tag:theconversation.com,2011:/us/topics/cetaceans-27990/articlesCetaceans – The Conversation2024-03-04T16:54:22Ztag:theconversation.com,2011:article/2248842024-03-04T16:54:22Z2024-03-04T16:54:22ZDiscovering the world of dolphins and their three ‘super senses’<figure><img src="https://images.theconversation.com/files/579179/original/file-20240129-15-onehyv.jpg?ixlib=rb-1.1.0&rect=0%2C12%2C4265%2C2826&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Dolphins can communicate very effectively.</span> <span class="attribution"><a class="source" href="https://unsplash.com/fr/photos/photographie-en-accelere-de-deux-dauphins-nageant-dans-la-mer-ZYPQDN_xSqk">Arielle Allouche/Unsplash</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Imagine that you’re in a comfortable room with your cat. You’re both sharing the same space, temperature and lighting. But while you’re enjoying the décor, and perhaps a book or the taste of hot chocolate, the cat seems intrigued by something else. Maybe she’s looking for a treat or making sure that no one infringes on “her” preferred spot, a comfortable armchair near the heater.</p>
<p>All this is to say that even if you and your pet are in the same place, you both perceive your environment differently. In 1934, the German scientist Jakob von Uexküll defined it as the “umwelt” (<em>environment</em> in German). The <em>umwelt</em> is each individual’s <a href="https://monoskop.org/images/1/1d/Uexkuell_Jakob_von_A_Stroll_Through_the_Worlds_of_Animals_and_Men_A_Picture_Book_of_Invisible_Worlds.pdf">perception of the world in which he or she lives</a>.</p>
<p>But how do other animals perceive the world around them? I’m particularly interested in those that live in habitats that are drastically different from those of humans, such as dolphins in the vastness of the ocean.</p>
<p>By understanding animals’ perceptions, we can better protect them. In the case of dolphins, knowing how they perceive their environment means knowing the impact of underwater noise on their communication and taking measures to control it in protected marine areas.</p>
<p>So let’s dive in and discover the three super-senses of dolphins: magnetic perception, electrical perception and echolocation.</p>
<h2>Magnetic perception</h2>
<p>Magnetic perception was first demonstrated in dolphins in 1981: American researchers found <a href="http://www.ncbi.nlm.nih.gov/pubmed/7256282">fragments of magnetite closely linked to neuronal connections</a> extracted from the brains of four stranded common dolphins. Surprised by the discovery, the scientists suggested that it could have a sensory function or play a role in navigation.</p>
<p>In 1985, another team of researchers discovered a <a href="https://journals.biologists.com/jeb/article/120/1/1/4953/Evidence-From-Strandings-for-Geomagnetic">relationship between cetacean stranding positions and the Earth’s geomagnetic field</a>: several species of whales and dolphins actually tend to strand in places where the magnetic intensity is low. If cetaceans use the Earth’s magnetic field to find their bearings, one hypothesis is that areas where the magnetic intensity is weaker would increase the likelihood of stranding due to a lack of bearings.</p>
<p>In 2014, with a team of scientists from the University of Rennes 1, I carried out a behavioural study that enabled us to show that <a href="https://hal.science/hal-01134557">bottlenose dolphins have a magnetic sense</a>. We tested the spontaneous response of six captive dolphins to the presentation of two objects with the same shape and density: the first contained a block of magnetically charged neodymium (a metal), while the second device was completely demagnetised.</p>
<p>The dolphins approached the device much more quickly when it contained a block of strongly magnetised neodymium. This allowed us to conclude that the dolphins are able to discriminate between the two stimuli on the basis of their magnetic properties.</p>
<p>These data support the hypothesis that cetaceans can determine their location using the Earth’s magnetic field and that, consequently, when this field is weaker, the tendency to strand is greater.</p>
<h2>Electrical perception</h2>
<p>When fish move their muscles and skeletons, they emit weak electric fields. Some marine predators, particularly in benthic areas (at the bottom of the ocean) – where visibility is reduced, are able to perceive their prey via these electric fields. A range of aquatic and semi-aquatic species share this ability.</p>
<p>In dolphins, electroreception was demonstrated for the first time in 2012. The structures known as hairless <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2011.1127">vibrissal crypts</a> on the rostrum of Guiana dolphins (one of the smallest species) serve as electroreceptors. In the study, the researchers noted that the vibrissal crypts have a well-innervated ampullary structure, reminiscent of the ampullary electro-receptors in other species such as <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/elasmobranch">elasmobranchs</a> (sharks and rays), lampreys, paddlefish, catfish, certain amphibians and even in the platypus and echidna). These vibrissal crypts are thought to function as sensory receptors capable of picking up small electric fields emitted by prey in aquatic environments.</p>
<p>The same study also found behavioural evidence of electroperception. A male Guiana dolphin was trained to respond to electrical stimuli of the order of magnitude of those generated by small-to medium-sized fish. For example, a goldfish 5 to 6 centimetres long produces electric fields of 90 microvolts per centimetre, with a peak energy at 3 hertz. Bioelectric fields of 1,000 microvolts per centimetre have been reported in flounders – a magnitude equivalent to 1/100,000 of the electric current of a light bulb.</p>
<p>The dolphin was trained to place its head in a hoop and touch a target with the tip of its rostrum. It had to leave the hoop when a stimulus was presented, and when no stimulus was presented, it had to remain in the hoop for at least 12 seconds.</p>
<p>This experiment showed that dolphins perceive weak electric fields – a sensitivity comparable to that of platypus electroreceptors. The first clear demonstration of electroreception in platypuses was carried out in Canberra in 1985 by a German-Australian team, which showed that <a href="https://www.nature.com/articles/319401a0">they sought out and attacked submerged and otherwise invisible batteries</a>. In 2023, a team of researchers found similar <a href="https://pubmed.ncbi.nlm.nih.gov/38035544/">detection thresholds in bottlenose dolphins</a>, using the same behavioural test.</p>
<p>It is now thought that electroreception can facilitate the detection of prey at close range and the targeted killing of prey on the seabed.</p>
<p>In addition, the ability to detect weak electric fields could enable dolphins to perceive the Earth’s magnetic field by means of magnetoreception, which could enable them to orientate themselves on a large scale.</p>
<h2>Echolocation</h2>
<p>The most studied sense in dolphins remains <a href="https://www.frontiersin.org/articles/10.3389/fevo.2016.00049/full">echolocation</a>.</p>
<p>A more active sense than the detection of electric or magnetic fields, echolocation involves the dolphins producing sequences of clicks with their phonic lips (located in the blowhole, the nostril on the dolphin’s head). The clicks produced are highly directional, moving forward. When the sound wave touches a surface, it returns and is perceived through the dolphin’s lower jaw. In this way, they perceive sound waves extremely well, without having external ears and so retaining their smooth hydrodynamic shape.</p>
<p>Thanks to this information, the dolphin can not only know the location of a target, but also deduce its density: a dolphin can distinguish at a distance of 75 metres whether a one-inch diameter sphere (2.54 cm) is made of <a href="https://pubs.aip.org/asa/jasa/article-abstract/68/4/1077/625152/Long-range-target-detection-in-open-waters-by-an">solid steel or filled with water</a>.</p>
<h2>Dolphins communicate through channels that are inaccessible to us</h2>
<p>Dolphins’ impressive ability to “see with their ears” doesn’t stop there. Dolphins can listen to the echoes of clicks produced by their fellow dolphins, an ability known as “eavesdropping”](https://link.springer.com/article/10.3758/BF03199007). In this way, they can “share” what they detect with the members of their group and coordinate their movements.</p>
<p>As part of my research, I was interested in <a href="https://go.gale.com/ps/i.do?id=GALE%7CA491087577">how dolphins use their clicks to synchronise their movements</a>. To do this, I exploited a <a href="https://www.aquaticmammalsjournal.org/article/vol-43-iss-2-lopez-marulanda/">recording method using four hydrophones and a 360° camera</a>, which make it possible to know which dolphin is making a sound – something that was previously impossible because dolphins do not open their mouths to vocalise.</p>
<p>I was able to show that <a href="https://www.sciencedirect.com/science/article/abs/pii/S0376635721000449">when the dolphins jump synchronously in a dolphinarium, one produces the clicks while the others remain silent</a>. In our experiment, we determined that the animal that produced the clicks was always the oldest female.</p>
<p>Will the same thing happen in the wild when dolphins fish in coordination? To find out, we would need to use the same 360° audiovisual recording method in the ocean. This would involve establishing an observation base in a feeding area with good visibility – for example, when dolphins are feeding around fish farms. The regular proximity of the dolphins would make it possible to record their solitary fishing behaviour, and to better understand how they cooperate and coordinate, using all of their three “super senses”.</p><img src="https://counter.theconversation.com/content/224884/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Juliana López Marulanda is co-founder of the Macuaticos Colombia Foundation for the research and conservation of cetaceans in Colombia.</span></em></p>Let’s delve into the three super-senses of dolphins: magnetic perception, electrical perception and echolocation.Juliana López Marulanda, Enseignante chercheuse en éthologie, Université Paris Nanterre – Université Paris LumièresLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2182532023-11-24T02:53:56Z2023-11-24T02:53:56ZAustralian dolphins have the world’s highest concentrations of ‘forever chemicals’<figure><img src="https://images.theconversation.com/files/561466/original/file-20231123-15-7lw4an.JPG?ixlib=rb-1.1.0&rect=89%2C19%2C4185%2C2824&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A Burrunan dolphin</span> <span class="attribution"><a class="source" href="https://www.marinemammal.org.au/gallery">Marine Mammal Foundation</a></span></figcaption></figure><p>As predators at the top of the food chain, dolphins tend to <a href="https://www.sciencedirect.com/topics/chemistry/bioaccumulation#:%7E:text=Bioaccumulation%20is%20a%20process%20of,dietary%20intake%20(trophic%20transfer).">accumulate and magnify</a> high levels of toxins and other chemicals in their bodies. So health problems in dolphins can be a warning that all is not well in the system as a whole. </p>
<p>One group of persistent pollutants has been dubbed “forever chemicals” because they almost never break down in the environment. Commonly known by the acronym PFAS, these per- and polyfluorinated substances are globally recognised as an environmental hazard and a <a href="https://doi.org/10.1002/etc.4890">potential human health issue</a>.</p>
<p>In our new research, we found dolphins with the <a href="https://doi.org/10.1016/j.scitotenv.2023.168438">highest concentration of PFAS</a> in the world live in Australian waters. One young Burrunan dolphin had liver concentrations almost 30% higher than any other dolphin ever reported.</p>
<p>This is a critically endangered species endemic to southeast Australia. While the consequences for dolphin health and the implications for humans remain unknown, the record-breaking concentrations are cause for alarm. </p>
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<a href="https://theconversation.com/controversial-forever-chemicals-could-be-phased-out-in-australia-under-new-restrictions-heres-what-you-need-to-know-210697">Controversial ‘forever chemicals’ could be phased out in Australia under new restrictions. Here’s what you need to know</a>
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<h2>The case of the Burrunan dolphin</h2>
<p>The Burrunan dolphin was recognised as a <a href="https://doi.org/10.1371/journal.pone.0024047">separate species in 2011</a>. Fewer than 200 individuals remain. Two small, isolated and genetically distinct populations reside in coastal Victoria, Australia. </p>
<p>In <a href="https://doi.org/10.1016/j.scitotenv.2023.168438">our research</a>, we took liver samples from Burrunan dolphins and three other dolphin species found dead and washed up on beaches. </p>
<p>We found the critically endangered <a href="https://www.marinemammal.org.au/burrunan-dolphin">Burrunan dolphin</a> had 50–100 times more PFAS than other dolphins in the same region. Their PFAS concentrations were the highest reported globally. </p>
<p>In 90% of these dolphins, the liver concentrations of these chemicals (1,020–19,500 nanograms per gram) were above those thought to cause <a href="https://doi.org/10.1021/acs.est.5b06076">liver toxicity</a> and <a href="https://doi.org/10.1002/etc.2122">altered immune responses</a>. </p>
<p>These record-breaking and potentially health-compromising PFAS concentrations are a major concern for the survival of the species. </p>
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<a href="https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A graphic illustrating the results of PFAS testing in Victorian dolphins" src="https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=232&fit=crop&dpr=1 600w, https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=232&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=232&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=291&fit=crop&dpr=1 754w, https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=291&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/561478/original/file-20231124-18-4fqtj6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=291&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">The Burrunan dolphin had the highest global PFAS concentrations in the study.</span>
<span class="attribution"><a class="source" href="https://www.sciencedirect.com/science/article/pii/S0048969723070663?via%3Dihub">Science of The Total Environment</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>Results from Australia and around the world</h2>
<p>By far the highest PFAS concentrations in the dolphins we studied were of a particular compound called PFOS (perfluorooctane sulfonate). PFOS is one of the most studied PFAS compounds. It is listed on the <a href="https://chm.pops.int/Implementation/IndustrialPOPs/PFAS/Overview/tabid/5221/Default.aspx">Stockholm Convention</a>, a global treaty on environmental pollutants, with international restrictions on use. </p>
<p>While Australia does not manufacture PFOS, heavy use of PFOS-containing firefighting foams occurred until the early 2000s. The Australian government <a href="https://www.epa.vic.gov.au/for-community/environmental-information/pfas/pfas-use-in-australia#:%7E:text=While%20PFOS%2C%20PFOA%20and%20other,as%20mist%20suppressants%20and%20coatings.">still allows PFOS import</a> for permitted purposes, such as mist suppressants in manufacturing and metal plating. </p>
<p>In recent years, public concern has prompted <a href="https://doi.org/10.1016/j.canep.2022.102296">ongoing investigations</a> into areas of high firefighting foam use, such as Royal Australian Airforce training facilities and airports. </p>
<p>While firefighting foam is a probable source of PFAS in waterways, there are others. <a href="https://theconversation.com/pfas-forever-chemicals-are-getting-into-ocean-ecosystems-where-dolphins-fish-and-manatees-dine-we-traced-their-origins-216254">Recent research in Florida</a> in the United States found leaking septic and wastewater systems in urban areas were sources of PFAS runoff into the aquatic environment. </p>
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<a href="https://theconversation.com/pfas-forever-chemicals-are-getting-into-ocean-ecosystems-where-dolphins-fish-and-manatees-dine-we-traced-their-origins-216254">PFAS 'forever chemicals' are getting into ocean ecosystems, where dolphins, fish and manatees dine – we traced their origins</a>
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<p>The Burrunan dolphins are not alone. In 2017, the <a href="https://www.epa.sa.gov.au/files/12580_report_pfas_marine.pdf">South Australian Environment Protection Authority investigated</a> PFOS concentrations in dolphins from Western Australia, South Australia and New South Wales. Dolphins in the Swan-Canning River Estuary in Perth, and in Port River or Barker Inlet, SA, had high PFOS levels (2,800–14,000ng per gram and 510–5,000ng per gram, respectively). These PFOS levels are similar to those in the Burrunan dolphin (between 494ng and 18,700ng per gram).</p>
<p>The globally significant PFAS and PFOS concentrations in multiple Australian dolphin populations demonstrates potential widespread contamination. This highlights our limited understanding of the short- and long-term consequences in our oceans and estuaries. </p>
<p>It is crucial we understand where different PFAS compounds are coming from, particularly PFOS, and whether the contamination is from a time when we didn’t know better (known as legacy sources) or if we are still releasing them. </p>
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<h2>Isn’t PFOS getting banned anyway?</h2>
<p>The Australian government has <a href="https://theconversation.com/controversial-forever-chemicals-could-be-phased-out-in-australia-under-new-restrictions-heres-what-you-need-to-know-210697">expressed an intention</a> to further regulate PFOS and two other PFAS. This marks a significant step forward. However, the problem with forever chemicals is they will be around for a really long time. </p>
<p>Typically, these chemicals are substituted with alternatives believed to be less detrimental, but unfortunately that is not always the reality. For example, early replacements for PFOS were initially thought to be less readily absorbed by body tissues and pose lower health concerns. But <a href="https://doi.org/10.1021%2Facs.est.3c00374">studies</a> have shown their high <a href="https://www.merriam-webster.com/dictionary/biomagnification">biomagnification</a> potential (with levels increasing higher up the food chain) and accompanying <a href="https://doi.org/10.1016/j.envint.2023.107846">health risks</a>.</p>
<p>While PFOS levels were highest in the Burrunan dolphins we studied, emerging contaminants such as PFMPA, PFECHS, and 6:2 Cl-PFESA were also detected. The presence of these emerging and replacement compounds in dolphins shows they are accumulating within our waterways and suggests it is more than our historic usage that might be a problem. </p>
<h2>It’s not too late</h2>
<p>Dolphins are the “canary in the coal mine” for coastal ecosystems. They live their lives in these inshore waterways and they consume tonnes of fish within their lifetimes. Finding these alarming contaminant concentrations is an important first step to highlighting the problem. </p>
<p>So now we know there’s a problem, we need to ask why. Then we need to determine what can be done about it. </p>
<p>The next step is mapping sources of PFAS so we can more effectively manage this threat to our wildlife and ecosystems. </p>
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Read more:
<a href="https://theconversation.com/we-found-long-banned-pollutants-in-the-very-deepest-part-of-the-ocean-204447">We found long-banned pollutants in the very deepest part of the ocean</a>
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<p class="fine-print"><em><span>Chantel Foord receives funding from a Holsworth Wildlife Research Endowment Grant. She is affiliated with the Marine Mammal Foundation. </span></em></p>Researchers are finding alarming concentrations of persistent pollutants such as PFAS in Australian dolphins. These record-breaking levels are cause for concern.Chantel Foord, Research Associate, Marine Mammal Foundation, PhD researcher, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1999772023-04-20T20:02:17Z2023-04-20T20:02:17ZWhale-watching guidelines don’t include boat noise. It’s time they did<figure><img src="https://images.theconversation.com/files/511111/original/file-20230220-20-3yvrjj.JPG?ixlib=rb-1.1.0&rect=36%2C0%2C4047%2C2683&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Humpback whale breach at Ningaloo. </span> <span class="attribution"><span class="source">Image: Kate Sprogis</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Imagine … eco-tourists enjoying views of undisturbed whales and dolphins, watching them doing what comes naturally.</p>
<p>This is ultimately what we all wish to see when spending time in nature watching animals. We can achieve this by using quieter boats.</p>
<p>But why do we need quieter boats? Whales and dolphins primarily use hearing to sense their surroundings (rather than sight like humans do). Sound travels almost <a href="https://oceanexplorer.noaa.gov/explorations/sound01/background/acoustics/acoustics.html#:%7E:text=Sound%20moves%20at%20a%20faster,of%20water%20differ%20from%20air.">five times faster underwater</a> than it does in the air, so it’s an important sense for whales. They rely on sounds to communicate, navigate, feed and detect predators. </p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0308597X23000520">Our new research</a> confirms noise from a boat watching whales at a distance of 300 metres can still disturb them. And watching whales involves a lot of boats and millions of tourists each year. This multi-billion-dollar <a href="https://www.sciencedirect.com/science/article/abs/pii/B9780128043271002624">industry</a> is active in waters off more than 100 countries. The Australian whale-watching industry is one of the biggest in the world.</p>
<p>Because the industry actively seeks out whales and dolphins, using quieter boats should be a priority. Yet current whale-watching guidelines, including <a href="https://www.agriculture.gov.au/sites/default/files/documents/aust-national-guidelines-whale-dolphin-watching-2017.pdf">Australia’s</a>, do not include noise levels. They should. </p>
<p>As the whale-watching season begins in Australia for humpback whales and southern right whales, we offer tips here for individual operators to reduce noise from their boats.</p>
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<span class="caption">This year’s humpback whale-watching season begins soon in Australia. Wouldn’t it be great if whale-watching guidelines set a limit on boat noise?</span>
<span class="attribution"><span class="source">Image: Kate Sprogis</span></span>
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<a href="https://theconversation.com/thar-she-blows-an-experts-guide-to-whale-watching-101-171954">Thar she blows! An expert's guide to whale watching 101</a>
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<h2>How does noise affect whales and dolphins?</h2>
<p>Besides income for local communities, whale watching has education and conservation benefits if tourists are inspired to care for the environment. </p>
<p>Despite these benefits, <a href="https://www.frontiersin.org/articles/10.3389/fmars.2021.696136/full">watching whales from a motorised boat</a> and <a href="https://www.sciencedirect.com/science/article/pii/S0022098119301194">swimming with whales</a> can disturb their natural behaviour. For example, it might prevent them from resting or feeding, or change their breathing, swimming and dive patterns. These impacts are especially important for whales with young. </p>
<p>If the cumulative effects of these short-term impacts are not considered, they can lead to long-term consequences for the animals, such as <a href="https://www.jstor.org/stable/4124706">population declines or leaving an area altogether</a>. </p>
<p>Such outcomes are not only negative for the animals, but also for the whale-watching industry that depends on them.</p>
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Read more:
<a href="https://theconversation.com/drones-gather-new-and-useful-data-for-marine-research-but-they-can-disturb-whales-and-dolphins-198985">Drones gather new and useful data for marine research, but they can disturb whales and dolphins</a>
</strong>
</em>
</p>
<hr>
<h2>Whale-watching guidelines overlook noise impacts</h2>
<p>Many countries have <a href="https://wwhandbook.iwc.int/en/responsible-management/guidelines-and-regulations">guidelines</a> on the boat’s minimum distance from the animals (typically around 100 metres), the speed at which it passes (typically below wake speed) and the approaching angle (typically from the side-rear). Guidelines, however, do not consider the noise level of the boat’s engine. A very loud boat is, in effect, considered to have the same impact on the animals as a very quiet boat.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/511107/original/file-20230220-20-vg6ih2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511107/original/file-20230220-20-vg6ih2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=341&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511107/original/file-20230220-20-vg6ih2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=341&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511107/original/file-20230220-20-vg6ih2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=341&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511107/original/file-20230220-20-vg6ih2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=428&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511107/original/file-20230220-20-vg6ih2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=428&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511107/original/file-20230220-20-vg6ih2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=428&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An example of a vessel approach to an adult whale under Australia’s whale-watching guidelines; underwater vessel noise is not considered.</span>
<span class="attribution"><span class="source">Australian National Guidelines for Whale and Dolphin Watching 2017</span></span>
</figcaption>
</figure>
<p><a href="https://elifesciences.org/articles/56760">Research</a> confirms louder boat noise disturbs whales more than quiet boat noise. Boats should be as quiet as possible. </p>
<p>We recommend a noise threshold be added to whale-watching regulations, ideally around the volume of the natural underwater background noise. At this level, boat noise is perhaps audible to the whales but with a low perceived loudness. This change to the guidelines will help minimise disturbance to whales and dolphins. </p>
<p>You can see how humpback whales change their behaviour in response to low, medium and high underwater boat noise in this video from <a href="https://elifesciences.org/articles/56760#video1">our study</a>.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/BSdr6U2W53M?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/underwater-noise-is-a-threat-to-marine-life-197432">Underwater noise is a threat to marine life</a>
</strong>
</em>
</p>
<hr>
<h2>What do whale-watching boats sound like underwater?</h2>
<p>A range of different boats are used for whale watching worldwide. We have <a href="https://www.sciencedirect.com/science/article/pii/S0308597X21003870">calculated</a> the underwater noise level of whale-watching boats operating at low speeds. The quietest boat was a hybrid boat using its electric engines. </p>
<p>The vessel with the quieter electric engines was later used in an experiment with short-finned pilot whales. This <a href="https://www.nature.com/articles/s41598-021-00487-0">study</a> compared the whales’ responses to the boat’s quieter electric engines and its louder petrol engines. </p>
<figure class="align-center ">
<img alt="A spectrogram of a motorised whale-watch vessel passing at slow speed" src="https://images.theconversation.com/files/519716/original/file-20230406-20-ugamda.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/519716/original/file-20230406-20-ugamda.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=474&fit=crop&dpr=1 600w, https://images.theconversation.com/files/519716/original/file-20230406-20-ugamda.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=474&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/519716/original/file-20230406-20-ugamda.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=474&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/519716/original/file-20230406-20-ugamda.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=596&fit=crop&dpr=1 754w, https://images.theconversation.com/files/519716/original/file-20230406-20-ugamda.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=596&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/519716/original/file-20230406-20-ugamda.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=596&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A spectrogram of a motorised whale-watch vessel passing at slow speed (about 4 knots). Red shows the higher-intensity noise and blue the lower-intensity noise.</span>
<span class="attribution"><a class="source" href="https://www.sciencedirect.com/science/article/pii/S0308597X21003870">Source: Whale-watch vessel noise levels with applications to whale-watching guidelines and conservation (2021)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>What was the result? The louder engines did indeed disturb the behaviour of short-finned pilot whales compared to the quieter engines. Notably, resting and nursing of young decreased. </p>
<p>Ultimately, some vessels are better designed to minimise noise emissions. You can hear the quieter electric-engined boat in this recording from <a href="https://www.nature.com/articles/s41598-021-00487-0">the study</a>. This makes this boat more appropriate for whale watching. </p>
<p><audio preload="metadata" controls="controls" data-duration="60" data-image="" data-title="This hybrid boat's electric engine produces much less noise underwater than its petrol engine." data-size="1449893" data-source="Author provided from Arranz et al 2021." data-source-url="https://www.sciencedirect.com/science/article/pii/S0308597X21003870" data-license="Author provided" data-license-url="">
<source src="https://cdn.theconversation.com/audio/2789/arranz-et-al-2021-sound-of-hybrid-vessel-electric-engine-from-whale-watching-paper.mp3" type="audio/mpeg">
</audio>
<div class="audio-player-caption">
This hybrid boat’s electric engine produces much less noise underwater than its petrol engine.
<span class="attribution"><a class="source" rel="nofollow" href="https://www.sciencedirect.com/science/article/pii/S0308597X21003870">Author provided from Arranz et al 2021.</a>, <span class="license">Author provided</span><span class="download"><span>1.38 MB</span> <a target="_blank" href="https://cdn.theconversation.com/audio/2789/arranz-et-al-2021-sound-of-hybrid-vessel-electric-engine-from-whale-watching-paper.mp3">(download)</a></span></span>
</div></p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/511109/original/file-20230220-16-13q98k.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/511109/original/file-20230220-16-13q98k.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=533&fit=crop&dpr=1 600w, https://images.theconversation.com/files/511109/original/file-20230220-16-13q98k.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=533&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/511109/original/file-20230220-16-13q98k.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=533&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/511109/original/file-20230220-16-13q98k.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=669&fit=crop&dpr=1 754w, https://images.theconversation.com/files/511109/original/file-20230220-16-13q98k.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=669&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/511109/original/file-20230220-16-13q98k.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=669&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A mother-calf pair of pilot whales resting on the surface.</span>
<span class="attribution"><span class="source">Image: Patricia Arranz Alonso</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-scientists-need-your-help-to-spot-blue-whales-off-australias-east-coast-164620">Why scientists need your help to spot blue whales off Australia’s east coast</a>
</strong>
</em>
</p>
<hr>
<h2>Noise when arriving and departing matters too</h2>
<p>Having a quiet boat will reduce the disturbance to animals. However, even when a whale-watch operator adheres to current best-practice guidelines, there may still be disturbance. </p>
<p>This is because as a vessel increases in speed to leave the whales, it produces higher underwater noise levels. Our <a href="https://doi.org/10.1016/j.marpol.2023.105525">research</a> shows this is likely to disturb whales. So we recommend boats maintain a slow speed when approaching and departing whales – say, less than 10 knots within 1km of the whales. </p>
<p>We know it is exciting to zoom off towards a breaching whale, leaving a sleeping whale behind, but the sudden increase in boat speed and noise may then disturb that sleeping whale. </p>
<h2>5 tips to reduce boat noise</h2>
<p>On an individual level, boat operators can easily reduce disturbance to whales and dolphins by considering the following five factors.</p>
<p><strong>Speed</strong> increases noise from the propeller, so lower the speed, even when arriving/departing.</p>
<p><strong>Distance</strong>: the closer a vessel is the greater the peak in noise, so keep to the regulated distance.</p>
<p><strong>Gear shifts</strong> cause high-level noise changes, so minimise shifting.</p>
<p><strong>Approach type</strong> to the animals can cause disturbance – driving in front of their path, for example, so drive in parallel to their path.</p>
<p><strong>Movements</strong> of a boat, such as fast and erratic movements, can disturb animals, so drive consistently.</p>
<p>To further reduce noise, whale-watching companies can use larger, slower-moving propellers (to minimise the water disturbance that creates noise), quieter/electric engines and/or install noise absorption gear. </p>
<p>Both the industry and the whales will benefit from companies using quieter whale-watch boats and approaches.</p><img src="https://counter.theconversation.com/content/199977/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The multi-billion-dollar whale-watching industry enables millions of people to see these magnificent creatures up close. But the noise made by so many boats is a threat to whales’ wellbeing.Kate Sprogis, Adjunct Research Fellow, UWA Oceans Institute, The University of Western AustraliaFredrik Christiansen, Senior Researcher in Marine Biology, Aarhus UniversityPatricia Arranz Alonso, Researcher in Marine Biology, Universidad de La LagunaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2017722023-03-15T23:51:03Z2023-03-15T23:51:03ZMinimum viable whale: Antarctic minke whales may be as small as a krill-eating filter feeder can get in our modern oceans<figure><img src="https://images.theconversation.com/files/515642/original/file-20230315-28-19k321.JPG?ixlib=rb-1.1.0&rect=0%2C278%2C5452%2C3709&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A group of tagged minke whales forage off the coast of the West Antarctic Peninsula.</span> <span class="attribution"><span class="source">Duke Marine Robotics and Remote Sensing. Taken under NMFS permit #23095.</span></span></figcaption></figure><p>Meagre giants hide in the ice-covered bays and fjords of the Antarctic peninsula. Antarctic minke whales spend their summers foraging in these waters, devouring the dense and abundant krill that feed and grow underneath the sea ice. </p>
<p>These sleek and subtle predators are the smallest members of the rorqual family, which includes some of the largest animals known to have existed, such as blue, fin and sei whales. Minke whales are much smaller than their giant relatives (only about one-twentieth the mass of a blue whale), but a typical minke still weighs about five metric tonnes. That’s equivalent to 18 large grizzly bears or 45 Arnold Schwarzeneggers. </p>
<p>Despite their size, remarkably little is known about the behaviour of minkes or their role in rapidly changing Antarctic ecosystems. So, in the summers of 2018 and 2019, my colleagues and I from Stanford University, UC Santa Cruz and Duke Marine Labs teamed up to study minke whale foraging ecology.</p>
<p>Our team, led by David Cade, made <a href="https://www.nature.com/articles/s41559-023-01993-2">an amazing discovery</a>: minke whales are huge (by human standards), but they are about as small as a whale that feeds by filtering large numbers of tiny prey out of the water can be.</p>
<h2>Follow the whale</h2>
<p>We recovered high-resolution movement data from 29 tagged minke whales around the west Antarctic peninsula. In addition to these new and enlightening behavioural data, the sizes of tagged individuals were studied from drone-based photographs. </p>
<p>The <a href="https://ecoevocommunity.nature.com/posts/measuring-the-ultra-high-foraging-rates-of-antarctic-minke-whales">combination of these two datasets</a> allowed us to investigate minke whale feeding strategies in previously unseen detail. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-recently-discovered-whale-feeding-strategy-has-turned-up-in-2-000-year-old-texts-about-fearsome-sea-monsters-200724">A ‘recently discovered’ whale feeding strategy has turned up in 2,000-year-old texts about fearsome sea monsters</a>
</strong>
</em>
</p>
<hr>
<p>Antarctic minke whales, along with their supersized rorqual cousins, use a technique called engulfment filtration feeding (or lunge feeding) to hunt Antarctic krill. This strategy requires the whale to accelerate to a speed of about 4 metres per second before filling its mouth with prey-laden water that is then filtered through a sieve-like structure known as baleen. </p>
<p>Engulfment filtration feeding is highly efficient, even for the largest individuals, as blue whales continue to <a href="https://doi.org/10.1242/jeb.048157">increase in feeding efficiency</a> with greater size.</p>
<h2>Hunting at night</h2>
<p>Compared to blue whales, each lunging gulp a minke takes contains far less food per kilogram of whale. However, the tag data revealed another way that minkes make up for this energy disparity. </p>
<p>Where a 20m blue whale can take up to two minutes to engulf and filter its prey, 7-10m minkes can complete an engulfment cycle in a matter of seconds. By day, minke whales are rarely able to capitalise on their speedy eating habits, as they may have to dive over 100m to reach their prey. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/humpback-whales-have-been-spotted-bubble-net-feeding-for-the-first-time-in-australia-and-we-have-it-on-camera-157355">Humpback whales have been spotted 'bubble-net feeding' for the first time in Australia (and we have it on camera)</a>
</strong>
</em>
</p>
<hr>
<p>This means much of their daytime foraging is spent at the surface or swimming to depth, as they need air just like any other mammal. But as night falls, the krill move upward in the water column to the surface. </p>
<p>Soon enough, the minke whales no longer need to hold their breath for minutes at a time just to reach their prey. Then, the minkes become like Pac-Man in their polar environment as they accelerate, engulf, filter and repeat as fast as they possibly can. They consume krill at the absolute limit that their body size imposes on their filtering time. </p>
<h2>An evolutionary mystery</h2>
<p>The smaller the minke, the faster it filters, but it also becomes less efficient with each gulp. By extrapolating the tag data, we found that minkes below a specific size – 5m, or about the length of a newly weaned minke whale – are not able to filter fast enough to meet their basic energetic needs (the cost of living imposed by metabolism and growth). </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-are-bigger-animals-more-energy-efficient-a-new-answer-to-a-centuries-old-biological-puzzle-188724">Why are bigger animals more energy-efficient? A new answer to a centuries-old biological puzzle</a>
</strong>
</em>
</p>
<hr>
<p>This tells us that while minke whales are still quite large, they are about as small as they can be in our modern ocean conditions. The specific minimum size limit of these whales is highly dependent on the rorqual foraging strategy, energetically costly lunge feeding and the high costs of heating and maintaining their mammalian bodies. </p>
<p>However, we suspect the basic principle of this minimum size constraint, that only a limited amount of water can be filtered per time, can help crack an evolutionary chicken-or-egg mystery: what came first, filter-feeding or large body size? </p>
<h2>Filter feeders have always lived large</h2>
<p>Way back in time, when animals first emerged in the early Cambrian era, the first free-swimming filter-feeder was the large (70cm was large for the time) <a href="https://doi.org/10.1038/nature13010">shrimp-like <em>Tamisiocaris borealis</em></a>, which raked planktonic creatures from the water with its comb-like front appendages. </p>
<p>Over the next 500 million years, the fossil record shows a diverse range of creatures occupying this free-swimming filter feeder role. They include bony fishes, cartilaginous sharks and rays, ancient reptilian ichthyosaurs and the gargantuan mammals we know as modern baleen whales. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-the-smallest-animal-ever-121528">What is the smallest animal ever?</a>
</strong>
</em>
</p>
<hr>
<p>While these animals originate from very different branches of the tree of life, they all have one thing in common: they are large. Most often the largest of their kind. </p>
<p>Our minke whales, the diminutive giants, tell us this is no coincidence. Filter feeding requires a large body size to evolve. But when filter feeding does evolve, it can drive large animals to become colossal.</p><img src="https://counter.theconversation.com/content/201772/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jake Linsky 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>Antarctic minke whales are elusive and hard to track – but a new study of their behaviour offers clues to their evolution and the limits of their filter-feeding behaviour.Jake Linsky, Researcher, School of Earth and Environmental Sciences, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1980902023-01-19T06:11:41Z2023-01-19T06:11:41ZOffshore wind farm construction is noisy – but gadgets used to protect marine mammals are working<figure><img src="https://images.theconversation.com/files/505122/original/file-20230118-22-euadqv.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4595%2C3061&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Harbour porpoises are the most common toothed whale in the turbine-rich North Sea.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/harbour-porpoise-phocoena-2137783321">Onutancu/Shutterstock</a></span></figcaption></figure><p><a href="https://energy.ec.europa.eu/topics/renewable-energy/offshore-renewable-energy_en#:%7E:text=The%20deployment%20of%20offshore%20wind,the%205%20EU%20sea%20basins.">The European Union</a> had 14.6 gigawatts (GW) of offshore wind energy installed in 2021, and this is projected to increase by at least 25 times in the next ten years. While an expanding renewable energy sector is necessary to replace fossil fuels and slow climate change, it must not come at a cost to <a href="https://theconversation.com/uk/topics/biodiversity-486">Earth’s embattled wildlife</a>. </p>
<p>To date, most offshore wind turbines have been built using fixed foundations, typically steel piles that are driven into the seabed with hydraulic hammers – often very large ones. The noise that pile-driving generates can be heard tens of kilometres from the source as short and sharp concussions like gunfire.</p>
<p>Sound travels much more efficiently in water than in air. Marine mammals like whales and porpoises use it to communicate over long distances, sense the environment and locate prey. This dependence on sound makes marine mammals <a href="https://doi.org/10.1644/07-MAMM-S-307R.1">particularly vulnerable</a> to the effects of man-made noise, including the noisy construction of offshore wind farms. Pile-driving can deafen, injure or even kill marine mammals at close range.</p>
<p>The harbour porpoise is the smallest and <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.606609">most common</a> species of cetacean in the North Sea, where EU countries hope to generate <a href="https://windeurope.org/policy/joint-statements/the-esbjerg-offshore-wind-declaration/">150 GW</a> of offshore wind energy by 2050. Like bats, these relatives of whales and dolphins emit clicks to echolocate almost continuously. This helps them find and identify objects, including food. Acoustic deterrents, small devices which emit pulses of sound, are used to scare marine mammals away from where wind farms are being built to protect them from the noise generated by pile-driving. Until recently though, no one was sure how well these deterrents worked.</p>
<figure class="align-center ">
<img alt="The dorsal fins and backs of two harbour porpoises emerging from the water." src="https://images.theconversation.com/files/505126/original/file-20230118-14-1r7n63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505126/original/file-20230118-14-1r7n63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505126/original/file-20230118-14-1r7n63.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505126/original/file-20230118-14-1r7n63.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505126/original/file-20230118-14-1r7n63.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505126/original/file-20230118-14-1r7n63.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505126/original/file-20230118-14-1r7n63.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">Harbour porpoises, as the name suggests, are found in coastal waters.</span>
<span class="attribution"><span class="source">University of Aberdeen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>My colleagues at the University of Aberdeen’s Lighthouse Field Station and the University of St. Andrews’ Sea Mammal Research Unit developed <a href="https://doi.org/10.1098/rsbl.2022.0101">a portable acoustic recorder</a> which can detect the movements of harbour porpoises. Using an array of these recorders during pile-driving at an offshore wind farm in north-east Scotland, we showed that acoustic deterrents work – porpoises swim directly away from the pulses of sound, ameliorating the most severe impacts of construction at sea. </p>
<h2>Fighting noise with noise</h2>
<p>A range of <a href="https://doi.org/10.3390/jmse9080819">measures</a> have been deployed to minimise the harm from offshore wind farm construction. Acoustic deterrent devices, which are switched on before pile-driving begins, are supposed to empty the sea of marine mammals tens to hundreds of metres around the construction site, where the noise is expected to be most damaging. These <a href="https://doi.org/10.3354/meps10482">electronic devices</a> were originally developed for use in the aquaculture industry to deter seals from fish farms.</p>
<figure class="align-center ">
<img alt="A wind turbine on a yellow platform in the ocean." src="https://images.theconversation.com/files/505128/original/file-20230118-22-rpeyaq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505128/original/file-20230118-22-rpeyaq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505128/original/file-20230118-22-rpeyaq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505128/original/file-20230118-22-rpeyaq.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505128/original/file-20230118-22-rpeyaq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505128/original/file-20230118-22-rpeyaq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505128/original/file-20230118-22-rpeyaq.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Offshore wind turbine foundations are driven into the seabed.</span>
<span class="attribution"><span class="source">University of Aberdeen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Despite <a href="https://doi.org/10.3354/MEPS10100">experimental trials</a>, there is limited evidence to show how well acoustic deterrents work during construction. This is, at least in part, due to the difficulties of working in the marine environment, but also because of the challenges involved in studying animals that are highly mobile, relatively rare and live most of their lives underwater and out of sight. These factors make it very hard to observe how marine mammals react to particular noises or disturbances. Fortunately, we were able to turn the dependence of harbour porpoises on sound to our advantage.</p>
<p>Recent advances in <a href="http://dx.doi.org/10.1371/journal.pone.0229058">passive acoustic monitoring</a> meant that we could use a sound recorder connected to a small cluster of underwater microphones, called hydrophones, to study porpoise movements. By measuring tiny differences in the time of arrival of porpoise echolocation clicks at the four hydrophones, we identified the direction from which they were echolocating. The harbour porpoise’s echolocation beam is <a href="https://doi.org/10.1121/10.0001376">narrow and forward-facing</a>, and so from these findings, we were able to determine the direction in which they were swimming.</p>
<figure class="align-center ">
<img alt="A drum covered in electronic devices is lowered over the side of a boat into the ocean." src="https://images.theconversation.com/files/505120/original/file-20230118-20-8vvg3x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505120/original/file-20230118-20-8vvg3x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505120/original/file-20230118-20-8vvg3x.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505120/original/file-20230118-20-8vvg3x.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505120/original/file-20230118-20-8vvg3x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505120/original/file-20230118-20-8vvg3x.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505120/original/file-20230118-20-8vvg3x.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">A hydrophone cluster being deployed.</span>
<span class="attribution"><span class="source">University of Aberdeen</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We found that when acoustic deterrents were in use, the clicks of harbour porpoises we detected indicated they were swimming directly away from the construction site. This proves that acoustic deterrent devices can make offshore wind farm construction safer. </p>
<p>We did detect responses among harbour porpoises up to 7 km from the construction site, suggesting that these deterrent devices may be almost too good at their job. Such a long-distance effect could displace animals from important feeding sites and highlights the importance of a balance between preventing injuries and minimising disturbance.</p>
<p>Our portable acoustic recorder can now improve protection for marine mammals by more accurately determining how they respond to disturbance across a wide range of habitats. It will also allow researchers to gauge the effectiveness of measures used to minimise disturbance during wind farm construction or other activities, including animal deterrents and systems for reducing the noise produced by piling at construction sites.</p>
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<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Isla Graham received funding from Moray Offshore Wind Farm (East) Ltd. The funding body had no input in data collection, data analysis or interpretation. The aims, scope and experimental design of the study were developed by the authors to meet Moray Offshore Wind Farm (East) Ltd planning consent conditions. These were agreed by the regulator Marine Scotland Licensing and Operations Team following consultation with statutory advisors represented on the Moray Firth Regional Advisory Group (MFRAG), a stakeholder group that was established by the Scottish government to oversee the monitoring programme.</span></em></p>A new acoustic recorder could track the movements of marine mammals more accurately.Isla Graham, Research Fellow, School of Biological Sciences, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1795412022-03-25T13:48:16Z2022-03-25T13:48:16ZWe’ve discovered why some whales stop feeding in response to the sound of sonar<p>In September 2002, a number of beaked whales were stranded and killed in the Canary Islands during a <a href="https://www.theguardian.com/world/2002/sep/28/animalwelfare.nato">NATO naval exercise</a>. It was the first time we started to get a real understanding of the negative <a href="https://www.researchgate.net/publication/228346496_Beaked_Whale_Strandings_and_Naval_Exercises">effects of sonar sounds</a> on cetaceans, which includes whales, dolphins and porpoises.</p>
<p>But why did the noise of sonar seem to affect beaked whales in particular, rather than other species of cetacean?</p>
<p>In our <a href="https://www.pnas.org/doi/full/10.1073/pnas.2114932119">new research</a>, we’ve discovered that the response of each species to predators could explain why some whales and dolphins are more sensitive to this human-made noise.</p>
<p>It was back in the early 2000s that we (along with other researchers around the world) began to study the <a href="https://www.int-res.com/abstracts/esr/v31/p293-315/">impact of sonar</a> on free-ranging whales. These new “behavioural responses studies” exposed different cetacean species to gradually increasing levels of sonar – with careful monitoring to keep the animals from harm. We were then able to identify the level of sonar noise at which behavioural changes began to occur. </p>
<p>From that early research we knew that feeding is commonly affected when marine mammals are disturbed by sonar, and some species are markedly more sensitive to this exposure than others. For example, <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2013.0223">Cuvier’s beaked whales</a> showed dramatically more severe changes in their feeding habits (swimming rapidly and silently away while extending their length of dive and non-feeding period) than <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2013.0657">blue whales</a>. </p>
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Read more:
<a href="https://theconversation.com/are-marine-protected-areas-helping-marine-mammals-and-birds-maybe-but-more-can-be-done-173045">Are marine protected areas helping marine mammals and birds? Maybe, but more can be done</a>
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<p>But until now the reasons for this differing response between species <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.12955">were unclear</a>. So, we decided to investigate whether they were responding to human-made sound in <a href="https://www.ecologyandsociety.org/vol6/iss1/art11/">a similar way</a> to their response to predators, as some theories suggested. </p>
<h2>Exposing whales to sound</h2>
<p>Most cetaceans are themselves the prey of another cetacean, the <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2907.1991.tb00291.x">killer whale</a>. Some species, including beluga and beaked whales, have few defence mechanisms. But others are safer due to their large body size, like sperm whales, or large social groups, such as pilot whales.</p>
<p>This means that different species respond differently to the presence of killer whales. We set out to discover whether four cetacean species respond to navy sonar in the same way they respond to the sounds of predatory killer whales – and whether differences across the species related to their natural level of risk from these fearsome predators.</p>
<p>By tagging the animals with <a href="https://ieeexplore.ieee.org/document/1190131">suction-cupped recording devices</a> – which capture the timing of both sound and movement – we were able to monitor the feeding and movement of 43 tagged whales off the coast of Norway: three toothed whale species (northern bottlenose, sperm and long-finned pilot) and one baleen whale species (humpback). </p>
<p>We measured their reduction in feeding time when exposed to naval sonar – varying from one to four kilohertz – and compared it to their response to recordings of predatory killer whale sounds. </p>
<h2>Links to predator threat</h2>
<p>We found that both naval sonar and the predator sounds caused a clear reduction in feeding time across the four whale species. By contrast feeding activity was unaffected when we exposed them to the sounds of sea vessels without sonar or other control sounds.</p>
<p>Strikingly, each species responded similarly to sonar and predatory sounds: northern bottlenose whales had the strongest response and ceased foraging for food entirely (100% loss of feeding time), followed by humpback whales and long-finned pilot whales (both approximately 75%). Sperm whales had the lowest response, reducing time spent feeding by approximately 50% to both sounds.</p>
<p>It’s clear that the different hearing sensitivity of each species is not sufficient to explain the observed difference – that’s because the humpback whales, which have the best hearing in the frequency band of the sonar, were not the most sensitive. </p>
<p>Instead our findings indicate that risk from killer whales plays a role in driving the responses, and that adaptations to their predators can explain cetacean sensitivity to human-made noise.</p>
<p>The northern bottlenose whales, who rely on crypsis (staying hidden) and flight to reduce their risk of death by killer whale, were very cautious and gave up feeding when detecting sounds of potential threats – but the species that are less vulnerable to predation were also less responsive to sounds of killer whales and sonar.</p>
<h2>Implications for Arctic whales</h2>
<p>Our findings can help to predict which cetaceans are likely to have extreme responses to human generated ocean noise – and help us to set appropriate conservation priorities.</p>
<p>The findings are particularly relevant to cetacean species in the Arctic as they are at highest risk of predation.</p>
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<strong>
Read more:
<a href="https://theconversation.com/killer-whales-taking-food-from-fishing-lines-reveal-something-intriguing-about-human-evolution-176050">Killer whales taking food from fishing lines reveal something intriguing about human evolution</a>
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<p>For example, Narwhal behaviour and distribution is influenced by <a href="https://www.pnas.org/doi/abs/10.1073/pnas.1611707114">Arctic killer whales</a> and, as we would expect, they are sensitive to <a href="https://www.frontiersin.org/articles/10.3389/fmars.2021.658173/full?fbclid=IwAR1UYzZw4AP7vOgzcqzQ3kpLaAuF83pCGbphddeV8rRzmeprMPlYOPtDNjU">human-made sounds</a> such as airgun pulses and ship noise.</p>
<p>As sea ice rapidly decreases, Arctic cetaceans face a double whammy of impacts – increasing levels of predation from more killer whale movements into ice-free zones, as well as increasing levels of noise from human activities, such as seismic exploration, military and shipping. </p>
<p>As well as the risk of immediate injury or death, it will be important to consider the effects of human disturbance on their feeding and other behaviours.</p><img src="https://counter.theconversation.com/content/179541/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>I was a member of the team that received funding from various navy sponsors to study the effects of sonar on cetaceans.
The research was carried out independently from sponsor influence, and our publication policy states: "...under no circumstances can sponsors claim the right to influence the scientific analysis, interpretation and publication of original data in a binding way." The polluter therefore appropriately paid for this research, but had no influence on the conduct or publication of the research. </span></em></p><p class="fine-print"><em><span>As with Patrick Miller.</span></em></p><p class="fine-print"><em><span>As with Patrick Miller</span></em></p>Whale species at higher risk of predation from killer whales are more adversely affected by the sound of sonar.Patrick Miller, Professor of Biology, University of St AndrewsCharlotte Cure, Researcher in Bioacoustics, UMRAE, FranceSaana Isojunno, Research fellow, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1788052022-03-14T11:20:58Z2022-03-14T11:20:58ZWhale migrations: how new UN treaty aims to protect species on the high seas<figure><img src="https://images.theconversation.com/files/450908/original/file-20220309-2144-7siqi9.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1599%2C1065&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Humpback whales (_Megaptera novaeangliae_) frolicking at the ocean surface.</span> <span class="attribution"><a class="source" href="https://www.naturepl.com/blog/">Tony Wu/WWF</a>, <span class="license">Author provided</span></span></figcaption></figure><p>A humpback whale we tagged while it was feeding off the <a href="https://doi.org/10.1186/s40317-021-00266-8">Western Antarctic Peninsula</a> made a nearly 19,000 km-round trip in 265 days, travelling north from Antarctica to its breeding area off Colombia and back. Whales migrate thousands of kilometres each year, gathering to mate and give birth in the tropics and subtropics during winter and then heading for cooler waters in higher latitudes to feast on abundant prey during summer.</p>
<p><a href="https://doi.org/10.1111/j.1748-7692.1999.tb00887.x">Theories abound</a>, but scientists still can’t agree on why whales undertake these <a href="https://doi.org/10.1111/j.1748-7692.2001.tb01289.x">epic migrations</a>, or even how they manage to navigate <a href="https://doi.org/10.3389/fmars.2020.00414">vast ocean basins</a>.</p>
<p><a href="https://wwfwhales.org/resources/protecting-blue-corridors-report">In a new report</a> from WWF, a global environment charity, scientists compiled the migration tracks of over 1,000 whales worldwide, recorded using satellite tags. For the first time, the global scale and extent of the routes whales traverse during their migrations were illuminated. The report adds to the <a href="https://doi.org/10.1098/rspb.2019.1472">growing understanding</a> among scientists that the routes between critical feeding and breeding habitats are as important to whales as the endpoints themselves.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the world with whale migration routes highlighted." src="https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=477&fit=crop&dpr=1 600w, https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=477&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=477&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=599&fit=crop&dpr=1 754w, https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=599&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/450907/original/file-20220309-30-1ezimew.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=599&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">Migration tracks of over 1,000 whales worldwide, from the WWF Protecting Blue Corridors report.</span>
<span class="attribution"><a class="source" href="https://wwfwhales.org/news-stories/protecting-blue-corridors-report">WWF</a>, <span class="license">Author provided</span></span>
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<p>These routes also reveal how <a href="https://doi.org/10.3354/esr01115">perilous</a> the <a href="https://doi.org/10.1126/science.aba4658">ocean</a> is becoming for these giants. Climate change is shifting the places and times that whales can <a href="https://doi.org/10.1111/gcb.15465">reliably find food</a>, while fisheries are discarding nets and ropes that can <a href="https://doi.org/10.3354/meps09923">ensnare and drown whales</a>. Meanwhile around <a href="https://www.ics-shipping.org/shipping-fact/shipping-and-world-trade-driving-prosperity/#:%7E:text=Some%2011%20billion%20tons%20of%20goods%20are%20transported%20by%20ship%20each%20year.">11 billion tons of cargo</a> is moved by sea each year. The routes these ships use cross the <a href="https://doi.org/10.1002/fee.1987">paths</a> of migrating whales and other marine animals which may be struck and killed.</p>
<p>Six out of the 13 largest whale species are either endangered or vulnerable according to the International Union for Conservation of Nature, even after decades of protection following the end of most commercial whaling in <a href="https://iwc.int/whaling">1986</a>.</p>
<p>Marine protected areas created by individual countries are one way to shield whales from some of these threats. These are zones where certain activities, like fishing, are restricted or prohibited. Currently, marine protected areas cover <a href="https://www.protectedplanet.net/en/thematic-areas/marine-protected-areas">less than 8%</a> of the ocean.</p>
<p>But whales move through the waters of multiple countries during their migration and spend much of this time in the high seas, where only <a href="https://www.sciencedirect.com/science/article/pii/S0308597X19309194">1.2%</a> of the ocean is under some form of protection. Clearly, protecting whales requires a global effort.</p>
<h2>Whales beyond borders</h2>
<p>Geopolitical boundaries are invisible to whales but have extraordinary consequences for them. Under the United Nations Convention on <a href="https://www.un.org/depts/los/convention_agreements/convention_overview_convention.htm">the Law of the Sea</a>, countries have rights to fish and pursue other activities in 200-nautical mile exclusive economic zones (EEZ) extending from their coastlines. Countries designating marine protected areas within their EEZs can help <a href="https://doi.org/10.1126/science.aad5443">conserve local ocean habitats</a>.</p>
<p>But since laws vary substantially from country to country, it’s difficult to coordinate efforts to protect whales, although international agreements like the <a href="https://www.cms.int/en/convention-text">Convention on the Conservation of Migratory Species of Wild Animals</a> try to do just this. </p>
<p>It does little good protecting whales in one country, using measures like marine protected areas or rules restricting shipping and fishing, when they may face looser regulation in another country’s EEZ during a single migration. The WWF report showed that 367 humpback whales tracked by satellite in the southern hemisphere together traversed the EEZs of 28 countries during their migrations.</p>
<p>The 64% of the ocean which encompasses the high seas is beyond any EEZ and the authority of any single nation. Whales migrate between habitats thousands of kilometres apart, so it’s unsurprising that many species spend much of their lives there. The 367 tracked humpbacks spent half their time in these areas of the ocean beyond national jurisdictions. </p>
<p>A <a href="https://doi.org/10.1038/s41559-018-0646-8">2018 study</a> tracked 14 large species, from leatherback turtles to white sharks, throughout the Pacific Ocean and revealed that 29% of all the positions recorded by satellite tags were in the high seas. In <a href="https://doi.org/10.1038/s41586-020-2126-y">a 2020 study</a>, we estimated that only 27% of important areas for marine mammals and seabirds in the Southern Ocean were within EEZs.</p>
<figure class="align-center ">
<img alt="Five large open whale mouths surrounded by sea gulls at the ocean surface." src="https://images.theconversation.com/files/451817/original/file-20220314-17-mxfq6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/451817/original/file-20220314-17-mxfq6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=351&fit=crop&dpr=1 600w, https://images.theconversation.com/files/451817/original/file-20220314-17-mxfq6x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=351&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/451817/original/file-20220314-17-mxfq6x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=351&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/451817/original/file-20220314-17-mxfq6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=441&fit=crop&dpr=1 754w, https://images.theconversation.com/files/451817/original/file-20220314-17-mxfq6x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=441&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/451817/original/file-20220314-17-mxfq6x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=441&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Some whales congregate in cool, productive waters to feed.</span>
<span class="attribution"><span class="source">Chad Graham/WWF-Canada</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Marine protected areas on the high seas</h2>
<p>International negotiations are underway to figure out how to protect ocean species, including whales, outside of EEZs. In the <a href="https://mpatlas.org/countries/HS">more than 222 million km²</a> that make up the high seas, there are almost no marine protected areas.</p>
<p>United Nations member states agreed in 2017 to <a href="https://www.un.org/bbnj/">negotiate</a> an international treaty for the conservation and sustainable use of marine biodiversity of the high seas. The fourth and final session of these negotiations takes place in New York on March 7-18. The treaty will include ways that marine protected areas could be designated in the high seas, and these areas could restrict activities that threaten whales and other marine species in areas critical for their survival.</p>
<p>The treaty won’t design and implement these marine protected areas, though. That will rely on organisations like the Marine Mammal Protected Areas Task Force, which, with the help of scientists, has located <a href="https://doi.org/10.1017/S0030605321000272">at least 159</a> <a href="https://www.marinemammalhabitat.org/immas/">important marine mammal areas</a> that could become protected. <a href="https://doi.org/10.1016/j.tree.2019.01.009">The migration tracks</a> in the WWF report will be essential when it comes to identifying them.</p>
<p>Marine protected areas are only one measure among several which will be needed to make the high seas safer for marine mammals. Conservationists have to address mounting threats from climate change, fisheries, shipping and pollution. </p>
<p>There are glimmers of hope, however. The <a href="https://doi.org/10.1073/pnas.2121360119">International Maritime Organization</a> and the <a href="https://iwc.int/ship-strikes">International Whaling Commission</a> are collaborating to prevent ships from striking whales. Meanwhile, modifications to fishing equipment and other tools have <a href="https://doi.org/10.3389/fmars.2021.754755">reduced the number</a> of dolphins caught in eastern tropical Pacific yellowfin tuna fisheries by 99%. Critical to any successful conservation effort is a solid foundation of scientific evidence and cooperation on local, regional and international scales.</p><img src="https://counter.theconversation.com/content/178805/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ryan Reisinger receives funding from the WWF, the Antarctic Wildlife Research Fund and the International Whaling Commission. </span></em></p><p class="fine-print"><em><span>Ari Friedlaender has received funding from the WWF, Antarctic Wildlife Research Fund, and the International Whaling Commission. </span></em></p><p class="fine-print"><em><span>Daniel M. Palacios receives funding from the US Navy, WWF, and the International Whaling Commission.</span></em></p>A new report shed light on the migratory routes of 1,000 whales worldwide.Ryan Reisinger, Lecturer in Marine Biology and Ecology, University of SouthamptonAri Friedlaender, Professor of Ocean Sciences, University of California, Santa CruzDaniel M. Palacios, Endowed Associate Professor in Whale Habitats, Oregon State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1617752021-06-21T15:41:42Z2021-06-21T15:41:42ZBlackfish: how captive killer whale documentary ended SeaWorld’s orca breeding programme<figure><img src="https://images.theconversation.com/files/407414/original/file-20210621-21-1b8xdi6.jpg?ixlib=rb-1.1.0&rect=0%2C4%2C1022%2C682&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tilikum, the orca who killed three trainers, was captured at the age of two and performed for most of his life.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Tilikum_(killer_whale)#/media/File:Tilikum_(orca)_(Shamu).jpg">Milan Boers/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>After its premiere at the Sundance Film Festival in January 2013, the documentary <a href="https://www.blackfishmovie.com/">Blackfish</a> reached nearly 21 million viewers within its first month of airing on CNN. The film tells the bleak story of Tilikum, a performing orca at the US marine park SeaWorld. </p>
<p>After being taken from his mother in the wild <a href="https://journals.sagepub.com/doi/full/10.1177/2329488419884139">at the age of two</a>, Tilikum was held in a tank at SeaLand Canada with two larger females who <a href="https://www.thedodo.com/tilileaks-exclusive-documents--639864949.html">routinely attacked him</a>. Together the three SeaLand orcas <a href="https://edition.cnn.com/2013/10/26/world/americas/orca-trainer-tilikum-keiko/index.html">killed a trainer</a>, and Tilikum was transferred to SeaWorld in Orlando on <a href="https://www.pbs.org/wgbh/pages/frontline/shows/whales/seaworld/tilikum/nmfsltr.html#conditions">the understanding</a> that he should no longer perform. This advice was ignored, and Tilikum went on to <a href="https://www.theguardian.com/environment/2015/mar/28/seaworld-trainer-john-hargrove-killer-whale-treatment">kill two more people</a>, including trainer Dawn Brancheau at SeaWorld in Orlando in 2010.</p>
<p>Blackfish presented Tilikum’s aggression as symptomatic of post-traumatic stress, induced by a life in captivity. This contradicted SeaWorld’s claims that orcas <a href="https://www.bizcominthenews.com/files/seaworlds-response-to-blackfish-1.pdf">cooperated willingly</a> during each show. The documentary sparked a public outcry against orca captivity.</p>
<p>The hashtag #EmptyTheTanks spread on Twitter and viewers pressured artists into cancelling their shows at SeaWorld and demanded corporate sponsors such as SouthWest Airlines to drop their partnerships with the company. There were also protests outside the park, and in cities worldwide.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/G93beiYiE74?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>In the year following Blackfish’s release, SeaWorld’s attendance dropped by one million visitors. In 2014, the company announced a 84% fall in income and saw its share price drop by 33%. Although SeaWorld attributed this to “<a href="https://www.seaworldinvestors.com/news-releases/news-release-details/2015/SeaWorld-Entertainment-Inc-Reports-Fourth-Quarter-and-Full-Year-2014-Results/default.aspx">the seasonal nature of the business</a>”, the <a href="https://www.marketwatch.com/story/will-seaworld-tank-after-expose-in-blackfish-2013-11-07">media</a> largely blamed Blackfish. In September 2014, SeaWorld’s shareholders launched a lawsuit against the park, claiming it had <a href="https://nypost.com/2014/09/10/seaworld-sued-by-shareholders-over-blackfish-scandal/">misled investors</a> about the effect the documentary would have on its business. In February 2020 SeaWorld agreed to pay out $65m to settle lawsuit claims. </p>
<p>In 2016, SeaWorld announced the immediate end of its orca breeding programme, and in the same year, California passed a ban on captive orca breeding. Five years on, we conducted a <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1002/pan3.10221">study</a> to find out just how influential Blackfish was in bringing about that decision.</p>
<h2>Blackfish’s impact</h2>
<p>The high number of viewers, social media engagement and press coverage indicate the documentary had a wide reach, but they cannot tell us the role that Blackfish actually played in changing SeaWorld’s policies compared to other factors. For this, we carried out an impact evaluation to disentangle the complex causes.</p>
<p>We used a method from conservation which attempts to understand why a <a href="https://conbio.onlinelibrary.wiley.com/doi/abs/10.1111/cobi.13218">species has recovered</a> in the wild. We compiled a list of 15 potentially important factors that could have led to the change in SeaWorld’s breeding policy and stock market drop, including competition from other marine or theme parks, economic factors that meant guests had less spending money, the 2015 change in SeaWorld’s leadership, and the effect of other media – like the 2015 book Beneath the Surface, written by a former SeaWorld trainer.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/405024/original/file-20210608-28218-d81fst.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/405024/original/file-20210608-28218-d81fst.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/405024/original/file-20210608-28218-d81fst.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/405024/original/file-20210608-28218-d81fst.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/405024/original/file-20210608-28218-d81fst.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/405024/original/file-20210608-28218-d81fst.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/405024/original/file-20210608-28218-d81fst.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Timeline of key events pre- and post-release of Blackfish.</span>
<span class="attribution"><span class="source">Laura Thomas-Walters</span></span>
</figcaption>
</figure>
<p>We interviewed 26 people with expertise in marine conservation, marine mammal training, zoo and aquarium collections, animal welfare and media communication. This included SeaWorld trainers, though SeaWorld’s leadership refused to take part. We asked them, based on their expert knowledge, whether they thought each of the 15 factors may have affected SeaWorld, and how. We then looked for corroborating evidence.</p>
<p>After eliminating less plausible explanations, our analysis indicated that the negative publicity resulting from Blackfish changed how people viewed orca captivity, and this, rather than a seasonal variation in guest numbers led to a drop in SeaWorld’s visitors and market value. This became particularly clear when we compared SeaWorld’s stock market value over the same period to other amusement parks, such as Disneyland and Universal Studios.</p>
<p>Interviewees identified several reasons why Blackfish had such an impact. The support from major distribution channels like CNN lent credibility to the documentary and allowed it to reach a large audience. As one former employee of SeaWorld said:</p>
<blockquote>
<p>Having that movie picked up by CNN gave it credence [and] made people think…this isn’t just a propaganda piece. This is news.</p>
</blockquote>
<p>Blackfish also made viewers empathise with Tilikum. One media communication expert screened Blackfish with her students and described its impact:</p>
<blockquote>
<p>They get really emotional, very sad or very angry but quite a strong emotional reaction.</p>
</blockquote>
<p>The testimonies of the diverse range of experts we interviewed suggested that viewers felt SeaWorld had been dishonest and reckless. As one animal welfare campaigner put it: </p>
<blockquote>
<p>It just really offended people that they’ve been lied to for so long… A very severe blow to a company that relies on the goodwill of the public.</p>
</blockquote>
<p>The company’s dismissal of Blackfish as <a href="http://web.archive.org/web/20140122131934/http://seaworld.com/en/truth/truth-about-blackfish/">propaganda</a> did not help either. One person who worked in the aquarium industry said SeaWorld had been “incredibly slow to anticipate the fallout.”</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/404911/original/file-20210607-27-ddhdvq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/404911/original/file-20210607-27-ddhdvq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=812&fit=crop&dpr=1 600w, https://images.theconversation.com/files/404911/original/file-20210607-27-ddhdvq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=812&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/404911/original/file-20210607-27-ddhdvq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=812&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/404911/original/file-20210607-27-ddhdvq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1020&fit=crop&dpr=1 754w, https://images.theconversation.com/files/404911/original/file-20210607-27-ddhdvq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1020&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/404911/original/file-20210607-27-ddhdvq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1020&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Overall theory of change depicting the impacts of Blackfish, including the contributing drivers that explain how Blackfish came to be so influential. The thick outlines show the original intervention (Blackfish) and outcomes of interest in the study.</span>
<span class="attribution"><span class="source">Laura Thomas-Walters</span></span>
</figcaption>
</figure>
<p>But our study also made clear that the timing of Blackfish’s release was vital. Various filmed and written works released prior to Blackfish, such as the 2009 documentary The Cove, had slowly influenced public attitudes towards marine mammal welfare and rights. </p>
<p>Blackfish benefited from a perfect storm, building upon decades of animal welfare and animal rights activism against marine mammal captivity. </p>
<p>By exploiting that and creating an emotional bond with viewers through the plight of Tilikum, Blackfish achieved what researchers have so far only speculated about when it comes to the potential of documentaries – sparking widespread activism and, ultimately, change.</p><img src="https://counter.theconversation.com/content/161775/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laura Thomas-Walters conducted this research with Laure Boissat, which formed part of Boissat's Master’s in Biodiversity Conservation and Management at the University of Oxford. Boissat went on to work for World Animal Protection.</span></em></p><p class="fine-print"><em><span>Diogo Veríssimo has consulted for several zoological parks in the US and UK.</span></em></p>Blackfish struck an emotional chord over the plight of a traumatised performing whale, prompting real change.Laura Thomas-Walters, Postdoctoral Research Fellow in Biological and Environmental Sciences, University of StirlingDiogo Veríssimo, Research Fellow in Conservation Marketing, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1591412021-04-28T20:06:59Z2021-04-28T20:06:59ZMammals’ brains: new research shows bigger doesn’t always mean smarter<figure><img src="https://images.theconversation.com/files/397292/original/file-20210427-21-vgtopa.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1280%2C417&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Javier Lazaro/www.lazaroillustration.com</span></span></figcaption></figure><p>If a friend boasts of having a “big-brained” dog, your reaction is probably not to ask “relative to what?”. You would simply assume your friend thinks their dog is pretty smart. But are we always right to equate big brains with greater intelligence?</p>
<p>In a study <a href="https://advances.sciencemag.org/content/7/18/eabe2101">published today in Science Advances</a>, we and our colleagues describe how the relationship between large brains and “intelligence” in mammalian evolution isn’t as straightforward as you might assume.</p>
<p>A key problem is that, in evolutionary terms, a “large brain” doesn’t just refer to the absolute size of the brain. Rather, we refer to mammals as big-brained when their brain volume is large relative to their body mass.</p>
<p>There are many examples of intelligent animals that are also large-brained for their size. Humans are a particularly extreme case; our brains are roughly seven times larger than expected for an animal of our size. Dogs are also famously large-brained and smart, as are whales, dolphins and elephants. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Scatter plot of brain size relative to body size" src="https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=508&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=508&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=508&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=638&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=638&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397485/original/file-20210428-23-1dtmwd3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=638&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Brain to body size plot highlighting humans and hominins (species ancestral to humans) in red, dolphins in black, other toothed whales in grey, bears in blue, and seals and sea lions in purple.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This big-equals-smart equivalence has also been applied in research on mammalian brain size evolution, under the assumption that relatively large mammalian brains evolve in situations where natural selection favours greater intelligence. But what if it’s not brain size that became larger, but body size that became smaller?</p>
<p>To investigate this question, we assembled the largest data set of brain and body masses of mammals from the existing literature. In total, we compiled size data for 1,400 mammal species, including 107 fossils. </p>
<p>We then assembled an evolutionary tree for these species. This allowed us to ask how brain and body size have related to each other throughout the evolution of mammals, starting from before the extinction of dinosaurs.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Evolutionary tree of mammals and brain sizes" src="https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=557&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=557&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=557&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=700&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=700&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397288/original/file-20210427-21-1yjgpwa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=700&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Evolutionary tree of mammals - different colours represent groups of species that share a similar brain-to-body size relationship.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our analysis revealed a mixed bag of evolutionary trajectories in brain and body sizes. For example, elephants are large, large-brained, and also known to be very intelligent. We saw that this combination arose through the elephants undergoing an even greater increase in brain size than expected for their large body size.</p>
<p>In contrast, the evolutionary lineages for humans and dolphins – both among the largest-brained mammals on Earth - were particularly unique in having larger brains but smaller bodies compared with their close relatives (chimps and gorillas for humans; other toothed whales for dolphins). This unusual combination makes their brains spectacularly large among mammals.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-which-is-smarter-a-blue-whale-or-an-orca-122789">Curious Kids: which is smarter – a blue whale or an orca?</a>
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</em>
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<p>Strikingly, some mammals that are known to be very intelligent underwent stronger natural selection on body size than on brain size. The California sea lion, for example, famous for its circus-trick smarts, has an unusually small brain relative to its body mass. This is because when the evolutionary ancestors of seals and sea lions began living in water, evolution favoured massive increases in body size — perhaps to conserve body heat, to ward off predators such as sharks, or more generally because gravity is less of an impediment to large body size in water than in air.</p>
<p>This means California sea lions’ relative brain size is much smaller than expected, given their intelligence. So how are they so smart? One possible explanation is that, despite their relatively smaller brain size compared with their close relatives, California sea lions have up to four times more volume dedicated to brain areas that support intelligent behaviour, such as learning complicated tricks.</p>
<p>This seems to make them much smarter than other mammals with comparable brain sizes, such as bears, and shows why sea lions can learn skills that are not in their innate repertoire of behaviours, such as making vocalisations on command.</p>
<h2>Evolutionary upheavals</h2>
<p>Our analysis also revealed that cataclysmic events in evolutionary history left their hallmarks in mammals’ brains. For example, there was an acceleration in increases in brain size relative to body mass after the extinction of the dinosaurs 66 million years ago. We think this may be due to the fact many mammals found new habitats to live in that were previously occupied by dinosaurs, often requiring new adaptations in either brain or body size. </p>
<p>Another intriguing pattern is a substantial rearrangement of the relationship between brain and body sizes between 30 million and 23 million years ago, when Earth cooled rapidly and some big evolutionary changes (such as the evolution of seals and sea lions) happened.</p>
<p>Some of these changes left legacies that still endure today. They have resulted in some of the biggest (elephants and whales) and smallest (bats and shrews) mammal brains on Earth.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/brain-versus-brawn-the-evolution-of-humans-and-other-animals-27910">Brain versus brawn: the evolution of humans and other animals</a>
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<p>Given that the evolution of brain size and intelligence is even more complex than we realised, how do we go about trying to understand it more fully? We definitely need to consider the evolutionary background of present-day mammals. However, it is also important to understand how the various parts of the brain evolve relative to one another. </p>
<p>For example, humans and dolphins not only have large brains overall, but also an astoundingly large neocortex, which is the powerhouse of mammal intelligence.</p>
<p>In the meantime, next time your friend boasts about their big-brained dog, remind them size isn’t everything.</p><img src="https://counter.theconversation.com/content/159141/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vera Weisbecker receives funding from The Australian Research Council. </span></em></p><p class="fine-print"><em><span>Jeroen Smaers receives funding from The US National Science Foundation. </span></em></p>Some animals, such as California sea lions, have small brains relative to their body size, but are still impressively intelligent, showing brain evolution is even more complex than it appears.Vera Weisbecker, Associate Professor, Flinders UniversityJeroen Smaers, Associate professor, Stony Brook University (The State University of New York)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1585342021-04-07T15:38:24Z2021-04-07T15:38:24ZWe discovered that whale and dolphin brains produce lots of heat. Why it matters<figure><img src="https://images.theconversation.com/files/393741/original/file-20210407-21-1m642x5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A humpback whale near the Antarctic ice.</span> <span class="attribution"><span class="source">Dr Olga Shpak </span></span></figcaption></figure><p>We have all heard the mantra that dolphins and whales (cetaceans) are highly intelligent animals. Some claim they’re on par with great apes and humans – maybe even smarter. But where does this concept come from? </p>
<p>There are two lines of thought. Firstly, a range of cetacean behaviours are <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1469-185X.2008.00049.x">interpreted</a> as displays of notable intelligence. Second, cetaceans have very <a href="https://www.karger.com/Article/Abstract/454797">large brains</a>; several species have brains that weigh more than human brains. We have large brains, and it is the structure and activity within these large brains that determines our abilities to examine, analyse and manipulate the world in a very complex way. So it has been thought that any other animal that has a brain as large, or larger, must be using their brain for the same thing. </p>
<p>But this logic is based on a very specific assumption: that 1 gram of brain tissue has, on average, the same capacity to process information in the same way irrespective of the brain in which it is found. It is this assumption that I have <a href="https://onlinelibrary.wiley.com/doi/abs/10.1017/S1464793106007019">questioned over the past 20 years</a> and I have come to a very different conclusion.</p>
<p>In my most <a href="https://www.nature.com/articles/s41598-021-84762-0">recent study</a>, my colleagues and I have ascertained that the cetacean brain is indeed special. Not for intelligence, though: it is special because it produces a lot more heat than the brains of other mammals. Through our research we’ve concluded that the cetacean brain has a specialised thermogenic system. It helps the animal’s brain to produce enough heat to maintain a functional brain temperature, and we believe this will combat the loss of heat to the water. This is separate to the special way whales and dolphins <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0116734">keep their bodies warm</a>.</p>
<p>Evidence suggests the neurothermogenic specialisation we describe evolved around 32 million years ago.</p>
<p>With this knowledge, scientists can better understand how important water temperature is to the survival of cetaceans. This, in turn, will allow us to understand what will happen to certain species of cetaceans during the <a href="https://science.sciencemag.org/content/363/6423/128.summary">inevitable rise in oceanic temperatures</a> associated with anthropogenic-induced climate change.</p>
<p>It is quite possible that some species, such as those dependent on the polar ice, like narwhals and beluga whales, may become victims of global warming. This new understanding of cetaceans will allow us to direct our conservation efforts in the most appropriate way to secure the future of as many species of cetacean as possible.</p>
<h2>Size and skill</h2>
<p>Compared to humans – and indeed many other mammals – cetacean brains have a very small <a href="https://onlinelibrary.wiley.com/doi/abs/10.1017/S1464793106007019">prefrontal cortex</a> (that part involved in our higher mental/executive activities), a tiny <a href="https://link.springer.com/article/10.1007/s00429-013-0660-1">hippocampus</a> (responsible for memory formation/retrieval and spatial navigation), and many other features that are very different to other mammals.</p>
<p>This means we can conclude that the structure of the cetacean brain does not endow them with the “hardware” necessary for the production of behaviours that are more complex than those seen in many other animals, unlike humans.</p>
<p>So, if the cetacean brain is not large for intellectual purposes, why is it so big? </p>
<p>Cetacean brains became truly large <a href="https://onlinelibrary.wiley.com/doi/abs/10.1017/S1464793106007019">around 32 million years ago</a>, about 20 million years after they became fully aquatic mammals. At this time, there was a <a href="https://science.sciencemag.org/content/292/5517/686">major cooling</a> of global oceanic temperatures. This coincided with the loss of the shallow, warm, nutrient-rich, equatorial <a href="https://www.britannica.com/topic/Neo-Tethys-Sea">Tethys sea</a>. These ancient cetaceans were faced with a quandary: adapt to this new, cold, open ocean environment, or become extinct.</p>
<p>The mammalian brain produces its own heat, independent of the body, to maintain a stable temperature of 37°C. Even a small drop in brain temperature leads to a reduction in neural activity. Cetaceans mostly live in oceanic waters; the mammalian body loses heat via conductive heat transfer to the water <a href="https://www.nature.com/articles/335675b0">90 times faster</a> than to air at the same temperatures; and mammal brains need to be maintained at 37°C. Given these factors, I proposed that perhaps the environmental pressure of colder water occurring around 32 million years ago was the trigger for the evolution of the larger brain in cetaceans.</p>
<h2>Inside the cetacean brain</h2>
<p>To provide support to this idea, my colleagues and I examined the heat-producing system within the brains of cetaceans and their close relatives the artiodactyls – such as hippopotamuses, pigs, antelopes, buffaloes and giraffes. </p>
<p>We reasoned that this heat-producing system would have to use the process of <a href="https://jeb.biologists.org/content/214/2/242">non-shivering thermogenesis</a>, a way to produce heat within cells rather than through muscular activity, as there are no muscles surrounding the brain. The most commonly studied part of the body that produces heat through non-shivering thermogenesis is <a href="https://www.mayoclinic.org/healthy-lifestyle/weight-loss/expert-answers/brown-fat/faq-20058388">brown fat</a>. Brown fat cells can change their internal metabolic pathways so as to produce heat, warming up the body. This happens when mitochondria (organelles within the cell that produce energy) change their activity so that rather than producing adenosine triphosphate (ATP), for chemical energy in the cell, they produce heat. This is achieved by activating uncoupling proteins (UCPs). </p>
<p>In the cetacean brain we found that almost three times as many neurons contain these proteins compared to their terrestrial relatives. We also found that between 30 and 70% of glial cells contain UCPs in cetaceans, while in artiodactyls the glial cells did not contain UCPs in readily detectable amounts. Glial cells are the housekeepers of the brain: they maintain the right micro-environment to support active neuronal functioning.</p>
<p>We conclude that the cetacean brain has a specialised thermogenic system that emerged around 32 million years ago. This, we believe, will combat the loss of heat to the water – and help cetaceans to maintain a functional brain temperature.</p>
<h2>A special brain</h2>
<p>So, yes: the cetacean brain is special, as long believed. But this brain isn’t used for special intellectual functions and complex thoughts. Instead, it’s special because it produces a lot more heat than the brains of other mammals, and this is necessary for their survival in the colder aquatic environment they inhabit.</p><img src="https://counter.theconversation.com/content/158534/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Manger receives funding from the National Research Foundation of South Africa. </span></em></p>The cetacean brain has a specialised thermogenic system that helps the animal’s brain to produce enough heat to maintain a functional brain temperature.Paul Manger, Professor of Comparative and Evolutionary Neurobiology, University of the WitwatersrandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1514872021-01-01T10:24:33Z2021-01-01T10:24:33ZThe hopeful return of polar whales<figure><img src="https://images.theconversation.com/files/373261/original/file-20201207-21-1m5stmt.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C9657%2C5574&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/beautiful-view-icebergs-whale-antarctica-543673003">Alexey Suloev/Shutterstock</a></span></figcaption></figure><p>The bleak history of whaling pushed many species to the brink of extinction, even in the remote waters of the north and south poles. Over 1.3 million whales were killed in just 70 years around Antarctica alone. The scale of this industrial harvest <a href="https://doi.org/10.1017/S0954102011000708">completely decimated</a> many populations of large whales in <a href="https://theconversation.com/an-ocean-like-no-other-the-southern-oceans-ecological-richness-and-significance-for-global-climate-151084">the Southern Ocean</a>. But nearly 40 years after commercial whaling ended, we’re finally seeing signs that some of the most heavily-targeted species are recovering. </p>
<p>In a recent study, scientists reported that blue whales, once prized by whalers for their gargantuan size, are <a href="https://www.int-res.com/articles/esr2020/43/n043p359.pdf">increasing in number</a> in the waters surrounding the sub-Antarctic island of South Georgia, with 41 new individuals catalogued over the past nine years. South Georgia saw around <a href="https://www.bbc.co.uk/news/science-environment-54994814">3,000 blue whales killed</a> each year at the hunt’s peak in the early 20th century. The waters surrounding the island are rich in the krill these whales eat, and scientists believe their return heralds a “rediscovery” of this oceanic larder by new generations.</p>
<figure class="align-center ">
<img alt="An aerial view of a blue whale surfacing." src="https://images.theconversation.com/files/374187/original/file-20201210-20-ug446e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374187/original/file-20201210-20-ug446e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374187/original/file-20201210-20-ug446e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374187/original/file-20201210-20-ug446e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374187/original/file-20201210-20-ug446e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374187/original/file-20201210-20-ug446e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374187/original/file-20201210-20-ug446e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Blue whales are thought to be the largest animals to ever exist.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Blue_whale#/media/File:Anim1754_-_Flickr_-_NOAA_Photo_Library.jpg">Anim Flickr/NOAA Photo Library</a></span>
</figcaption>
</figure>
<p>Similar signs of recovery have been documented for humpback whales around the <a href="http://dx.doi.org/10.1098/rsos.180017">western Antarctic Peninsula</a>. In the far north, <a href="https://doi.org/10.1111/j.1748-7692.2004.tb01191.x">western Arctic bowhead whales</a> appear to be <a href="https://www.theguardian.com/environment/2020/dec/12/bowhead-whale-arctic-recovery-scientists">approaching numbers</a> last seen in pre-whaling days, while fin and minke whales are now regularly seen <a href="https://dx.doi.org/10.1098/rsbl.2016.0251">in the Chukchi Sea</a> near Alaska.</p>
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<img alt="" src="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>This story is part of <a href="https://theconversation.com/uk/topics/oceans-21-96784">Oceans 21</a></em></strong>
<br><em>Our series on the global ocean opened with <a href="https://oceans21.netlify.app/">five in depth profiles</a>. Look out for new articles on the state of our oceans in the lead up to the UN’s next climate conference, COP26. The series is brought to you by The Conversation’s international network.</em></p>
<hr>
<p>With the whaling industry gone, polar seas are among the best places for these ocean giants to re-establish their populations. Their habitats here are still relatively pristine and, for the moment, contain fairly stable food supplies. <a href="https://theconversation.com/arctic-ocean-climate-change-is-flooding-the-remote-north-with-light-and-new-species-150157">The Arctic</a> still hosts subsistence harvests by indigenous communities, though these hunts are carefully managed.</p>
<p>The 1984 suspension of commercial whaling prevented the extinction of large whales in polar waters, but it cannot protect them from the new pressures which will emerge as <a href="https://doi.org/10.1016/j.biocon.2018.02.021">global warming</a> reshapes these regions. So what do these rapid changes mean for the still fragile recoveries of polar whale species?</p>
<h2>Let’s not blow it</h2>
<p>Over the next few decades, whales at the poles will face several new sources of stress, from warming waters disrupting their food supply to pollution and commercial fishing. With less sea ice and longer ice-free periods in the summer, easier access to the Arctic and Southern oceans and their resources is tempting many industries to expand or establish themselves in these remote waters. Vessel traffic, particularly <a href="https://thebarentsobserver.com/en/industry-and-energy/2020/07/ships-moving-arctic-sea-ice-level-reaches-record-low">in the Arctic</a>, is increasing, and <a href="https://www.pnas.org/content/115/29/7617">whales</a> are among the <a href="https://www.frontiersin.org/articles/10.3389/fmars.2019.00647/full">most vulnerable</a> to the increasing noise and the potentially lethal threat of collision.</p>
<figure class="align-center ">
<img alt="A pod of narwhals, with one tusk exposed, swimming together." src="https://images.theconversation.com/files/374190/original/file-20201210-15-16qaik0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374190/original/file-20201210-15-16qaik0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=310&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374190/original/file-20201210-15-16qaik0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=310&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374190/original/file-20201210-15-16qaik0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=310&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374190/original/file-20201210-15-16qaik0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=390&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374190/original/file-20201210-15-16qaik0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=390&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374190/original/file-20201210-15-16qaik0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=390&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Narwhals are an Arctic species that is particularly vulnerable to boat traffic.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Narwhal#/media/File:Pod_Monodon_monoceros.jpg">Dr. Kristin Laidre/NOAA Photo Library</a></span>
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</figure>
<p>We’ve learned how to minimise the impacts of human activity on whales in busier waters outside of the Arctic and Antarctic. As part of an ongoing research project funded by the European Commission, myself and colleagues are trying to apply those lessons in the Arctic, to <a href="https://doi.org/10.1016/j.ocecoaman.2018.03.042">help protect whales</a> from the growing presence of shipping.</p>
<p>We know that slowing vessels down reduces the likelihood of fatal collisions <a href="https://conbio.onlinelibrary.wiley.com/doi/abs/10.1111/j.1523-1739.2009.01329.x">with whales</a>, and it has the added benefit of reducing <a href="https://www.frontiersin.org/articles/10.3389/fmars.2019.00344/full">how much noise the ships produce</a>. Much like the speed restrictions planners place in busy town centres to reduce the risk of cars hitting pedestrians, we can create slow-down areas for ships in locations we know are used by whales. </p>
<p>The challenge in the Arctic is finding where such measures will be most effective, where they are safe to be implemented (ice already makes sailing in the Arctic dangerous) and how we can ensure such measures are carried out when people aren’t around to easily monitor compliance.</p>
<figure class="align-center ">
<img alt="Two polar bears eat a seal on sea ice with a ship in the background." src="https://images.theconversation.com/files/374193/original/file-20201210-13-5xx8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374193/original/file-20201210-13-5xx8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374193/original/file-20201210-13-5xx8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374193/original/file-20201210-13-5xx8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374193/original/file-20201210-13-5xx8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374193/original/file-20201210-13-5xx8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374193/original/file-20201210-13-5xx8b.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">The Arctic isn’t as isolated and ice-bound as it once was.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pair-polar-bears-bloody-killed-seal-540005638">Ondrej Prosicky/Shutterstock</a></span>
</figcaption>
</figure>
<p>One source of stress that we can monitor and assess quite well is the prevalence of marine noise pollution, thanks to underwater recording devices called hydrophones. Large ships produce loud, low-frequency noise that can travel far underwater. Whales rely on sound to help them navigate their dark underwater habitats, but vessel noise can prevent them communicating and foraging effectively. It’s a bit like trying to talk to your friend in a crowded restaurant. </p>
<p>But for whales, this can be more than a simple annoyance, it can be deadly: <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2435.12871">one study</a> found that ambient noise increased the risk of humpback mothers and calves being separated. Research is now underway <a href="https://www.sciencedirect.com/science/article/pii/S0025326X17307622">in the Arctic</a> to identify areas where increasing noise from ships may be affecting whales, and where action – such as moving shipping lanes further away – might help.</p>
<p>In many cases, fascination has replaced greed in our relationship with whales. We now understand them as useful indicators of ocean health, as well as highly intelligent beings with complex cultures which we have an obligation to protect.</p>
<p>Still, it has still taken more than 40 years to get where we are, and the fact that many whale populations – including <a href="https://doi.org/10.1111/mms.12648">belugas</a>, <a href="http://dx.doi.org/10.1098/rsbl.2020.0148">bowheads</a> and some <a href="https://doi.org/10.3354/meps13329">humpbacks</a> – are still struggling, suggests we still have a way to go. Not all the species commercial whalers once hunted appear to be recovering, even with long-term protection measures. Sperm whales in <a href="https://doi.org/10.3354/esr00584">the southern hemisphere</a> and western grey whales in <a href="https://doi.org/10.1038/s41598-020-58435-3">the Russian Arctic</a> are notable examples.</p>
<p>As scientists, we still have much to learn. But we know enough to understand that a far-sighted view of the needs and vulnerabilities of these beautiful creatures is necessary to preserve a future for them.</p><img src="https://counter.theconversation.com/content/151487/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lauren McWhinnie receives funding from the European Commissions H2020 funding scheme and has recieved funding from Department of Fisheries and Oceans Canada, Transport Canada, CHONe and MEOPAR. </span></em></p>Whales are rediscovering their old haunts in the Arctic and Southern oceans after centuries of hunting.Lauren McWhinnie, Assistant Professor in Marine Geography, Heriot-Watt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1469622020-10-02T13:56:04Z2020-10-02T13:56:04Z500 whales stranded in Tasmania – indigenous elders are best guides to understanding this tragedy<p>Close to 500 pilot whales beached themselves in September 2020, in what has been described as Australia’s <a href="https://www.firstpost.com/world/380-pilot-whales-dead-in-largest-mass-stranding-ever-recorded-in-australia-nearly-500-still-stranded-in-tasmania-8847071.html#:%7E:text=Hobart%3A%20More%20pilot%20whales%20were,ever%20recorded%20in%20the%20country.">biggest mass stranding</a> on record. Rescue efforts <a href="https://www.nytimes.com/2020/09/26/world/australia/tasmania-beached-whales.html">saved</a> 108 of the marine mammals, which belong to the dolphin family, but <a href="https://institutions.newscientist.com/article/dn4428-predator-theory-for-whale-mass-stranding/">scientific attempts</a> to explain the tragedy have so far offered only theories, including sickness, navigational errors, and sudden changes in the tide.</p>
<p>Indigenous peoples throughout the Pacific, including the Maori of Aotearoa (New Zealand), have been <a href="https://www.theguardian.com/environment/2019/jan/03/what-is-the-sea-telling-us-maori-tribes-fearful-over-whale-strandings">raising the alarm</a> for some time. For generations, people here have watched the movements of these whales closely to help them navigate the world’s largest ocean. </p>
<p>For the Aboriginal people of Australia and indigenous communities throughout the Pacific, changes in whale behaviour are ominous. With a rich oral history to draw from, the indigenous people of the Pacific are among our best guides for making sense of the recent strandings, and the wider environmental changes they portend.</p>
<h2>Ocean giants in Pacific folklore</h2>
<p>The slipstreams of whales and dolphins weave throughout the folklore of the Pacific Islands. The Maori tell the story of Paikea who, when faced with drowning due to the machinations of his evil brother, recited an incantation and summoned a whale to save himself. </p>
<p>The seaways between the Central Carolines and the Marianas would chant of Ikelap – “the big fish” – when it was sighted by voyagers. It was a signpost that the journey was nearing the east coast of Guam. Western mariners would come to know this big fish as the pilot whale – a namesake that speaks to it being a dependable guide.</p>
<figure class="align-center ">
<img alt="A black long-finned pilot whale mother swims with her grey calf close behind." src="https://images.theconversation.com/files/361368/original/file-20201002-17-1qiawbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/361368/original/file-20201002-17-1qiawbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361368/original/file-20201002-17-1qiawbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361368/original/file-20201002-17-1qiawbr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361368/original/file-20201002-17-1qiawbr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361368/original/file-20201002-17-1qiawbr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361368/original/file-20201002-17-1qiawbr.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">Ancient voyagers tracked pilot whales in order to help navigate the Pacific Ocean.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/long-finned-pilot-whale-mother-calf-565369348">Andrew Sutton/Shutterstock</a></span>
</figcaption>
</figure>
<p>It’s a common belief among many different Pacific communities that whales and dolphins are spirit transformations or carriers of ancestors. As such, whales are often sought for spiritual guidance to <a href="https://www.doc.govt.nz/about-us/science-publications/conservation-publications/native-animals/marine-mammals/conservation-of-whales-in-the-21st-century/whaling-and-new-zealand/the-indigenous-relationship-with-whales-in-new-zealand/">decide</a> where to settle and when to avoid fishing or sailing. </p>
<p>Changes in whale migratory routes, songs and unusual surfacing behaviour are all instructive, and observations of distressed whales – to a degree that’s far outside the norm – are interpreted as significant omens. In Tikopia, part of the Solomon Islands, the stranding of whales signified imminent spiritual danger.</p>
<p>Since their whaling rights are protected under the International Whaling Commission, indigenous catch reports have also been used to help <a href="https://iwc.int/humpback-whale">track whale populations</a> and to identify when commercial whaling was depleting populations in the past.</p>
<p>Indigenous accounts are invaluable as they provide a reliable, long-term record of how whale populations have changed over time according to changes in their environment.</p>
<h2>What the whales foretold</h2>
<p>Environmental change in the Pacific is not new. Oral history recalls when, at the end of the last ice age, <em>fenua imi</em> (an island-eating demon), swallowed the land and forced the migration of its peoples across Oceania. The history of the Pacific is a history of migration, and the whales and dolphins have accompanied these movements, guiding voyagers across the vast ocean. </p>
<p>Climate change could be considered the modern return of <em>fenua imi</em>. But it comes with additional barriers. Political and legal borders now restrict the free movement of people across the Pacific, even as climate change threatens to inundate these vulnerable islands with storms, rising tides and the destruction of vital habitat such as mangroves and coral reefs. </p>
<p>While much international attention has focused on what sea level rise will mean for the low-lying lands of the Pacific, deep changes within the oceans are just as urgent. One of the North Pacific’s <a href="https://theconversation.com/worst-marine-heatwave-on-record-killed-one-million-seabirds-in-north-pacific-ocean-129842">worst marine heatwaves</a> on record killed one million seabirds between the summer of 2015 and the spring of 2016. Hotspots of marine biodiversity are threatened by <a href="https://theconversation.com/galapagos-how-to-protect-the-islands-amazing-marine-life-from-huge-chinese-fishing-fleets-144927">overfishing</a> and <a href="https://theconversation.com/deep-sea-mining-threatens-indigenous-culture-in-papua-new-guinea-112012">deep-sea mining</a>. And while many people have heard of the <a href="https://theconversation.com/uk/topics/great-pacific-garbage-patch-46255">Great Pacific Garbage Patch</a>, fewer know about the poisons that this <a href="https://theconversation.com/plastic-poisons-ocean-bacteria-that-produce-10-of-the-worlds-oxygen-and-prop-up-the-marine-food-chain-117493">floating plastic waste</a> produces, killing microorganisms that produce oxygen and feed marine life. The recent whale strandings, historic in scale, are a reminder that problems in the biosphere cannot be treated in isolation.</p>
<p>Listening to indigenous communities throughout the Pacific about environmental change is not only important, but it is also vital in our attempts to correct the damage done to marine ecosystems.</p><img src="https://counter.theconversation.com/content/146962/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Niki JP Alsford 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>It’s time to listen to warnings from the people of the Pacific.Niki JP Alsford, Professor in Asia Pacific Studies, Director of the Asia Pacific Studies Institutes, University of Central LancashireLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1431522020-07-28T11:15:24Z2020-07-28T11:15:24ZMysterious evolution of wonky whale skulls revealed by new study<figure><img src="https://images.theconversation.com/files/349881/original/file-20200728-21-fy4rcn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sperm whale skull.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/-jvl-/29436677618">JvL/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Some whales are wonky. You might not know it to look at them, but their skulls are actually incredibly asymmetrical. This mysterious feature helps with echolocation, the way that whales work out where things are by making sounds and sensing how they are reflected back.</p>
<p>But this wonkiness isn’t present in all whales. My colleagues and I recently <a href="https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-020-00805-4">conducted research</a> to find out why and when wonky whales started to evolve in a different way to their symmetrical cousins. We now know wonky whale skulls first appeared around 30 million years ago, and that they continued to become even more asymmetrical as the creatures evolved into the modern species we know today.</p>
<p>In order to understand how wonky whales got this way, we needed to look at how they lived and adapted in the past. Fortunately for us, the whale fossil record is so remarkably represented that scientists have even called the whale <a href="https://science.sciencemag.org/content/327/5968/993">“a posterchild of evolution”</a>. Complete skulls and skeletons stretch right back to the earliest whales of 50 million years ago, and more fossils are dotted throughout whale history, right up to the living animals we know today. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="3D scan of a narwhal skull showing asymmetry" src="https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=642&fit=crop&dpr=1 600w, https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=642&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=642&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=806&fit=crop&dpr=1 754w, https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=806&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/349877/original/file-20200728-27-1ughoqg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=806&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Asymmetrical narwhal skull - the red arrows highlight the skewed bones.</span>
<span class="attribution"><span class="source">Ellen Coombs/UCL</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>With this record, we’re able to see that whales’ nostrils have moved from the tip of their snout to the top of their head, an evolutionary tactic to make for easy breathing at the surface of the water. And the skulls of whales with teeth (which technically includes dolphins, as well as species such as sperm whales) have become more lopsided, with the bones on one side in different positions to the same bones on the other side.</p>
<p>This is because of a mass of fatty tissue called a “melon” that toothed whales <a href="https://www.tepapa.govt.nz/about/touring-exhibitions/whales-tohora/whale-lab/whale-sounds">use for echolocation</a>. The melon and the soft tissue needed for echolocation are positioned leftwards above the skull on toothed whales, giving them a bulbous forehead and also causing the bones in the skull underneath to grow skewed to the left. As toothed whales evolved, their skulls got wonkier.</p>
<p>But why don’t all whales have this wonkiness? The first whales were called “archaeocetes” (which literally means “ancient whales”). They evolved from walking on land to <a href="https://evolution.berkeley.edu/evolibrary/article/evograms_03">being fully aquatic</a> in a relatively short 8 million years or so. </p>
<p>We know that archaeocete fossils have wonky rostrums (or snouts). This might be a distortion of the fossils or <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3167538">a feature</a> that helped archaeocetes work out which direction sounds were coming from underwater.</p>
<figure class="align-center ">
<img alt="Skeleton of four-legged whale-like creature." src="https://images.theconversation.com/files/349628/original/file-20200727-21-6f80mj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/349628/original/file-20200727-21-6f80mj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=348&fit=crop&dpr=1 600w, https://images.theconversation.com/files/349628/original/file-20200727-21-6f80mj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=348&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/349628/original/file-20200727-21-6f80mj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=348&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/349628/original/file-20200727-21-6f80mj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=437&fit=crop&dpr=1 754w, https://images.theconversation.com/files/349628/original/file-20200727-21-6f80mj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=437&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/349628/original/file-20200727-21-6f80mj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=437&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"><em>Ambulocetus natans</em>, an early whale ancestor.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Ambulocetus#/media/File:Ambulocetus_natans.jpg">Ghedoghedo</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Then, around 39 million years ago, whales diverged into two groups: those with teeth in their mouths, known as the “odontocetes, and those with baleen (rows of bristles that allow whales to <a href="https://www.nationalgeographic.com/news/2017/04/blue-whale-krill-feeding-habits-drone-video/">filter food from the water</a>), known as the "mysticetes”. </p>
<p>At some point, the toothed whales evolved wonky skulls and echolocation. However, the mysticetes, which include the big baleen whales (such as blue whales), diverged down a completely different evolutionary path. They evolved baleen and filter feeding and skulls that are more symmetrical than both the archaeocetes and the toothed whales. </p>
<p>We wanted to understand why, and exactly when, this happened. So to track asymmetry in the evolution of the whale skull, we produced 3D scans of 162 skulls, 78 of which were fossils. By mapping this wonky shape change in the skull across the whale family tree, we could track precisely when in evolutionary history it first appeared and in which families it evolved. </p>
<h2>Asymmetry appears</h2>
<p>Based on analyses of these skulls, naso-facial asymmetry (wonkiness) appears to have first evolved around 30 million years ago. This was after the transition from archaeocetes to modern whales, and after the split between the odontocetes and the mysticetes. Around the same time this wonkiness was appearing, these early toothed whales were evolving high-frequency hearing and complex echolocation. </p>
<p>We also confirmed that early ancestors of living whales had little cranial asymmetry in the naso-facial area and likely were not able to echolocate. As such, it’s likely that baleen whales have never been able to echolocate. </p>
<p>Most surprisingly, this asymmetry has reached its highest levels in some specific animals such a sperm whales and narwhals and other species that live in deep or extreme environments. </p>
<p>This suggests that animals living in these complex environments, including belugas that live in icy, cluttered waters and river dolphins that live in shallow, murky rivers, have evolved a different echolocation ability such as a more diverse or discrete sound repertoire to help them navigate and hunt, and with it the bones around the nasal and face have become more asymmetrical. </p>
<p>This evolutionary path of toothed whales becoming ever more asymmetrical suggests that their skulls and the overlying soft tissues may continue to get wonkier as their echolocation techniques become more specialised. </p>
<p>These findings remind us not only of the complex evolutionary pathways that cetaceans have undergone to become the superbly adapted iconic ocean inhabitants that we know today, but also that despite living alongside some of the largest animals that have ever existed, there is still a lot for us to learn about them.</p><img src="https://counter.theconversation.com/content/143152/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ellen Coombs is a PhD student at the Natural History Museum and University College London. She receives funding from the London Natural Environment Research Council Doctoral Training Partnership (London NERC DTP) </span></em></p>How we worked out when whales first evolved asymmetrical skulls.Ellen Coombs, PhD Candidate in Biosciences, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1285122020-01-15T13:54:46Z2020-01-15T13:54:46ZMeet the narwhal, ‘unicorn of the sea’<figure><img src="https://images.theconversation.com/files/309978/original/file-20200114-151876-1w18k8d.JPG?ixlib=rb-1.1.0&rect=304%2C330%2C3026%2C1998&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Over 100,000 narwhals swim the Earth's Arctic waters.</span> <span class="attribution"><span class="source">Kristin Laidre</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Narwhals are often called the unicorns of the sea. The long tusk of the male narwhal sets these whales apart, but it’s not the only thing that makes <em>Monodon monoceros</em> among the most intriguing and mysterious marine mammals.</p>
<p>A deep-diving cetacean in the odontocete family (which means “toothed whales”), narwhals live in cold Arctic and sub-Arctic waters. They’re highly adapted to <a href="https://doi.org/10.1007/s00227-004-1371-1">living in areas almost completely covered with sea ice</a>. Narwhals are among the only whales that live in areas with such dense sea ice cover for up to six months each winter.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/308224/original/file-20191223-11900-12ebhgl.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Laidre and colleagues spot narwhals from shore in northwest Greenland.</span>
<span class="attribution"><span class="source">D. Rees</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>As a <a href="https://staff.washington.edu/klaidre/">scientist who studies animal ecology in the Arctic</a>, I know firsthand that seeing a narwhal in the wild is a special experience. They usually travel in pods and can be quite sneaky. When they pass by, you may only see a small sliver of their mottled black and white skin above the water when they surface to breathe. No wonder glimpses of these whales and their unique tusks have fueled myths for centuries.</p>
<h2>The tusk that is the narwhal’s claim to fame</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=665&fit=crop&dpr=1 600w, https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=665&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=665&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=836&fit=crop&dpr=1 754w, https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=836&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/310078/original/file-20200114-151844-uuy3ci.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=836&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nature’s only spiral tooth is found in the male narwhal.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/narval-sea-unicorn-horn-detail-1371351476">Andrea Izzotti/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Unlike all other toothed whales, the narwhal actually has no teeth in its mouth. Instead, the <a href="https://www.penumbrapress.com/book.php?id=10">male develops a long straight tooth</a>, called a tusk, that protrudes 6 to 10 feet out of his upper left jaw. A long tusk on an adult male can be more than half the usual total body length of about 16 feet. The tooth grows in a counterclockwise spiral – nature’s only spiral tooth.</p>
<p>The tusk is essentially unique to male narwhals. Very rarely, a female will grow a tusk, or even more rarely a male narwhal will grow two. Tusks exported from the Arctic, perhaps by the Vikings, <a href="https://en.wikipedia.org/wiki/Throne_Chair_of_Denmark">reached Europe</a>, the Mediterranean and even the Far East as early as the Middle Ages and became the <a href="http://www.slate.com/blogs/atlas_obscura/2015/06/23/the_ceremonial_throne_of_denmark_passes_off_narwhal_tusk_as_unicorn_horn.html">source of the unicorn myth</a>. The tusks were sold to the very rich without a good description of the animal from which they came and inspired a <a href="https://www.lrb.co.uk/the-paper/v41/n01/katherine-rundell/consider-the-narwhal">great deal of fantasy</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/308152/original/file-20191220-11951-1w9dwow.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&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 Danish coronation chair from the 1600s is made of narwhal tusks.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Rosenborg_Palace,_Copenhagen,_early_1600s_(7)_(36237310202).jpg">Richard Mortel/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>To some extent, tusks still inspire fantasies, as people have proposed many unsupported explanations for their purpose – whether breaking ice, sword fighting with other whales, spearing or smacking fish for food, sensing temperatures or digging in the bottom the sea. </p>
<p>One thing is clear: The tusk cannot serve a critical function for narwhals’ survival, because females, who do not have tusks, live just as long as males. And they do it surviving in the same harsh areas, finding the same food and additionally being responsible for reproduction and calf-rearing.</p>
<p>The tusk is <a href="http://darwin-online.org.uk/EditorialIntroductions/Freeman_TheDescentofMan.html">a sexual trait</a>, much like the antlers of a stag, the mane of a lion or the feathers of a peacock. <a href="https://doi.org/10.1139/z81-319">Males use the tusk</a> to determine social rank and compete for females. It is not entirely clear how this works, but male narwhals may be able to visually size each other up as competitors; they may interact with their tusk with some unknown level of aggression underwater; or possibly a female could use the tusk as a visual signal for choosing her mate. </p>
<p>During the summertime in the northern Arctic bays and fjords, male narwhals can be seen interacting at the surface, carefully crossing their tusks and touching them together. Such behavior might help adult males compare themselves and maintain dominance hierarchies. Or perhaps it helps young males nearby learn skills necessary for performance in adult sexual roles.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=394&fit=crop&dpr=1 600w, https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=394&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=394&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=495&fit=crop&dpr=1 754w, https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=495&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/309980/original/file-20200114-93792-126cz0u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=495&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 pod of narwhals in Northwest Greenland.</span>
<span class="attribution"><span class="source">Kristin Laidre</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Living in a changing Arctic</h2>
<p><a href="https://doi.org/10.1111/acv.12000">Narwhals’ extensive migrations</a> follow the <a href="https://www.wiley.com/en-us/Sea+Ice%2C+3rd+Edition-p-9781118778388">formation and retreat of annual sea ice</a>. Some can travel thousands of miles in a single year.</p>
<p>The <a href="https://doi.org/10.1111/cobi.12474">over 100,000 narwhals worldwide</a> today are <a href="https://doi.org/10.1111/acv.12000">divided into subpopulations</a> of between a few thousand to up to 30,000 animals, based on where they spend the summer, in ice-free bays and fjords or at glacial fronts. In autumn, they migrate to <a href="https://doi.org/10.3354/meps261269">overwintering areas</a> that are <a href="https://doi.org/10.3354/meps08941">deep, offshore and ice-covered</a>, usually along the continental slope. <a href="https://doi.org/10.1111/j.1748-7692.2005.tb01207.x">Most feeding takes</a> <a href="https://doi.org/10.3354/meps261269">place in winter</a>, and then females give birth in spring.</p>
<p>During the winter months in the dense pack ice, narwhals can make dives that are over a mile deep, sometimes swimming upside down as they descend into pitch black water. They sometimes seek prey close to the bottom, such as Greenland halibut, and swallow them whole.</p>
<p>Narwhals are part of an Arctic environment that is rapidly changing. The region is warming twice as fast as the rest of the world – <a href="https://doi.org/10.1126/sciadv.aaw9883">1.35 degrees Fahrenheit (0.75 degrees Celsius)</a> in the last decade alone. By comparison, it’s taken the Earth as a whole the past 137 years to warm by nearly the same amount, 0.8°C.</p>
<p>In order to understand how narwhals may or may not adapt to the climate change in the Arctic, it is vital to develop a basic understanding of their ecology. Furthermore, narwhals are an important cultural, nutritional and economic resource for native communities in Greenland and Canada. My colleagues and I are continuing to study the structure and dynamics of narwhal populations in a changing climate, in hopes we can conserve their populations and ensure they remain sustainable biological resources.</p>
<p>[ <em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/128512/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kristin Laidre receives funding from The National Science Foundation (NSF), National Aeronautics and Space Administration (NASA), and Office of Naval Research (ONR). </span></em></p>The long tusk of the male narwhal earned these whales their fanciful nickname. But there’s more to these Arctic mammals than their unique spiral tooth.Kristin Laidre, Associate Professor of Aquatic and Fishery Sciences, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1195832019-07-08T20:36:28Z2019-07-08T20:36:28Z‘Free Willy’ law spotlights contradictions in how Canadians see animal rights<figure><img src="https://images.theconversation.com/files/282951/original/file-20190707-51273-1u9pn59.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Canada's Parliamentary debate around captive whales and dolphins touched on the animals' intellectual and social properties. </span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Watching captive whales or dolphins for entertainment will eventually become a thing of the past in Canada. Lawmakers recently adopted the Ending the Captivity of Whales and Dolphins Act — dubbed <a href="https://www.cnn.com/2019/06/10/americas/canada-whale-dolphin-bill-intl-hnk/index.html">the “Free Willy” bill</a>, named after the 1993 hit movie.</p>
<p><a href="https://www.parl.ca/LegisInfo/BillDetails.aspx?billId=8063284&Language=E">Bill S-203</a> prohibits keeping, breeding and importing marine mammals from the <a href="http://www.marinemammalcenter.org/education/marine-mammal-information/cetaceans/">cetacean family (including whales, dolphins and porpoises</a>) for entertainment or for any other reason besides rescue and rehabilitation. Now-retired senator Wilfred Moore sponsored the bill after <a href="https://www.theglobeandmail.com/politics/article-house-passes-bill-to-end-whale-dolphin-captivity/">viewing the 2015 documentary</a> <a href="http://www.blackfishmovie.com"><em>Blackfish</em> about the orca Tilikum</a> and the sea park industry. </p>
<p>The only captive whales or dolphins in Canada are now at Marineland in Ontario near Niagara Falls and the Vancouver Aquarium. The latter announced <a href="https://www.cbc.ca/news/canada/british-columbia/vancouver-aquarium-will-no-longer-keep-whales-dolphins-in-captivity-1.4492316">plans to end its captive cetacean program in early 2018</a> and only <a href="https://nationalpost.com/news/politics/free-willy-bill-to-end-whale-captivity-in-canada-set-to-become-law">one dolphin is now there</a>. There are <a href="https://globalnews.ca/news/5376846/canada-whale-dolphin-captivity-ban-marineland/">about 60 cetaceans housed at Marineland</a>, including Kiska, the lone “killer whale,” or orca, captive in Canada. Kiska and the <a href="https://www.cbc.ca/news/canada/hamilton/whales-1.5169138">estimated 55 beluga whales and five bottlenose dolphins</a> at Marineland won’t be freed by the bill, because the ban exempts those already in captivity. </p>
<p>Protecting marine mammals is important and Canada has made itself a leader through the passage of Bill S-203. A <a href="https://d31j74p4lpxrfp.cloudfront.net/sites/default/files/the_case_against_marine_mammals_in_captivity_1.pdf">number of countries</a>, such as Costa Rica, India and Switzerland, prohibit displaying cetaceans for entertainment. In the U.S., some states or counties have banned display and the country strictly regulates the import of wild-caught cetaceans.</p>
<p>With Bill S-203, Canada becomes the first North American country to ban both displaying for entertainment and importing or exporting. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/283123/original/file-20190708-51268-6l8u55.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283123/original/file-20190708-51268-6l8u55.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283123/original/file-20190708-51268-6l8u55.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283123/original/file-20190708-51268-6l8u55.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283123/original/file-20190708-51268-6l8u55.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283123/original/file-20190708-51268-6l8u55.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283123/original/file-20190708-51268-6l8u55.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">Bottlenose dolphin.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Not progressive enough</h2>
<p>As a professor of animal law, I was delighted to see this bill become law, but I am also aware that Canadian law relating to non-human animals is not progressive enough. </p>
<p><a href="https://www.canlii.org/en/bc/bcsc/doc/1957/1957canlii466/1957canlii466.html?autocompleteStr=pacific%20mea&autocompletePos=1">Since the 1950s</a>, the animal cruelty provision in Canada’s criminal code has been interpreted to exempt most common farming practices from its application.</p>
<p>Instead, where animals’ lives on farms are concerned, farms are subject to <a href="https://www.nfacc.ca/codes-of-practice">codes of practice</a> created primarily by industry stakeholders. These codes are referred to in some, but not all, provincial animal protection laws. They set out minimum standards based on common farming practices and they contain weak enforcement mechanisms. Legal pressure brought to bear on farms is mostly driven by complaints. </p>
<p>With respect to the welfare of farmed animals, <a href="http://diplomatonline.com/mag/2013/09/the-eu-vs-canada-fixing-factory-farms-by-granting-the-5-freedoms/">Canada lags far behind comparable jurisdictions like Australia, New Zealand and the European Union</a>. Compare this situation with the stiff maximum penalty of up to $200,000 for now bringing whales or dolphins into captivity and the <a href="https://www.humanecanada.ca/realities_of_farming_in_canada">contradiction becomes stark</a>. </p>
<p>What Bill S-203 does not address are the interests of the hundreds of millions of other sentient animals — <a href="https://www.animaljustice.ca/blog/over-819-million-land-animals-slaughtered-by-canadian-meat-industry-in-2018">approximately 800 million per year in Canada, and growing</a> — captive on industrial farms for the purpose of producing food.</p>
<h2>Shifting legal landscape</h2>
<p>To be sure, there are differences between animals held captive for our entertainment and those raised for food. Humans need to eat; we don’t need to visit a marine park or aquarium to survive.</p>
<p>But as the field of animal law continues to grow, so does public awareness of the problems with the inconsistent ways that Canadian law protects some animals, while leaving others behind.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Fr26scqsIwk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Animal rights lawyer Lesli Bisgould discusses re-evaluating human’s relationships with animals.</span></figcaption>
</figure>
<p>And the legislature is beginning to take notice. In addition to Bill S-203, <a href="https://globalnews.ca/news/5411341/canada-shark-fin-ban-sharkwater/">Parliament recently banned</a> the import and export of shark fins and <a href="https://www.cbc.ca/news/politics/animal-protection-bill-c84-bestiality-1.5181494">strengthened the Criminal Code</a> related to the offences of animal fighting and bestiality. But there remains work to be done.</p>
<p>Canada’s Bill S-203 debate touched on the intellectual and social properties of dolphins and whales. During the debate on the bill, Sen. Moore argued: </p>
<blockquote>
<p>“Whales, dolphins and porpoises, which together are known as cetaceans, are highly intelligent, emotional and social mammals that roam vast distances in the oceans. In the wild, many species of whales and dolphins live in large family groups, or pods, that can grow to over 100 members. Distinct populations communicate using complex vocalizations that resemble languages.” </p>
</blockquote>
<p>Elizabeth May, leader of the Green Party, and a sponsor of the bill, argued that “the science increasingly makes us understand that what might seem to be simple entertainment and a simple pleasure is actually animal cruelty, because these animals cannot be held in a swimming pool without…real pain and a loss of social contact and normal activities.”</p>
<p>Defenders of the bill reminded Parliament that their offices had heard overwhelming support for the bill from their constituencies. They argued Canadians are no longer willing to abide keeping these animals captive in unnatural environments or forcing them to perform tricks for food.</p>
<h2>Sentient, intelligent, social</h2>
<p>In following the evolution of Bill S-203, I found myself wondering what the world might look like if similar arguments were used to ground reform to the practices related to animals in agriculture — animals that are similarly sentient, intelligent and social.</p>
<p>Hens, for example, can anticipate the future and demonstrate self-control, according to <a href="https://www.sciencedirect.com/science/article/pii/S0003347205000412">research at the University of London</a>. On Canadian farms, however, egg-producing hens continue to be housed in <a href="https://www.cbc.ca/news/business/cage-free-eggs-1.3435333">cramped battery cages</a>, where they cannot spread their wings or engage in natural behaviours. </p>
<p>Research suggests that <a href="https://www.springer.com/gp/book/9781402089084">pigs are fast learners with good memories and complex social structures</a>. And yet, it is common knowledge that pregnant sows on industrial farms are confined in barren metal crates, where they are unable to turn around, for weeks or even months at a time.</p>
<p>Canada should be applauded for freeing Willy from captivity. But the true celebrations should be reserved for when Canadians, as a progressive and compassionate society, decide it’s time to free Babe.</p><img src="https://counter.theconversation.com/content/119583/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jodi Lazare 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>As the field of animal law continues growing, so does public awareness of the problems with inconsistent ways that Canadian law protects some animals, while leaving others behind.Jodi Lazare, Assistant Professor, Dalhousie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1195732019-07-01T13:15:16Z2019-07-01T13:15:16ZJapan resumes commercial whaling – researchers on how the world should respond<p>Japan recently left the <a href="https://iwc.int/home">International Whaling Commission (IWC)</a> and has now <a href="https://twitter.com/adamvaughan_uk/status/1145619114091847681">caught the first whale in its waters</a> since resuming commercial whaling, 33 years after a global ban came into effect. As a non-member, Japan is no longer bound by the International Convention for the Regulation of Whaling (ICRW) – the rules that the IWC has used to manage whaling since 1946.</p>
<p>The IWC’s moratorium on commercial whaling has broadly been a success – whale populations have increased where whaling was the primary threat. The <a href="http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=38">humpback whale</a> is one example of successful recovery, but species such as the northern right whale have never recovered from centuries of whaling and <a href="https://www.theatlantic.com/science/archive/2019/06/1-north-atlantic-right-whales-have-died-month/592840/">are in critically low numbers</a>.</p>
<p><a href="https://www.cbc.ca/news/world/g20-japan-environmentalists-commercial-whaling-1.5193390">Outrage and despair</a> greeted Japan’s decision to relaunch commercial whaling in its waters, although the conservation status of many species may be unaffected. Still, Japan’s exit from the IWC is a worrying message to the international community at a time when collaboration on environmental issues is sorely needed.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/281908/original/file-20190630-94712-t6la1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281908/original/file-20190630-94712-t6la1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281908/original/file-20190630-94712-t6la1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281908/original/file-20190630-94712-t6la1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281908/original/file-20190630-94712-t6la1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281908/original/file-20190630-94712-t6la1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281908/original/file-20190630-94712-t6la1.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">Protesters march in London to demonstrate against Japan’s decision to resume commercial whaling, January 2019.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/london-uk-january-26-2019-placrd-1295534266?src=a8OHyYaTdVsJCKCXMbwnNw-1-5&studio=1">Kevin J. Frost/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Why has Japan left the IWC?</h2>
<p><a href="https://www.japantimes.co.jp/news/2018/09/15/national/science-health/japan-brink-leaving-international-whaling-commission-commercial-whaling-proposal-blocked/">Japan introduced a proposal at the IWC</a> in 2018 which would allow it to restart commercial whaling. This was voted down – the <a href="https://phys.org/news/2018-09-iwc-brazil-whales.html">proposal</a> that was approved in its place supported a shift in the commission’s goal towards banning all commercial whaling in perpetuity. </p>
<p>A permanent commercial whaling ban might sound like an ordinary step, but the <a href="https://iwc.int/history-and-purpose">IWC’s purpose</a> since 1946 has been “the orderly development of the whaling industry”. The IWC has gradually pivoted to focus more on conservation and other threats to whales since then, but one of its founding goals was to support the whaling industry and the people it employed. As the whaling industry has declined and attitudes towards whales have changed around the world, the IWC has changed too. Japan meanwhile has always been clear it wants to resume commercial whaling and is leaving the IWC because the moratorium was only meant to be temporary and lifted when whale populations could support whaling.</p>
<p>Japan isn’t the first country to leave the IWC because of frustration with its rules on commercial whaling. Iceland left in 1992 and <a href="https://2001-2009.state.gov/p/eur/rls/fs/10228.htm">rejoined in 2002</a> as a full member but with a reservation to the moratorium that allows it to <a href="https://theconversation.com/why-iceland-is-set-to-resume-whaling-despite-international-opposition-95642">commercially whale</a>. Norway <a href="https://iwc.int/commercial">objected to the moratorium decision in 1982</a> and so kept its right to <a href="https://www.theguardian.com/environment/2018/mar/07/norway-boosts-whaling-quota-international-opposition">commercially whale</a> while remaining a full IWC member. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/281900/original/file-20190630-94684-1j6h7gu.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6720%2C4476&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281900/original/file-20190630-94684-1j6h7gu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281900/original/file-20190630-94684-1j6h7gu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281900/original/file-20190630-94684-1j6h7gu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281900/original/file-20190630-94684-1j6h7gu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281900/original/file-20190630-94684-1j6h7gu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281900/original/file-20190630-94684-1j6h7gu.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">A common minke whale (<em>Balaenoptera acutorostrata</em>) in the Pacific Ocean.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dwarf-minke-whale-balaenoptera-acutorostrata-underwater-1213127632?src=mHXgyIgW2uz-ujuFvQgCqw-1-2&studio=1">Aquapix/Shutterstock</a></span>
</figcaption>
</figure>
<h2>A mixed outcome for whales</h2>
<p>For most whale species, the exit of Japan from the convention banning commercial whaling will have <a href="https://www.sciencemag.org/news/2019/01/why-japan-s-exit-international-whaling-treaty-may-actually-benefit-whales">few consequences</a>. Whale populations in the Southern Ocean are even likely to benefit as Japan will lose its special research permit for scientific whaling in the region by leaving the IWC. Japan mostly took Antarctic minke whales (<em>Balaenoptera bonaerensis</em>) here, but this species is not considered <a href="https://www.iucnredlist.org/species/2480/50350661#population">endangered</a>.</p>
<p>It’s a different story for whales found within Japan’s Exclusive Economic Zone (EEZ). No longer bound by the IWC’s rules, Japan can harvest whales here under the right given by the UN Convention on the Law of the Sea but the number and species it will decide to take hasn’t been announced. One vulnerable population living in Japan’s EEZ which may be affected are common minke whales (<em>Balaenoptera acutorostrata</em>), which are genetically distinct and <a href="https://www.frontiersin.org/articles/10.3389/fmars.2019.00247/full">possibly number fewer than 5,500</a>. It’s worrying this population hasn’t shown the same robust recovery seen among other minke whales. </p>
<p>Japan will want to prove to the world it can whale sustainably but the long-term future of whaling is uncertain. The market for whale meat in Japan peaked after World War II and is now a shadow of its former self. Although still eaten in cultural ceremonies and a few localities in northern Honshu, consumption is around <a href="https://www.pri.org/stories/2019-04-17/japan-few-people-eat-whale-meat-anymore-whaling-remains-popular">40g per capita each year</a> - about the size of a slice of ham. Whether Japan’s diminished appetite for whale meat will reduce its whaling efforts though remains to be seen.</p>
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<img alt="" src="https://images.theconversation.com/files/282011/original/file-20190701-105164-ur421n.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4913%2C3096&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/282011/original/file-20190701-105164-ur421n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282011/original/file-20190701-105164-ur421n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282011/original/file-20190701-105164-ur421n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282011/original/file-20190701-105164-ur421n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=476&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282011/original/file-20190701-105164-ur421n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=476&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282011/original/file-20190701-105164-ur421n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=476&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In the Southern Ocean, the ban on commercial whaling has helped some populations of humpback whale increase by 10% per year.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/humpback-whale-jumping-out-water-australia-776180275?src=pUPKYch_2oxMFhbTy0go2w-1-0&studio=1">Nico Faramaz/Shutterstock</a></span>
</figcaption>
</figure>
<h2>A way forward?</h2>
<p>Research by the <a href="https://iwc.int/index.php?cID=html_16">IWC scientific committee</a> has greatly advanced our understanding of whale ecology and how to address other threats to their survival, like pollution, bycatch and climate change. Japan’s exit from the IWC doesn’t threaten the organisation’s activities and every effort should be made to continue this important research. But if the “International Whaling Commission” is to become a conservation organisation, then maybe its status as a whaling commission is outdated. </p>
<p>Countries could continue to work together on whale conservation by using the <a href="https://www.cms.int/en/legalinstrument/cms">Convention on Migratory Species</a>. This specifically targets the conservation of migratory species and their habitats, and would apply to protecting whales. In fact, there is already <a href="https://www.cms.int/en/legalinstrument/accobams">a regional agreement</a> between countries that’s focused on whale conservation.</p>
<p>Agreements made under this convention might be better able to deal with the diverse threats facing whales. A whale research programme focused on conservation – as opposed to a whaling research programme – made up of the IWC scientific committee and Japan might have fewer conflicts as their objective would be clearer.</p>
<p>Japan’s exit from the IWC is a <a href="https://www.nature.com/scitable/blog/eyes-on-environment/the_japanese_whaling_controversy_8211">complicated issue beyond just whale conservation</a> – it highlights the need for the international community to overcome disagreements. Asking why the IWC has <a href="https://www.ethicsandinternationalaffairs.org/2012/almost-saving-whales-the-ambiguity-of-success-at-the-international-whaling-commission-full-text/">succeeded and failed at different times</a> can help us improve the way we work together on global challenges as after all, whaling is only one example of the many urgent and complex environmental issues that demand a global response. How well we work together determines more than just the fate of the world’s whales.</p><img src="https://counter.theconversation.com/content/119573/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Bridgewater was Chairman (1995-1997) and Vice Chair (1992-1994) of the International Whaling Commission.</span></em></p><p class="fine-print"><em><span>Sui Phang 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>Japan’s exit from the IWC should spur on more global cooperation on environmental issues, not less.Sui Phang, Research Fellow in Blue Governance, University of PortsmouthPeter Bridgewater, Adjunct Professor, University of CanberraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/907262018-01-31T00:00:28Z2018-01-31T00:00:28Z‘Talking’ killer whale reveals orcas can learn to mimic human speech<figure><img src="https://images.theconversation.com/files/204017/original/file-20180130-107676-ggbyy3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/killer-whale-water-3656209?src=HBPKb1xn8tpMVeHklDriDA-1-51">Shutterstock</a></span></figcaption></figure><p>History will record that in the second decade of the third millennium, a killer whale uttered the word “hello” to a human. After eons of existential wandering in the forest of cosmic loneliness, has humanity finally made contact with another consciousness, not from another world but, astonishingly, the oceans of our own?</p>
<p>Although scientists <a href="http://rspb.royalsocietypublishing.org/lookup/doi/10.1098/rspb.2017.2171">have reported</a> an <em>Orcinus orca</em> at a marine park in Antibes, France, making noises that sound like human speech, the whale was not talking, any more than <a href="http://sites.bu.edu/guentherlab/miscellaneous-videos-and-oddities/hoover-the-talking-seal/">Hoover the seal</a> or <a href="https://www.theguardian.com/science/video/2012/nov/01/koshik-elephant-talks-korean-video">Koshik the elephant</a> or uncountable parrots were when they produced recognisable copies of human words.</p>
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<p>Nevertheless the study, from researchers led by José Abramson at the Complutense University of Madrid and including my St Andrews colleague Josep Call, is still important. Not because it means whales can speak English, but that they are capable of one of the core building blocks of language development in humans: vocal learning, the ability to copy novel sounds.</p>
<p>The astonishing thing about a whale saying “hello” is not what it means to us, but what it means to them – absolutely nothing. It was specifically chosen, along with some other words, phrases and nonsense sounds, as being something completely outside the normal sound repertoire of the whales. So when the whale produced reasonable copies of the sounds when instructed to, often on the very first attempt, it was pretty conclusive evidence that these animals have the capability to learn new sounds by copying.</p>
<p>Abramson and his colleagues did more than this, as they tested multiple sounds in three situations. In one, the whale was instructed using gestures to produce a sound to copy. In another, the target sound was played back through a loudspeaker. And in a third, a human produced the target sound. Each time, the whale’s responses were subjected to forensic acoustic analysis to measure just how good the copies were. The answer? Pretty darn good.</p>
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<p>The evidence that killer whales can show vocal learning provides us with a missing piece of understanding about their lives in the wild. We’ve long known that killer whales have group specific dialects, collections of distinctive calls that are unique to single pods, or sets of pods. For decades scientists have suggested that <a href="http://www.nrcresearchpress.com/doi/abs/10.1139/z91-206">these dialects are the result of learning</a>, and many clues have supported this view.</p>
<p>We have tracked parallel changes in the calls of wild pods <a href="https://www.sciencedirect.com/science/article/pii/S0003347200914544">over time</a>, we know that captive killer whales moved to different locations have changed their calls to fit in with the other whales <a href="http://jeb.biologists.org/content/217/8/1229">at their new home</a>. The genetic data is <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.2012.01872.x/abstract">also consistent with this idea</a>. And we have circumstantial evidence of an individual copying the sound <a href="http://rsbl.royalsocietypublishing.org/content/2/4/509">of another species</a> (a sea-lion). But now we have gold-standard controlled experimental evidence. Now, any explanation of these vocal dialects that doesn’t involve learning looks pretty outlandish.</p>
<p>Killer whales live in a society organised around females. The vocal traditions that these animals learn as they grow up are crucial components of their behaviour. But they are only part of a suite of knowledge and behaviour that they acquire, largely from their mothers, aunts, and grandmothers</p>
<p>My colleague Hal Whitehead and I have argued that <a href="http://press.uchicago.edu/ucp/books/book/chicago/C/bo12789830.html">this cultural inheritance is vital to whales’ lives</a>. Without it, they are incomplete. So it is somewhat ironic that this study, performed on captive animals, adds to a growing picture of the importance of cultural inheritance in their lives and to the case that these animals should never be kept captive. It is impossible for the whales in captivity to develop and express their cultures in anything like the richness we see in the wild.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/204018/original/file-20180130-107690-1j6egy0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/204018/original/file-20180130-107690-1j6egy0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/204018/original/file-20180130-107690-1j6egy0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/204018/original/file-20180130-107690-1j6egy0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/204018/original/file-20180130-107690-1j6egy0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/204018/original/file-20180130-107690-1j6egy0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/204018/original/file-20180130-107690-1j6egy0.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">Whales learn in families.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/killer-whales-orcinus-orca-show-water-733900609?src=HBPKb1xn8tpMVeHklDriDA-1-2">Shutterstock</a></span>
</figcaption>
</figure>
<p>Of course, killer whales are not alone in their ability to mimic human speech. We’ve known for centuries that some birds can do it, as can a select other few species of mammal including <a href="http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2002556">bats</a>, seals, elephants, and other cetaceans such as <a href="http://www.pnas.org/content/110/32/13216.full">bottlenose dolphins</a>. Notably absent on this list are our closest living relatives, the chimpanzees and bonobos. True, chimps can subtly modify an existing call to match <a href="https://www.sciencedirect.com/science/article/pii/S0960982214016352">their group mates</a>, but they have never been shown to be able to copy a completely novel sound.</p>
<p>While vocal learning underpins something only humans do – communicate via spoken language – it is intriguing that our closest primate relatives can’t do it. It tells us something crucial happened in human evolution after our ancestors separated from the other apes some 5m years ago.</p>
<p>We don’t know why this is, but studying the surprising distribution of vocal learning across the animal kingdom is one way to look for clues. Was it, for example, a result of a more mobile lifestyle? Birds, bats, and cetaceans are all highly mobile, but elephants less so. No current answer completely explains all the data, but then our picture is still far from complete.</p>
<p>What’s next for the science of “talking” whales? It is clear that there is a lot of complex communication going on in whale and dolphin societies, much of which we still don’t understand. We are facing a vast ocean of ignorance. To rectify this, in my view, we need to drop our stifling and frankly navel-gazing, human-centric focus on asking “can whales talk?”. Instead, we should learn more about how each cetacean species has ways of communicating that are specific to their environment and how they have evolved. Only then will we be able to appreciate their true wonder.</p><img src="https://counter.theconversation.com/content/90726/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Luke Rendell receives funding from the Marine Alliance for Science and Technology for Scotland (MASTS) pooling initiative (Scottish Funding Council HR09011). </span></em></p>An animal behaviour expert gives his view on finding that a killer whale can copy the sound ‘hello’.Luke Rendell, MASTS Lecturer in Biology, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/899282018-01-28T09:51:50Z2018-01-28T09:51:50ZA rare glimpse into the world of the Red Sea’s dolphins and whales<figure><img src="https://images.theconversation.com/files/203173/original/file-20180124-72600-eqt70i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bottlenose dolphins, are very coastal and subsist on small fish connected to reefs and smaller bays.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><em>The Red Sea is one of the world’s least studied regions when it comes to whales and dolphins – until now. <a href="http://cms.int/sites/default/files/publication/red_sea_cetaceans_report_web_final.pdf">A report</a> was released recently that brings together historic records and the latest information on a range of the sea’s mammal species. This will supply some of the information needed for science based conservation measures. I interviewed <a href="http://www.disciara.org/">Giuseppe Notarbartolo di Sciara</a>, one of the reports’ authors who is also among the region’s most respected marine mammal specialists, on the findings and their implications.</em> </p>
<p><strong>What is special about the Red Sea and the habitat it provides to whales and dolphins?</strong></p>
<p>While <a href="https://www.elsevier.com/books/encyclopedia-of-marine-mammals/wursig/978-0-12-804327-1">huge progress</a> has been made globally in our ecological knowledge of marine mammals, this hasn’t been the case for the Red Sea. With the exception of <a href="https://africageographic.com/blog/video-dugong-fairytale-red-sea/">dugongs</a>, very little is known about the Red Sea’s mammals. This is one of the main reasons we put <a href="http://cms.int/sites/default/files/publication/red_sea_cetaceans_report_web_final.pdf">this report</a> together, conducting and collating research from 1983 to 2017. </p>
<p>Among the things we learned was that the fertility of the Red Sea’s environment affects marine mammal presence in the region. </p>
<p>Life in any ocean starts from the water’s <a href="https://www.science.oregonstate.edu/ocean.productivity/">productivity</a>. This is the ability of phytoplankton (microalgae) to bloom because of the nutrients contained in the water, like phosphates and nitrates. This is triggered by upwelling currents that bring nutrient-rich deeper waters to the surface. This fertilises the phytoplankton, which need sunlight. The phytoplankton bloom gets eaten by zooplankton, which are then eaten by little fish, and so on up the food web. </p>
<p>Such upwellings are rare in the Red Sea. This makes it a hard place to live for the great whales, which need big swarms of krill, small crustaceans, to survive. </p>
<p>This could be why only a few whale species have been able to colonise the Red Sea. </p>
<p>We also found out more about how dolphins – which are known collectively with whales as cetaceans – survive in the Red Sea.</p>
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<img alt="" src="https://images.theconversation.com/files/203019/original/file-20180123-182973-jj28xz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/203019/original/file-20180123-182973-jj28xz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=346&fit=crop&dpr=1 600w, https://images.theconversation.com/files/203019/original/file-20180123-182973-jj28xz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=346&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/203019/original/file-20180123-182973-jj28xz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=346&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/203019/original/file-20180123-182973-jj28xz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/203019/original/file-20180123-182973-jj28xz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/203019/original/file-20180123-182973-jj28xz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=435&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Spinner dolphins.</span>
<span class="attribution"><span class="source">Shutterstock/Melissa Burovac</span></span>
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</figure>
<p>The environment is better for smaller dolphin species like spinner dolphins and pan-tropical spotted dolphins. Spinner dolphins take advantage of a community of smaller critters living in what scientists call the <a href="https://www.nature.com/articles/172275a0">deep scattering layer</a>. It’s mostly made up of small crustaceans, fishes and squid. They live in a narrow layer that rises towards the surface at night to feed, and returns to the depths during the day to shelter. It provides the critical source of food for the dolphins to tap into in an otherwise poor marine environment. </p>
<p><strong>What threats do cetaceans face in the Red Sea?</strong></p>
<p>What worries me most is that the Red Sea is crossed by a huge amount of ship traffic carrying oil. It is a key strategic channel: an <a href="https://www.globalsecurity.org/military/world/yemen/bab-al-mandab.htm">estimated</a> 4% of global oil supply passes through it. The proportion sounds small, but it represents a vast amount of oil. A major accident would be disastrous for marine life in the narrow Red Sea.</p>
<p>An immediate and obvious threat today is disturbance by tourists. For example, spinner dolphins enter a reef in an area known as Samadai, on the southern coast of Egypt, to rest. They do this because they’ve been hunting at night and the reef gives them protection from sharks during the day. </p>
<p>The tourism industry discovered this and started to advertise swimming with dolphins in the area. It very quickly became a mess, creating an outcry on social media calling for people to stop bothering the animals. Fortunately, the Egyptian government took action and I helped to explore the situation and draft a plan. <a href="http://panorama.solutions/en/solution/creating-sustainable-tourism-samadai-dolphin-house-egypt">There is now</a> a large area of the reef that is completely off limits to tourism, and the dolphins have enough space to rest.</p>
<p>Unfortunately these situations aren’t always so well managed. Another area called Sataya, also in Egypt, has no management plan and the spinner dolphins are very stressed. It’s likely the entire reef area will be taken over by people and the animals will be pushed out. </p>
<p>In terms of fishing, I’m aware of situations in which particularly Yemeni fishermen travel widely across the Red Sea to hunt sharks for the Far East fin trade. I know that they have been using dolphin meat as bait for catching sharks. But we really don’t know how big this practice is or its impact on dolphin populations. </p>
<p><strong>What immediate and longer-term steps should be taken to mitigate the threats</strong></p>
<p>It would be great to have a model in the Red Sea similar to the one applied in the Mediterranean and Black Seas. Since 2002 there’s <a href="http://www.accobams.org">been an agreement</a> between most countries bordering those seas. It commits the coastal countries to protecting those seas’ cetaceans. Something like that would be extremely helpful in the Red Sea, and raise their visibility at the policy level.</p>
<p>It’s also important to protect marine mammal habitats in the Red Sea. This could come partly from the identification of important marine mammal areas, work that’s being done by a <a href="https://www.marinemammalhabitat.org">task force</a> established within the International Union for Conservation of Nature. The identification of the areas is based on specific criteria, and is modelled on earlier work on <a href="https://www.birdlife.org/worldwide/programmes/sites-habitats-ibas-and-kbas">birds</a>. The areas are critical for some aspect of a species life, for example feeding, breeding or migrating. Identifying them gives decision makers an easy tool to help select which areas need protection. </p>
<p>The task force is in the process of identifying these mammal areas in large portions of the southern hemisphere, and there are plans to do this in the Red Sea in 2019.</p><img src="https://counter.theconversation.com/content/89928/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Obura works at the non-profit research organisation CORDIO East Africa, in Mombasa, Kenya</span></em></p>A new report will supply some information needed for science based conservation measures in the Red Sea.David Obura, Adjunct Fellow, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/867412017-11-14T02:43:30Z2017-11-14T02:43:30ZResearchers find pathological signs of Alzheimer’s in dolphins, whose brains are much like humans’<figure><img src="https://images.theconversation.com/files/193487/original/file-20171106-1014-v0l70p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A bottlenose dolphin leaping from the ocean in Panama.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bottlenose-dolphin-jumping-bay-panama-567767455?src=Vzx3gyzMeNAPuCWVXeCi1Q-1-11">Christian Wittman/Shutterstock.com</a></span></figcaption></figure><p>A team of scientists in the United Kingdom and the U.S. recently reported the <a href="https://www.ncbi.nlm.nih.gov/pubmed/28972881">discovery of pathological signs</a> of Alzheimer’s disease in dolphins, animals whose brains are similar in many ways to those of humans.</p>
<p>This is the first time that these signs – <a href="https://www.ncbi.nlm.nih.gov/pubmed/9748670">neurofibrillary tangles and two kinds of protein clusters called plaques</a> – have been discovered together in marine mammals. As neuroscience researchers, we believe this discovery has added significance because of the similarities between dolphin brains and human brains.</p>
<p>The new finding in dolphins supports the research team’s hypothesis that two factors conspire to raise the risk of developing Alzheimer’s disease in dolphins. </p>
<p>Those factors are: longevity with a long <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0144353">post-fertility life span</a> – that is, a species living, on average, many years after the child-bearing years are over – and insulin signaling.</p>
<p>Gallego-Iradi, one of the authors of the paper, began the study on the dolphins’ brains more than a decade ago on the shores of Spain. It took several more years for other researchers to establish the connection between metabolic dysfunction and insulin resistance in dolphins and humans. This recent study also did that. </p>
<p>Together, the insight into the similarities between dolphins and humans has led us to hypothesize that Alzheimer’s and diabetes are diseases not of old age but of a long post-fertility life span. </p>
<h2>A disastrous disease</h2>
<p><a href="https://www.alz.org/alzheimers_disease_what_is_alzheimers.asp#basics">Alzheimer’s</a> is a progressive brain disease that leads to memory loss and changes in cognitive ability. There is no cure, and the disease ultimately leads to death. </p>
<p>It is hard to overstate the burden of the disease, both on those who are diagnosed with it and their families. It is the <a href="https://www.cdc.gov/media/releases/2017/p0525-alzheimer-deaths.html">sixth-leading cause of death</a> in the U.S. Deaths from the disease in the U.S. rose <a href="https://www.cdc.gov/media/releases/2017/p0525-alzheimer-deaths.html">55 percent</a> from 1999 to 2014. </p>
<p>Alzheimer’s disease has two major pathological hallmarks: The development of clusters of a protein called <a href="https://www.alz.org/national/documents/topicsheet_betaamyloid.pdf">beta-amyloid</a> outside the cells and tangles of another <a href="https://www.alz.org/braintour/tangles.asp">protein called tau</a> inside the cell. </p>
<p>The protein clusters outside the cells are called senile plaques. The tangles inside are called neurofibrillary tangles. </p>
<p>We saw both of these in the brains of the deceased dolphins. </p>
<h2>The big brain theory</h2>
<p>Dolphins belong to an order of mammals called <a href="http://www.ucmp.berkeley.edu/mammal/cetacea/cetacean.html">cetaceans</a> that have adapted to live in the water. </p>
<p>Although dolphins live in water and humans live on Earth, dolphins and humans are very much alike in some key ways. In the last 50-60 million years, the brains of dolphins and other <a href="http://www.ucmp.berkeley.edu/mammal/cetacea/cetacean.html">cetaceans</a>, including porpoises and whales, have hyperexpanded. So have human brains. This is a process called <a href="https://en.oxforddictionaries.com/definition/encephalization">enchephalization</a>. </p>
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<p>Also, as do humans, dolphins have a highly evolved brain development and a very complex social relationship. This brain similarity with humans suggests the possibility that dolphins, as humans, have developed similar molecular machineries and pathological characteristics, including similar neurodegenerative diseases. </p>
<p>And, cetaceans and humans live long. This is important, as longevity is one of the most relevant factors in neurodegenerative diseases. Cetaceans have longevity ranges between 20-100 years, which is enough time to develop brain amyloid deposits. </p>
<p>Some aspects of Alzheimer’s pathology have been reported in a wide range of other animals. Our evolutionary relatives, such as apes and monkeys, and our pets, dogs and cats, develop one of the pathologies, the amyloid pathology. <a href="https://www.alz.org/braintour/plaques.asp">Amyloid plaques</a> also have been described in captive wild animals such as bears. </p>
<p>But to see both plaques and tangles in another species is rare. </p>
<p>We believe this makes our findings in dolphins of both neuritic plaque and tangle pathology in dolphins all the more remarkable. </p>
<h2>Stranded dolphins led to the first discovery</h2>
<p>Cetaceans become stranded many times each year all over the world. This stranding generates alarm, and scientists study to understand why it happens. Some of the factors include poor water quality; animals living in very deep water who detect the shore too late; unbalance and confusion created by Earth’s magnetic field changes; contamination by heavy metals such as mercury, cadmium or zinc; or contamination by compounds such as PCBs and DDTs. Other possible causes are viruses and parasites, traumatic death, predation or fishing mutilation, or ship sonars interfering with animal echolocation.</p>
<p>Dolphins stranded in Spain between 2003 and 2006 led to Gallego Iradi’s <a href="http://mbi.ufl.edu/2017/11/01/uf-researchers-find-signs-of-alzheimers-pathology-in-dolphins/">findings about the Alzheimer’s pathology</a>.</p>
<p>The samples represented three different species of dolphins (bottlenose, striped and Risso’s) stranded on the coasts of Spain. Their brains all had the same twisted strands and protein clusters in their brain as human patients with Alzheimer’s disease. They also had neuronal loss, strengthening the idea that dolphins and humans could have the same Alzheimer’s pathology. </p>
<p>Years after those findings, other scientists began to explore a possible connection between a failure in insulin signaling and Alzheimer’s. </p>
<p><a href="https://www.psych.ox.ac.uk/research/dementia-research-group">Dr. Simon Lovestone</a> at the University of Oxford and Dr. <a href="https://risweb.st-andrews.ac.uk/portal/en/persons/frank-j-gunnmoore(b00c5dd1-3606-4696-9ce8-4504b04977bf).html">Frank Gunn-Moore</a> at the University of Saint Andrews began to develop a hypothesis that this failure in insulin signaling in humans, related to post-fertility longevity, could be a cause of Alzheimer’s in humans. </p>
<p>And here’s another connection. </p>
<p>Cetaceans are uniquely prone to a prediabetes state and are one of the few animals, other than humans, with a naturally long post-fertility life span. </p>
<p>We postulated a linked mechanism that led us to hypothesize that animals with a long post-fertility lifespan would be at risk for both insulin resistance and Alzheimer’s. This hypothesis led us to the prediction that cetaceans and other animals with unusual longevity would be at risk for both insulin resistance and would have Alzheimers’ pathology – a prediction for which we have provided some proof in our recent article.</p><img src="https://counter.theconversation.com/content/86741/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors 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>Researchers have found evidence of the same brain pathologies in dolphins that are present in the brains of humans who died with Alzheimer’s. What might this suggest about Alzheimer’s in humans?Maria Carolina Gallego-Iradi, Assistant Scientist, University of FloridaDavid Borchelt, Professor of Neuroscience, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/858582017-10-18T10:11:33Z2017-10-18T10:11:33ZWhales and dolphins have rich cultures – and could hold clues to what makes humans so advanced<figure><img src="https://images.theconversation.com/files/190666/original/file-20171017-30422-eb1qx5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A pod of spinner dolphins in the Red Sea</span> <span class="attribution"><span class="source">Alexander Vasenin/wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Humans are like no other species. We have constructed stratified states, colonised nearly every habitat on Earth and we’re now looking to <a href="https://theconversation.com/what-nasas-simulated-missions-tell-us-about-the-need-for-martian-law-84790">move to other planets</a>. In fact, we are so advanced that some of our innovations – such as fossil fuel technologies, intensive agriculture and weapons of mass destruction – may ultimately lead to our downfall. </p>
<p>Even our closest relatives, the primates, lack traits such as developed language, cumulative culture, music, symbolism and religion. Yet scientists still haven’t come to a consensus on why, when and how humans evolved these traits. But, luckily, there are non-human animals that have evolved societies and culture to some extent. Our latest study, <a href="https://www.eurekalert.org/pub_releases/2017-10/uom-wad101217.php">published in Nature Evolution & Ecology</a>, investigates what cetaceans (whales and dolphins) can teach us about human evolution.</p>
<p>The reason it is so difficult to trace the origins of human traits is that social behaviour does not fossilise. It is therefore very hard to understand when and why cultural behaviour first arose in the human lineage. Material culture such as art, burial items, technologically sophisticated weapons and pottery is very rare in the archaeological record.</p>
<p>Previous research in primates <a href="http://www.sciencedirect.com/science/article/pii/004724849290081J">has shown</a> that a large primate brain is associated with larger social groups, cultural and behavioural richness, and learning ability. A larger brain is <a href="https://www.nature.com/articles/s41559-017-0112">also tied to energy-rich diets</a>, long life spans, <a href="https://doi.org/10.1006/jhev.1997.0140">extended juvenile periods</a> and large bodies. But researchers trying to uncover whether each of these different traits are causes or consequences of large brains find themselves at odds with each other – <a href="http://rstb.royalsocietypublishing.org/content/372/1727/20160244.article-info">often arguing at cross purposes</a>.</p>
<p>One prevailing explanation is the <a href="https://theconversation.com/our-large-brains-evolved-thanks-to-an-ancient-arms-race-for-resources-and-mates-79183">social brain hypothesis</a>, which argues that our minds and consequently our brains have evolved to solve the problems associated with living in an information rich, challenging and dynamic social environment. This comes with challenges such as competing for and allocating food and resources, coordinating behaviour, resolving conflicts and using information and innovations generated by others in the group. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/190785/original/file-20171018-32341-tw3bq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/190785/original/file-20171018-32341-tw3bq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=423&fit=crop&dpr=1 600w, https://images.theconversation.com/files/190785/original/file-20171018-32341-tw3bq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=423&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/190785/original/file-20171018-32341-tw3bq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=423&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/190785/original/file-20171018-32341-tw3bq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=532&fit=crop&dpr=1 754w, https://images.theconversation.com/files/190785/original/file-20171018-32341-tw3bq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=532&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/190785/original/file-20171018-32341-tw3bq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=532&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Primates with large brains tend to be highly social animals.</span>
<span class="attribution"><span class="source">Peter van der Sluijs/wikipedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
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<p>However, despite the abundance of evidence for a link between brain size and social skills, the arguments rumble on about the role of social living in cognitive evolution. Alternative theories suggest that primate brains have evolved <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2409100/">in response to the complexity of forest environments</a> – either in terms of searching for fruit or visually navigating a three dimensional world. </p>
<h2>Under the sea</h2>
<p>But it’s not just primates that live in rich social worlds. <a href="https://www.newscientist.com/article/mg21428666-300-what-insect-societies-tell-us-about-cells/">Insects</a>, birds, <a href="https://www.livescience.com/42576-elephant-matriarchs-guide-society.html">elephants</a>, <a href="http://esc.rutgers.edu/fact_sheet/the-basics-of-equine-behavior/">horses</a> and cetaceans do, too. </p>
<p>The latter are especially interesting as, not only do we know that they do interesting things, some live in multi-generational societies and they also have the largest brains in the animal kingdom. In addition, they do not eat fruit, nor do they live in forests. For that reason, we decided to evaluate the evidence for the social or cultural brain in cetaceans.</p>
<p>Another advantage with cetaceans is that research groups around the world have spent decades <a href="https://doi.org/10.1371/journal.pbio.0050139">documenting and uncovering their social worlds</a>. These include signature whistles, which appear to identify individual animals, cooperative hunting, complex songs and vocalisations, social play and social learning. We compiled all this information into a database and evaluated whether a species’ cultural richness is associated with its brain size and the kind of society they live in. </p>
<p>We found that species with larger brains live in more structured societies and have more cultural and learned behaviours. The group of species with the largest relative brain size are the large, whale-like dolphins. These include the <a href="http://uk.whales.org/species-guide/false-killer-whale">false killer whale</a> and <a href="https://www.seashepherd.org/faroes/about-campaign/the-pilot-whale.html">pilot whale</a>.</p>
<p>To illustrate the two ends of the spectrum, killer whales have cultural food preferences – where some populations prefer fish and other seals. They also hunt cooperatively and have matriarchs leading the group. Sperm whales have actual dialects, which means that different populations <a href="http://rsos.royalsocietypublishing.org/content/3/6/160061">have distinct vocalisations</a>. In contrast, some of the large <a href="https://www.afsc.noaa.gov/nmml/education/cetaceans/baleen1.php">baleen whales</a>, which have smaller brains, eat krill rather than fish or other mammals, live fairly solitary lives and only come together for breeding seasons and at rich food sources.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/190784/original/file-20171018-32345-kf73f5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/190784/original/file-20171018-32345-kf73f5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/190784/original/file-20171018-32345-kf73f5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/190784/original/file-20171018-32345-kf73f5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/190784/original/file-20171018-32345-kf73f5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=567&fit=crop&dpr=1 754w, https://images.theconversation.com/files/190784/original/file-20171018-32345-kf73f5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=567&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/190784/original/file-20171018-32345-kf73f5.jpg?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">
<figcaption>
<span class="caption">The lives of beaked whales are still a big mystery.</span>
<span class="attribution"><span class="source">Ted Cheeseman/wikipedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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</figure>
<p>We still have much to learn about these amazing creatures. Some of the species were not included in our analysis because we know so little about them. For example, there is a whole group of beaked whales with very large brains. However, because they dive and forage in deep water, sightings are rare and we know almost nothing about their behaviour and social relationships.</p>
<p>Nevertheless, this study certainly supports the idea that the richness of a species’ social world is predicted by their brain size. The fact that we’ve found it in an independent group so different from primates makes it all the more important.</p><img src="https://counter.theconversation.com/content/85858/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Susanne Shultz receives funding from The Royal Society. </span></em></p>Complex behaviour such as regional accents and cultural food preferences in whales and dolphins seems to be linked to brain size.Susanne Shultz, University Research Fellow, University of ManchesterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/729852017-02-15T09:53:13Z2017-02-15T09:53:13ZWhat causes whale mass strandings?<p>Around 600 pilot whales recently became stranded on a <a href="http://www.telegraph.co.uk/news/2017/02/11/another-pod-whales-stranded-new-zealand-bringing-total-650/">New Zealand beach</a>, around 400 of which died before volunteers could refloat them back into the sea. Sadly, this kind of mass whale stranding has occurred since human records began, and happens somewhere in the world on a regular basis. </p>
<p>At the end of 2015, 337 sei whales died in a fjord in Chile after the largest ever beaching of whales <a href="http://news.nationalgeographic.com/2015/11/151120-worlds-largest-whale-stranding-sei-chile-animals/">of this species</a>. Mass strandings can also occur in northern Europe. In February 2016, 29 sperm whales were found stranded on the coasts of <a href="http://www.seawatchfoundation.org.uk/largest-sperm-whale-stranding-ever-recorded-in-the-north-sea/">Germany, the Netherlands, eastern England, and northern France</a>, a record for this species in the North Sea.</p>
<p>Why do these creatures, which are masters of living in a totally aquatic environment, enter an inhospitable land environment where inevitably some, if not all, will die?</p>
<p>Mass strandings almost invariably involve oceanic species of whales. Long-finned and short-finned pilot whales tend to be the most frequent casualties. Other species typically are false killer whales, melon-headed whales, Cuvier’s beaked whales and sperm whales. All of these normally live in waters over 1,000 metres deep and are very social, forming cohesive groups that in some cases may number hundreds of animals. </p>
<p>Although it’s tempting to automatically blame whale strandings on human activity, the fact that deep-dwelling species of whales most often get stranded, and in the same locations, indicates that in many cases natural causes are more likely to be to blame. Mass strandings of these oceanic species tend to be in very shallow areas with gently sloping, often sandy, seabeds. In those situations, it is no surprise that these animals, which are used to swimming in deep waters, can get into difficulties and even if re-floated will often re-strand.</p>
<p><a href="http://www.afsc.noaa.gov/nmml/education/cetaceans/cetaceaechol.php">The echolocation</a> they use to aid navigation also does not work well in such environments. So it is quite possible that the majority of such strandings are simply due to navigational error, for example when whales have followed a valuable prey resource into unfamiliar and dangerous territory. This may have been the cause of the mass stranding of sperm whales in the North Sea, some of which had recently digested oceanic squid in their stomachs.</p>
<p>The ratio of strandings to sightings for sperm whales in the North Sea is significantly higher south of the Dogger Bank where shallow, often sandy, <a href="http://www.seawatchfoundation.org.uk/largest-sperm-whale-stranding-ever-recorded-in-the-north-sea/">environments prevail</a>. And the same goes for Farewell Spit, Golden Bay in the South Island of New Zealand, where the recent pilot whale stranding took place and where <a href="http://www.bbc.co.uk/news/world-asia-16675613">similar incidents</a> <a href="http://www.bbc.co.uk/news/world-asia-31450651">have occurred</a> <a href="http://news.bbc.co.uk/1/mobile/world/asia-pacific/8432260.stm">several times</a> in the last few years. </p>
<p>Both areas have seen a number of mass strandings of those particular species in the past. In the southern North Sea, there are records of mass strandings of sperm whales dating back <a href="http://www.ecomare.nl/en/encyclopedia/organisms/animals/mammals/cetaceans/whales/sperm-whale/">at least to 1577</a>.</p>
<p>However, mass strandings aren’t only caused by whales getting lost or misjudging the depth of the water. One or more individuals may be diseased and, as they become weaker, they seek shallower waters so they can more easily come to the surface to breathe. Once their bodies come to rest on a hard surface for any extended period, there is a greatly increased chance that their chest walls will be compressed and their internal organs damaged.</p>
<h2>Sonar effects</h2>
<p>Occasionally, live strandings may derive from human activities, particularly military activity that involves the <a href="http://acousticstoday.org/wp-content/uploads/2015/05/Sonars-and-Strandings-Are-Beaked-Whales-the-Aquatic-Acoustic-Canary.pdf">use of sonar</a>. This connection was <a href="http://www.pelagosinstitute.gr/en/pelagos/pdfs/Frantzis%202003%20Active%20Sonar%20Workshop.pdf">first suggested</a> in 1996 after a NATO military exercise off the coast of Greece coincided with the stranding of 12 Cuvier’s beaked whales. Unfortunately, there was no opportunity for veterinary examination. </p>
<p>But <a href="http://www.nmfs.noaa.gov/pr/pdfs/health/stranding_bahamas2000.pdf">in May 2000</a>, another beaked whale mass stranding took place in the Bahamas alongside naval activity using similar loud mid-frequency sonar. A number of the whales were examined, and haemorrhaging, particularly around the inner ear, was discovered, indicating acoustic trauma.</p>
<p>After a similar incident in the Canary Islands in September 2002, veterinary pathologists analysing the whales also identified symptoms of <a href="http://journals.sagepub.com/doi/abs/10.1354/vp.42-4-446">decompression sickness</a>. This suggests that the animals do not always die from stranding but may be injured or die at sea first. Many researchers <a href="http://www.seawatchfoundation.org.uk/wp-content/uploads/2012/08/Active_Sonar_Workshop.pdf">now believe</a> that naval sonar might produce behaviour in whales that interferes with their ability to manage the gases inside their bodies, affecting their ability to dive and rise to the surface safely.</p>
<p>Loud noise in the ocean has become a major conservation concern as humans introduce sounds of varying intensities and frequencies into the marine environment from different technologies and even explosions. Seaquakes are another source of intense underwater sound and those might also lead to physical damage or behaviour resulting in strandings, although no one has yet produced a statistical link between the two. </p>
<h2>Social following</h2>
<p>The kind of strandings seen in New Zealand, where very large numbers of whales become beached but a significant proportion can be rescued, also raises the question of whether some healthy animals simply follow others into dangerously shallow waters.</p>
<p>Many years ago, I went to the aid of two short-beaked common dolphins that stranded alive in the Teifi Estuary, west Wales. One of the individuals died quite quickly and a subsequent post-mortem revealed it had a heavy lung parasite infection, which was thought to have affected breathing. The other individual remained close to its dying companion and appeared to be in great distress, whistling frequently.</p>
<p>We managed to successfully refloat this other dolphin in the end and it swam away, but the incident highlighted to me the strong social bonds that can exist between individuals. When we see large numbers of whales or dolphins undertaking what appears to be <a href="https://theconversation.com/do-whales-attempt-suicide-50165">mass suicide</a>, the chances are that they are vocally responding to one another, reflecting <a href="http://press.uchicago.edu/ucp/books/book/chicago/C/bo12789830.html">their strong sociality</a>.</p>
<p><a href="http://jhered.oxfordjournals.org/content/104/3/301.short">Recent research</a> suggests that whales in mass strandings aren’t necessarily even related to one another. So perhaps mass strandings are a reflection of just how strong the social bonds between whales really are.</p><img src="https://counter.theconversation.com/content/72985/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Evans 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>More than 400 whales have died on a beach in New Zealand.Peter Evans, Honorary Senior Lecturer, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/662552016-10-31T16:21:14Z2016-10-31T16:21:14ZWhy the current plan to save the endangered vaquita porpoise won’t work<figure><img src="https://images.theconversation.com/files/142681/original/image-20161021-1782-11wgnqa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A dead vaquita entangled in a gillnet.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/nmfs_northwest/26367279334/in/photolist-zfwVYD-yNfNgh-zhGQWx-yNmGW6-z14ig1-yXYxar-ynThFe-zjLrbg-z3aCFu-zjLhLa-zgnmHt-z3aEYA-HGxTJc-zfm2QG-zerNcQ-ykLSQ2-zjGHgR-zdbTRA-zgkRBV-zfu3DZ-zZdzD6-GZrnF4-H6usAX-GXchEJ-GaZcwo">NOAA Fisheries West Coast</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>With fewer than 60 individuals left, the world’s smallest porpoise, the <a href="http://www.iucnredlist.org/details/17028/0">vaquita marina (<em>Phocoena sinus</em>)</a>, continues to balance on the edge of extinction. Constant pressures from conservation groups have lead to a two-year emergency gillnet ban, which will end in May 2017, and government-led efforts are now pushing fishers to use gear that won’t threaten the vaquita through bycatch. </p>
<p>Despite these steps, in a <a href="http://onlinelibrary.wiley.com/doi/10.1111/conl.12317/full">new study</a> my colleagues and I warn that unless further big changes are made in the Upper Gulf of California, Mexico, we may soon be saying goodbye to this charismatic little animal. </p>
<p>The history of vaquita conservation is <a href="http://www.ecologyandsociety.org/vol21/iss2/art9/">long and convoluted</a>. It has been characterized by intermittent top-down management interventions that have often had little more than short-term outlooks. These have perpetuated the <a href="https://swfsc.noaa.gov/MMTD-vaquita/">decline of the vaquita population</a>, which is now estimated to contain <a href="http://www.marinemammalcenter.org/science/Working-with-Endangered-Species/vaquita.html?referrer=https://www.google.com/">less than 25</a> reproductively mature females.</p>
<p>The new <a href="http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1755-263X/earlyview">Conservation Letters</a> study describes how the gillnet ban now in effect, and the introduction of new trawl gear may address the immediate problem of vaquita bycatch but even taken together, they will likely be yet another short-term – and, most likely, ineffective – attempt to pull the vaquita back from the brink of extinction. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/140662/original/image-20161006-20152-152ann7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&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 end of a day’s fishing in the Upper Gulf of California, where conservationists fight with fishers over the declining populations of the vaquita marina porpoise.</span>
<span class="attribution"><span class="source">Octavio Aburto / ILCP - author provided</span></span>
</figcaption>
</figure>
<h2>Switching gears</h2>
<p>Gillnets sit in midwater and are made of fine line, which is difficult to see in the Upper Gulf’s murky waters. Similar to almost all cetacean bycatch, vaquita are unable to free themselves once entangled and risk being drowned while held under water. </p>
<p>Trawl gear is an alternative that reduces the risk of bycatch. These heavy gears are towed along the seafloor catching any animal not quick enough to outswim the mouth of the approaching net. The mouth of the net is much smaller than the area of a gillnet, which reduces the effective catch area that poses a risk to the vaquita. Also, the use of trawl gear is noisy, more easily visible and therefore more easily avoidable than gillnets for cetacean species.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=902&fit=crop&dpr=1 600w, https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=902&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=902&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1133&fit=crop&dpr=1 754w, https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1133&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/140663/original/image-20161006-20110-jcdlsg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1133&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 young fisherman in the Upper Gulf of California, Mexico holds up his prawn catch, caught with gillnets that threaten the vaquita’s survival, yet earn the local fishers a healthy livelihood.</span>
<span class="attribution"><span class="source">Octavio Aburto / ILCP - author provided</span></span>
</figcaption>
</figure>
<p>But this alternative is more expensive. After accounting for lower catch rates, higher fuel expenditure and the cost of the switch from gillnets to trawls, we estimated that an annual subsidy of at least US$8.5 million would be needed to compensate fishers in the Upper Gulf for loss of employment and earnings. Long term, the economic losses from the new management interventions could have one or two side effects: 1) a reliance on subsidies and/or 2) increased illegal fishing activities. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/141300/original/image-20161011-15645-17cn6r7.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/141300/original/image-20161011-15645-17cn6r7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/141300/original/image-20161011-15645-17cn6r7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/141300/original/image-20161011-15645-17cn6r7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/141300/original/image-20161011-15645-17cn6r7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=457&fit=crop&dpr=1 754w, https://images.theconversation.com/files/141300/original/image-20161011-15645-17cn6r7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=457&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/141300/original/image-20161011-15645-17cn6r7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=457&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="source" href="https://www.flickr.com/photos/nmfs_northwest/27369509811/in/album-72157659101243641/">NOAA Fisheries West Coast</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>What’s more, an endangered yet highly prized fish is caught in these waters with gillnets. Swim bladders known as buche from the endangered <a href="http://www.iucnredlist.org/details/22003/0">totoaba (<em>Totoaba macdonali</em>)</a> can sell for <a href="http://qz.com/468358/how-chinas-fish-bladder-investment-craze-is-wiping-out-species-on-the-other-side-of-the-planet/">tens to hundreds of thousands of dollars per kilo</a>, depending on the size of the bladder and the demand of the Chinese market. This <a href="http://www.huffingtonpost.com/entry/aquatic-cocaine-is-killing-the-worlds-cutest-porpoise_us_57e19279e4b0e80b1b9ec56a">“aquatic cocaine”</a> complicates the plight of the vaquita because illegal fishing to catch the totoaba pose a risk to the few vaquita that remain.</p>
<p>There are also significant ecological risks to the new management plan. The <a href="http://onlinelibrary.wiley.com/doi/10.1046/j.1467-2979.2002.00079.x/full">impacts of trawl gear</a> to seafloor species are significantly greater than those posed by gillnets because they are dragged along sea floors, <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2011.02036.x/full">reducing productivity</a> in many shelf sea ecosystems and <a href="http://www.sciencedirect.com/science/article/pii/S0022098106001341">negatively affecting community compositions and diversity</a>. In just 26 days of gear testing in the Upper Gulf prior to the the gillnet ban, 30 percent, or 2,819 square kilomters (1,715 square miles), of the Upper Gulf biosphere reserve’s total area was scoured by the new trawl gears. Longer term, we warn in our study this could have severely detrimental consequences for the health of the Upper Gulf marine ecosystem.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1187&fit=crop&dpr=1 600w, https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1187&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1187&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1492&fit=crop&dpr=1 754w, https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1492&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/141292/original/image-20161011-15636-1971tzl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1492&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Trawl tracks after (a) 1 day and (b) 26 days of gear-testing in the Upper Gulf of California, Mexico.</span>
<span class="attribution"><span class="source">Moreno Báez - Author provided</span></span>
</figcaption>
</figure>
<h2>Community involvement</h2>
<p>My colleagues and I believe there is little use in pointing the finger of blame at this point, as seems to be the case in many articles discussing the fight for the vaquita. Instead, the vaquita situation urgently needs a new way of thinking, a paradigm shift. </p>
<p>Consistent exclusion of fishers from the design of management plans, typically driven by conservation groups and implemented by the government, has led to polarized opinions and a large divide between what should be a close collaboration between fishers and conservation agencies. Rushed, short-sighted management must be replaced by longer-term goals that involve local communities and address conservation challenges associated with both the vaquita and the totoaba. </p>
<p><a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2004.00077.x/full">Community support</a> of management measures, in particular, seems essential for long-term success in conservation stories. We recommend that the local communities in the Upper Gulf require external investment. Specifically, the development of infrastructure, such as road networks to connect fishers to new markets and processing facilities, would benefit the current situation by providing new employment opportunities as well as increased returns on ever dwindling fish catches.</p>
<p>Education is also key. This should include programs to educate fishers in the consequences of unsustainable fisheries practices, techniques to help add value to their catches and alternative livelihoods to fishing such as tourism or potential service industry employment.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/142682/original/image-20161021-1748-g3bckc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/142682/original/image-20161021-1748-g3bckc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=744&fit=crop&dpr=1 600w, https://images.theconversation.com/files/142682/original/image-20161021-1748-g3bckc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=744&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/142682/original/image-20161021-1748-g3bckc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=744&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/142682/original/image-20161021-1748-g3bckc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=935&fit=crop&dpr=1 754w, https://images.theconversation.com/files/142682/original/image-20161021-1748-g3bckc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=935&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/142682/original/image-20161021-1748-g3bckc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=935&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Vaquita are found only in the uppermost Gulf of California, Mexico.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/nmfs_northwest/21528015329/in/album-72157659101243641/">NOAA Fisheries West Coast</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>At present there are few employment alternatives for fishers in the Upper Gulf. Often, men are recruited into the fishery as young as 15 and the common story of “once a fisher, always a fisher” prevails. We highlight that an investment in education could both help promote marine stewardship as fishers better understand the longer-term consequences of current fisheries practices. It could also provide the younger generation with the training to build new business or follow paths in higher education instead of joining the local fisheries. </p>
<p>As with many of the world’s ecological problems, overcapacity seems to be key. In the case of the upper Gulf fisheries, too many people are catching too many fish from finite stocks. Continued overexploitation of any natural resource ultimately means communities risk destroying the finite natural resources they depend on. </p>
<p>To put it simply, communities in the Upper Gulf of California need help to reduce both the number of fishers currently fishing and the number of future fishers entering the fisheries. This will help promote alternative, nonextractive activities in order to alleviate the impacts that current fisheries practices have on fish stocks, the vaquita and, with the new trawl gear intervention, sea floor habitats. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/140661/original/image-20161006-20123-1p0hhuj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/140661/original/image-20161006-20123-1p0hhuj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/140661/original/image-20161006-20123-1p0hhuj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/140661/original/image-20161006-20123-1p0hhuj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/140661/original/image-20161006-20123-1p0hhuj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/140661/original/image-20161006-20123-1p0hhuj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/140661/original/image-20161006-20123-1p0hhuj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A fisher in the Upper Gulf of California, Mexico tears up old fish to feed to the pelicans.</span>
<span class="attribution"><span class="source">Octavio Aburto / ILCP - author provided</span></span>
</figcaption>
</figure>
<h2>Another band-aid</h2>
<p>A meeting in late July of this year between Presidents Obama and Peña Nieto <a href="https://www.whitehouse.gov/the-press-office/2016/07/22/fact-sheet-united-states-mexico-relations">concluded with a tentative proposal</a> for a permanent extension of the Upper Gulf’s gillnet ban and a crack down on the totoaba trade. Although eliminating vaquita bycatch is crucial for the species’ survival, ignoring economic losses, local livelihoods and new ecological problems related to trawl impacts, the Mexican government may have missed the point again. </p>
<p>With one foot of the vaquita firmly in the grave, now does not seem to be the time to make somewhat incomplete decisions regarding the survival of the vaquita, the health of the Upper Gulf of California’s ecosystem and the social well being of the families that live in this remote area of Mexico.</p><img src="https://counter.theconversation.com/content/66255/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Frederick Johnson receives funding from the National Science Foundation. </span></em></p>As the vaquita porpoise heads towards extinction, new management measures in Mexico still may have missed the point – affecting not one but two critically endangered marine species.Andrew Frederick Johnson, Postdoctoral Researcher of Marine Biology at Scripps Insitution of Oceanography, University of California, San DiegoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/602842016-06-02T15:03:02Z2016-06-02T15:03:02ZHow insight into southern Africa’s dolphins is being deepened<figure><img src="https://images.theconversation.com/files/125000/original/image-20160602-23298-phwk0g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some dolphins live close to the shore, where they regularly encounter humans. This is affecting their numbers.</span> <span class="attribution"><span class="source">Simon Elwen</span></span></figcaption></figure><p><em>South Africa has a wide range of oceanographic conditions around the coast. As a result, there is a diversity of cetacean species. These are large-bodied, fast-moving top predators like dolphins and whales. Globally, at least a quarter of these species are listed as endangered. Understanding how these species move and live is crucial to understanding their ecological relationships with the environment.</em> </p>
<p><em>The E3C – Effect of Climate Change on Cetaceans – <a href="https://seasearchafrica.wordpress.com/2016/03/29/mapping-dolphin-distribution-using-citizen-science/#more-526">project</a> looks at the impact climate change has on these species. The Conversation Africa’s energy and environment editor Ozayr Patel spoke to Dr Simon Elwen, a researcher with South Africa’s University of Pretoria working on the project.</em></p>
<p><strong>Globally, at least a quarter of whale and dolphin species have been listed as endangered. What are the main reasons?</strong></p>
<p>Many of the large whale species and populations that were subjected to commercial whaling have been very slow to recover, notably the Antarctic blue whale and the North Atlantic right whale. But the majority of large whale populations have been increasing slowly over the past few decades. Species are gradually leaving the threatened lists, thanks to wide-ranging international conservation efforts. The most important of these is the end of whaling, showing that stopping directed take – in other words “not killing animals” – is one of the most effective conservation strategies. </p>
<p>But the bad news is that many dolphin and porpoise populations are the ones now facing extirpation. The Maui’s dolphin of New Zealand and the vaquita of the gulf of California are both critically <a href="http://www.hectorsdolphins.com/news-releases.html">endangered</a>. The baiji, the Chinese river dolphin, has already been declared extinct due almost entirely to habitat loss in the <a href="http://news.nationalgeographic.com/news/2006/12/061214-dolphin-extinct_2.html">Yangtze River in China</a>. </p>
<p><strong>What is the state of dolphin species around Africa’s coasts? What threats do they face?</strong></p>
<p>In southern Africa most dolphin populations are thought to be fairly healthy. There are five species that are regularly seen from shore, including the Heaviside’s and dusky dolphin on the west coast and the Indo-Pacific bottlenose and Indian Ocean humpback dolphin, which are found to the east of Cape Point in Cape Town. There are several other species that inhabit the shelf and offshore waters, with the common dolphin being one of the few of these regularly seen close to shore, especially along the south-eastern part of the continent. The only species that is currently thought to be of concern is the <a href="http://www.sousaproject.org/">humpback dolphin</a>, <em>Sousa plumbea</em>. </p>
<p>The humpback dolphin lives along the southern Cape coast and off northern KwaZulu-Natal province. This entire population in South Africa likely numbers less than 1,000 individuals and lives extremely close to shore, where it regularly encounters humans. This results in things like boat traffic, pollution, habitat loss and prey depletion having an impact on these species. </p>
<p><strong>Why are dolphins, in particular, important in the ocean’s ecosystem?</strong></p>
<p>Dolphins and whales are large, highly mobile top predators. They can eat a lot of food and respond quickly to changes in the environment by moving large distances, depending on the species. As large predators, they can have a top-down role in ecosystems, suppressing the numbers of prey animals. What this means is that sometimes species near the bottom of the food chain, like sardine or anchovy, can increase when medium-level predators are removed by top predators such as seals, sharks and dolphins, a result shown in a number of ecosystems globally.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125001/original/image-20160602-23298-1n81plu.jpg?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"></a>
<figcaption>
<span class="caption">Dolphins and
whales are known to be top predators.</span>
<span class="attribution"><span class="source">Simon Elwen</span></span>
</figcaption>
</figure>
<p><strong>What is unique about the South African coast that makes it so diverse?</strong></p>
<p>South Africa’s marine life at all trophic levels is remarkably diverse, thanks largely to the diversity of habitats available around the coast. It ranges from tropical at the Mozambique border, to temperate along the south coast and cool-temperate along the west coast. </p>
<p>From a mammal point of view, the cold waters of the Benguela ecosystem along the west coast provide a link to sub-Antarctic environments, so some species that are usually only found south of 40 degrees of latitude also occur in the Benguela, like southern right whale dolphins and pygmy right whales.</p>
<p><strong>Commercial fishing practices, gill nets and pollution are viewed as the most serious challenge to dolphins. Are these serious problems in African and South African waters?</strong></p>
<p>To the best of my knowledge, bycatch – the unintentional catching of a species – is thankfully not a major problem in South Africa. There is no gill netting in South Africa. Coastal net fisheries are scarce and most of the large-scale commercial fishing activities in South Africa occur in deeper waters than most of our coastal dolphin species occur.</p>
<p>But entanglement in lobster and octopus trap lines is an increasing concern for large whales in coastal waters. Recent data on organic pollutants in dolphins from the east coast suggests that DDT and polychlorinated biphenyls are <a href="http://pubs.acs.org/doi/pdf/10.1021/acs.est.5b06009">still a concern</a>, especially for coastal dolphin species like the humpback and bottlenose. </p>
<p><strong>What effect is climate change having on dolphins?</strong></p>
<p>Essentially, assuming no other changes in the ecosystem – which is somewhat naive – we expect a general pole-ward shift in the distribution ranges of most cetacean species. This isn’t likely to be a major problem for animals that move large distances in the relatively uniform and connected environment of the open ocean. But it will potentially have major impacts on some coastal species, especially those that live in habitats that are “dead ends” in this respect (like the southern coast of Africa).</p>
<p>Along the South African coast, several dolphin species live in the Benguela, which is currently thought to be cooling – against the general trend of climate change – due to increased winds and upwelling of cold water. Right now we don’t really know how adaptable these animals are to massive changes in temperature in either direction, should they occur.</p>
<p><strong>What other major conservation tactics are used to help dolphins survive and thrive?</strong></p>
<p>1) Don’t kill them! In any form, including entanglement or bycatch, hunting or pollutants.</p>
<p>2) Stop polluting the oceans – including noise, plastics and organic pollutants.</p>
<p>3) Stop harassing them – obey the laws and use responsible tour operators.</p>
<p>4) Don’t steal their food – eat <a href="http://wwfsassi.co.za/">sustainably</a> caught fish </p>
<p><strong>You have started a project involving citizen scientists. Why have you taken this route?</strong></p>
<p>Citizen science projects have been extremely successful both locally and internationally. Modern communication methods like mobile phones and the internet allow scientists to rapidly communicate with thousands of interested and knowledgeable observers to increase the number of eyes and ears available to collect data. We can’t be everywhere, and our boat surveys and acoustic methods are limited in the amount of area or time they can cover, so we are trying to take advantage of the large number of keen whale and dolphin watchers around our Cape Town’s coasts to report sightings to us.</p>
<p>Remarkably, the area around Cape Town itself has been quite poorly studied by cetacean scientists in the past. So citizen science offers us a potentially powerful route to massively increase the number of data points of dolphin and whale sightings around the area.</p><img src="https://counter.theconversation.com/content/60284/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Elwen works for the University of Pretoria and runs the Sea Search Africa research group. He receives funding from the National Research Foundation amongst others. </span></em></p>Globally, a quarter of whale and dolphin species are endangered. Though South African dolphin populations are generally in good heath, the humpback dolphin is cause for concern.Simon Elwen, Research Fellow, Mammal Research Institute, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.