After four years of research, the DNA map of the world’s oceans has been finally completed. The framework is the result of an international expedition Tara-coordinated by the French National Research Council (Cnrs)-which also saw the participation of Italy with the “Stazione Zoologica “Anton Dohrn” in Naples. Since 2009 up to 2013, the scientific expedition has studied thousands of micro-organisms, which have been collected in 210 different oceanic sites. The immense work conducted has identified 40 million genes, almost all unknown, and 35,000 new species have been catalogued in a huge database which is freely accessible.
The first results, published in the Science journal, have made it possible to bring to light some fundamental mechanisms of this oceanic ecosystem, of primary importance in the food supply chain that can affect global climate and produce half of the world’s oxygen. One of the major discoveries about the temperature of the seas which has a profound influence on the species of organisms moving in depth. Off South Africa , a sort of natural barrier tht separates the cold from the warm currents of the Atlantic and Indian ocean has been discovered. “It is as if the plankton passes through a cold wash cycle,” said Daniel Iudicone, a research-worker of Anton Dohrn. “The currents-he says-form huge water-swirls that mix and cool the plankton carried, thereby limiting the number of species that manage to cross it”.
Translation provided by Marina Stronati