A drop in the ocean

A drop in the ocean Tara under full sail
©F. Latreille

As Tara’s distinctive orange nose plunged in and out of the crashing waves, the team – among them, EMBL scientists – worked against tiring conditions to record variables such as acidity, temperature and currents, and sample the water and its tiny occupants in order to deliver an illustration of the biodiversity beneath their feet.

The main goals of the two-and-a-half-year Tara Oceans expedition, which came to an end on 31 March 2012, are to understand more about the function, evolution, and ecology of marine species, analyse the effects of climate change on marine biodiversity, and to increase general awareness about environmental issues.

Just one percent of life forms in the sea have been properly identified and studied. By using advanced instruments that enable extensive sampling, sorting, underwater sensing, and imaging, the project aims to change this. Samples collected – from the surface, down over 1000 meters below to the mesopelagic region, or the ocean’s ‘twilight zone’ – will enable researchers to learn more about the billions of viruses, bacteria, and larger organisms present in each litre of seawater, providing crucial data on different species, their interactions, and genomes, for scientists in fields as diverse as ecology and molecular biology.

In this podcast you can hear how and why the expedition took place, what life was like at sea, and how scientists managed a global operation covering 60 000 nautical miles and stopping in more than 50 ports around the world.


  • Genomics

    Samples taken on the expedition were separated according to the size of organisms during collection at each station. Comprehensive sequencing of genetic material for each fraction follows. Some of the major challenges scientists have to overcome in analysing these genetic sequences include the diversity of organisms and hitherto unknown genes. Scientists in the Bork group will support and develop sophisticated bioinformatic analysis to help overcome these hurdles and make the most of the genomic data.

  • Evolution

    Ecosystems in the oceans differ remarkably from place to place and are structured by rotating currents, or gyres, generated by changes in temperature, the rotation of the earth, and the position of the continents. The extent of mixing between surface layers and the deep ocean also varies dramatically. Scientists in the Arendt group will be studying how these interactions might have influenced the evolution of some of the most primitive marine organisms.

  • Imaging

    Scientists led by Rainer Pepperkok are using technology to quantitatively analyse organisms between 5 and 200 microns in size, and developing methods to automatically recognise and count different species in the samples. Utilising advanced high-throughput fluorescence microscopy equipment and expertise at EMBL, scientists can pinpoint  features and even molecules in the cells or organisms, and follow their every move.

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