{"id":4150,"date":"2007-10-03T10:35:20","date_gmt":"2007-10-03T08:35:20","guid":{"rendered":"http:\/\/www.laterredufutur.com\/accueil1\/?p=4150"},"modified":"2015-04-12T10:43:07","modified_gmt":"2015-04-12T08:43:07","slug":"les-zones-mortes-sagrandissent","status":"publish","type":"post","link":"https:\/\/www.laterredufutur.com\/accueil\/les-zones-mortes-sagrandissent\/","title":{"rendered":"Les zones mortes s&rsquo;agrandissent"},"content":{"rendered":"<div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"1\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n<p align=\"justify\"><span style=\"font-size: small;\">Une immense \u00abzone morte\u00bb d\u00e9rive actuellement dans le golfe du Mexique. 15 000 kilom\u00e8tres carr\u00e9s d&rsquo;oc\u00e9an rendus inhabitables pour les esp\u00e8ces vivantes \u00e0 cause d&rsquo;un taux d&rsquo;oxyg\u00e8ne beaucoup trop bas. En cause : les engrais d\u00e9vers\u00e9s par le Mississippi.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">La menace est prise de plus en plus au s\u00e9rieux : la \u00abzone morte\u00bb qui revient tous les \u00e9t\u00e9s hanter les eaux du golfe du Mexique a gagn\u00e9 2 000 km2 depuis l&rsquo;ann\u00e9e derni\u00e8re, atteignant l&rsquo;\u00e9quivalent de trois petits d\u00e9partements fran\u00e7ais.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Le ph\u00e9nom\u00e8ne est r\u00e9current depuis trente ans : des masses de substances nutritives, nitrates et phosphates, sont rejet\u00e9es dans le Mississippi \u00e0 travers les engrais des exploitations agricoles et les r\u00e9sidus d&rsquo;\u00e9levage. Le fleuve va se jeter dans le golfe, o\u00f9 ces substances favorisent le d\u00e9veloppement de certaines algues. Celles-ci consomment alors l&rsquo;oxyg\u00e8ne dissout dans l&rsquo;eau. Ce ph\u00e9nom\u00e8ne, appel\u00e9 eutrophisation, la rend impropre \u00e0 la vie animale. <i>\u00abLes poissons et les crabes s&rsquo;enfuient. (&#8230;) Tout le reste meurt\u00bb<\/i>, explique Nancy Rabalais, oc\u00e9anographe travaillant sur l&rsquo;hypoxie (le manque d&rsquo;oxyg\u00e8ne) \u00e0 l&rsquo;universit\u00e9 de Louisiane. Si rien n&rsquo;est fait pour limiter le taux de nitrates rejet\u00e9s, il n&rsquo;y a pas de raison que le ph\u00e9nom\u00e8ne s&rsquo;arr\u00eate. Pour l&rsquo;heure, il semble surtout empirer : en plus de s&rsquo;\u00e9tendre, l&rsquo;aire nocive tend \u00e0 se rapprocher des c\u00f4tes \u00e0 cause des vents et des courants.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Zone morte dans le Golfe du Mexique :<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Avec plus de 3 millions de km\u00b2 le bassin hydrographique du Mississippi couvre pr\u00e8s d\u2019un tiers des Etats-Unis.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Le fleuve lui-m\u00eame et ses nombreux affluents collectent jour apr\u00e8s jour les polluants de l\u2019agriculture intense du pays, tout particuli\u00e8rement ses fertilisants [1].<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Si cela ne semble pas trop probl\u00e9matique au niveau du fleuve lui-m\u00eame, en revanche les choses se g\u00e2tent \u00e0 l\u2019arriv\u00e9e des eaux dans le Golfe du Mexique, en particulier l\u2019\u00e9t\u00e9.<\/span><\/p><div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"2\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n\n<p align=\"justify\"><span style=\"font-size: small;\">Comme l\u2019explique Time dans son \u00e9dition dat\u00e9e du 6\/08\/07, \u00ab les fertilisants terminent leur course dans le Golfe du Mexique, o\u00f9 ils provoquent une prolif\u00e9ration d\u2019algues, qui, \u00e0 leur tour, absorbent \u00e0 peu pr\u00e8s tout l\u2019oxyg\u00e8ne disponible de l\u2019eau. R\u00e9sultat, une mortalit\u00e9 massive de la faune marine. \u00bb<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Selon Time, la \u00ab\u00a0zone morte estivale\u00a0\u00bb s\u2019\u00e9tendait sur environ 13.000 km\u00b2 en moyenne dans les ann\u00e9es 90. En 2006, elle s\u2019est \u00e9tendue sur 17.280 km\u00b2.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">D\u2019apr\u00e8s le professeur Eugene Turner de l\u2019universit\u00e9 de Louisiane, cit\u00e9 par BBC News, elle pourrait atteindre cette ann\u00e9e 22.000 km\u00b2.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Celui-ci pr\u00e9voit en effet un record historique du fait de la charge de nitrates particuli\u00e8rement \u00e9lev\u00e9e en mai de cette ann\u00e9e \u00ab peut-\u00eatre due \u00e0 une agriculture plus intensive sur des surface plus importante, y compris avec les cultures pour agro-carburants ou \u00e0 des changements de pratique agricole, \u00bb explique le professeur.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Seule une saison riche en temp\u00eates, qui favorisent l\u2019oxyg\u00e9nation, pourrait changer la donne.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Dans sa \u00ab\u00a0revue mondiale de l\u2019environnement\u00a0\u00bb, en 2003, l\u2019organisation des Nations Unies pointait d\u00e9j\u00e0 le fait que le nombre de zones en hypoxie [2] saisonni\u00e8re doublait tous les 10 ans depuis les ann\u00e9es 60.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">[1] On estime que le volume des nutriments charri\u00e9s par le fleuve a tripl\u00e9 en 50 ans.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">[2] Hypoxie : diminution de la concentration d\u2019oxyg\u00e8ne.<br \/>\n<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">sources : <\/span><a href=\"http:\/\/citron-vert.info\/\"><span style=\"font-size: small;\">http:\/\/citron-vert.info\/<\/span><\/a><span style=\"font-size: small;\">\u00a0\/ <\/span><a href=\"http:\/\/ecolesdifferentes.free.fr\/\"><span style=\"font-size: small;\">http:\/\/ecolesdifferentes.free.fr\/<\/span><\/a><\/p>\n<p class=\"bawpvc-ajax-counter\" data-id=\"4150\">(172)<\/p>\n<!--CusAds0-->\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Une immense \u00abzone morte\u00bb d\u00e9rive actuellement dans le golfe du Mexique. 15 000 kilom\u00e8tres carr\u00e9s d&rsquo;oc\u00e9an rendus inhabitables pour les&#8230;<\/p>\n","protected":false},"author":1,"featured_media":4151,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"ngg_post_thumbnail":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[28],"tags":[866,3219,2867,3221,241,519,286,2514,2524,3220],"class_list":["post-4150","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-pollution","tag-agriculture","tag-fertilisants","tag-massive","tag-mortalite","tag-ocean","tag-oceanique","tag-oxygene","tag-poissons","tag-zone-morte","tag-zones-mortes","wpcat-28-id"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/zonemorte.jpg?fit=250%2C180&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p631RN-14W","jetpack-related-posts":[{"id":2750,"url":"https:\/\/www.laterredufutur.com\/accueil\/zone-morte\/","url_meta":{"origin":4150,"position":0},"title":"Zone Morte","author":"Admin","date":"20 mars 2005","format":false,"excerpt":"Imaginez un monde o\u00f9 les oc\u00e9ans ne poss\u00e8deraient plus de vie. Imaginez un monde o\u00f9 l'oxyg\u00e8ne aurait disparu dans les mers. Imaginez un monde o\u00f9 se nourrir de poissons marins n'appartiendrait seulement qu'au pass\u00e9. Imaginez vous un monde o\u00f9 ce paysage idyllique appartiendrait aux r\u00eaves. Alors n'imaginez plus et soyez\u2026","rel":"","context":"Dans &quot;Pollution&quot;","block_context":{"text":"Pollution","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/pollution\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/spaw\/images\/gulf-of-mexico-noaa.jpeg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":16586,"url":"https:\/\/www.laterredufutur.com\/accueil\/la-zone-morte-de-la-mer-darabie-est-devnue-la-plus-grande-du-monde\/","url_meta":{"origin":4150,"position":1},"title":"La \u00abzone morte\u00bb de la mer d&rsquo;Arabie est devenue la plus grande du monde","author":"Admin","date":"12 mai 2018","format":false,"excerpt":"Une \"zone morte\" massive dans la mer d'Arabie est devenue la plus grande du monde, selon une nouvelle \u00e9tude. Les zones mortes sont des r\u00e9gions oc\u00e9aniques priv\u00e9es d'oxyg\u00e8ne o\u00f9 peu d'organismes peuvent survivre. Ils \u00e9mergent dans des profondeurs oc\u00e9aniques allant de 200 \u00e0 800 m\u00e8tres, lorsque des influx de nutriments\u2026","rel":"","context":"Dans &quot;Pollution&quot;","block_context":{"text":"Pollution","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/pollution\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/05\/golfeoman.jpg?fit=750%2C480&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/05\/golfeoman.jpg?fit=750%2C480&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/05\/golfeoman.jpg?fit=750%2C480&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/05\/golfeoman.jpg?fit=750%2C480&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":23600,"url":"https:\/\/www.laterredufutur.com\/accueil\/les-zones-mortes-du-pacifique-cartographiees-et-toujours-plus-grandes\/","url_meta":{"origin":4150,"position":2},"title":"Les zones mortes du Pacifique cartographi\u00e9es et toujours plus grandes","author":"Admin","date":"29 d\u00e9cembre 2021","format":false,"excerpt":"Des chercheurs du MIT ont cartographi\u00e9 en trois dimensions les zones aquatiques mortes de l'oc\u00e9an Pacifique afin de pouvoir pr\u00e9dire leur \u00e9volution \u00e0 mesure que le climat se r\u00e9chauffe. Ces aires priv\u00e9es d'oxyg\u00e8ne sont la source d'oxyde nitreux, un puissant gaz \u00e0 effet de serre, qui remonte \u00e0 la surface.\u2026","rel":"","context":"Dans &quot;Pollution&quot;","block_context":{"text":"Pollution","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/pollution\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/12\/zones-mortes-pacifique.jpg?fit=930%2C618&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/12\/zones-mortes-pacifique.jpg?fit=930%2C618&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/12\/zones-mortes-pacifique.jpg?fit=930%2C618&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/12\/zones-mortes-pacifique.jpg?fit=930%2C618&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":6385,"url":"https:\/\/www.laterredufutur.com\/accueil\/de-gigantesques-zones-mortes-decouvertes-au-milieu-de-latlantique\/","url_meta":{"origin":4150,"position":3},"title":"De gigantesques \u00ab\u00a0zones mortes\u00a0\u00bb d\u00e9couvertes au milieu de l&rsquo;Atlantique","author":"Admin","date":"12 mai 2015","format":false,"excerpt":"Les \"zones mortes\" r\u00e9cemment d\u00e9tect\u00e9es au milieu de l'Oc\u00e9an Atlantique se forment dans des tourbillons analogues \u00e0 celui ci-dessus, en bleu. Cr\u00e9dits : NASA Earth Observatory Des chercheurs ont d\u00e9couvert dans l'Oc\u00e9an Atlantique l'existence de zones se caract\u00e9risant par des taux d'oxyg\u00e8ne si bas qu'ils y interdisent toute forme de\u2026","rel":"","context":"Dans &quot;Pollution&quot;","block_context":{"text":"Pollution","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/pollution\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/05\/zone-morte-atlantique.jpg?fit=600%2C288&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/05\/zone-morte-atlantique.jpg?fit=600%2C288&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/05\/zone-morte-atlantique.jpg?fit=600%2C288&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":25949,"url":"https:\/\/www.laterredufutur.com\/accueil\/la-terre-vue-de-lespace-un-tourbillon-dalgues-se-developpe-au-coeur-dune-vaste-zone-morte-de-la-baltique\/","url_meta":{"origin":4150,"position":4},"title":"La Terre vue de l&rsquo;espace : Un tourbillon d&rsquo;algues se d\u00e9veloppe au c\u0153ur d&rsquo;une vaste \u00ab zone morte \u00bb de la Baltique","author":"Admin","date":"2 juin 2024","format":false,"excerpt":"L'ann\u00e9e 2018 a \u00e9t\u00e9 marqu\u00e9e par l'apparition d'une \u00e9tonnante spirale de cyanobact\u00e9ries dans la mer Baltique. La masse tourbillonnante de microbes a contribu\u00e9 \u00e0 cr\u00e9er une \u00ab zone morte \u00bb massive de la taille de la Virginie-Occidentale qui a r\u00e9duit l'oxyg\u00e8ne de l'eau avoisinante. Cette spirale verte impressionnante est apparue\u2026","rel":"","context":"Dans &quot;Pollution&quot;","block_context":{"text":"Pollution","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/pollution\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/05\/La-spirale-de-cyanobacteries-faisait-partie-dune-proliferation-dalgues.webp?fit=650%2C366&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/05\/La-spirale-de-cyanobacteries-faisait-partie-dune-proliferation-dalgues.webp?fit=650%2C366&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/05\/La-spirale-de-cyanobacteries-faisait-partie-dune-proliferation-dalgues.webp?fit=650%2C366&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":303,"url":"https:\/\/www.laterredufutur.com\/accueil\/tornades-made-in-usa\/","url_meta":{"origin":4150,"position":5},"title":"Tornades Made in USA","author":"Admin","date":"28 avril 2011","format":false,"excerpt":"NEW YORK, 28 avril (Reuters) - Sept Etats du sud des Etats-Unis ont \u00e9t\u00e9 touch\u00e9s ces derniers jours par des temp\u00eates et des tornades qui ont fait 300 morts, ras\u00e9 des quartiers entiers, renvers\u00e9 des v\u00e9hicules et abattu arbres et lignes \u00e9lectriques, selon des bilans provisoires diffus\u00e9s jeudi. \u00a0 Des\u2026","rel":"","context":"Dans &quot;Ev\u00e8nement Brutal&quot;","block_context":{"text":"Ev\u00e8nement Brutal","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/evenement-brutal\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/wordpress\/wp-content\/uploads\/2011\/04\/storm-usa-2011.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/4150","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/comments?post=4150"}],"version-history":[{"count":2,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/4150\/revisions"}],"predecessor-version":[{"id":4153,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/4150\/revisions\/4153"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media\/4151"}],"wp:attachment":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media?parent=4150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/categories?post=4150"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/tags?post=4150"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}