28 November 2017
Six researchers constitute the new scientific team aboard Tara on a leg called “Biodiversity and Interactions”. All hope to discover new species during repeated underwater explorations in 4 major regions of Kimbe Bay (Papua New Guinea). Some of the scientists hope to reveal the secrets of chemical interactions between species; others would like to discover new molecules useful in human health. Whatever their specialty, they are already busy under water but also on board, in front of a lab bench or a gene sequencer.
Scientific director of this new leg and marine biologist at CRIOBE, Emilie Boissin has been on board for several weeks. She’s the only one remaining from the former team. Before the new scientific members even set foot on deck, Emilie described the purpose of this mission which is slightly different from other legs of Tara Pacific: « We are sailing in the Coral Triangle, extremely rich in marine biodiversity. Probably many of the species here are still unknown. We will inventory the little-studied groups such as hydrozoans, brittle stars and sponges. We’ll also try to genetically identify the coral species in the laboratory on board, because a simple morphological observation is often not enough. We hope to obtain genetic confirmations in real time, using a small DNA sequencing device called MinION ».
Beautiful crinoids on a sponge - © Jonathan Lancelot / Fondation Tara Expéditions
At the introductory meeting that opened this new scientific chapter, Emilie pointed out the exploration zones on a map including Kimbe, Kapepa and Restorf Islands. Everyone then discussed the reasons for their presence on the schooner. Julie Poulain, engineer at the Genoscope and a “regular” aboard Tara, piqued the curiosity of Taranauts by unveiling the famous DNA sequencer: “Smaller than a smart phone!”
Bernard Banaigs, researcher at INSERM, immediately added some humor: « You’re lucky to have 2 chemists aboard Tara, Olivier and myself, 2 barbarians. We’ll first focus on the target species Millepora platyphylla by studying the competition that exists with other corals. Observations show that Millepora platyphylla protects itself quite well from competitors for space. We want to understand the influence of its neighbors on the defense molecules produced by this species. In the marine environment, an intense chemical warfare is going on at all times. To fight against competitors, predators or colonizers, Millepora releases a whole bunch of molecules to protect themselves, creating a chemical shield of sorts! We will try to understand if these defense molecules could be interesting for human health, plant protection or anti-fouling ».
Small green and pink ascidia attached to a sponge – © Jonathan Lancelot / Fondation Tara Expéditions
To date, only 10% of marine biodiversity has been catalogued of all species combined: 200,000 species out of a total estimated at 2,210,000*. By looking more closely at only the cnidarian group which includes corals, hydrozoans and jellyfish, 9,795 species have been catalogued, but no global estimate has been made for cnidarians. The oceans have not finished revealing their riches to contemporary explorers.
Emilie Boissin says the Taranauts will have to open their eyes and pay attention to each form of life — « since even what might look like a known species at first sight, may not be one ».
*Brett R. Scheffers, et al. (2012), What we know and don’t know about Earth’s missing biodiversity, Trends in Ecology & Evolution.