22 May is the International Day for the Biological Diversity (IDB), proclaimed by the United Nations in 1993 to mark the entry into force of the Convention on Biological Diversity, signed in Nairobi. For several decades now, experts have shown that biological diversity is an essential resource for the planet and an immeasurable wealth for local economies. To date, 1,700,000 living species including animals, plants and micro-organisms belonging to the various kingdoms have been described, but experts speculate that there may be as many as 13,000,000. A large proportion of species could be hiding in the oceans, which from the point of view of biodiversity are real treasure troves still largely unknown. Although water covers two-thirds of the planet’s surface, we have explored only 5% of it. Yet there is also another factor to take into account when we count the number of species on the planet: by the end of the century, 50% of living species in fact risk extinction and it is precisely in order to raise our awareness on this issue that the World Biodiversity Day was established.