Expedition hits the waves to explore link between climate change and plankton - Metro US

Expedition hits the waves to explore link between climate change and plankton

Science takes time, patience and stamina. In the middle of the Mediterranean, the schooner Tara is at the beginning of a three-year odyssey around the world: A 150,000-kilometre expedition to explore the largely unknown world of the oceans.

“Ninety per cent of the biological mass of the oceans is made of plankton,” explains Spanish marine biology researcher Silvia Acinas, scientific co-ordinator for Tara.

“These organisms are responsible for absorbing 50 per cent of the CO2 emissions on the Earth and producing 50 per cent of the oxygen we breathe, but we only know one per cent of them: This expedition is about discovering the remaining 99 per cent.”

The uncertainty of current climate models has a great deal to do with this unknown life. As a matter of fact, oceans are the major factor influencing climate, working as carbon pumps to a greater extent than rainforests do.

Every other day, the boat stops for a 12-hour scientific station. Pumping, filtering, sorting and labelling: The five researchers on board have a long day ahead of them. More than a thousand litres of sea water is pumped on board and filtered in the wet lab to separate the different kinds of sea plankton — viruses, bacteria and protista.

At the back of the boat, the oceanographic winch allows sea water sampling of up to 2,500 metres in depth, thanks to the special Niskin bottles.

“A very ingenious device, because their lids can be closed at a given depth taking samples at an exact point of interest,” explains French ocean engineer Hervé Le Goff.

The plankton on the surface of the water will not escape the meticulous scientists either. Nets a few metres long are thrown from the back of the boat. For some minutes they trail behind the boat like giant jellyfish, under the impatient eyes of the researchers, before being pulled back up and sampled. Other scientific equipments, such as the STD are sunk to measure temperature and salinity and study the currents.

A few hundred samples are carefully labeled and preserved either to be analyzed in the on board dry lab or to be sent to the research centers on land. Every eight weeks a special parcel is sent in extremely rigorous conditions of temperature and time to get the planktons to destination safe and sound. This ambitious expedition will lead to the creation of a world-wide database of planktonic forms of life, along with supplying a great deal of information on currents, corals and pollution. But just as sampling is time-consuming, research also takes patience. The results of this extraordinary expedition will not be known until a few years after its end.

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