Messing up the mesocosms…all for zooplankton! (by Thanos)

Thanos processing samples after collecting the zooplakton

If you ever find yourself in the middle of a mesocosm experiment somewhere in the Mediterranean Sea and you decide to mess up with it, then you have only one choice. Call us. Call the ZMUT*.

We can do almost anything. We can do cubiing, pumping and sampling all free of charge ;). We collect copepods and their eggs and feed them with the soup from the mesocosms (each soup with different pH flavour), trying to understand how acidification of the seas affects those living creatures.

But the most important…

We are the only ones who can professionally mess up the mesocosms. The only thing that is needed is a net, just a common zooplankton sampling net.

And after that …

No microlayers, no samples, no filtration, no sediment traps.

Simple as that.

PS1: Our best wishes (double for those who are here from the beginning) for a safe return back home and for good results to all cubists of STARESO.

PS2: Thanks all of you for your help!

* Zooplankton Messing Up Team (ISO 2000)

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…

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?

back from the beautiful Corsica Island (by Patrizia Ziveri)

Working in the mesocosms and the mesocosms under water

I am back from the beautiful Corsica Island where I went during the preparation and starting of the MedSeA mesocosm experiments on acidification, off Stareso Laboratory near Calvi. This is an important event for the MedSeA project and for the theme dealing with the “Effects of ocean acidification and temperature on pelagic ecosystem function”. We are testing for the first time in the Mediterranean Sea, future acidification scenarios on microplanktonic organisms and key biogeochemical processes. This is very exciting and it was good to see that the testing went well and the actual experiment is started. There is a great group of people, all very motivated, excited and hard working. The people from LOV in Villefranche, led by Frederique Gazeau, are doing a great job in keeping everything under control and building a good and efficient sampling planning to make sure that the experiments will be successful.

I looked at same samples from the mesocosm by scanning electronic microscope and there are coccolithophores! (several species but all quite small and in different stages of their life cycle). These are very interesting samples for Angela’s PhD project.

Coccolithophores from Stareso!

All the best to the mesocosm team for a successful sampling and great results!

… and the experiment started!

After a long preparation, mainly done by the Villefranche team, and some days of test samplings were we all learned how to deal with the ropes, the platforms, the hydrobios integrater sampler, pumps etc, each of us have already sampled for its own data. During this preparation we had some troubles (mainly in the windy days). For example, the pump used to acidify felt once in the water (luckily it was saved), one of the carrying boxes with all the empty bottles also felt in the water in a windy day, but after a refreshing swim it was saved as well. Some of the scientist also felt in the water but came back swimming and finally, one team was caught in pictures when, unlocked themselves from the mesocososm units and, taken by the currents, started to drift in the platforms… soon they were brought back by zodiac.

Sample team is brought back by boat after drifting with the currents. On the platform they were probably just enjoying the little trip 😉

All these experiences made us stronger and ready for the real samplings and subsequent processing of the samples. In my case it meant filtering about 80 liters of water. These because I want to see coccolithophores, marine calcifying phytoplanktonic organisms that are at the base of the food web and particularly sensitive to the changing ocean carbonate chemistry. Coccolithophores produce plates (coccoliths) of calcium carbonate which they use to cover their bodies (single cells).

For these organisms, a decreasing pH of the ocean is expected to affect the production of calcium carbonate by coccolithophores (see Image from Beaufort et al. 2011 article where evidence from sediment samples seem to agree this hypothesis). From each of the nine mesocosms I will be filtering 9 liters of water to later observe the filters under the scanner electron microscope (SEM). I will check whether those coccolithophores living in the more acidic ambient have more malformed, incomplete or thinner coccoliths than those living under normal conditions (in the Mediterranean “normal” means high alkalinity and saturation state for calcite, impeding the dissolution of calcium carbonate). Half of the water will be used to measure Ca in the smaller than 40um fraction (if I manage to get sufficient material). First samples are in the oven!

Modified from Beaufort et al. 2011