Tara: a major player in the scientific research on marine ecosystems

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Tuesday, September 26 : Tara and its orange masts slipped in the city’s harbor where they are about to moor for more than a week. The schooner whose captains used to be Jean-Louis Etienne and Sir Peter Blake arrives from New York after a few days of eventful sailing.

The Tara schooner in the Boston harbor

© Céline Belanger / Tara Expeditions Foundation

Tara is the flagship of Tara Expéditions, funded by Etienne Bourgois at the instigation of agnès b., a renowned French fashion designer. The foundation aims to promote marine ecosystem protection against climate change. To this end, Romain Troublé, who is at the helm of the foundation since 2004, set three different targets:

  • A scientific objective: enhancing our knowlege about oceans and marine ecosystems ;
  • An education objective: communicating about oceans and climate change impacts, especially to the youth;
  • An advocacy objective: raising awareness among policy-makers about marine environmental protection.



I. Raising awareness among young people:

Eric Karsenti’s conference at the International School of Boston.


On the 27th of September, Eric Karsenti, a French cell biology researcher, gave a conference at the International School of Boston to 11th and 12th grade students. Eric Karsenti is the scientific director of the Tara Oceans expedition as well as a very experienced sailor. He was also awarded the CNRS Gold Medal in 2015, the highest scientific distinction in France.

For this lecture, Eric Karsenti was not coming alone: two TV journalists from France 2 - who will broadcast a report about the scientist and Tara in the next few months - and Céline Belanger, onboard reporter, were accompanying him. Through amazing pictures, Eric Karsenti introduced students to the unknown yet beautiful world of plankton.

Eric Karsenti and the students from the ISB’s Upper School

© Céline Belanger / Tara Expeditions Foundation

Plankton can be divided in two categories : zooplankton and phytoplankton.
The former consists of tiny marine animals such as copepods as well as huge ones like jellyfish or siphonophores. Their common feature? They all feed on bacteria, protists or other multicellular organisms.
The later, phytoplankton, is very diverse. It can be bacteria or protists. Most of them are unicellular organisms that are photosynthetic. They alone produce half of the oxygen on the planet and absorb half of the CO2. They are the submarine lung of the Earth ! Along with cyanobacteria, they are the base of the food chain. Consequently, they are major regulators of climate change.

Tara on the Science’s frontpage (22/05/15)

© C. Sardet/TARA OCEANS/CNRS Photothèque

In addition to plankton, oceans are filled with bacteria and viruses that scientists onboard Tara also collect.


II. Discovering Tara: an exceptional lab.


On the 27th of September, Eric Karsenti and Chris Bowler - CNRS Research Director at the Institute of Biology of the Ecole Normale Supérieure and scientific coordinator of Tara - welcomed Yves Frenot, Counselor for Science and Technology at the Embassy of France in the United States in Washington, DC. The objective of the meeting was to present Tara, the research conducted on board and the lobbying activities that the foundation carries out to international insitutions like the United Nations.

It was also a great opportunity to discover the boat and her unique architecture (she has a rounded hull) but also the different measurement instruments and her two labs - the dry one (inside) and the wet one (on the deck).

Tara has developed different data collection and observation methods:

  • Scientists can use nets, whose mesh have different sizes depending on the types of organisms that they look for. The "manta net" is used to collect plastics on the surface of the water. Most of these nets are very fragile. Sailors must pay attention to the boat speed when these nets are towed in the back of the boat.
  • The schooner is also equipped with a peristaltic pump. It can pump seawater filled with billions of different organisms in water depths between 10 and 120 meters.
  • A "rosette " - an assembly of a Conductivity-Temperature-Depth measuring device and 10 sampling bottles - is located at the bow of the boat. It weighs 250kg and is made of aluminum. It is a key scientific instrument on Tara. It can collect water at different depths and has several sensors to measure pressure, temperature, conductivity, nitrogen and oxygen levels and fluorescence while diving to the seabed. In addition, an imaging sensor, the Underwater Vision Profiler (UVP), enables scientists to directly visualize underwater particles and organisms and even to identify them.

Infographics of some scientific instruments used onboard Tara published in Science (05/22/2015)


The data collection protocols are standardized. This is a sine qua non condition to be able to compare and analyze the data between different places. All the samples must be stocked in freezers that are located at the bow. It requires a lot of space - especially for coral samples - and electric power. Every six or eight weeks, during stopovers, these samples are sent to partner laboratories when possible. The expedition also has to manage and treat waste produced by scientific activities, some of which are highly toxic. This requires an advanced technology that is not always available during some stopovers. In these cases, the crew has to keep waste on board.

Discover the schooner and some members of the crew HERE !


Tara Captain Martin Hertau (on the left) and Eric Karsenti (on the right) in front of the « wet lab ».

© Nadia Benallal



III. The future of Tara Oceans: scientific discussions and outlooks


As part of Tara’s arrival in Boston, a scientific workshop was hosted on the 2nd of October by the renowned Radcliffe Institute of Advanced Studies at Harvard University.

This workshop was entitled « The New Age of Ocean Discovery: Opportunities from Tara Oceans » and organized by Chris Bowler, RI ’17, and Colleen Cavanaugh, Edward C. Jeffrey Professor of Biology at the Harvard Faculty of Arts and Sciences. The objective for the participating scientists was to present and discuss research based on the data collected during Tara Oceans. Indeed, one of the scientific successes of this expedition was the data collected on an unprecedented scale on oceans, which has enabled researchers to develop extensive databases of samples and images.

Besides Chris Bowler and Eric Karsenti, two other French scientists also attended this workshop: Olivier Jaillon, researcher at the François Jacob Institute of Biology - Génoscope (Commissariat à l’énergie atomique et aux énergies alternatives, CEA), and Hélène Morlon, CNRS Research Director at the Ecole Normale Supérieure, Irène Joliot-Curie Award winner and CNRS bronze medalist. These two scientists are interested in the geographical structure of organisms collected by Tara, although from different perspectives. Hélène Morlon develops a comprehensive understanding of the geographical distribution of numerous species, focusing on different factors - currents and environment for example - influencing this distribution. She also attempts to trace the history of species diversification through a phylogenetic analysis. Thus, she echoed Olivier Jaillon’s presentation about genomic biogeography. The genome sequencing of samples collected during the expedition was made by Génoscope which demonstrated the richness of marine biodiversity that was until then totally underestimated. This shows how crucial the research conducted onboard Tara is, as reflected by all the academic articles published in renowned reviews such as Nature and Science.

The objectives of the discussions that followed the presentations were to share knowledge about the different collected data sets and to exchange about available data analysis technologies. This workshop was the occasion to underline the broad scope of knowledge that scientists still need to acquire about marine environments, especially on ocean biodiversity. Tara’s role in this scientific conquest is decisive.

Alyssa Goodman, Robert Wheeler Willson Professor of Applied Astronomy, introduces Eric Karsenti’s conference that was part of a science lecture series entitled « The Undiscovered » at the Radcliffe Institute of Advanced Studies.

© Anne Puech


After this workshop, Eric Karsenti gave a lecture entitled ’Tara Oceans : Cells, Embryos and the Origins of Complexity in Life’. This conference was open to the public and introduced by Alyssa Goodman, Co-Director for Science at the Radcliffe Institute for Advanced Studies. She described the significant number of genes that are still unidentified as an "invisible multitude" and a "dark matter of the oceans" which caused a sensation.

Eric Karsenti giving a public lecture at the Radcliffe Institute.

© Céline Belanger / Tara Expeditions Foundation

Eric Karsenti took the opportunity to share some thoughts about his research path. All along his professional career, he successfully contributed to the understanding of molecular mechanisms that control the cell cycle, that is, cell division and embryogenesis mechanisms. He very recently recounted how diversity of living systems skyrocketed in the oceans during almost 3 billion years in his last book Aux Sources de la vie (At the Sources of Life). Eric Karsenti also presented the research conducted on board and the knowledge acquired during the Tara Oceans expeditions that he directed from 2009 to 2013.

Drawing inspiration from Kant as well as in Darwin’s travel stories, Eric Karsenti and his crew remind us of naturalist 19th-century expeditions, highlighting how much the scientific discovery is also a human, artistic and philosophical adventure.

From left to right: Eric Karsenti, Martin Hertau – Captain, Nicolas Bin – First Mate, David Monmarché – Dive Master, Charlène Gicquel - Head Mechanics, Clémentine Moulin – Logistics Manager and Sophie Bin – Chef.

© Anne Puech



IV. Tara’s expeditions across all the oceans of the world


Since 2003, Tara has already completed 11 scientific expeditions.

Tara Arctic. From September 2006 to February 2008, the schooner stayed in the Arctic ice. The objective was to drift with the ice, nearly a century after the exploit of the Norwegian explorer Fridtjof Nansen in 1893 with the Fram, and to conduct observations on ice packs, oceans and atmosphere at the North Pole and in the Arctic. These studies aimed to improve our understanding of the effects of climate change on this very specific environment. With its aluminum round hull that solidies with cold, Tara drifted on almost 1800km, captained by Expedition Leader Grant Redvers.

Tara in the Arctic ice

© Tara Expeditions Foundation

Tara Oceans. From September 2009 to December 2013, Tara made a round-the-world 50-stopover expedition in order to study impacts of climate change on plankton and coral ecosystems that play an essential role for the planet and human life. This expedition generated an invaluable amount of data that has improved climate change modelling. Indeed, 80% of marine genes that are now in databases – of which 80% are still unknown – were collected aboard Tara. This expedition also raised awareness about how dangerous plastics are for the oceans. When it crossed the Antarctic in January 2011, the schooner collected between 956 and 42,826 plastic pieces/km in this very isolated part of the globe.

Tara Mediterranean. From May to November 2014, Tara set sail on the Mediterranean Sea to better understand the scale and the impacts of plastic pollution on this very fragile yet extremely busy environment. During this expedition, Tara also promoted awareness of environmental challenges along the Mediterranean coasts where 450 million people live in order to encourage them to better protect these fragile marine ecosystems.

Tara Pacific. From May 2016 to October 2018, the schooner sailed in the Pacific Ocean to explore resistance, adaptation and resilience capacities of coral reefs to climate and demographic changes. From Wallis-et-Futuna to Clipperton via Japan, scientists collected valuable information for a better understanding of corals. After this last stopover in Boston, the schooner went back to Lorient – her home port – on the 27th of September.

Map of Tara PACIFIC expedition (2016-2018).

© Tara Expeditions Foundation



V. Make Our Planet Great Again: a successful initiative in the United States.


On June 1st 2017, the President of the United States Donald Trump announced the US withdrawal from the Climate Paris Agreement adopted in December 2015. The following day, President Macron launched the « Make Our Planet Great Again » initiative. It was a call to researchers and students, entrepreneurs, associations and NGOs, students and all civil society to mobilize and join France to lead the fight against global warming.

To that end, a specific online platform was created: makeourplanetgreatagain.fr. This was very successful in the US: more than half of the application came from American researchers and students!

An exceptional financial support was put at the disposal of some embassies, like the Embassy of France in the United States, to support the development of this initiative. Thanks to this financial input, joint research projects between French and American teams on climate were reinforced, new collaborations were developed and transatlantic student mobility was strongly encouraged. This fund also enabled the Office for Science and Technology to support the organization of Franco-American events on environment and climate change.

It is within this context that the scientific workshop « The New Age of Ocean Discovery: Opportunities from Tara Oceans » was organized on Tuesday, October 2 at the Radcliffe Institute of Advanced Studies.


Author: Paola Tanguy.