Tuesday, 4 April 2017


04.03.2013 (Monday).
My clock rings at 05:00. Fortunately, I hear it this time. As previous days, not cold outside at the end of the night. The dredge is put in the water at 06:06. Not much sediment in it (black sand) when it comes back. Moderate number of amphipods. The Agassiz trawl follows immediately and the sorting of the dredge is not yet finished when it comes up. Marie goes on deck and I finish the sorting. I missed something interesting: the trawl caught more than 40 huge Paraceradocus gibber, which were crawling in the mud. Still early in the morning (09:10), the trap system are released from the sea floor. It comes up without problems. Since it is still fairly dark, the flash system did work. I made a short video of that. The new flagpole survived its mission in the abysses but this time we lost the flag itself! The yellow flag, with the little iguanodon (the logo of our museum) sketched with a pen... One of the six traps is broken. Technically, the trap model conceived by Henri Robert is wonderful and extremely practical but since they are in rigid plastic, they are also fragile. I don't know if we will use the traps a third time during this cruise; it will depends on our tough time schedule and on the weather conditions in the Drake Passage. Once back in the lab, we first look at the samples of the trawl, and especially the Paraceradocus gibber. Their colour pattern is all clearly different from that of the deep Paraceradocus of the previous days, with almost no variation. This confirms our feeling of yesterday that two species are currently confused under the name Paraceradocus gibber: a shallow-water brown and white one  and a deep-water all livid brown one. It appears that the issue of the transport of the biological material back to Belgium is not yet solved as I believed.  Just after lunch, we sort the material of the trap. Not so many specimens but again a good diversity. One species not found the first time (Pseudorchomene coatsi) and two no longer found (Parschisturella carinata and Orchomenella pinguides). In the afternoon, the waves increase in strength. We have the luck to see twice humpback whales fairly close to the ship. Marie is so happy to see them...

(Cédric)


 
Paraceradocus gibber sensu stricto, lateral view. Total body length about 90 mm.



Paraceradocus gibber sensu stricto, dorsal view. Total body length about 90 mm.


Trap system coming up.


Trap system on surface.
 
 
Trap system back on board.
 
 
The traps.

 

The traps has come up (videos).
 
 
Pseudorchomene coatsi, total length about 12 mm.
 
 
Humpback whale.

Monday, 3 April 2017


03.03.2013 (Sunday).
I get up at 05:00. As very often, the operations are a bit behind schedule.  So I am starring at the night ocean, half sleeping. Like during the previous days it is not cold. To my big surprise I see lights at sea. Apparently it is a fishing boat. Then the dredge is put at sea. Depth: about 700 m. The cable goes down at 0.6m/s. The ship moves at 0.2 m/s for 7 minutes (i.e. a short time) during the dredging operation. The dredge is hauled up at 0.7 m/s (length of cable: 1300 m). When the dredge is at sea, we prepare the traps for the next operation (cutting the fishes into pieces and putting them in the bait boxes). This time, they do not stink. The dredge comes up with a muddy sample. Catch of medium importance.
We have now enough daylight to see that this will be again a gray foggy day. The Agassiz trawl is deployed in the same zone as the dredge, even a little deeper. It also comes up full of mud. Not many amphipods but big ones: large Eusirus complex giganteus form gray back / crimson legs and a huge Paraceradocus (about 100 mm). Its morphology corresponds to P. gibber but (as the specimens from the previous deep station), it has not the two white longitudial dorsal stripes of the P. gibber collected at depths of less than 500 m. Phenotypical variations related to depth? Or are there two very similar species confused under the name Paraceradocus gibber? We don't know for sure but both of us are enclined to favour the second hypothesis.
At 12:44, the lander with the amphipod traps is put at sea. We should recover it tomorrow at about the same hour. In the afternoon I am updating the blog, which was not done for two weeks. It takes an incredible amount of time to upload very light pictures and even text from here at the end of the world, with a poor satellite connection. And there are always little problems of layout to fix again and again...
(Cédric)
 
 
Eusirus complex giganteus form with gray back and crimson legs. Size: about 80 mm.
 
Paraceradocus aff. gibber "all brown", lateral view. Size: about 100 mm.
 
 
Paraceradocus aff. gibber "all brown", dorsal view. Size: about 100 mm.


Trap system ready to be released.
 
Releasing the trap system (video).
 

02.03.2013 (Saturday).
Fog and sea rather rough. Agassiz trawl late in the morning, on a rich sponge bottom at 460-480 m. We get a good catch of amphipods, amongst which the gorgeous Bathypanoploea schellenbergi. We also get a ten-legged species of ophiurids (something I had never seen before). I intended to photograph it but the specimens, which I kept for that purpose have been discarded before I could do it. So, sorry no pictures of them. Since the Agassiz trawl was very successful, I order to leave the dredge for 20 minutes on the sea floor (which is a long time for it). It comes up full of black muddy sand and gravel. We get beautiful gorgonians (for Pablo López-Gonzalez) and urchins in perfect condition, which make the delight of the 'urchin team' (Bruno David, Chantal De Ridder and Philippe Dubois), a lot of small stones with colonies of bryozoans, which are supposed to be studied by Hans De Blauwe (external scientific collaborator to our Institute in Brussels). As concerns amphipods, we get one undescribed Melitidae, which is known for years by amphipodologists but which has not been described so far. It is usually referred under the informal name "Antamelita". Not a common species; this is the first time I see a living specimen of it. Tomorrow morning we are supposed to have a dredge at 05:30 and to deploy the traps for the second time. A lot of things to finish in a hurry, as I want to sleep enough to be functional tomorrow. Finishing the sorting of the specimens from the dredge, putting order in our lab, fixing a new flagpole on lander, de-freezing the fishes (the bait); fixing the nuts on the bolts of the ballast system. Job finished at 22:22.


Bathypanoploea schellenbergi. Body length about 30 mm.



"Antamelita". Body length about 20 mm.


(Cédric)
01.03.2013 (Friday). 

The waves decrease a bit but the sea is still strong. During the night, people from the crew closed the window of our lab with a lid. They will never be opened again during this cruise. Our lab looks now like a kind of cellar, without sight on the open sky. Marie carries out DNA extraction as we have one day without benthic sampling. A lot of small things to fix during this "calm" day, as finishing some pages of this blog.

(Cédric)




For reasons, that will not been discussed here, this blog has been discontinued during 4 years. However, a logbook has been written until the end of the expedition. It will now finally be released ...in April 2017.

(Cédric)

Wednesday, 27 March 2013

Please be patient for the end of the narrative of the expedition

We have been extremely busy in March on board of the Polarstern and we did not had the time to update the blog. However a detailed logbook has been written during that period (at least by me) and a lot of photographs have been made by us. Our narrative of the expedition will be completed but this will take more time than expected. I am already back in Belgium, but Marie is still in Patagonia and will only arrive in early April. We have a lot of other things to do, and the content of the blog (at least the part concerning the expedition itself) also has to be checked and approved by the scientific leader of the expedition (for justified reasons). So, please be patient and expect a long update at an undetermined date in April 2013.

(Cédric)


Thursday, 7 March 2013

28.02.2013 - colourful giant amphipods

28.02.2013 (Thursday). The trawl of today was quite unusual. The station was the deepest so far : 770m, so we were expecting (and hoping) to find some different kinds of animals than the usual. When the trawl was brought back above the working deck, everyone was surprised to see an enormous amount of mud in the net. The deck has never been so dirty. At first we cannot see anything, so it´s always a surprise to wash some of this mud and see if there´s something in it. There was a lot of organism hidden in there: seestars, a lot of ophiurids, sponges … and amphipods. Not so much (or most probably we couldn´t find them so easily in the mud) but really interesting ones. We found some Eusirus giganteus of an unusual coloration. I did my master thesis on the pseudocryptic diversity inside this genus, so this interested me a lot. We found out during my thesis that the species of Eusirus can most probably be distinguished with the coloration, along with other less visible morphological characters.  There was a species in the complex giganteus of a bright red coloration that we called the “red dragon”. At first, I thought the specimens we found today belonged to this species, but the coloration is still different, the body is grayish with blood red appendices. It´s another piece of the Eusirus problem, and raises even more the interest in continuing the study of the genus.

In the evening, I dissect the first serie of specimens of interest for my Phd thesis, in order to begin the DNA extractions. I withdraw one or two pleopods and put them in absolute alcohol. At the end, the work with the stereomicroscope begins to get very hard, as the sea is getting rougher and rougher. We make sure that everything is fixed and attached with ropes, because the night will be quite agitated, with a wind of force 9. Indeed, we are woken up around 4 am by a violent bump that makes everything fall on the ground in the cabin. I sleep real bad, I´m probably not used anymore to such movements but I fortunately don´t feel any seasickness. 

(Marie)


28.02.2013 (Thursday). Oh, its already the last day of February. Time is running like a meteor on the planet Antarctica... In the morning, same weather than yestrerday evening: foggy. The wave are moderate but are supposed to increase seriously later today. We are at our second sampling area in the Bransfield Strait. We will again do three or four stations here at various depths and at bottom topologies for estimating the influence of these parameters on the structure of the benthic communities. Today we will have our deepest station so far: about 770 m depth. The net comes full with a huge load of brown pasty mud. It does not smell. We find a lot of Eusirus of the complex giganteus. Most of them belong to the chromotype 'gray back/crimson legs', not yet found during this cruise. Truly giant amphipods reaching 100 mm with a vibrant colouration.

In the coming days we will probably have a second trap operation. So we need more ballast (piece of rail of 50 kg). They have rermained in a container in the hold. The second officer Felix Lauber told me that there is a problem. The main door of that container has been soldered. The other door can only be slightly open and only a narrow-chested man can go inside. This will be difficult but normally it will be possible.

In the evening, the strength of the waves increases considerably. We have to fix everything in our lab (and the dredge outside). Waves hit the window of our lab. During the night, I hear in my sleep that the telephone and the bin of our cabin fel down and are rolling from one corner to the other. Marc, who sleep below me, put them in security in a safe corner.

(Cédric)


 Eusirus complex giganteus, chromotype gray back / crimson legs.


This is the tip of the spine of a cidaroid sea urchin. There are tiny bivalve molluscs and holothurians (the pink sausage) living specifically on them.


Detail of the same.