Monthly Archives: July 2012

Nutrients sampling

The Mediterranean Sea in general, and the Calvi Bay in particular, are very oligotrophic areas. As a result, organisms living in their waters are adapted to low nutrient concentrations, and even small changes in these concentrations can cause big perturbations of natural communities.

Thanks to the mesocosm experiment, we (Sylvie Gobert from University of Liège, and Loïc Michel, from the Stareso research station) will try to understand if ocean acidification could modify nutrient concentrations in Calvi Bay. To do so, we take daily samples to monitor nitrates and nitrites, ammonium, phosphates and silicates concentrations in each of the mesocosms, as well as an “extra” sample out of the mesocosms. We look forward to seeing which trends emerge from the data, and we hope that they can be useful for other scientists taking part of the experiment too…

Once the water is sampled, we have to condition the samples. This is the most critical part of our jobs, because by this time, it is usually around 11 AM. Since labs are quite crowded, we work directly on the Stareso dock, under the burning Corsican sun. During this dangerous task, the only things that prevent us from baking are 1) our beloved straw hats (see fig. 1) and 2) a very good hydration plan based on refreshing Corsican beer. After conditioning, we place the samples in the freezer (for NO2- + NO3-, NH4+ and PO43-) or in the fridge (for SiO44-).

Nutrient conditioners hard at work under the Corsican sun.

Now the experiment is nearly finished, and nearly all samples are stored, patiently awaiting analysis. On Sunday (July 15th), our colleague Renzo Biondo (also from Lab of Oceanology, University of Liège) will join us, and we will start the analysis step. All nutrient concentrations will be determined at Stareso, using our Skalar automated continuous flow automated analyser. Methods differ for each compound, but all are based on colorimetric detection. When everything runs smoothly, this type of analysis is rather quick, and we hope to be done in about a week… However, the analyser is a whimsical machine, and a lot of things can go wrong. To ensure that the Nutrient God is with us, we consider sacrificing one of the station’s cats to him. Let’s hope it will be enough to please him!

(NOT!) gone with the wind!! (by Cécile)

Sampling with wind conditions at least 15 kt has become very usual for the MedSea mesocosm team and we are now able to work such very difficult conditions. It is amazing and the participants are amazing on their cubi. We have put diving weights in the samples boxes to avoid any flying boxes to the water! Yes, we have been experiencing high winds since several days now and yes, we are ok but most surprisingly, the mesocosms are still in very good shape and no damage were found by our diving team (Amélie and Sylvain) who go to the mesocosms everyday to change the sediment traps. As they go under water from the Stareso station using funny ‘underwater scooter’, they could go to the site, even yesterday. They said it was very nice and calm at 15 m depth! Indeed yesterday, the wind was so strong that we were not able to go out with the boat as the security was concerned. We have been deciding on the sampling strategy by following very carefully the forecast: for those who are used to sail in the Med Sea, they know as the wind can change rapidly, and as it can increase its speed even more rapidly. We have a ‘Special Forecast Warning’ since 4 days now and it seems difficult in the present condition to predict what will really happen in term of wind …. Apparently, the worse has to come as they predict a huge wind event for tomorrow (figure from… Huh, no doubt that tomorrow will be a quiet day in the labs, except for the incubated samples that hopefully we will be able to withdraw quickly with the rubber boat early tomorrow morning!

Here is the forecast map. Corsica is surrounded by red wind areas! This is for tomorrow (Sunday) at 12pm.

Apart from being quite annoying for our daily sampling routine, this event is going to be very interesting in term of results as a specific forcing on the structure of the surface mixed layer, on the air-sea exchanges and on the functioning of the ecosystem.

CTD (by Anastasia)

CTD (standing for: Concise and Terribly Distressful)
Date of birth: end of 2011
Place of birth: Washington, USA
Parents: Raquel, Angela, Grigor and Vincent
Siblings: The Radiometer


-Handle the CTD with immense care and don’t rush it!
-A good teacher (while on the cubi) will definitely help you take accurate measurements and will explain in depth the principals of its use, unless singing/listening Greek songs distracts him!
-Singing in general will help you a lot to concentrate and find the perfect – appropriate rhythm for lowering the CTD in the water
-Use an umbrella while using it and hide below it, in order to protect from light (and be fashionable!)
-Drift with the currents and trust the waves when “travelling” from one cluster to another, without being attached to any of the ropes. Oops! If the weather changes unexpectedly and floats you towards Calvi, jump in the water and save the CTD!
-Don’t panic! Instructions for correct handling are given on board the cubi. Try to keep calm
-Real time data will only come after a quite long processing day that requires patience and … knowledge of course
-Rinse the CTD with water (and affection…) immediately after each use and, if necessary, forget about your lunch

Vincent and his second baby

Principal(ok, let’s be a bit more serious now!)

The CTD (actually standing for Conductivity, Temperature, Depth) is an instrument that takes continuous measurements of several water characteristics (temperature, conductivity – from which salinity is derived -, pH, fluorescence of chlorophyll pigments, photosynthetically available radiation, and dissolved oxygen concentration), with the use of sensors that are placed whether in external or internal flows. It provides you with a detailed description of your water sample, with measurements taken four times per second. These measurements are then aligned to depth (by converting pressure to meters) and are saved in digital form in order to be processed later…

Do you think it is too hot? (By Eija)

We “atmospheric people” are working on that! Let me explain.

Ocean is a source of gases and tiny particles which help to make clouds and cool the atmosphere. Isn’t this great news during these super hot days at Stareso?

Bubble bursting aquarium

To be more exact: The goal of the atmospheric experiments here is to understand which type of particles and in which quantities are released into the atmosphere from Mediterranian Sea. We take samples from three mesocosms of different levels of acidification. Then we “bubble” the samples in an aquarium simulating the particle release process by winds and waves over the sea. For this, a bit noisy pump is needed.. When we have the particles in the air inside the aquarium, we study their ability to form clouds (to make the climate less hot). This depends, at most, on the particle chemical composition and size. In addition to this, several types of samples are taken of the aquarium air, in order to analyse the gas and particle phase compositions afterwards in the lab. Quantities and properties of organics are on top of our interest list. Thanks to Alina, we can also sometimes “enrich” our samples with the surface layer – this is important since surface is in direct contact with the atmosphere.

It is amazing how little we still know on the fluxes of particles (and gases which can condense on the particles) from the oceans. And even less on the possible effects of ocean acidification on these fluxes. So this can be really mind blowing science we’re doing (mind blowing not only because of the noise…)! Bear with us for couple of more days…

Mauro’s vision of the story

Part of Stareso´s fauna.
Once upon a time a bizarre concrete landslide gave birth to the station of Stareso in the savage coastline of Corsica. The place was soaked with grey magic and many biodiverse creatures started settling. The undiscussed king of this realm was the Vampire Eel, having as subjects carnivourous pirana-like marine fishes, French speaking wasps, immortal mosquitoes (you can smash them but they never decrease in number), a zombie cat, diarrhoea-generating sea gulls and a variety of electricity-resistant flying bugs.
more of Staresos´s fauna (introduced)

Since when the human kind initiated the so called global change that kingdom has remained preserved by unwanted invasions… until now… A bunch of intelligent, good-looking, brilliant, nice, sexy, over-the-top scientists arrived in that magical place to study the effect of increasing C dioxide on its marine system. That apparently peaceful system could just not stand those unwanted creatures and reacted. Yes, it reacted. Will those scientists survive to such a massive reaction?

will they?

The food at Stareso ;)

First day: Paella!
There is key factor making our days easier, tastier, and happier here in Stareso research station; that is: the FOOD! (capital letters are needed because it reflects the size of our dishes). Since the first day it was clear to us that food was not going to be something to worry about. We were welcoming with a delicious paella, salads, sweets and cheese, always present French cheese, and specially the nice Corsican cheese with fig mermelade….yummmi

Some of the dishes we have had

And so, our days pass awaiting for 12:30 and 19:30 were the bell rings and everybody gathers around the table. Team work is a constant even when making the table: one puts the napkins, someone else the plates, forks, knives, water for all (Oasis for Samir)…and the table is ready!. During our meals we hear happy conversations and laughs in English, French, Spanish, Greek, Italian and international laughs. Then, always with full bellies, one by one stands up and goes filtering, sampling, or just for a break.

Richard and Joseph!!

Every day I said to myself I will eat less next day…but that never comes 😉 I guess that happens to most of us… Just now, while I am writing this post, the smell of something being cook by Joseph reach me and Raquel, we look at each other and say…”hmmmm”.
and all this thanks to Joseph and Richard! …Lets see what it will be today!

Las comunicaciones (by Raquel)

Ya son 19 días que llevamos por la estación y ahora empiezo entender la importancia de la buenas comunicaciones.
A la llegada tuvimos unos días mientras que el equipo de Villefranche ponía a punto los mesocomos, tiempo para poder organizarnos y conocernos un poquito. Eso si, al principio fue algo caótico y muy gracioso ver como aquél que no domina el idioma se ingeniaba con gestos y expresiones para entenderse.-Comment Ça va?
-Ciao, come stai?
-Jak se máš?
-How are you ?
-Hei, mitä kuuluu?
-¿Cómo estás?
-Tι Kάνεις?

Como ven, hay personas de muchas nacionalidades pero esto no ha sido impedimento para llegar a una buena convivencia y a realizar un buen trabajo en equipo.

Y ahora, después de 13 días de experimento empiezan los problemas de comunicación , pero no con los compañeros, sino con los equipos, hemos tenido que reparar el cable del radiómetro y después mucha paciencia (miren la cara de Vicent) se pudo poner en funcionamiento de nuevo.

“La paciencia es la madre de todas las ciencias”


It´s been 19 days in the station and now I understand how important good comunications are. When we arrived we had some days while the Villefranche team got ready the mesocosms, days to get to know each other and organize things. At the bginig was very funny to see how those who didn´t master Eanglish were ingenous with gesticulations to communicate.

-Comment Ça va?
-Ciao, come stai?
-Jak se máš?
-How are you ?
-Hei, mitä kuuluu?
-¿Cómo estás?
-Tι Kάνεις?

As you see, there is people from many nationalities but this has not been a barrier to achieve a good community and make a good team work.

And now, at day 13th of the experiment communication problems start, but not within the group, rather with the equipment . We had to repair the radiometer cable, and with a LOT of patience (take a look at Vicent´s face) it was working again.

An Early Morning Treat! (by Lisa)

As I live in one of the wettest and windiest areas of the UK, some might say that I should be well able to cope with gusty weather!

However, I don’t think anything quite prepares you for the experience of balancing yourself, your sampling boxes and the integrated sampler on a floating plastic cubi in gusts of 30-40mph. Being somewhat inelegant at the best of times you can only imagine the resulting chaos! Trying to negotiate guide ropes and pulling yourself close enough to the mesocosms to enable the safe deployment of the integrated sampler whilst battling against the wind gives the added benefit, for this unfit scientist at least, of a full-body workout!

It was somewhat gratifying therefore to arrive on station early this morning in order to collect my 24 hour incubations (for nitrogen fixation and nitrification) and find a flat, calm sea with the sun just appearing over the horizon.

The incubation lines are set up as close to the mesocosms as possible in order to replicate the conditions (light, temperature etc) within, whilst at the same time causing as little interference with the guide ropes and the mesocosms themselves. Cecile and I headed out for the lines, both saying little and just enjoying the peace and tranquillity. After a brief panic of thinking my bottles had broken free (they weren’t on their usual lines!) we were turning around to head back in when Cecile said “Oh wow, look at that!” Thinking she was referring to the amazing sunrise I replied “Yes, it’s stunning isn’t it?” “No, look! It’s huge! Is it a whale or a dolphin?” she replied. Not having my lenses in it took a while for me to focus (hey, it was early!) It was then that I noticed two groups, fairly close together, of what appeared to be fairly dark coloured dolphins. We edged slowly forward in order to get a closer look and just stood and watched in awe as the groups joined together to play.

After starting to come back in, we then became concerned that the dolphins may have been attracted by what I had been told were fishing nets and might get caught up in them. We turned back in order to make sure they were okay and watched as the little family swam out further to sea.

What an amazing experience, and a perfect start to the day!

Ocean Acidification impact on trace elements (by Justine)

The target of the experiment is to study the impact of the acidification on the physical and chemical speciation of the nutrient elements as phosphorus, nitrogen and iron. Since ten days, the typical day at Stareso begins by the sampling inside the nine mesocosmes and outside mesocosms thanks to the cubi platforms. Oooohh the cubi … it’s very funny … and again more with the wind like yesterday and today!! Fortunately, a yoga class have been installed in Stareso (appointment time: 6:00 pm !!) and I’m going to try it !
After sampling, we go to the lab to filter the samples at two different fractions (0.2 µm and 0.015 µm).

Filtration device used in Stareso

After analysis of Dissolved Inorganic Nitrogen (DIN), Dissolved Inorganic Phosphorus (DIP) and Dissolved Iron (DFe) by spectrophotometry at the lab (LOV), in cleaned and controlled conditions, these filtrations will allow us to quantify the nutrient elements on two forms: dissolved (0.015 µm) and colloidal (0.2 µm).

UV irradiation system

With Cecile, we use also the samples filtered at 0.2 µm to determine the organic nitrogen and organic phosphorus. For that, the samples are irradiated by UV during 1h30. We are very impatient to discover the relation between inorganic and organic phosphorus after to have seen the data of alkaline phosphatase of Mauro in the most perturbated mesocosmes (P4-P5-P6).

Other experience: thanks to Alina’s help the microlayer (=thin layer between the ocean and the atmosphere) is taken, and so we have decided to analyze its composition at nutrients on forms inorganic and organic.