{"id":1505,"date":"2025-04-08T17:49:08","date_gmt":"2025-04-08T17:49:08","guid":{"rendered":"https:\/\/www.oceanblogs.org\/capeverde\/?p=1505"},"modified":"2025-04-08T17:49:09","modified_gmt":"2025-04-08T17:49:09","slug":"stowaways","status":"publish","type":"post","link":"https:\/\/www.oceanblogs.org\/capeverde\/2025\/04\/08\/stowaways\/","title":{"rendered":"Stowaways!"},"content":{"rendered":"\n<p>Flap! Flap! Coo&#8230;. These pigeon noises, perfectly normal in any congested city, are entirely unexpected here. We are sailing through the eastern tropical North Atlantic on the German icebreaker POLARSTERN that is our home for two weeks. Water to the horizon in all directions and then\u2026 a pigeon! A quick look to portside solves the mystery &#8211; in the distance the island of Tenerife passes slowly by, doubtless the home port of our stowaway.&nbsp;<\/p>\n\n\n\n<p><em>(German version below)<\/em><\/p>\n\n\n\n<p>Soon our massive floating home comes to a halt and the nautical officer declares that we were \u201con station\u201d, code for \u201ctime to let instruments over board\u201d. This is a special station, the European Station for Time-Series in the Ocean (ESTOC), a spot in the ocean at which continuous measurements of ocean properties have been taken since 1994. How else is one to identify changes in the ocean that document climate change effects fueled by humans?&nbsp;<\/p>\n\n\n\n<p>On board our Floating University are 15 trainees, of which 13 are from West African countries. With some oversight from their instructors they deploy instruments to measure, for example, physical properties and take samples in the water column. One small and important contribution to a valuable global data set!<\/p>\n\n\n\n<p>Not long after, we see our chief scientist Bj\u00f6rn Fiedler, helmeted and armed with a 4-m hooked rod, shuffling down the railing, his sights on the water surface. He is calling out to marine ecologist Jamileh Javidpour, who is also leaning over the railing though with a more conventional sampling gear, a small plankton net. Soon a seaman joins with his own contraption (self-made tool) and suddenly it becomes clear that they are trying to collect small clumps of algae that are floating past the ship\u2019s rump. \u201cNow!\u201d, \u201cGet it!\u201d \u2013 \u201cOh No!\u201d \u201canother one coming\u201d\u2026 and with an efficient swoop the net comes up with a handful of macroalgae. We have sampled sargassum, the ubiquitous algae that form huge mats in the central tropical North Atlantic, aka the \u201cSargassum Sea\u201d. Taking a ride on this mat is our second stowaway, a 3-cm\u00a0<em>Portunus sayi<\/em>\u00a0a sargassum crab\u00a0camouflaged\u00a0into the algae. Barnacles, plankton, fish eggs and countless other co-passengers are attached to the sargassum and have made it on board the POLARSTERN.\u00a0<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"http:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/IMG_0049-avan-antia-zoom-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"http:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/IMG_0049-avan-antia-zoom-1024x576.jpg\" alt=\"sargassum crab on a wet surface\" class=\"wp-image-1510\" srcset=\"https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/IMG_0049-avan-antia-zoom-1024x576.jpg 1024w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/IMG_0049-avan-antia-zoom-300x169.jpg 300w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/IMG_0049-avan-antia-zoom-768x432.jpg 768w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/IMG_0049-avan-antia-zoom-1536x864.jpg 1536w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/IMG_0049-avan-antia-zoom-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption>A sargassum crab took a ride on board the POLARSTERN. \n(c) Avan Antia, Kiel University<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"http:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/2025-04-05_PS147-2_studentswork_tobias-hahn-IMG_7400-small-1-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"http:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/2025-04-05_PS147-2_studentswork_tobias-hahn-IMG_7400-small-1-1024x576.jpg\" alt=\"Three people looking at sargassum.\" class=\"wp-image-1512\" srcset=\"https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/2025-04-05_PS147-2_studentswork_tobias-hahn-IMG_7400-small-1-1024x576.jpg 1024w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/2025-04-05_PS147-2_studentswork_tobias-hahn-IMG_7400-small-1-300x169.jpg 300w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/2025-04-05_PS147-2_studentswork_tobias-hahn-IMG_7400-small-1-768x432.jpg 768w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/2025-04-05_PS147-2_studentswork_tobias-hahn-IMG_7400-small-1-1536x864.jpg 1536w, https:\/\/www.oceanblogs.org\/capeverde\/wp-content\/uploads\/sites\/6\/2025\/04\/2025-04-05_PS147-2_studentswork_tobias-hahn-IMG_7400-small-1-2048x1152.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption>Jamileh Javidpour and two students finding the stowaway in a sargassum clump. (c) Tobias Hahn, GEOMAR <\/figcaption><\/figure>\n\n\n\n<p>At the end of the day our pigeon has vanished, doubtlessly on the fastest aerial route home. The crab is still on board.&nbsp;We can\u2019t return it to the water without its algal infrastructure; without its own \u201cship\u201d to hold on to it would face a free fall of several kilometers to the sea bed.<\/p>\n\n\n\n<p>The POLARSTERN continues on its way to its home port of Bremerhaven, the Canary Islands fall behind us and we resume our work as usual after this short interlude.<\/p>\n\n\n\n<p>Avan Antia<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><strong>Blinde Passagiere<\/strong><\/p>\n\n\n\n<p>Flap! Flap! Coo&#8230;.&nbsp;Diese Taubenger\u00e4usche, die in jeder \u00fcberf\u00fcllten Stadt v\u00f6llig normal sind, sind hier v\u00f6llig unerwartet. Wir segeln durch den \u00f6stlichen tropischen Nordatlantik auf dem deutschen Eisbrecher POLARSTERN, der f\u00fcr zwei Wochen unser Zuhause ist. Wasser bis zum Horizont in alle Richtungen und dann&#8230; eine Taube! Ein kurzer Blick nach Backbord l\u00f6st das R\u00e4tsel &#8211; in der Ferne zieht langsam die Insel Teneriffa vorbei, zweifellos der Heimathafen unseres blinden Passagiers.&nbsp;<\/p>\n\n\n\n<p>Bald kommt unser massives schwimmendes zu Hause zum Stillstand und der nautische Offizier erkl\u00e4rt, dass wir \u201eauf Station\u201c sind, was so viel bedeutet wie \u201eZeit, die Instrumente ins Wasser zu lassen\u201c. Es handelt sich um eine besondere Station, die Europ\u00e4ische Station f\u00fcr Zeitreihen im Ozean (ESTOC), eine Stelle im Ozean, an der seit 1994 kontinuierlich Messungen der Meereseigenschaften vorgenommen werden. Wie sonst soll man Ver\u00e4nderungen im Ozean feststellen, die die Auswirkungen des vom Menschen verursachten Klimawandels dokumentieren?&nbsp;<\/p>\n\n\n\n<p>An Bord unserer schwimmenden Universit\u00e4t befinden sich 14 Studierende und 1 Sch\u00fcler, von denen 13 aus westafrikanischen L\u00e4ndern stammen. Unter Anleitung ihrer Lehrenden setzen sie Instrumente ein, um z.B. physikalische Eigenschaften zu messen und Proben in der Wassers\u00e4ule zu nehmen. Ein kleiner und wichtiger Beitrag zu einem wertvollen globalen Datensatz!<\/p>\n\n\n\n<p>Kurz darauf sehen wir unseren wissenschaftlichen Fahrtleiter Bj\u00f6rn Fiedler, behelmt und mit einer 4 m langen Angel bewaffnet, \u00fcber die Reling schlurfen, die Wasseroberfl\u00e4che im Visier. Er ruft der Meeres\u00f6kologin Jamileh Javidpour zu, die sich ebenfalls \u00fcber die Reling lehnt, allerdings mit einem eher konventionellen Probenahmeger\u00e4t, einem kleinen Planktonnetz. Bald gesellt sich ein Seemann mit seinem eigenen Ger\u00e4t dazu, und pl\u00f6tzlich wird klar, dass sie versuchen, kleine Algenklumpen zu sammeln, die am Rumpf des Schiffes vorbeischwimmen. \u201eNow!\u201c, \u201cGet it!\u201c &#8211; \u201eOh nein!\u201c \u201eDa kommt noch was\u201c&#8230; und mit einem effizienten Schwung taucht das Netz mit einer Handvoll Makroalgen auf. Wir haben Sargassum beprobt, die allgegenw\u00e4rtigen Algen, die im zentralen tropischen Nordatlantik, auch bekannt als \u201eSargassum-Meer\u201c, riesige Matten bilden. Auf dieser Matte reitet unser zweiter blinder Passagier, ein 3 cm gro\u00dfer Portunus sayi, ein in den Algen getarnter Sargassum-Krebs. Seepocken, Plankton, Fischeier und zahllose andere Mitreisende kleben am Sargassum und haben es an Bord der POLARSTERN geschafft.&nbsp;<\/p>\n\n\n\n<p>Am Ende des Tages ist unsere Taube verschwunden, zweifellos auf dem schnellsten Luftweg nach Hause. Die Krabbe ist noch an Bord. Ohne ihre Algeninfrastruktur k\u00f6nnen wir sie nicht ins Wasser zur\u00fcckbringen; ohne ein eigenes \u201eSchiff\u201c, an dem sie sich festhalten kann, droht ihr ein freier Fall von mehreren Kilometern auf den Meeresgrund.<\/p>\n\n\n\n<p>Die POLARSTERN setzt ihren Weg zum Heimathafen Bremerhaven fort, die Kanarischen Inseln liegen hinter uns und wir nehmen nach diesem kurzen Zwischenspiel unsere Arbeit wie gewohnt wieder auf.<\/p>\n\n\n\n<p>Avan Antia<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Flap! Flap! Coo&#8230;. These pigeon noises, perfectly normal in any congested city, are entirely unexpected here. We are sailing through the eastern tropical North Atlantic on the German icebreaker POLARSTERN that is our home for two weeks. Water to the horizon in all directions and then\u2026 a pigeon! A quick look to portside solves the [&hellip;]<\/p>\n","protected":false},"author":244,"featured_media":1506,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13,15,12,14],"tags":[],"class_list":["post-1505","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ocean-and-climate","category-ocean-observation","category-ozean-und-klima","category-ozeanbeobachtung"],"geo":{"latitude":32.5986595,"longitude":-96.6093826,"description":"Ferris, Texas, 75125, US"},"_links":{"self":[{"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/posts\/1505","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/users\/244"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/comments?post=1505"}],"version-history":[{"count":1,"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/posts\/1505\/revisions"}],"predecessor-version":[{"id":1513,"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/posts\/1505\/revisions\/1513"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/media\/1506"}],"wp:attachment":[{"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/media?parent=1505"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/categories?post=1505"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.oceanblogs.org\/capeverde\/wp-json\/wp\/v2\/tags?post=1505"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}