="https://www.nationalgeographic.com/animals/mammals/facts/sea-otter">hunted nearly to extinction for their fur</a>. <a href="https://oceanconservationtrust.org/ocean-advocacy/think-ocean/ways-to-think-ocean/">Marine habitats have been degraded</a> by human activities including overfishing, oil spills, plastic, chemical and sonic pollution, and climate change. It’s easy to <a href="https://www.theguardian.com/commentisfree/2023/may/25/orcas-ramming-yachts-spanish-whale-behaviour-trauma-humans">imagine they might be responding to human actions</a>, including bodily harm and interference with their turf.</p>
<h2>What is solidarity with nonhuman animals?</h2>
<p>Sharing memes that <a href="https://www.instagram.com/p/Cu-2mxcRkpz/">cheer on wild animals</a> is one thing. But there are more substantive ways to demonstrate solidarity with animals.</p>
<p>Legal scholars support nonhuman animals’ resistance by proposing that their current classification as property should be replaced with that of <a href="https://tupress.temple.edu/books/animals-property-and-the-law">personhood</a> or <a href="https://utorontopress.com/9781487525873/animals-as-legal-beings/">beingness</a>.</p>
<p>Nonhuman animals including songbirds, dolphins, <a href="https://www.nonhumanrights.org/wp-content/uploads/Happy-Brief.pdf">elephants</a>, horses, <a href="https://www.animallaw.info/case/suica-habeas-corpus">chimpanzees</a> and <a href="https://changingtimes.media/2017/08/03/habeas-corpus-victory-for-bear-in-colombia-encourages-animal-rights-lawyers/">bears</a> increasingly <a href="https://ssrn.com/abstract=4387696">appear as plaintiffs</a> alleging their subjection to extinction, abuse and other injustices.</p>
<p><a href="https://global.oup.com/academic/product/zoopolis-9780199599660">Citizenship for nonhuman animals</a> is another pathway to social and political inclusion. It would guarantee the right to appeal arbitrary restrictions of domesticated nonhuman animals’ autonomy. It would also mandate legal duties to protect them from harm.</p>
<p>Everyday deeds can likewise convey solidarity.</p>
<p>Boycotting industries that oppress nonhuman animals by becoming vegan is a powerful action. It is a form of political “counter-conduct,” a term philosopher Michel Foucault uses to describe <a href="https://doi.org/10.1057/978-1-137-52120-0_7">practices that oppose dominant norms</a> of power and control.</p>
<p>Creating <a href="http://www.lawatsonart.com/the-roadside-memorial-project.html">roadside memorials for nonhuman animals</a> killed by motor vehicles encourages people to see them as beings whose lives and <a href="https://www.routledge.com/Economies-of-Death-Economic-logics-of-killable-life-and-grievable-death/Lopez-Gillespie/p/book/9780367599331">deaths matter</a>, <a href="https://www.amandastronza.com/passions#:%7E:text=I%20began%20creating%20memorials%2C%20not,seeds%2C%20weeds%2C%20and%20grasses">rather than mere “roadkill</a>.”</p>
<p>Political scientists recognize that human and nonhuman animals’ <a href="https://doi.org/10.1017/CBO9781107045392">struggles against oppression are intertwined</a>. At different moments, the <a href="https://hemisphericinstitute.org/en/emisferica-101/10-1-dossier/akbar-stole-my-heart-coming-out-as-an-animalist.html">same strategies</a> leveraged against nonhuman animals have <a href="https://theconversation.com/when-trump-calls-someone-a-dog-hes-tapping-into-ugly-history-128589">cast segments of the human species as “less than human”</a> in order to exploit them.</p>
<p>The category of the human is <a href="https://press.uchicago.edu/ucp/books/book/chicago/A/bo3622788.html">ever-shifting and ominously exclusive</a>. I argue that no one is safe as long as there is a <a href="https://doi.org/10.2307/300203">classification of “animality.”</a> It confers <a href="https://english.elpais.com/society/2022-12-04/how-nazi-propaganda-dehumanized-jews-to-facilitate-the-holocaust.html">susceptibility to extravagant forms of violence</a>, legally and ethically condoned.</p>
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<figcaption><span class="caption">Otter 841 is the wild sea otter off Santa Cruz, California, who some observers suspect has had it with surfers in her turf.</span></figcaption>
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<h2>Might an ‘otter world’ be possible?</h2>
<p>I believe quips about the marine mammal rebellion reflect awareness that our human interests are entwined with those of nonhuman animals. The desire to achieve sustainable relationships with other species and the natural world feels palpable to me within the memes and media coverage. And it’s happening as human-caused activity makes our shared habitats increasingly unlivable. </p>
<p>Solidarity with nonhuman animals is consistent with democratic principles – for instance, defending the right to well-being and opposing the <a href="https://www.worldcat.org/title/8481629">use of force against innocent subjects</a>. Philosopher Amir recommends extending the idea that there can be no freedom as long as there is still unfreedom beyond the species divide: “While we may not yet fully be able to picture what this may mean, <a href="https://btlbooks.com/book/being-and-swine">there is no reason we should not begin to imagine it</a>”.</p><img src="https://counter.theconversation.com/content/210622/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexandra Isfahani-Hammond does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A few marine mammals in apparent revolt pushed meme-makers into overdrive. But a scholar who thinks about justice and human-animal relations suggests something deeper is behind the schadenfreude.Alexandra Isfahani-Hammond, Associate Professor Emerita of Comparative Literature, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1658042021-12-02T13:42:06Z2021-12-02T13:42:06ZSea otters demonstrate that there is more to muscle than just movement – it can also bring the heat<figure><img src="https://images.theconversation.com/files/432004/original/file-20211115-21-1852gim.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5472%2C3637&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sea otters are born with a supercharged metabolism.
</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/cute-sea-otter-making-a-splash-royalty-free-image/1304610196">Adria Photography/Moment via Getty Images</a></span></figcaption></figure><p>Life in the cold can be difficult for animals. As the body chills, organs including the brain and muscles slow down. </p>
<p>The body temperature of animals such as reptiles and amphibians mostly depends on the temperature of their environment – but mammals can increase their metabolism, using more energy to warm their body. This allows them to <a href="https://doi.org/10.1146/annurev.ph.57.030195.000441">live in colder areas and stay active when temperatures drop</a> at night or during winter months. </p>
<p>Although scientists know mammals can increase their metabolism in the cold, it has not been clear which organs or tissues are using this extra energy to generate more heat. Staying warm is especially challenging for small, aquatic mammals like sea otters, so we wanted to know how they have adapted to survive the cold. </p>
<p>We assembled <a href="https://scholar.google.com/citations?hl=en&user=j27jLwUAAAAJ">a</a> <a href="https://scholar.google.com/citations?hl=en&user=oWs13ikAAAAJ">research</a> <a href="https://scholar.google.com/citations?hl=en&user=-BQkMmoAAAAJ">team</a> with expertise in both human and marine mammal metabolism, including <a href="https://scholar.google.com/citations?hl=en&user=hsiWIEEAAAAJ">Heidi Pearson</a> of the University of Alaska Southeast and <a href="https://scholar.google.com/citations?hl=en&user=G3AiPisAAAAJ">Mike Murray</a> of the Monterey Bay Aquarium. Understanding energy use in animals adapted to life in the cold may also provide clues for manipulating human metabolism.</p>
<h2>Sea otter metabolism</h2>
<p>It is especially difficult for water-living mammals to stay warm because <a href="https://doi.org/10.1080/23328940.2021.1988817">water conducts heat away from the body much faster than air</a>. Most marine mammals have large bodies and a thick layer of fat or <a href="https://doi.org/10.1080/23328940.2021.1988817">blubber for insulation</a>. </p>
<p>Sea otters are the smallest of the marine mammals, and do not have this thick layer of blubber. Instead, they are insulated by the densest fur of any mammal, with as many as <a href="https://doi.org/10.1111/j.1748-7692.1992.tb00120.x">a million hairs per square inch</a>. This fur, however, is high maintenance, requiring <a href="https://www.youtube.com/watch?v=sgFMVRtkpVY&list=PLq_DVMr7CmlIb0n3DhtcU8lESsxX-wqP7&index=2">regular grooming</a>. About 10% of a sea otter’s <a href="https://doi.org/10.1242/jeb.02767">daily activity</a> involves maintaining the insulating layer of air trapped in their fur.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/Z4OKk2lErwc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Grooming is a never-ending job.</span></figcaption>
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<p>Dense fur is not enough, by itself, to keep sea otters warm. To generate enough body heat, their metabolic rate at rest is <a href="https://link.springer.com/book/10.1007%2F978-3-319-98280-9">about three times higher</a> than that of most mammals of similar size. This high metabolic rate has a cost, though.</p>
<p>To obtain enough energy to fuel the high demand, sea otters must eat <a href="https://doi.org/10.1086/physzool.55.1.30158441">more than 20% of their body mass</a> in food each day. In comparison, humans eat around 2% of their body mass – about <a href="https://doi.org/10.1079/BJN19810074">3 pounds (1.3 kilograms) of food per day</a> for a 155-pound (70 kg) person.</p>
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<a href="https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sea otter floating on its back eating a crab." src="https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432007/original/file-20211115-17-rlq9ul.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Feeding on Dungeness crab in Monterey Bay, California.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/sea-otter-and-crab-royalty-free-image/1209955271">Chase Dekker Wild-Life Images/Moment via Getty Images</a></span>
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</figure>
<h2>Where does the heat come from?</h2>
<p>When animals eat, the energy in their food cannot be used directly by cells to do work. Instead, the food is broken down into simple nutrients, such as fats and sugars. These nutrients are then transported in the blood and absorbed by cells. </p>
<p>Within the cell are compartments called mitochondria where nutrients are converted into <a href="https://www.nature.com/scitable/definition/atp-318/">ATP</a> – a high-energy molecule that acts as the energy currency of the cell. </p>
<p>The process of converting nutrients into ATP is similar to <a href="https://www.usgs.gov/special-topic/water-science-school/science/hydroelectric-power-how-it-works?qt-science_center_objects=0#qt-science_center_objects">how a dam turns stored water into electricity</a>. As water flows out from the dam, it makes electricity by spinning blades connected to a generator – similar to wind turning the blades on a windmill. If the dam is leaky, some water – or stored energy – is lost and cannot be used to make electricity.</p>
<p>Similarly, leaky mitochondria are less efficient at making ATP from nutrients. Although the leaked energy in the mitochondria cannot be used to do work, it generates heat to warm the sea otter’s body.</p>
<p><a href="https://doi.org/10.1152/physrev.1997.77.3.731">All tissues in the body use energy and make heat</a>, but some tissues are larger and more active than others. Muscle makes up 30% of the body mass of most mammals. When active, muscles consume a lot of energy and produce a lot of heat. You have undoubtedly experienced this, whether getting hot during exercise or <a href="https://theconversation.com/its-cold-a-physiologist-explains-how-to-keep-your-body-feeling-warm-108816">shivering when cold</a>. </p>
<p>To find out if muscle metabolism helps keep sea otters warm, we studied small muscle samples from sea otters ranging in size and age from newborn pups to adults. We placed the muscle samples in small chambers designed to monitor oxygen consumption – a measure of how much energy is used. By adding different solutions that stimulated or inhibited various metabolic processes, we determined how much energy the mitochondria could use to make ATP – and how much energy could go into heat-producing leak. </p>
<p>We discovered the mitochondria in <a href="https://doi.org/10.1126/science.abf4557">sea otter muscles could be very leaky</a>, allowing otters to turn up the heat in their muscles without physical activity or shivering. It turns out that sea otter muscle is good at being inefficient. The energy “lost” as heat while turning nutrients into movement allows them to survive the cold.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sea otter floats on her back, feeding her pup small bits of food." src="https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=410&fit=crop&dpr=1 600w, https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=410&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=410&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=516&fit=crop&dpr=1 754w, https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=516&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/431999/original/file-20211115-17-1g2znp7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=516&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A mother sea otter ‘hand-feeds’ her baby bits of crab. Moro Bay, California.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/feeding-baby-dinner-royalty-free-image/582228357">PhotoviewPlus/Moment Open via Getty Images</a></span>
</figcaption>
</figure>
<p>Remarkably, we found newborn pups have the same metabolic ability as adults, even though their muscles have not yet matured for swimming and diving. </p>
<h2>Broader implications</h2>
<p>Our research clearly demonstrates that muscle is important for more than just movement. Because muscle makes up such a large portion of body mass, even a small increase in muscle metabolism can dramatically increase how much energy an animal uses. </p>
<p>[<em>More than 140,000 readers get one of The Conversation’s informative newsletters.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140K">Join the list today</a>.]</p>
<p>This has important implications for human health. If scientists discover ways to safely and reversibly increase skeletal muscle metabolism at rest, doctors could possibly use this as a tool to reduce climbing rates of obesity by increasing the amount of calories a patient can burn. Conversely, reducing skeletal muscle metabolism could conserve energy in patients suffering from cancer or other wasting diseases and could reduce food and resources needed to support astronauts on long-duration spaceflight.</p><img src="https://counter.theconversation.com/content/165804/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Randall Davis has received research funding from the National Science Foundation and NOAA.</span></em></p><p class="fine-print"><em><span>Melinda Sheffield-Moore and Traver Wright do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research finds that ‘leaky mitochondria’ help keep sea otters warm.Traver Wright, Research Assistant Professor of Health and Kinesiology, Texas A&M UniversityMelinda Sheffield-Moore, Professor of Health and Kinesiology, Texas A&M UniversityRandall Davis, Regents Professor, Department of Marine Biology, Texas A&M UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1088722019-04-17T10:54:24Z2019-04-17T10:54:24ZSea creatures store carbon in the ocean – could protecting them help slow climate change?<figure><img src="https://images.theconversation.com/files/269377/original/file-20190415-147502-15sm3nq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A sperm whale goes down for a dive off Kaikoura, New Zealand. </span> <span class="attribution"><span class="source">Heidi Pearson</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>As the prospect of catastrophic effects from climate change becomes increasingly likely, a search is on for innovative ways to reduce the risks. One potentially powerful and low-cost strategy is to recognize and protect natural carbon sinks – places and processes that store carbon, keeping it out of Earth’s atmosphere.</p>
<p><a href="https://theconversation.com/forests-gain-long-awaited-recognition-in-paris-climate-summit-52238">Forests</a> and <a href="https://theconversation.com/what-the-world-needs-now-to-fight-climate-change-more-swamps-99198">wetlands</a> can capture and store large quantities of carbon. These ecosystems are included in climate change adaptation and mitigation strategies that <a href="https://climatefocus.com/sites/default/files/20181203_Article%206%20and%20Coastal%20Blue%20Carbon.pdf">28 countries have pledged to adopt to fulfill the Paris Climate Agreement</a>. So far, however, no such policy has been created to protect carbon storage in the ocean, which is Earth’s largest carbon sink and a central element of our planet’s climate cycle. </p>
<p>As a marine biologist, my research focuses on <a href="https://scholar.google.com/citations?user=hsiWIEEAAAAJ&hl=en">marine mammal behavior, ecology and conservation</a>. Now I also am studying how climate change is affecting marine mammals – and how marine life could become part of the solution. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269395/original/file-20190415-147487-1g3qy2d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A sea otter rests in a kelp forest off California. By feeding on sea urchins, which eat kelp, otters help kelp forests spread and store carbon.</span>
<span class="attribution"><span class="source">Nicole LaRoche</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>What is marine vertebrate carbon?</h2>
<p>Marine animals can sequester carbon through a range of natural processes that include storing carbon in their bodies, excreting carbon-rich waste products that sink into the deep sea, and fertilizing or protecting marine plants. In particular, scientists are beginning to recognize that vertebrates, such as fish, seabirds and marine mammals, have the potential to help lock away carbon from the atmosphere. </p>
<p>I am currently working with colleagues at <a href="http://www.grida.no/activities/193">UN Environment/GRID-Arendal</a>, a United Nations Environment Programme center in Norway, to identify mechanisms through which marine vertebrates’ natural biological processes may be able to help mitigate climate change. So far we have found <a href="http://grid-arendal.maps.arcgis.com/apps/Cascade/index.html?appid=05f6dc47c20a41d8a0df68c0c99cc2f2">at least nine examples</a>.</p>
<p>One of my favorites is Trophic Cascade Carbon. <a href="https://www.britannica.com/science/trophic-cascade">Trophic cascades</a> occur when change at the top of a food chain causes downstream changes to the rest of the chain. As an example, sea otters are top predators in the North Pacific, feeding on sea urchins. In turn, sea urchins eat kelp, a brown seaweed that grows on rocky reefs near shore. Importantly, kelp stores carbon. Increasing the number of sea otters reduces sea urchin populations, which <a href="http://max2.ese.u-psud.fr/epc/conservation/PDFs/HIPE/Estes1995.pdf">allows kelp forests to grow</a> and trap more carbon. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269397/original/file-20190415-147525-1bfmv5r.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Scientists have identified nine mechanisms through which marine vertebrates play roles in the oceanic carbon cycle.</span>
<span class="attribution"><a class="source" href="http://www.grida.no/resources/12674">GRID Arendal</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Carbon stored in living organisms is called Biomass Carbon, and is found in all marine vertebrates. Large animals such as whales, which may weigh up to 50 tons and live for over 200 years, can store large quantities of carbon for long periods of time. </p>
<p>When they die, their carcasses sink to the seafloor, bringing a lifetime of trapped carbon with them. This is called Deadfall Carbon. On the deep seafloor, it can be eventually buried in sediments and potentially locked away from the atmosphere for millions of years.</p>
<p>Whales can also help to trap carbon by stimulating production of tiny marine plants called phytoplankton, which use sunlight and carbon dioxide to make plant tissue just like plants on land. The whales feed at depth, then release buoyant, nutrient-rich fecal plumes while resting at the surface, which can fertilize phytoplankton in a process that marine scientists call the <a href="https://doi.org/10.1371/journal.pone.0013255">Whale Pump</a>. </p>
<p>And whales redistribute nutrients geographically, in a sequence we refer to as the <a href="https://doi.org/10.1890/130220">Great Whale Conveyor Belt</a>. They take in nutrients while feeding at high latitudes then release these nutrients while fasting on low-latitude breeding grounds, which are typically nutrient-poor. Influxes of nutrients from whale waste products such as urea can help to stimulate phytoplankton growth.</p>
<p>Finally, whales can bring nutrients to phytoplankton simply by swimming throughout the water column and mixing nutrients towards the surface, an effect researchers term <a href="http://dx.doi.org/10.5194/bgd-9-8387-2012">Biomixing Carbon</a>.</p>
<p>Fish poo also plays a role in trapping carbon. Some fish migrate up and down through the water column each day, swimming toward the surface to feed at night and descending to deeper waters by day. Here they release carbon-rich fecal pellets that can sink rapidly. This is called Twilight Zone Carbon. </p>
<p>These fish may descend to depths of 1,000 feet or more, and their fecal pellets can sink even farther. Twilight Zone Carbon can potentially be locked away for tens to hundreds of years because it takes a long time for water at these depths to recirculate back towards the surface. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Lt8rDz0vx2o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">‘Marine snow’ is made up of fecal pellets and other bits of organic material that sink into deep ocean waters, carrying large quantities of carbon into the depths.</span></figcaption>
</figure>
<h2>Quantifying marine vertebrate carbon</h2>
<p>To treat “blue carbon” associated with marine vertebrates as a carbon sink, scientists need to measure it. One of the first studies in this field, published in 2010, described the Whale Pump in the Southern Ocean, estimating that a historic pre-whaling population of 120,000 sperm whales could have trapped <a href="https://doi.org/10.1098/rspb.2010.0863">2.2 million tons of carbon yearly through whale poo</a>. </p>
<p>Another 2010 study calculated that the global pre-whaling population of approximately 2.5 million great whales would have exported <a href="https://doi.org/10.1371/journal.pone.0012444">nearly 210,000 tons of carbon per year to the deep sea through Deadfall Carbon</a>. That’s equivalent to <a href="https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator">taking roughly 150,000 cars off the road each year</a>. </p>
<p>A 2012 study found that by eating sea urchins, sea otters could potentially help to trap <a href="https://doi.org/10.1890/110176">150,000 to 22 million tons of carbon per year</a> in kelp forests. Even more strikingly, a 2013 study described the potential for lanternfish and other Twilight Zone fish off the western U.S. coast to store <a href="https://doi.org/10.1016/j.pocean.2013.05.013">over 30 million tons of carbon per year in their fecal pellets</a>. </p>
<p>Scientific understanding of marine vertebrate carbon is still in its infancy. Most of the carbon-trapping mechanisms that we have identified are based on limited studies, and can be refined with further research. So far, researchers have examined the carbon-trapping abilities of less than 1% of all marine vertebrate species. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/269400/original/file-20190415-147483-1o7d30r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The brownish water at the base of this humpback whale’s fluke is a fecal plume, which can fertilize phytoplankton near the surface. Photo taken under NMFS permit 10018-01.</span>
<span class="attribution"><span class="source">Heidi Pearson</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>A new basis for marine conservation</h2>
<p>Many governments and organizations around the world are working to rebuild global fish stocks, prevent bycatch and illegal fishing, reduce pollution and establish marine protected areas. If we can recognize the value of marine vertebrate carbon, many of these policies could qualify as climate change mitigation strategies. </p>
<p>In a step in this direction, the International Whaling Commission passed two resolutions in 2018 that recognized <a href="https://news.grida.no/international-endorsement-of-whale-carbon">whales’ value for carbon storage</a>. As science advances in this field, protecting marine vertebrate carbon stocks ultimately might become part of national pledges to fulfill the Paris Agreement. </p>
<p>Marine vertebrates are valuable for many reasons, from maintaining healthy ecosystems to providing us with a sense of awe and wonder. Protecting them will help ensure that the ocean can continue to provide humans with food, oxygen, recreation and natural beauty, as well as carbon storage. </p>
<p><em>Steven Lutz, Blue Carbon Programme leader at GRID-Arendal, contributed to this article.</em></p><img src="https://counter.theconversation.com/content/108872/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heidi Pearson received funding from the US-Norway Fulbright Foundation for Educational Exchange to support the research and writing of this article. </span></em></p>Protecting forests and wetlands, which absorb and store carbon, is one way to slow climate change. Scientists are proposing similar treatment for marine animals that help store carbon in the oceans.Heidi Pearson, Associate Professor of Marine Biology, University of Alaska SoutheastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/931332018-04-17T20:10:52Z2018-04-17T20:10:52ZCurious Kids: Why do sea otters clap?<figure><img src="https://images.theconversation.com/files/211304/original/file-20180321-165577-148pjsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Mai Lam/The Conversation NY-BD-CC</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky!</em> </p>
<hr>
<blockquote>
<p><strong>Why do sea otters clap? Is it fun? – Alex, age 5, Melbourne.</strong></p>
</blockquote>
<p>Hi Alex. Those are some great questions. Sea otters are one of my favourite animals.</p>
<p>Something we have to ask ourselves when trying to work out why an animal does something is whether or not the behaviour is natural. </p>
<p>If you’ve been lucky enough to observe a sea otter clapping in a zoo or aquarium, you might have been watching an animal that has been trained to clap by its human keepers.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/PtrAIFgsbOw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Sea otters can sometimes be taught to clap in zoos and aquariums.</span></figcaption>
</figure>
<p>But what about wild sea otters? Do they clap too, and if so, what might it be for? </p>
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<p>
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Read more:
<a href="https://theconversation.com/imagine-this-a-new-podcast-tackling-tricky-questions-from-inquisitive-young-minds-94659">Imagine This: a new podcast tackling tricky questions from inquisitive young minds</a>
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</em>
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<hr>
<h2>How do wild sea otters use their hands?</h2>
<p>Sea otters are fascinating creatures. They are air-breathing mammals and yet spend almost their entire lives at sea. They swim mostly with their back feet, which leaves their hands free to do other things while swimming about. </p>
<p>In the wild, sea otters sleep out on the water. To stop themselves drifting away in their sleep, they use their hands to hold onto seaweed (or each other), creating a raft of animals floating together. When resting during the day, they’ve even been seen covering their eyes with their paws to help them sleep. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213974/original/file-20180410-114092-1qbdogu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sea otters sometimes hold hands while floating.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Sea_otters_holding_hands.jpg">Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Sea otters also use their paws to groom their fur. They have one of the thickest fur coats of any animal, which helps them to keep warm in the freezing waters of the North Pacific Ocean. To keep their coat healthy, they use their hands to rub down their fur, trapping air against their skin to stay warm and dry. This can look like clapping their hands against their sides. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/213976/original/file-20180410-114076-1is8d7k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sea otters groom with their hands.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Sea-otter-grooming.jpg">Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/pnO11Mm9XNM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Sea otters sometimes clap their hands wild grooming their fur.</span></figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-dont-dogs-live-as-long-as-humans-93374">Curious Kids: Why don't dogs live as long as humans?</a>
</strong>
</em>
</p>
<hr>
<p>But the most interesting thing sea otters do with their paws happens while feeding. After catching hard-shelled prey like shellfish or sea urchins, sea otters will break open the shell by hitting it against a stone resting on their belly. Otters have even been known to have a favourite stone that they carry around in their armpits. As well as looking like they are clapping when doing this, you can even hear the “clap” sound of the hard shell hitting the stone! </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Uc7Ahp5--eE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>So, even for wild sea otters, “clapping” may play a useful role in both grooming their fur and preparing their food.</p>
<p>Is clapping fun though? Hopefully, one day you will meet some sea otters and you can ask them yourself.</p>
<hr>
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<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age, and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/93133/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Hocking does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Sea otters can break the shell on a shellfish by hitting it against a stone resting on their belly. This can look like clapping. Some even have a favourite stone they carry around in their armpits.David Hocking, Research associate, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/831562017-08-29T23:00:52Z2017-08-29T23:00:52ZOtter Tupperware party we threw reveals how animals copy each other to learn<figure><img src="https://images.theconversation.com/files/183731/original/file-20170829-10418-sjhf44.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Sea otters don’t just make good subjects for photos to share on social media. They’re also very smart. For example, unlike most animals, they make use of tools, namely rocks to break open shellfish and clams.</p>
<p>One question that has fascinated scientists is whether otters have an innate tendency to bash rocks and clams together or if they learn the practice from their mothers. A <a href="http://rsbl.royalsocietypublishing.org/content/13/3/20160880">recent study</a> indicated that sea otters have been using tools for thousands of years and suggests that <a href="http://www.smithsonianmag.com/smithsonian-institution/unlike-dolphis-sea-otters-use-tools-are-not-closely-related-180962716/">this ability is probably innate</a>.</p>
<p>But not all sea otters use tools. A <a href="https://academic.oup.com/beheco/article-abstract/doi/10.1093/beheco/arx011/4001444/Food-abundance-prey-morphology-and-diet?redirectedFrom=fulltext">study of what factors predict their tool use</a> found that – besides sex, age, feeding habitats and availability of prey – learning from their mother may also contribute to a sea otter’s tool use. But whether sea otters or any of the other 12 otter species are actually capable of learning from others was still unknown.</p>
<p>To address this question, my colleagues Zosia Ladds, William Hoppitt and I investigated whether otters can solve problems by watching and copying each other, exhibiting what’s known as “social learning”. <a href="http://rsos.royalsocietypublishing.org/lookup/doi/10.1098/rsos.170489">Our results</a>, published in the journal Royal Society Open Science, suggest that some otters can indeed learn from each other but that not all species do.</p>
<p>This could have important implications for conservation. If we could find a way to make use of this learning ability among captive otters, it might help increase their chances of survival in nature.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/183783/original/file-20170829-10424-9gjy0d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/183783/original/file-20170829-10424-9gjy0d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/183783/original/file-20170829-10424-9gjy0d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/183783/original/file-20170829-10424-9gjy0d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/183783/original/file-20170829-10424-9gjy0d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/183783/original/file-20170829-10424-9gjy0d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/183783/original/file-20170829-10424-9gjy0d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Smooth-coated otters: here’s how you do it.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Our investigation involved two otter species that, unlike the sea otter, are available to study in zoos and wildlife centres across the UK: smooth-coated otters and Asian short-clawed otters. Both species live in family groups in the wild, but limited field observations suggest that they have different feeding habits. <a href="https://academic.oup.com/mspecies/article-lookup/doi/10.1644/786.1">While smooth-coated otters hunt cooperatively for fish</a>, <a href="http://www.iucnredlist.org/details/44166/0">Asian short-clawed otters seem to forage mostly individually for crabs and shellfish</a>.</p>
<p>To test whether these otters could learn how to find food from other group members, we presented captive groups with a battery of food puzzles. These puzzles consisted of Tupperware containers of different shapes and sizes baited with otter treats including fish (heads), peanuts, mealworms, chick legs and shrimp.</p>
<p>While most of us can probably open a Tupperware container blindfolded, this is a challenging task for otters. One otter took over three hours to screw a lid off a cylindrical Tupperware container. But the majority of the otters solved most puzzles within 20 minutes.</p>
<h2>Social problem solving</h2>
<p>We found that, among the smooth-coated otters, those individuals that spent most time together were also most likely to start solving the puzzles together. In other words, the puzzle solutions spread along the smooth-coated otters’ social network, indicating that they were copying each other.</p>
<p>We also found evidence for a “copy when young” strategy in this species. The offspring in this group were more than six times faster than their parents to solve the tasks. Our data suggest that these youngsters were good at copying their siblings as well as learning from their own experiences with the tasks.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/183784/original/file-20170829-10414-1f2qk0y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/183784/original/file-20170829-10414-1f2qk0y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/183784/original/file-20170829-10414-1f2qk0y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/183784/original/file-20170829-10414-1f2qk0y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/183784/original/file-20170829-10414-1f2qk0y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/183784/original/file-20170829-10414-1f2qk0y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/183784/original/file-20170829-10414-1f2qk0y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Asian short-clawed otters: I don’t care what he’s doing.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Our data on the Asian short-clawed otters presented a very different picture. We found no evidence that these otters learned from each other to solve the tasks. </p>
<p>This finding makes sense if we consider the animals’ natural history. If they tend to forage on their own in the wild, Asian short-clawed otters may be less inclined to turn to each other for foraging information than the group-hunting smooth-coated otter.</p>
<p>Both species used to be widespread in South and South-East Asia but their global populations have declined by more than 30% in the past 30 years <a href="http://www.otter.org/Public/Default.aspx">due to major habitat loss and poaching</a>. As a result, both <a href="http://www.iucnredlist.org/details/12427/0">smooth-coated otters</a> and <a href="http://www.iucnredlist.org/about/overview">Asian short-clawed otters</a> now have “vulnerable” status on the <a href="http://www.iucnredlist.org/about/overview#introduction">International Union for Conservation of Nature (IUCN) Red List of Threatened Species</a>.</p>
<p>We hope that understanding more about how and from whom otters learn may help conservation efforts. We need to know if captive-bred individuals that are released into the wild will copy their wild counterparts to acquire the life skills they need to face new predators such as dogs and other human threats, as well as learning to catch live prey.</p>
<p>It may be that some otters can act as particularly effective role models to spread successful coping mechanisms in wild populations and increase their chances of survival. But first we need to know whether wild populations show similar social learning tendencies to those we observed in captivity. This will be a challenging endeavour given that it’s increasingly rare to spot one of these fascinating creatures in the wild.</p><img src="https://counter.theconversation.com/content/83156/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Neeltje Boogert receives funding from The Royal Society. This study was funded by an Association for the Study of Animal Behaviour Undergraduate Project Scholarship to Zosia Ladds.</span></em></p>New research suggests otters’ learning ability could help captive animals to thrive in the wild.Neeltje Boogert, Royal Society Dorothy Hodgkin Research Fellow, University of ExeterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/803622017-07-02T15:24:16Z2017-07-02T15:24:16ZOcean life: 5 essential reads<figure><img src="https://images.theconversation.com/files/176467/original/file-20170630-22491-19u8axr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Great white photobomb.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/usoceangov/18604997632/in/album-72157653831502969/">George T. Probst/NOAA/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>If you’re spending this holiday weekend at the beach or headed there later this summer, take a moment to consider how many amazing life forms inhabit the oceans. From microscopic plankton to apex predators like great white sharks, the marine world teems with bizarre and often beautiful life forms. Here we offer looks at a few of them.</p>
<h2>My, what big teeth you have</h2>
<p>Readers who grew up with the 1975 hit movie “Jaws” may still hear <a href="https://www.youtube.com/watch?v=e3mKAKPYh6k">its ominous two-note theme</a> in the back of their minds when they step into the surf. And it’s true that along many U.S. coastlines you could sight a shark, possibly even a great white. But that’s good news, <a href="https://theconversation.com/white-shark-populations-are-growing-heres-why-thats-good-news-44872">explains</a> George Burgess, director of the Florida Program for Shark Research and coordinator of operations at the Florida Museum of Natural History:</p>
<blockquote>
<p>“Like it or not, sharks are part of a balanced ocean ecosystem. After a decline of up to 90 percent for some species in the United States, they are beginning a gradual rise toward the numbers of a century ago.</p>
<p>"That suggests some of the damage we’ve done to the oceans has been reversed, and that’s something to celebrate.”</p>
</blockquote>
<p>Burgess readily acknowledges that great whites and a few other shark species will attack humans. But in his view, the burden is on us to understand that when we step into the ocean, we enter their world, and should understand the risks and take reasonable precautions – just as we do to guard against drowning.</p>
<p>That’s especially true for people who engage in activities like surfing, where the chances of encountering sharks are higher. Policies such as culling sharks near popular surfing beaches won’t work, <a href="https://theconversation.com/culling-sharks-wont-protect-surfers-73801">Burgess warns</a>:</p>
<blockquote>
<p>“Sharks are low-density, highly migratory animals that readily recolonize areas denuded of their kind, rendering any attempt to cull an ineffective strategy.”</p>
</blockquote>
<p>Moreover, Burgess points out, culling programs kill many nondangerous sharks, thereby harming ocean ecosystems that need these large predators to keep smaller species in check. </p>
<h2>Welcome back, otters</h2>
<p>If great white sharks are the most-feared species in the oceans, sea otters may be the most-loved. But otters’ congenital cuteness didn’t stop fur traders from hunting them to near-extinction along the Pacific coast in the 18th and 19th centuries. </p>
<p>Since they received international protection in 1911, otters have gradually repopulated the West Coast. But it’s tricky for scientists to count and track wild animal populations, especially when their targets spend a lot of time underwater. </p>
<p>Colorado State University associate professor Melvin Hooten and postdoctoral fellow Perry Williams <a href="https://theconversation.com/the-extraordinary-return-of-sea-otters-to-glacier-bay-74909">turned to math</a> to document sea otters’ return to Alaska’s Glacier Bay. Starting with a mathematical model that used partial differential equations to describe the growth and spread of sea otters, they used statistical methods to infer how quickly the Glacier Bay otter population was growing.</p>
<blockquote>
<p>“Using our new approach, we discovered that the Glacier Bay sea otter population grew more than 21 percent per year between 1993 and 2012…That means that the Glacier Bay sea otter growth rate was near or at maximum, and greater than any recorded sea otter population in history,” they write.</p>
</blockquote>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/176468/original/file-20170630-8225-pt3dgr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/176468/original/file-20170630-8225-pt3dgr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=213&fit=crop&dpr=1 600w, https://images.theconversation.com/files/176468/original/file-20170630-8225-pt3dgr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=213&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/176468/original/file-20170630-8225-pt3dgr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=213&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/176468/original/file-20170630-8225-pt3dgr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=267&fit=crop&dpr=1 754w, https://images.theconversation.com/files/176468/original/file-20170630-8225-pt3dgr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=267&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/176468/original/file-20170630-8225-pt3dgr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=267&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Chilling in Glacier Bay.</span>
<span class="attribution"><a class="source" href="https://www.nps.gov/glba/blogs/otters-on-ice.htm">National Park Service</a></span>
</figcaption>
</figure>
<h2>Aquatic hitchhikers</h2>
<p>Since there are no borders in the oceans, scientists need to know where sea creatures travel in order to make effective conservation plans. That’s especially true for sea turtles, which can migrate thousands of miles to reach their preferred nesting beaches.</p>
<p>Nathan Jack Robinson, a postdoctoral fellow at Indiana University, studies epibionts – tiny organisms that attach to sea turtles’ shells as they swim. Examining sea turtles that came ashore to nest in Costa Rica, Robinson and his colleagues found diverse epibionts, from barnacles to small remora fish. Different turtle species carried different colonies of tiny hitchhikers. Robinson <a href="https://theconversation.com/sea-turtle-hitchhikers-could-play-an-important-role-in-conservation-62081">believes these tagalongs provide valuable data</a>. </p>
<blockquote>
<p>“[I]t’s becoming clear that the creatures found on each sea turtle can tell a story about where that turtle has been and what it was doing there. The information encoded in each sea turtle’s unique set of hitchhikers can, in turn, help guide management decisions to protect these animals during their lives at sea.”</p>
</blockquote>
<p>As a bonus, he points out that saving endangered sea turtles will also help conserve the tiny organisms that catch rides with them.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/176470/original/file-20170630-8407-1m6cejv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/176470/original/file-20170630-8407-1m6cejv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=319&fit=crop&dpr=1 600w, https://images.theconversation.com/files/176470/original/file-20170630-8407-1m6cejv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=319&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/176470/original/file-20170630-8407-1m6cejv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=319&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/176470/original/file-20170630-8407-1m6cejv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=401&fit=crop&dpr=1 754w, https://images.theconversation.com/files/176470/original/file-20170630-8407-1m6cejv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=401&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/176470/original/file-20170630-8407-1m6cejv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=401&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Barnacles on an Olive Ridley sea turtle, photographed in Oaxaca, Mexico.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/warriorwoman531/16291269419">Heather Paul/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Going with the flow</h2>
<p>Most marine organisms don’t travel via turtle. Numerous plankton species and fish larvae drift freely, steered by ocean currents. Intriguingly, however, some species show up in the same places every year, even though they seem to be at the mercy of winds and tides.</p>
<p>Researchers at North Carolina State University and the University of California, Davis teamed up to study where marine larvae go and how they get there. NCSU’s Tom and Donna Wolcott designed floating robots that could swim vertically like marine larvae and record data on their surroundings, such as depth and water temperature. UC Davis researchers released the bots (nicknamed ABLEs) in California’s Bodega Bay to see how larvae programmed with different swimming patterns would behave.</p>
<p>They found that vertical positioning in currents – whether larvae floated at the surface or sank to deeper water – <a href="https://theconversation.com/underwater-robots-help-scientists-see-where-marine-larvae-go-and-how-they-get-there-65141">strongly affected where the larvae moved</a>:</p>
<blockquote>
<p>“Larvae of many species occur near the surface in offshore-flowing currents early in their development and are carried away from shore. Older larvae descend into deep shoreward-flowing currents and return onshore to habitats in which they can metamorphose and become adults. In effect, they use currents like conveyor belts to travel out and back across the continental shelf.”</p>
</blockquote>
<p>Next, the scientists want to tease out connections between larvae’s vertical migration patterns and whether they travel far offshore or stay near the coast. Knowing how larvae behave could inform many ocean policies, from designing marine protected areas to tracking the spread of invasive species.</p><img src="https://counter.theconversation.com/content/80362/count.gif" alt="The Conversation" width="1" height="1" />
The world’s oceans are home to innumerable life forms, from sponges to sea lions, and scientists have many creative ways of studying them.Jennifer Weeks, Senior Environment + Cities Editor, The ConversationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/749092017-04-19T22:35:25Z2017-04-19T22:35:25ZThe extraordinary return of sea otters to Glacier Bay<figure><img src="https://images.theconversation.com/files/165688/original/image-20170418-32716-dgt62a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A sea otter floats in Kachemak Bay, Alaska.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Sea-Otter-Bounty/d17ce8d14b9f4427a9a917fe952b0233/13/0">AP Photo/Laura Rauch</a></span></figcaption></figure><p>Human beings have a long history of persecuting apex predators such as wolves, tigers and leopards. The loss of these predators – animals at the top of the food chain – has resulted in ecological, economic and social <a href="http://science.sciencemag.org/content/333/6040/301">impacts around the globe</a>. Rarely do the predators fully recover from human oppression, and, when they do, we often lack data or tools to assess their recovery.</p>
<p>The sea otters in Glacier Bay, Alaska, are an exception. In <a href="http://dx.doi.org/10.1002/ecy.1643">a recent study</a>, our team chronicled the incredible return of sea otters to an area where they’ve been absent for at least 250 years. </p>
<p>Our approach – which fuses mathematics, statistics and ecology – can help us better understand the role of sea otters in marine ecosystems and the ability of apex predators to return to an ecosystem after they’ve been absent. It may even help us learn what a changing climate means for many other species.</p>
<h2>Return to Glacier Bay</h2>
<p>Although not typically viewed in the same vein as wolves, tigers and leopards, sea otters are an apex predator of the nearshore marine ecosystem - the narrow band between terrestrial and oceanic habitat.</p>
<p>During the commercial maritime fur trade in the 18th and 19th centuries, sea otters were nearly hunted to extinction across their range in the North Pacific Ocean. By 1911, only a handful of small isolated populations remained.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=458&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=458&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=458&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=576&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=576&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165689/original/image-20170418-32726-fwtx0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=576&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Historic range (gray shading) and 1911 remnant populations (red icons) of sea otters. The populations at Queen Charlotte Islands and San Benito Islands went extinct by 1920.</span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>But sea otter populations have recovered in many areas, thanks to a few changes. The <a href="http://celebrating200years.noaa.gov/events/fursealtreaty/welcome.html">International Fur Seal Treaty</a> in 1911 protected sea otters from most human harvest. Wildlife agencies also made an effort to aid sea otter recolonization.</p>
<p>Eventually, sea otters began to increase in abundance and distribution, and they made their way to Glacier Bay, a tidewater glacier fjord and national park in southeastern Alaska. Glacier Bay is functionally one of the largest marine <a href="https://www.nps.gov/glba/index.htm">protected areas</a> in the northern hemisphere. </p>
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<img alt="" src="https://images.theconversation.com/files/164959/original/image-20170411-26751-7y67vg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/164959/original/image-20170411-26751-7y67vg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1246&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164959/original/image-20170411-26751-7y67vg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1246&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164959/original/image-20170411-26751-7y67vg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1246&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164959/original/image-20170411-26751-7y67vg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164959/original/image-20170411-26751-7y67vg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164959/original/image-20170411-26751-7y67vg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Glacier Bay National Park, southeastern Alaska.</span>
<span class="attribution"><span class="source">Map used with permission from the National Park Service</span></span>
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<p>Glacier Bay was completely covered by glacier ice until approximately 1750 – about the same time sea otters vanished from the surrounding area due to over-harvest. It then endured the most rapid and extensive tidewater glacier retreat in recorded history. After glacier retreat, a rich environment emerged. This new environment supported high concentrations of wildlife, including sea otter prey species – such as crabs, mollusks and sea urchins – that were able to increase in size and abundance in the absence of sea otters. </p>
<p>Sea otters first reappeared at the mouth of Glacier Bay in 1988. Here they encountered vast habitat, abundant prey populations and protection from all human harvest.</p>
<h2>Our approach</h2>
<p>It’s challenging to estimate how populations grow and spread, due to their dynamic nature. Each year, animals move to new areas, increasing the amount of area and effort required to find them. Airplanes searching for sea otters have to cover more ground, usually with the same amount of time and money. Additionally, individuals may move from one area to the next during any time period for a number of reasons, including sea otter social behavior and their reaction to the environment. Because these challenges can interfere with accurate population estimates, it’s important to understand and address them. </p>
<p>Shortly after sea otters arrived in Glacier Bay, scientists from the U.S. Geological Survey began collecting data to document their return. Although the data clearly indicated that sea otters were increasing, we needed novel statistical methods to unveil the extent of this increase.</p>
<p>First, we developed a mathematical model using partial differential equations to describe the growth and spread of sea otters. Partial differential equations are commonly used to describe phenomena such as fluid dynamics and quantum mechanics. Therefore, they were a natural choice to describe how a mass – in our case, the sea otter population – spreads through space and time. </p>
<p>The new approach allowed us to incorporate our current understanding of sea otter ecology and behavior, including habitat preferences, maximum growth rates and where sea otters were first observed in Glacier Bay. </p>
<p>Second, we incorporated our equations within a hierarchical statistical model. Hierarchical models are used to draw conclusions from data that arise from complex processes. They provide flexibility to describe and distinguish among various sources of uncertainty, such as uncertainty in data collection and ecological processes.</p>
<p>Partial differential equations are not new to the field of ecology, dating back to <a href="http://www.math.wm.edu/%7Eshij/math490-2006/skellam.pdf">at least 1951</a>. However, by fusing these equations with formal statistical models, we can reliably infer dynamic ecological processes, while appropriately quantifying the uncertainty associated with our findings. It provides a data-driven way to analyze surveys of sea otter abundance for the past 25 years. </p>
<p>This gave us rigorous and honest estimates of colonization dynamics that incorporated our understanding of the ecological system. </p>
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<a href="https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164963/original/image-20170411-26730-1e4kmo5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Group of sea otters in Glacier Bay National Park, 2016.</span>
<span class="attribution"><span class="source">Photo by Jamie Womble</span></span>
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<h2>A record-breaking recovery</h2>
<p>Using our new approach, we discovered that the Glacier Bay sea otter population grew more than 21 percent per year between 1993 and 2012. </p>
<p>By comparison, the estimated growth rates of sea otters in other populations in Alaska, who were also recovering, have been limited to 17 to 20 percent. Furthermore, the maximum biological reproductive rate – the fastest rate sea otters can reproduce – is between 19 to 23 percent per year. That means that the Glacier Bay sea otter growth rate was near or at maximum, and greater than any recorded sea otter population in history. </p>
<p>In the wake of glacier retreat, sea otters went from nonexistent to colonizing nearly all of Glacier Bay in a span of 20 years. Today, they are one of the most abundant marine mammals in Glacier Bay. Recent observations have documented large groups of more than 500 sea otters in some parts of lower Glacier Bay, suggesting that prey resources are abundant. </p>
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<p>The fusion of state-of-the-art statistical and mathematical methods depicted, for the first time, just how extraordinary the growth and spread of this population was. </p>
<p>Sea otters had great success in the wake of tidewater glacier retreat in Glacier Bay. While climate-induced loss of sea ice can negatively affect some wide-ranging apex predators – such as polar bears or walruses – other species may benefit from the emergence of newly available habitat and prey resources. </p>
<p>Humans have caused the global decline of apex predators, and these declines are often difficult to reverse. However, our results suggest that, when there is minimal human interference, apex predators can be widely successful at recolonizing suitable habitat.</p><img src="https://counter.theconversation.com/content/74909/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mevin Hooten receives funding from the National Park Service, U.S. Geological Survey, National Oceanic and Atmospheric Administration, and the National Science Foundation. </span></em></p><p class="fine-print"><em><span>Perry Williams does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Sea otters had been absent from this Alaskan national park for at least 250 years. By marrying math and statistics, scientists map this animal’s successful comeback.Perry Williams, Postdoctoral Fellow in Statistics and Fish, Wildlife, and Conservation Biology, Colorado State UniversityMevin Hooten, Assistant Unit Leader, U.S. Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit; Associate Professor, Fish, Wildlife, and Conservation Biology and Statistics, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/618342016-07-19T10:37:57Z2016-07-19T10:37:57ZThe social life of sea mammals is key to their survival<figure><img src="https://images.theconversation.com/files/130404/original/image-20160713-12372-41nke5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">School of thought.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The beguiling behaviour of marine mammals in their natural environment is fascinating to us human observers. Watching <a href="http://uk.whales.org/whales-and-dolphins/facts-about-dolphins">dolphins</a> leap gracefully through the surf, or <a href="http://uk.whales.org/whales-and-dolphins/facts-about-whales">whales</a> making waves with their massive tale flukes is the stuff of countless bucket lists and high definition <a href="http://www.bbc.co.uk/programmes/b008044n">wildlife documentaries</a>.</p>
<p>Perhaps part of the appeal lies in marine mammals behaving a lot like we do. They share many of our biological characteristics, such as bearing live young, suckling them with rich fatty milk and investing time and energy into rearing them into adulthood. </p>
<p>Studying their behaviour, what makes them tick as complex social creatures, is essential for their conservation in an aquatic environment which remains almost entirely alien to us. And while it may be alien, it is an environment with a massive human footprint. </p>
<p>For unfortunately mammalian attributes are not all we share with our oceanic cousins. There is arguably now no marine habitat that remains unaffected by human activities. Prey depletion caused by humans, noise, temperature changes, chemical pollution and entanglements in fishing gear have all changed the place in which marine mammals evolved. </p>
<p>Our <a href="http://biosciences.exeter.ac.uk/cec/">research</a> shows that this simple reality makes the need to understand their behaviour and social structures all the more urgent, a call which is being echoed by the charity <a href="http://whales.org">Whale and Dolphin Conservation</a>. </p>
<p>In recent decades there has been a strong emphasis in conservation circles on understanding the population size and distribution of marine mammals, as well as their genetic diversity. </p>
<p>Conservation is principally obsessed with conserving genetic diversity, which is exactly as it should be, as diverse gene pools help ensure resilience against environmental change. But genes may not be the whole story.</p>
<p>Marine mammal behaviour, just like ours, is partially determined by genes and the environment in which they live. However there are also social factors at play, and what makes marine mammals behave the way they do is potentially as complex as the processes which drive human behaviour. </p>
<p>In some cases, nurture may play just as important a role as nature for marine mammals. Almost 20 years ago, renowned conservation biologist <a href="http://www.zoo.cam.ac.uk/directory/bill-sutherland">Bill Sutherland</a> examined how the behaviour of different species could be used to improve conservation efforts. He <a href="http://faculty.washington.edu/wirsinga/Sutherland1998.pdf">concluded</a> that behavioural ecology needed to be better integrated into conservation science and policy making. But to what extent has this message from 1998 been taken on board? </p>
<p>Marine mammals exhibit a wide range of fascinating behaviours, from the complex cooperative <a href="https://www.youtube.com/watch?v=z00G0RxeSP0">bubble-net feeding</a> of humpback whales, to <a href="http://www.alaskawild.org/alaskas-polar-bears/">ice-cave building polar bears</a> and <a href="http://www.bbc.co.uk/nature/life/Sea_otter">tool-using sea otters</a>. They also have a great diversity in their social structures and changing social dynamics, which range between the complex <a href="http://blogs.scientificamerican.com/thoughtful-animal/what-can-dolphins-tell-us-about-the-evolution-of-friendship/">third-order alliances of bottlenose dolphins</a>, close relationships between non-related males, to the more solitary lives of beaked whales. </p>
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<p>As well as having innate behaviours, which they acquire through their genes, these species, like humans, can learn individually and from each other. Social learning may be of particular importance to conservation efforts, because it can influence the resilience of a population to changes in their environment. </p>
<p>Killer whales learn foraging strategies from their social group and tend to stick to them. As a result, if there is a decline in their preferred prey, they may be less likely to switch to other species, or use alternative foraging tactics. Such a behaviourally conservative species is likely to be more vulnerable to change.</p>
<h2>Survival skills</h2>
<p>But learning is only part of marine mammal social dynamics. Social structure, and the various roles played by individuals may also be important for how a population responds to change. The loss of individuals that hold key information on the location of critical habitat or a food source may have significant consequences.</p>
<p>Humans live in many different types of cultures, environments and circumstances. We make important choices about what to eat, who to socialise with, where to live and how many offspring to have. These factors can strongly influence our fertility rates, survival, and even our evolution. It is certainly plausible that many of these factors influence the success of marine mammals as well.</p>
<p>A better understanding of the behavioural ecology of marine mammals is therefore hugely important. It is difficult to envision an approach toward conserving a population of modern humans which merely preserved their genetic integrity and did not also consider their socially learnt behaviour. </p>
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<p>While there are some attempts to incorporate behaviour, efforts to conserve marine mammal biodiversity still focus strongly on maintaining genetic integrity and diversity. But the <a href="http://journal.frontiersin.org/article/10.3389/fmars.2016.00087/full#h26">emerging evidence</a> indicates that social and behavioural diversity may also be central to individual, group, and population viability. The challenge ahead is teasing out the most relevant factors and understanding how to incorporate this new knowledge into conservation efforts.</p>
<p>On the whole, policy makers have been slow to keep up with the emerging behavioural research. More alarming still, from the perspective of the marine mammals themselves, is that the degradation of their environment has continued apace.</p><img src="https://counter.theconversation.com/content/61834/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Philippa Brakes is a post-graduate researcher at the Univeristy of Exeter and receives funding from the NGO Whale and Dolphin Conservation. </span></em></p>Understanding this will boost conservation efforts.Philippa Brakes, Post-grad Researcher, University of ExeterLicensed as Creative Commons – attribution, no derivatives.