Behind the expression "high seas" lies an imaginary world for most of us. Reserved for adventurous sailors, ocean-going captains, deep-sea fishermen, scientists and oceanographers, and military sailors,....the High Seas are more a concept than a place to live for ordinary mortals. And yet, it is in the High Seas that most ocean-atmosphere interactions are played out: representing 43% of the earth's surface, the High Seas conceal treasures of biodiversity that enable the atmosphere to be viable.

The threats

These areas, long protected from human aggression because they are inaccessible, are now endangered by over-fishing, rising ocean temperatures, and plastic, chemical and noise pollution. In terms of CO2 alone, the high seas have trapped 25% of the carbon produced by man over the last 20 years. The ocean stores 10 times more carbon than vegetation. These exchanges of carbon between the Ocean and the Atmosphere take place either directly at the surface (waves, storms, etc.) or indirectly through the submarine biodiversity (plankton and other fish) present at all depths, including the abyssal plains.

These High Seas are threatened by 5 factors:

• Overfishing: increasingly efficient boats, technologies and methods are increasing fishing volumes. Although the high seas only provide a little over 10% of the world's total catch, this fishing generates considerable stress on certain species, such as tuna and cetaceans.
• Mining: known through the craze for poly-metallic nodule harvesting, this type of exploitation endangers the eco-systems that develop along seamounts and volcanoes, such as the " lost city". The dangers of this type of mining include habitat destruction, toxin release, chemical and noise pollution...
• Bioprospecting: the harvesting of natural resources for the needs of certain industries, such as cosmetics or food.
• Climate change: the ocean absorbs as much CO2 as all plants. This may sound like good news, but in reality, this carbonate concentration is changing the chemical composition of the oceans, making them more acidic and increasing the size of their low-oxygen zones.
• Chemical, noise and plastic pollution: well-documented, these pollutions are dramatic for the survival of certain marine species.

To protect the High Seas, the United Nations has launched negotiations with states to establish a binding international treaty for the protection of international maritime zones. For the first time, scientists have drawn up a report advocating the establishment of a network of marine parks, or marine reserves, to protect their biodiversity. Like the ecological bridges on our freeways, this network would enable the free circulation of marine species in marine corridors.

What's interesting about Greenpeace's approach is that it takes into account the need to continue exploiting the oceans, but with greater emphasis on observation methods for their impact on biodiversity within the oceans, which is still relatively unknown at this stage. The criteria for the creation of these marine parks are oceanographic (temperature, currents, etc.), biophysical (seamounts, thermal vents, complexity of the seabed, etc.), biological (population of certain species, rays, sharks, tuna, etc.) and biogeographic (abyssal plains, proximity to the continental shelf, etc.). Based on these criteria, Marxan, a benchmark software package in the field of environmental protection, has made it possible to establish strategic deep-sea sites.

The network of marine reserves

Most of these sites are not independent of one another, particularly in terms of marine mammal migration. They had to be interconnected to ensure their integrity and persistence, while preserving economic exploitation zones as far as possible. As a result, only 22% of current fishing grounds have been relocated.

We can help the UN to be stronger in the face of the States and succeed in setting up these marine reserves on the high seas. Greenpeace is asking us to sign a petition to help this project succeed.