In what sense is the ocean “a public good with no price tag”, as you once said? Is this why bluefin tuna, for example, is considered as a “free resource”, although it is a threatened species?

Yes, a plant that is gathered or a species that is captured belongs to the person who goes looking for it. It is clear that this is not an economically sustainable system in the long term. Therefore, it has been proposed to give a value not only to ecosystems but also to the species that can be found in them. There is a real fight to be fought to ensure that every species - from bluefin tuna to sardines to deposits of fossil shark teeth in New Caledonia – is included in a resource management system.

Are decision-makers starting to be sensitive to these issues?

Yes, they are. Moreover, countries are as well, countries which are ready to set values for resources. People who have economic activities in common are becoming organized in cooperatives or in companies, which have the sole rights to make use of certain ecosystems. Because of course, when people own an ecosystem, they will protect it much better and protect the resource much better. While this is easy to explain for coastal waters, it is much more difficult for the open sea. I am especially thinking about the deposits of polymetallic nodules, those pellets rich in metals which cover seabeds at abyssal depths.

Why?

Those who have the means to go and search for them will tend to consider that they own them. You see why we must legislate in order to impose the payment of royalties for drawing on resources, with the royalties reinvested in the protection of these ecosystems and in their long-term intelligent and sustainable management. Fishing cooperatives in Japan are an example of this type of management, which in return gives the right to control the management of the resource.

How can we assess the number of species and their rate of disappearance?

We know the number of species that are in museums, i.e. just under two million. But there are many “synonyms”. This is the case when someone describes a species under one name and when this person has not carefully checked that it has not already been described elsewhere. How can we estimate the number of species that we do not know? By doing very accurate inventories. You enclose one square kilometre of forest in Borneo or in the Amazon, for example; then you count everything and sequence everything. It is the same at sea: you take one cubic metre of seawater, remove the fish, filter everything under two microns and sequence all the DNA to be found. Wherever you are, you find approximately 20% of known species and 80% of unknown species: therefore, there are at least five times as many species. In fact, this means that there are between 10 and 30 million unknown species, as we think that many of them slip through the net. This is in fact a problem for us when we discuss the issue with officials, who remind us how ignorant we are about the number of species. And if microorganisms, microbes and bacteria are included, it is even more complicated.

Do we have an idea of the number of species which have disappeared?

It is estimated that there have been two billion species since life began.  Between 1% and 1.5% still remain, while the others have been naturally eliminated. Today, we are making them disappear at a rate that is 1,000 times higher than during the last 100 million years, according to the calculations of palaeontologists. Normally, one species in 1,000 disappears every millennium. But in the 20th century between 600 and 1,000 times as many species disappeared as might have been expected, according to the Millennium Ecosystem Assessment (MA).

(*) Millennium Ecosystem Assessment (MA): a report drawn up in 2005 by 1,360 experts from all over the world at the request of the United Nations. The objective of the Millennium Ecosystem Assessment was to assess the consequences of ecosystem change for human well-being. This assessment also had to establish the scientific basis for the implementation of the action required for improving conservation and the sustainable use of these systems.