19 to 25 November 2007
The fourth and last week of our month-long cruise has passed quickly. We occupied additional stations south of the Walvis Ridge (west of Namibia) and carried out our sampling there successfully. The last samples were collected and the nets were reduced to their component parts. Our instrumentation was removed, packed into boxes, and stored in shipping containers. The ship-board labs and cold rooms were cleaned to a high polish.
We are going home with much data and many samples, which will keep many of us busy for the next months and even years. The full extent of our scientific findings cannot yet be fully assessed, but there is already clear evidence that our expedition is a great success.
More than 1 million cubic meters of seawater was filtered with our nets, and more than 60,000 specimens have been sorted and identified (Table 1).
In all, 2,043 specimens of 389 species were submitted for DNA barcoding during the cruise, and the on-board DNA sequencing lab determined 122 DNA sequences of the targeted barcode region for 66 species. The taxonomists have not yet identified all of the animals found in the samples, yet they are certain that there are new species among them. A truly magnificent treasure trove for taxonomists and molecular genetics!
While the zooplanktologists were sorting and identifying animals under the microscope, the non-zooplanktologists were eagerly collecting and analyzing air and water samples. The phytoplanktologists, for instance, filtered about 3,700 L of seawater, using 485 filters and making 56,778 measurements of chlorophyll a fluorescence in surface water collected from the “moon pool” – the central well of the ship. Meanwhile, meteorologists from Kiel took 71,202 cloud photos.
On November 24, to mark the end of our cruise, we had a final barbeque on the working deck and in the big wet lab.
ANT XXIV/1 was a very harmonious and successful cruise. The competent, friendly and encouraging support of Captain Jakobi and the entire crew has contributed considerably to the success of our cruise: we thank them very much!
On November 26, we will disembark in Cape Town. We will say goodbye to Polarstern, our friends and colleagues sadly, but we are also looking forward to Cape Town and to returning home.
With best regards from all of us
Table 1: Summary of the numbers of sorted specimens and identified species during the cruise