64PE370 - Dagboek 5 (Engels)

It is Tuesday 28th of 2013. I joined the RV Pelagia on the departure from Texel Island in the Netherlands on the 8th of May, which is 21 days of sailing so far. With sunny and hot, others overcast and windy days, as well as flat seas and storms and all other things that after all made an oceanographic cruise great.

I am Marine Biologist from Chile, with an overall background on biological oceanography and I`ve just gotten a PhD position on the department of Chemistry at the University of Science and Technology (NTNU) in Norway. Due to a cooperation between this institution and the Marine Science and technology institute (DEU) in Turkey, and by invitation of the Dutch Geotracers program, I got the opportunity to participate on this cruise.

I am Marine Biologist from Chile, with an overall background on biological oceanography and I`ve just gotten a PhD position on the department of Chemistry at the University of Science and Technology (NTNU) in Norway.

Due to a cooperation between this institution and the Marine Science and technology institute (DEU) in Turkey, and by invitation of the Dutch Geotracers program, I got the opportunity to participate on this cruise.

The general scope of my PhD will deal with iron and phytoplankton, reason why am one of the other scientists that are working onboard with this "popular" element. A little more in detail, I'm collecting samples for two purposes mainly, one of which consist to study the bioavailability of iron. Since the dissolved fraction of this element is greatly affected by the type and quantity of organic compounds present in seawater, the aim is to determine which percentage is readily available as nutrient for uptake by phytoplankton. My approach here is to deploy passive samplers (DGTs) in a known volume of water. I determine the metals that diffuse through a gradient concentration between the surface of the DGT unit and the binding resin in its interior. The other purpose is to study the distribution of the iron within the dominant groups of phytoplankton. This is done by performing fractionation of the particulate matter in the water column, using sequential filtration through the three mains size classes within natural phytoplankton (0.2 - 2 - 20 µm). The latter, together with some taxonomic and abundance analysis can render information on the distribution of the iron content within the phytoplankton community in the Mediterranean Sea. My job, some would say unfortunately others fortunately, is not completed onboard and further processing have to be carried out back in the laboratory. Consequently, and due to the fact that am not sampling every station, spare time can be used to assist when needed, mainly in sampling the water from the Ultra Clean CTD for everyone´s requests. Also, getting acquainted with other´s work and techniques, some of which are somehow new to my time in this field, is a useful way to spend this time.

For the two previous years I was focused on my masters so I´ve been out of fieldwork and the sea for quite a while. For that reason getting onboard this ship for the 1st Leg of the MedBlack Geotraces cruise was a great opportunity. At the same time, my experience on board cruises is related to more relatively colder environments like Chilean fjords and the Antarctic Peninsula, reason why wearing shorts, enjoying a chat-break with colleagues or perhaps an ice cream on deck after lunch is quite unfamiliar to me. All these, part of a new great experience in the Mediterranean Sea.

Although three weeks onboard and bit more than one left, still a good number of stations remain to be covered, so busy days are ahead us before reaching port in Istanbul. Fortunately, with the valuable assistance and experience of the crew and technicians, plus a bit of luck, work will be completed successfully.

Nicolas Sanchez Puerto