Agassiz trawl planned at 6 am. A bit before
7, we´re all set on the deck. It´s still dark outside. The fog is thick, so we
can´t see anything further than a few meters. The temperature rose again and is
now around 1°C, so it´s not so cold anymore for the work outside. When the
trawl is lifted above the ocean, I soon see a lot of mud getting out of it : a
big hole of a few meters-long is visible at the back of the net. A sharp rock
probably damaged the gear at the bottom. Everything´s not lost though, a fair
amount of mud and rocks is released on the deck floor. When we begin to sieve,
we soon realize than this sediment is completely sterile of life, no animals at
all can be found. After all the sieving and cleaning, we gather in the mess for
breakfast, as the catch was zero for everybody. Later during the day, it´s
decided to deploy the Agassiz again in the
evening at the next station.
The evening catch is more
successful. A lot of rocks make the sorting quite difficult, but some animals
can be found in the mud. We find for the first time some really big Epimeria robustoides, completely white
with bright red eyes. Some more spiny Epimeria from the similis complex, Eusirus
perdentatus and for the first time also, some Eusirus of the complex giganteus possibly belonging to different
species. We try to keep some of the fine sediment, to look for smaller
amphipods, but we find later that it´s quite poor and that the few animals we
can find have been badly damaged from the rocks in the trawl. However, the total catch keeps us working
until almost 3 am.
(Marie)
Epimeria robustoides, which can reach 45 mm is one of the largest and fattest Epimeria species.
24.02.2013. (Sunday). The clock of Marc rings at 06:00, mine at
06:10. Difficult to get out of my bed. Outside it is still pitch black. Indeed,
we use the time zone of Europe, which is not the same as the astronomical one
for the area. By the way this completely perturbs our biological clock. The
trawl is put in the water at 06:18 (same area than yesterday but on shallower
and flatter bottom, about 175 m depth).
I go to the mess room two. I am obviously in the way, but I really need
a cup of coffee to start to work. I go down. The winch is already going up at
06:40. Around 07:00, we are on deck. We see the very first light of dawn, but
it is still very dark. The trawl goes up. It proves to be badly torn (it will
need reparation) but apparently we did not loose so much of its content, as a
large compact mass of mud mixed with shingles and gravel, looking (in my
imagination) like the faeces of a huge dinosaur. To our surprise, this mass of
sediment is completely sterile. We get absolutely NOTHING in sieving it. I
order to cancel the planned dredging operation (it would me wasting our time
and that of our colleagues). This samples is of course disappointing for our
point of view of taxonomists, but it is also quite enigmatic from an ecological
point of view. Why such a sterility? Sometimes, we had poor catches, but never
such a sterility. As a consolation, I eat a solid breafast: fried eggs with
onions, bacon, mushrooms and ketchup (no tomatoes - they are all long gone) and
bread with eggs of forel. The sea is calm; the sky is gray; it is foggy, not
cold. As we are short of time, we will
make a second Agassiz trawl early in the evening (next station/environment of
Bransfield East). Julian Gutt asks me to use the Rauschert dredge fixed on the
side of the trawl and not separately. I do not like at all this idea because
previous experiences prove that this method increases the risk to loose the
dredge if it is stuck between rocks or if the net of the trawl twists as
yesterday. After further thought, I decide to skip the dredge operation because
I want to take no risk. The Agassiz trawl comes up with huge stones and a lot
of life. The first thing I spot is an Epimeria
robustoides. This is one of the biggest species of the genus (about 45 mm)
and a very fat one, snow white with the oral fields and anterior legs purple. A
really cute species. Later on, we find other specimens of the same species but
smaller ones. We also get Eusirus perdentatus
'spotted chromotype' and Eusirus
giganteus 'spotted chromotype'. No E.
perdentatus 'marbled chromotrype'. Too deep? Since we did not use the
dredge we sieve the sediment of the trawl. Not many animals in that fraction,
but Marie spots a very strange one (for specialists), which I can only identify
the day after, as Prolaphystius isopodops. I go to bed on 25.02.2013 at 02:45.
(Cédric)
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