{"id":3530,"date":"2026-04-09T18:36:00","date_gmt":"2026-04-09T18:36:00","guid":{"rendered":"https:\/\/climatevdo.com\/?p=3530"},"modified":"2026-04-14T20:38:41","modified_gmt":"2026-04-14T20:38:41","slug":"giant-otters-river-sentinels-now-listed-as-threatened-migratory-species","status":"publish","type":"post","link":"https:\/\/climatevdo.com\/?p=3530","title":{"rendered":"Giant otters, river sentinels, now listed as threatened migratory species"},"content":{"rendered":"<div id=\"post-317227\">\n<div class=\"bulletpoints-wrapper\">\n<div class=\"bulletpoints\">\n<ul>\n<li><em>The giant otter was added to the list of animals needing protection under the UN Convention on Migratory Species, paving the way for international conservation actions.<\/em><\/li>\n<li><em>Studies reveal that their population decreased by 50% over the past 25 years as their habitat disappears and fragments and growing pollution fouls rivers.<\/em><\/li>\n<li><em>The new listing should promote cooperation between countries to protect the species as well as Amazon and Pantanal aquatic ecosystems, which are the otter\u2019s strongholds.<\/em><\/li>\n<\/ul>\n<\/div>\n<p><button class=\"content-expander\"><span>See All Key Ideas<\/span><\/button><\/p>\n<\/div>\n<p>With evidence that the giant river otter is in an increasingly perilous state, delegates to the United Nations <a href=\"https:\/\/www.cms.int\/\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">Convention on the Conservation of Migratory Species<\/a> (CMS) listed it as an animal requiring urgent conservation action at its March 2026 meeting in Campo Grande, Brazil.<\/p>\n<p>The giant otter (<em>Pteronura brasiliensis<\/em>), endemic to tropical river systems in South America, once lived east of the Andes mountains from northern Venezuela to Argentina, a territory covering <a href=\"https:\/\/www.researchgate.net\/publication\/396186739_Identifying_spatial_conservation_priorities_for_the_giant_otter_Pteronura_brasiliensis\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">9,021,590 square kilometers<\/a> (3,483,255 square miles). The <a href=\"https:\/\/www.cms.int\/sites\/default\/files\/document\/2025-11\/cms_cop15_doc.30.2.3_listing-proposal-giant-otter_e_0.pdf\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">proposal<\/a> advocating for stronger protection, submitted by France, noted that it was listed as endangered on the IUCN Red List in 2021, though it is extinct in Uruguay and Argentina, is critically endangered in Paraguay and\u00a0 Ecuador and vulnerable in Brazil.<\/p>\n<p>The same document\u00a0mentions a 50% decline in the giant otter population over the last 25 years. Individuals\u2019 size has also been reduced, indicating a decrease in pups\u2019 survival rates. Using climate projections such as reduced rainfall due to climate change, specialists point out that the downward trend in the species\u2019 population will continue for a few decades.<\/p>\n<p>Illegal hunting for their fur wiped them out in large parts of their range , many populations never recovered, according to a 2025 <a href=\"https:\/\/www.researchgate.net\/publication\/389314303_ASSESSING_AN_AQUATIC_ICON_A_RANGE_WIDE_PRIORITY_SETTING_EXERCISE_FOR_THE_GIANT_OTTER_Pteronura_brasiliensis\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">report<\/a> published by the Wildlife Conservation Society, a U.S.-based nonprofit.<\/p>\n<p>Although commercial hunting is no longer a serious threat, these otters still face serious challenges. Conflict continues, with local people competing for the fish that otters eat. Their habitat continues to disappear, frequently converted to farmland and cities. Rivers are dammed and mines leak mercury and sediment into waters , rivers are increasingly polluted. Meanwhile, climate change-driven catastrophes, especially extreme drought and wildfire, are hitting hard.<\/p>\n<p>Biologists predict a continued downward trend in otter numbers, which could drop by 50% over the next 25 years without intervention, according to biologist Caroline Leuchtenberger, who coordinates the IUCN Otter Specialist Group and founded the <a href=\"https:\/\/projetoariranhas.org\/sobre-nos\/\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">Giant Otter Project<\/a>.<\/p>\n<h5>A video of a giant otter feeding in the Brazilian Pantanal. Video by Sharon Guynup.<\/h5>\n<p>\u00a0<\/p>\n<h2><strong>The largest otter in the world<\/strong><\/h2>\n<p>The <em>ariranha<\/em> \u2014 as it\u2019s known in Brazil \u2014 is the \u00a0largest of the world\u2019s 13 otter species. Its name comes from the Indigenous Tupi-Guarani word <em>ari\u2019ra\u00f1a<\/em>, which means \u201cwater jaguar.\u201d It once inhabited\u00a0 river basins across South American, but it\u2019s now mostly <a href=\"https:\/\/giantotterproject.org\/\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">restricted<\/a> to the Amazon River and Pantanal wetland biomes.<\/p>\n<p>This territorial, semi-aquatic animal is an athletic swimmer that lives in social groups, anywhere from two to 16 members, and builds its dens on riverbanks. With its sharp claws and teeth, the giant otter is an apex predator that feeds largely on fish. It\u2019s known for its skittish behavior and loud, shrill calls.<\/p>\n<p>As an apex predator, it feeds on fish, and only the jaguar (Panthera onca) sits higher on the food chain. It plays a crucial role in maintaining the balance of the aquatic ecosystems and is an indicator species for environmental health.<\/p>\n<p>\u201cWe often say that the giant otter is the sentinel of the rivers, as its presence means that ecosystems are healthy,\u201d Leuchtenberger said.<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/flo.uri.sh\/visualisation\/28297309\/embed\" title=\"Interactive or visual content\" class=\"flourish-embed-iframe\" frameborder=\"0\" scrolling=\"no\" style=\"width:100% ,height:600px ,\" sandbox=\"allow-same-origin allow-forms allow-scripts allow-downloads allow-popups allow-popups-to-escape-sandbox allow-top-navigation-by-user-activation\" width=\"100%\" height=\"500\"><\/iframe><\/p>\n<p><em>In the map above, on the left, the historical distribution of the giant otter in South America , in the map on the right, in red, the areas where it\u2019s extinct. Source: \u201c<a href=\"https:\/\/www.researchgate.net\/publication\/389314303_ASSESSING_AN_AQUATIC_ICON_A_RANGE_WIDE_PRIORITY_SETTING_EXERCISE_FOR_THE_GIANT_OTTER_Pteronura_brasiliensis\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">Assessing an aquatic icon: a range-wide priority setting exercise for the giant otter (Pteronura brasiliensis).\u201d<\/a><\/em><\/p>\n<p>She explained that the species doesn\u2019t undertake a classic migration \u2013 that is, moving with the seasons to find food or a mate. However, the extent of its territories along rivers in the Amazon and Pantanal warrants transnational actions, Leuchtenberger said.<\/p>\n<p>When water connections allow, this excellent, acrobatic swimmer and diver easily travels between countries through transboundary rivers. Therefore, loss of connectivity between river basins is a major threat.<\/p>\n<p>Protecting the otter and the waterways it calls home will reverberate throughout its freshwater habitat. \u201cAll other species that depend on the integrity of these rivers will benefit from a greater effort towards conservation of giant otters,\u201d Leuchtenberger said.<\/p>\n<p>Harmonious coexistence between humans and giant otter populations is not yet a reality in many parts of the Amazon and the Pantanal, Leuchtenberger said. \u201cThe giant otter is not an invisible animal. When it\u2019s around, it\u2019s always noticed,\u201d and its presence isn\u2019t always welcome. Many people still see them as aggressive animals, and fishers have long <a href=\"https:\/\/www.researchgate.net\/publication\/240252879_Conflict_between_Fishermen_and_Giant_Otters_Pteronura_brasiliensis_in_Western_Brazilian_Amazon\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">considered them to be a fierce competitor<\/a>.<\/p>\n<p>Expanding work with the communities living near the giant otter\u2019s habitat is likely to be one of the main challenges ahead. As part of its conservation initiatives, the Giant Otter Project fosters coexistence through environmental education and follows social media to understand the common sentiment towards the species.<\/p>\n<p>In places like Brazil\u2019s Pantanal, the influx of ecotourism dollars may blunt resentment, as the giant otters are a must-see animal for the mostly international visitors who are drawn by the jaguars (<em>Panthera<\/em><em>\u00a0<\/em><em>onca<\/em>) that are easily visible on riverbanks during the dry season.<\/p>\n<figure id=\"attachment_317229\" class=\"wp-caption alignnone\"><figcaption class=\"wp-caption-text\">Giant otters in a river in the Pantanal. Image: \u00a9 Gr\u00e9goire Dubois.<\/figcaption><\/figure>\n<h2><strong>A French proposal with wide support<\/strong><\/h2>\n<p>France proposed adding the giant otter to the approximately 1,200 species listed under the Convention because the animals lives in its overseas territory of French Guiana. The proposal was also supported by Brazil, Peru, Bolivia, Panama, Ecuador, Paraguay, the European Union, Senegal and Venezuela, and was approved without opposition.<\/p>\n<p>In all, <a href=\"https:\/\/www.eurekalert.org\/news-releases\/1121962\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">40 species or populations of migratory birds,<\/a> terrestrial animals and aquatic wildlife were added to the list or had protections upgraded. The 47-year-old treaty includes 133 \u201ccontacting parties\u201d plus another 28 nations that participate in some way.<\/p>\n<p>Under the Convention on Conservation of Migratory Species framework, a species can be listed on its appendices to initiate coordinated conservation actions. Appendix I covers endangered or critically endangered species that require strong action from member states. Appendix II, in turn, encourages cooperation between countries to adopt joint measures for conservation.<\/p>\n<p>Because of its dangerously threatened status, the giant otter was included on both appendices. The next step will be creating an action plan, coordinated among countries, \u00a0which must be approved at a future COP. The next meeting is scheduled to take place in Germany in 2029.<\/p>\n<p>\u201cListing the giant otter on both Appendix I and Appendix II of CMS will send a clear signal that urgent, coordinated international action is needed to conserve this species and the freshwater ecosystems it depends on,\u201d said Susan Lieberman, vice president for international policy at the Wildlife Conservation Society.<\/p>\n<p>The Government of Brazil, as host of this recent meeting, will be responsible for moving implementation of these protections forward.<\/p>\n<p>\u201cWe protect species that may never remain within our borders, said Jo\u00e3o Paulo Capobianco, COP15 chair and executive secretary of Brazil\u2019s Ministry of the Environment and Climate Change. \u201cWe invest in a natural heritage we do not own but are all responsible for. In doing so, we give concrete meaning to global solidarity.\u201d<\/p>\n<p><em>The English version of this story was edited by <a href=\"https:\/\/mongabay.org\/person\/sharon-guynup\/\" data-wpel-link=\"external\" target=\"_blank\" rel=\"external\">Sharon Guynup<\/a>.<\/em><\/p>\n<p><strong><em>Banner image:<\/em><\/strong><em> Giant otter fishing in a river in the Pantanal. Image: \u00a9 Gr\u00e9goire Dubois.<\/em><\/p>\n<p><strong>Citations<\/strong><strong>:<\/strong><\/p>\n<p>Rosas Ribeiro, Patricia &#038; Rosas, Fernando &#038; Zuanon, Jansen. (2012). Conflict between Fishermen and Giant Otters Pteronura brasiliensis in Western Brazilian Amazon. Biotropica. 44. 437-444. 10.1111\/j.1744-7429.2011.00828.x. DOI:<a class=\"nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-decorated\" href=\"https:\/\/doi.org\/10.5597\/lajam00356\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">10.5597\/lajam00356<\/a><\/p>\n<p>Wallace, Robert &#038; Reinaga, Ariel &#038; Ayala, Guido &#038; Bowler, Mark &#038; Buschiazzo, Martin &#038; Martino, Sebastian &#038; Groenendijk, Jessica &#038; Hoops, Hauke &#038; Marmontel, Miriam &#038; Michalski, Fernanda &#038; Mujica, Oscar &#038; P\u00e9rez, Karen &#038; Recharte, Maribel &#038; Rheingantz, Marcelo &#038; Trujillo, Fernando &#038; Zapata-R\u00edos, Galo &#038; Choque, Leydi &#038; Cardona, Mar\u00eda &#038; Bentti, Salvador &#038; Zambrana, Veronica. (2025). Identifying spatial conservation priorities for the giant otter (Pteronura brasiliensis). Latin American Journal of Aquatic Mammals. 10.5597\/lajam00356. DOI:<a class=\"nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-decorated\" href=\"https:\/\/doi.org\/10.1111\/j.1744-7429.2011.00828.x\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">10.1111\/j.1744-7429.2011.00828.x<\/a><\/p>\n<p>Wallace, Robert &#038; Reinaga, Ariel &#038; Groenendijk, Jessica &#038; Leuchtenberger, Caroline &#038; Hoops, Hauke &#038; Choque, Leydi &#038; Ayala, Guido &#038; Bowler, Mark &#038; Marmontel, Miriam &#038; Michalski, Fernanda &#038; Mujica, Oscar &#038; P\u00e9rez, Karen &#038; Recharte, Maribel &#038; Rheingantz, Marcelo &#038; Roopsind, Indranee &#038; Trujillo, Fernando &#038; Zapata-R\u00edos, Galo &#038; Pilar, Mar\u00eda &#038; Cardona, Becerra &#038; Damme, Paul. (2025). ASSESSING AN AQUATIC ICON: A RANGE WIDE PRIORITY SETTING EXERCISE FOR THE GIANT OTTER (Pteronura brasiliensis). 10.19121\/2024.Report.51079. DOI:<a class=\"nova-legacy-e-link nova-legacy-e-link--color-inherit nova-legacy-e-link--theme-decorated\" href=\"https:\/\/doi.org\/10.19121\/2024.Report.51079\" target=\"_blank\" rel=\"noopener external\" data-wpel-link=\"external\">10.19121\/2024.Report.51079<\/a><\/p>\n<div id=\"single-article-footer\">\n<div class=\"container in-column about-editor-translator gap--40 pv--80\">\n<div class=\"container grid--3 repeat gap--40\">\n<div class=\"in-row gap--16\">\n<div class=\"author-avatar\">\n                    <img loading=\"lazy\" alt=\"\" src=\"https:\/\/climatevdo.com\/wp-content\/uploads\/2026\/04\/As-EU-Mercosur-agreement-goes-into-effect-environmentalists-raise-red-flags.png\" srcset=\"https:\/\/secure.gravatar.com\/avatar\/870a95eb3583fff7607c23be4b8b425f9a2fb10578f8fea548b6029b4d934951?s=64&#038;d=identicon&#038;r=g 2x\" class=\"avatar avatar-32 photo\" height=\"32\" width=\"32\" decoding=\"async\"\/>        <\/div><\/div><\/div><\/div><\/div>\n<p>                            <span class=\"article-comments\"><a href=\"\" data-wpel-link=\"internal\"\/><\/span><\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>The giant otter was added to the list of animals needing protection under the UN Convention on Migratory Species, paving the way for international conservation actions. Studies reveal that their population decreased by 50% over the past 25 years as their habitat disappears and fragments and growing pollution fouls rivers. The new listing should promote [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3531,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[82],"tags":[],"class_list":["post-3530","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-nature-biodiversity"],"_links":{"self":[{"href":"https:\/\/climatevdo.com\/index.php?rest_route=\/wp\/v2\/posts\/3530","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/climatevdo.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/climatevdo.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/climatevdo.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/climatevdo.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3530"}],"version-history":[{"count":1,"href":"https:\/\/climatevdo.com\/index.php?rest_route=\/wp\/v2\/posts\/3530\/revisions"}],"predecessor-version":[{"id":3532,"href":"https:\/\/climatevdo.com\/index.php?rest_route=\/wp\/v2\/posts\/3530\/revisions\/3532"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/climatevdo.com\/index.php?rest_route=\/wp\/v2\/media\/3531"}],"wp:attachment":[{"href":"https:\/\/climatevdo.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3530"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/climatevdo.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3530"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/climatevdo.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3530"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}