Science between Dudinka and Pevek


2 August 2013

Interview with the new chief scientist on board 

Pascal Hingamp embarked in Dudinka (Russia), replacing Lee Karp Boss as chief scientist.
The first daily sampling station of the leg between Dudinka and Pevek will start in 2 days. But before maneuvers start on deck, Pascal takes a moment to explain the scientific program for the coming months.

Pascal Hingamp, nouveau chef scientifique du bord embarqué à Doudinka. A.Deniaud/Tara Expéditions

Pascal Hingamp, nouveau chef scientifique du bord embarqué à Doudinka. A.Deniaud/Tara Expéditions

- Before we get to the heart of the subject, please introduce yourself.
I am a biologist specializing in genomics at the IGS* laboratory in Marseille. I also teach at Luminy, the Faculty of Science. Our laboratory processes the samples of gyrus (giant viruses) from the Tara Oceans, and now the Tara Oceans Polar Circle expeditions. As usual for Tara samples, we work in collaboration with the Genoscope and other genomics laboratories on the computer analysis of DNA sequences. This is my third voyage aboard Tara. I sailed in the Mediterranean Sea and in the South Atlantic, but this will be my first experience as chief scientist on aboard. Besides coordination of the team, I will take care of sampling viruses, gyrus, and bacteria.
- Who are the members of your team on this month-long scientific adventure?
Sergey Pisarev and Claudie Marec are still on board from the previous leg. They deal respectively with  zooplankton sampling and deployment of instruments. Thomas Leeuw, who arrived in Dudinka the same day as me, comes from the United States. He is a graduate student in Emmanuel Boss’s laboratory, and will take care of imaging in the dry lab. Diana Ruiz Pino, from the Ocean Laboratory in Paris, is replacing Stephane Pesant, doing biogeochemical sampling with the rosette. Diana is a frequent participant in polar oceanographic expeditions, but like Thomas and Simon, this is her first voyage aboard Tara. Simon Morisset will work in tandem with Claudie launching the instruments, as well as taking continuous measurements. And finally, there’s Margaux Carmichael from the Roscoff Laboratory, a veteran of Tara Oceans, who will take care of protists*.
- What is the scientific program planned?
We had planned to do 2 long stations, sampling at 3 different depths. But given the shallow waters of the continental shelf we’ll be traversing, we modified the program slightly. After discussions with the team, we opted for 3 or 4 long stations. We’re still not sure about the fourth.
The first station will take place at the edge of the ice, in the Kara Sea, before we reach Cape Tchelyouskine. For the second station, Tara will be positioned over the slope between the Laptev Sea and the Nansen Basin. This area is particularly interesting, since it provides access to the deepest part of the Arctic – approximately 2 500 meters deep. We will do sampling at 3 different depths. It’s possible that we’ll still detect the influence of fresh water from the Lena River which plays a major role in the fertilization of the Arctic. For the third station, we plan to sample shallow water, less than 50 meters deep, near the New Siberian Islands, a location that may also be under the influence of the Lena River. With samples from the second and third stations, we would like to study the transport of particles from the Lena River to the depths of the Arctic, in what is commonly called the nepheloid layer.
We’re still considering a fourth station, which would be East Siberian Sea. It all depends on the number of depths that we sample during each station, since we’re limited in terms of  ‘consumables’ –  the materials needed for sampling.
- What are the constraints of the mission, and particularly of this leg?

The stock of consumables  is a primary constraint. We have to respect what was planned ahead of time, since we won’t receive any more supplies during this expedition. There is also the ‘corridor’, the regulatory area in which we’re permitted to take samples. The corridor has been defined in accordance with the Russian authorities, but it is relatively narrow – only 40 nautical miles wide. Weather conditions can also influence the sampling stations, but it seems that the weather is in our favor for this leg. Last but not least, the constraint of the North East passage! It seems that the ice is still very thick at Cape Tchelyouskine – about 3 meters thick. Tara won’t be able to pass without the help of an icebreaker. Loïc the captain and Sergey our Russian colleague, are currently getting information about the next passage of ‘caravans’. The idea is to fit into a convoy of ships, but we won’t be able to choose the date. So we have to be very flexible and responsive. For once, science is not the priority, but the passage of Cape Tchelyouskine is. The rest of the expedition depends on it!
Interview by Anna Deniaud Garcia
* IGS: Genomic and Structural Information
* Protists: unicellular ancestors with nuclei of all plants and animals. Some, such as diatoms are photosynthetic. They build shells and skeletons of silica, calcium or cellulose, and transfer carbon from the atmosphere into the deep sediments of the ocean.