Tara Oceans schooner. IMAGE: J.Girardot/Tara Expéditions
EMBL's Eric Karsenti joins Ban Ki-Moon on Tara's bow. IMAGE: J.Girardot/Tara Expéditions
Telling the story of life – its past and future
Life began in the ocean. It tells the story of how the most complex organisms evolved from primordial bacteria and it will tell us about the fate of the myriad organisms present today. As the oceans are the largest cohesive eco-system on earth the insights that researchers will be able to derive are crucial not only for the preservation of mankind but also of our planet.
Plankton and the climate
Plankton’s importance for the earth’s climate is at least equivalent to that of the rainforest. Yet only a small fraction of organisms that compose it have been classified and analysed. Tiny organisms are collaborating in huge numbers for maximum impact, absorbing CO2 and releasing O2 back into the atmosphere. What are they, how do they function, and why does it matter?
Plankton ecosystems contain a phenomenal reservoir of life: more than 10 billion organisms inhabit every litre of oceanic water, including viruses, prokaryotes, unicellular eukaryotes (protists), and metazoans.
The extreme turnover rates and complex biotic interactions that characterise plankton as compared to terrestrial or benthic marine communities, make plankton ecosystems a natural cyclotron for life, accelerating the pace of evolution/selection of fundamental metabolisms and phenotypes, and thus of organisms that transform matter and energy on a planetary scale. Moreover, the efficient symbiosis between plankton and scleractinian corals is a pivotal interaction for the growth and maintenance of coral reefs, known to harbour the highest benthic biodiversity in the oceans.
We currently know very little about plankton ecosystems, their evolution, and the critical roles they play in Earth's chemical, ecological and climatic states. Yet they represent an enormous but largely untapped source of unique organisms and bioactive compounds relevant for bio-industries involved in pharmaceutics, nutrition, cosmetics, bioenergy and nanotechnology. The dramatic lack of knowledge on plankton biota has hindered the development of this kind of applications as well as our understanding of this major earth ecosystem.
Tara Oceans expedition
On 31 March 2012, the schooner Tara – equipped with technology for sampling an 11 organism size-range covering entire plankton communities from viruses to animals, and benthic diversity in coral reef ecosystems – came back to her home port, Lorient, France.
During the two-and-a-half-year expedition, high quality and standardised genetic (total DNA/RNA), morphological, and physico-chemical (contextual) samples from 210 stations across the world oceans were collected. The sampling locations were carefully selected using near-realtime remote sensing, numerical models and in-situ hydrographic criteria.
A team of international scientists is currently analysing samples from this €10 million public/private scientific expedition (Tara Oceans 2009–2013): the total of ~35,00 biological samples and ~13,000 contextual measures from three depths constitutes the largest modern-day worldwide collection of plankton sampled 'end to end' around the world. Metagenomes and meta barcodes from stations are being built as well as well as quantitative and high-resolution image databases. Genomics data are published as soon as they are validated at EMBL-EBI, correlated with . The Tara Oceans consortium has a fast release policy of data.
EMBL and Tara Oceans
The scientific activities of the Tara Oceans expedition, led by EMBL senior scientist Eric Karsenti, present an unprecedented effort that resulted in 35,000 samples containing millions of small organism collected in more than 210 ocean stations, chosen for their climatic significance or biodiversity. Putting to work its extremely advanced microscopy facility, analysing the genetic sequences of all organism with sophisticated bioinformatics tools, and explaining the story of life through surprising opportunities in evolutionary biology, EMBL is putting the crowning analysis on top of one of the most ambitious projects of our time.