exoCean Laboratory
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exoceanlab.bsky.social
exoCean Laboratory
@exoceanlab.bsky.social
Laboratory of experimental oceanography based at CEREGE 🦚, Aix-en-Provence 🇫🇷. We culture, measure, and dissolve carbonates!
📨 [email protected]
🌡️🌊🫧🐚🪸🔬
@juliemeilland.bsky.social, @sulpis.bsky.social, @chalkyoceans.bsky.social
#exocean advent calendar day 24!
Today we thought it was a good fit to show an image/talk about “conception”…
One of the thing we (try to) do best at ExoCean is planktonic foraminifera reproduction. Here two immaculate mummies… 😏

We would like to wish you all a beautiful Christmas Eve!
December 24, 2025 at 1:34 PM
Thanks to @erc.europa.eu #Deep-C, we’re building reactors that reproduce the ocean’s most serious pressures, the kind you really don’t want to “beta test” at sea. We’ll revisit old mysteries from HMS Challenger, & bring deep-sea microbes into the lab to see what life does when the pressure is real.
December 23, 2025 at 6:21 PM
CaCO3 takes less volume dissolved between water and salts than as a crystal. Two consequences: higher pressure favors dissolution, and carbonate dissolution from acidification (very) slightly lowers sea level. Yep! Guaranteed to spice up the family dinner conversation. 🧠
December 23, 2025 at 6:21 PM
#exoCeanadvent Day 23: at exoCean we also look at some old questions: in the late 1800s, during the HMS Challenger expedition, they discovered that you can have a constant rain of shells from above, and still end up with a seafloor that looks like the carbonate budget never existed. Why? Pressure. 🌊
December 23, 2025 at 6:21 PM
We spray the samples into a bright ball of plasma, which enables them to be made into ions and sent into the mass spec. Perfect for our tiny carbonate samples home-grown in the lab.
December 22, 2025 at 4:28 PM
(a nano-gramme is 10^-9 grammes, a billion times less than a gramme!). In the Mission Control room (love this feature...you can pilot the instrument and drink coffee!) we carefully input the sample information and let the automated machine do the rest.
December 22, 2025 at 4:28 PM
#exoCeanadvent Day 22: Winding down for the holidays often means one thing... more mass spectrometry time is available! With our friends in @cerege.bsky.social's #ENVITOP facility, we're making use! Thanks to their equipment we're working on measuring elemental compositions down to the nano-gramme!
December 22, 2025 at 4:28 PM
#exocean advent calendar Day 21! The strongest link between all of us is our love for the ocean. Leaving Marseille with a magnificent sunrise reminds us each time we go out how lucky we are to do what we love for a living!
We already have our ship time for the first 6 months of 2026 - exciting!
December 21, 2025 at 7:13 PM
#exoCeanadvent Day 19: Friday edition: today’s post is about the peacocks at CEREGE, because it’s Friday and our brains are in weekend mode. They wander around like they own the campus, scream for no reason, and block paths with absolute confidence. Honestly, goals. 🦚
December 19, 2025 at 6:00 PM
At exoCean, we're ahead of the game, been dissolving carbonates for ages, for free 🧑‍🔬! We stay fundamental: carbonates, dissolution, pressure. Ocean alkalinity enhancement sits right at the overlap, so we look at what “more alkalinity” does to things like forams. Mechanisms before megatonnes 🔬
December 18, 2025 at 11:34 AM
In CNRS Le Journal (and to journalists brave enough to ask what alkalinity is), the message is simple: scientists don’t vote “yes/no” on mCDR, we provide the cards for society to decide, based on values, political choices, economical priorities. No MRV, no scaling. lejournal.cnrs.fr/articles/rec...
December 18, 2025 at 11:34 AM
#exoCeanadvent Day 18: looking for a good read waiting for Santa? 🌊 Try marine carbon removal: @sulpis.bsky.social co-chaired the working group behind the @emarineboard.bsky.social MRV brief, because “trust me bro” isn’t a monitoring protocol. Emissions cuts first; then *maybe* carbon removal.
December 18, 2025 at 11:34 AM
Phronima are pelagic amphipods, tiny, transparent crustaceans drifting in the open ocean: pure sci-fi. Some species hollow out a gelatinous salp and turn it into a floating “barrel” shelter. Those big eyes are built for the dim mid-water world, where everything is either invisible or glowing.
December 17, 2025 at 4:39 PM
#exoCeanadvent Day 17: Net accident, happy outcome. Ex-lab member Laura caught this phronima (monster in a barrel) “by mistake”, so we adopted it - alive - in a lab aquarium. One haul turned into days of behaviour notes.
December 17, 2025 at 4:39 PM
...The visit to Mainz is also a great opportunity to share samples. Thanks to everyone there for helping us out with some exciting new material.

Sample sharing is great, more people should do it. More info, less waste, & more collaborations.

The @exoceanlab.bsky.social is always open to sharing.
December 16, 2025 at 5:22 PM
#exoCeanadvent Day 16: We're getting closer to the holidays, but we don't stop yet. @erc.europa.eu postdoc @jysuarezibarra.bsky.social was out today presenting his work @maxplanck.de in Mainz. @soniachaabane.bsky.social is also visiting to chat with colleagues.
December 16, 2025 at 5:22 PM
As part of the @erc.europa.eu project #ForCry we have been working alongside ESI to make this process a little easier with this custom device, the #Cryostage, ready to hold onto our tiny plankton samples whilst they are measured. Cool! (Yeah, no really.) ❄️ 😎
December 15, 2025 at 6:11 PM
The cryostage lets us keep things in place, but without adding anything nasty (looking at you glue, resin), only water! Then we can target them with a laser to look at the chemical composition. Laser + mass spectrometer = data! ⚡
December 15, 2025 at 6:11 PM
#exoCeanadvent Day 15: Some plankton are tiny [citation needed?], and for those we need ways to measure tiny (this is a theme you'll hear us talking about a lot). Sometimes just holding samples in place can be hard.... enter the #Cryostage! ❄️
December 15, 2025 at 6:11 PM
We still go to sea, mud, plankton, and pressure won’t sample themselves. Our view on sobriety: fewer trips, local trips & collaborators, smaller boats, longer stays, bundled projects, shared samples. Let the data travel, not us. We've just started this journey, but we aim to do better every year.
December 14, 2025 at 6:05 PM
Our shiny titanium reactors and fancy sensors aren’t “low footprint”, true, new science requires resources. But they will let us test many scenarios in one place, & go to sea with fewer questions. If we can answer it in the lab, we save the boat fuel for the questions that really need the boat trip.
December 14, 2025 at 6:05 PM
#exoCeanadvent Day 14 Footprint reduction: we do lab-based ocean science because we genuinely love it, but also because lab experiments can replace lots of field trips. More control, more insight, and in part, fewer emissions. Bonus: dissolving old sediment cores neutralizes a bit of CO2. 😇
December 14, 2025 at 6:05 PM
Some of the species we find in this core are the very same we can here and now, so we can tell quite a lot about how they lived. We'll use these samples to understand #CO2, and climate, via their chemistry. Thanks to Bremen for having us & @erc.europa.eu ForCry for the project and funding.
December 13, 2025 at 4:53 PM
With lab member Louisa and ex-lab member (🥲) Rachel, we went to @marumunibremen.bsky.social to samples #IODP @ecord.bsky.social cores. Despite being drilled ~30 years ago, the mud we were looking at was once surface creatures, in the Miocene, 6 million years ago! Thanks Rachel for coming to help!
December 13, 2025 at 4:53 PM
#exoCeanadvent Day 12: End-of-year celebration - raclette edition. On the agenda for this team meeting: cheese, cheese, cheese, goals for next year: even more cheese. We’ve officially reached our melting point. 🧀
December 12, 2025 at 2:25 PM