news…. Until the next experiment!!
news…. Until the next experiment!!
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)
Mesocosms are like iceberg, the big part is underwater, the bottom is around 14m of depth and at the bottom of the bag there are the famous sediment traps.
I am in charged of sediment traps, they need to be changed everyday! It’s the best part of the mission, every afternoon I go with Sylvain to replace the sediment traps (which consiste in a plastic bottle screwed on the sediment particules manifold). We are totally independent, we go under water from the station to the mesocosms using underwater scooter, it’s so cool!!! It’s very fast around 20 minutes to go, change the nine traps and come back.
Under water it’s so calm (even when very windy at the surface), everyday we are welcomed by a multitude of curious fish.
We found a lot of swimmers in sediment traps and sometimes jellyfish!
The sediment traps collection is done to measure the export of organic and inorganic carbon and see if there are differences between treatments.
I would like to sincerely thank Sylvain who come with me everyday and Alex (the Sunday afternoons) as well as Stephen who took a really nice pictures of mesocosms.
The name alludes to seagulls that unfortunately made their dwelling place above the roof of the mesocosms..
“If you love someone, set them free..If they come back they are yours..if they don’t they never were.”
The wind keeps blowing powerfully and samplings from today were cancelled. Although is bad news, we will surely occupy the time in other activities besides filtering and measuring. Some only want to sleep, others might go for a walk on the beautiful mountains around, plans to get to walk around Calvi might develop, and others plan to join the already established Yoga classes (daily at 18.20).
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-).
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!
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 http://www.lamma.rete.toscana.it/meteo/modelli/vento-e-mare)… 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!
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.