{"id":7303,"date":"2022-02-05T14:40:19","date_gmt":"2022-02-05T13:40:19","guid":{"rendered":"https:\/\/www.mio.osupytheas.fr\/fr\/archive_page\/jour-6-ca-brille\/"},"modified":"2022-02-05T14:40:19","modified_gmt":"2022-02-05T13:40:19","slug":"day-6-ca-brille","status":"publish","type":"archive_page","link":"https:\/\/www.mio.osupytheas.fr\/en\/jour-6-ca-brille\/","title":{"rendered":"Day 6 - It's shining!"},"content":{"rendered":"
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05 February 2022<\/h2> <\/div>

It's all about the rosette<\/strong><\/p>

The scientists on board are interested in the microbiology of seawater, and the rosette is one of the most important instruments.
This measuring device is used to sample different layers of water using 12 bottles arranged in a circle. Temperature, depth and conductivity are measured at the same time. Conductivity measures the ease with which electrical charges move through a medium, and in this case the medium is salty seawater. The saltier the water, the better its conductivity. So we can make the following shortcut: measuring conductivity is an indicator of salinity.<\/p>

The water catcher works like the Marine Snow Catcher (described on day 4<\/a>), i.e. the bottles are immersed in an open position and then closed again at the desired depth. Having multiple bottles means that samples can be collected at different depths and the data obtained can be compared.
This rosette includes additional measurement tools:
- a fluorometer: this indicates the quantity of phytoplankton biomass by measuring the chlorophyll present in the micro-algae
- a granulometer: this measures and classifies particles in the water using laser measurement, a tool borrowed from geologists and applied to oceanology
- an Underwater Video Profiler: this can be used to take specific measurements of plankton particles using images taken by a camera
- a transmissiometer: this measures the content of particles that cloud the water, known as turbidity<\/p>

With all these parameters, you've got a lot to live up to!<\/p>

Photo credit: Nicolas Fromont - @nicolasfromontphoto<\/span><\/em>
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Rosette morning and evening<\/strong><\/p>

The list of key players in the laboratory is long: Dominique, Marc, Christian, Chlo\u00e9, Pauline, Najib and Sophie are all involved in rosette missions in one way or another.
They are looking to study the nycthemeral migration of plankton. This word, of Greek origin, means \"a night and a day\", so a nycthemeral migration is a migration that takes place according to day and night. To study this phenomenon, they have to immerse the rosette twice a day at 600m, once very early in the morning and once in the evening. And to make their studies meaningful, they need to use as much data as possible, which means repeating this choreography every day. It's a demanding rhythm of work, but when you love it, you don't count!<\/p> <\/div> <\/div>

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All that fiddling attracted a whole host of little fairies on board!<\/strong><\/p>

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Photo credit: Nicolas Fromont - @nicolasfromontphoto<\/em><\/span><\/p> <\/div> <\/div>

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More like bacteria fairies...<\/strong><\/p>

That's it, the bacteria responsible for bioluminescence in the deep have been cultivated in this petri dish! Each dot is a colony, a veritable bacterial micro-city!
These bacteria will soon be isolated, which in laboratory terms means that they will be separated and grown in different dishes. Researchers will be able to bring them back to Marseille to identify them.<\/p>

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Photo credit: Nicolas Fromont - @nicolasfromontphoto<\/em><\/span><\/p>

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\u2190 Previous day<\/strong><\/a><\/p> <\/div> <\/div>

Next day \u2192<\/strong><\/a><\/p> <\/div> <\/div> <\/div> <\/div> <\/div><\/section><\/div><\/div><\/div><\/div> <\/div> <\/div> <\/div> <\/div><\/div>","protected":false},"featured_media":4489,"parent":0,"template":"","class_list":["post-7303","archive_page","type-archive_page","status-publish","has-post-thumbnail","hentry"],"acf":{"id_old":"3601","category_old":"EMSO-LO \/ BathyCruise"},"_links":{"self":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/archive_page\/7303","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/archive_page"}],"about":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/types\/archive_page"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/media\/4489"}],"wp:attachment":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/media?parent=7303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}