A significant portion of Earth’s biodiversity, around one million species, resides in the ocean, with the majority yet to be discovered in the deep sea.
The deep sea and its biodiversity play a key role in ecosystem services, such as climate regulation, fish production and the elemental cycle.
Deep-sea mining, which could seriously and irreversibly harm marine ecosystems and have lasting consequences for the health of the Earth, could be given the green light to begin in 2023.
“By Hercules! In the sea and in the ocean, vast as it is, there is nothing that is unknown to us, and, truly marvelous, it is of those things that nature has locked up in the depths that we know the better ! Pliny the Elder, 40 AD
Pliny then listed only 176 species. Two thousand years later, we are only just beginning to realize that his statement was not only incorrect, but also echoed the complacent ignorance of the time.
Estimates now suggest that a significant proportion of Earth’s biodiversity, around one million species, resides in the ocean, with the majority yet to be discovered in the deep sea. Although we know more about the deep sea than ever before, despite centuries of research, our knowledge of these mysterious depths remains limited.
Time and again, as we explore and study the depths of the sea, we encounter species, habitats and ways of life that are beyond our imagination. From hydrothermal vents gushing super hot black fluid to giant glass sponges thought to be thousands of years old, and animals that communicate via flashes, pulses and glows.
The deep sea plays a vital role in the health of the Earth
This richness and diversity of organisms in the deep sea supports the ecosystem processes necessary for the functioning of the Earth’s natural systems. The deep ocean also constitutes more than 90% of all living space on the planet and plays a key role in services such as climate regulation, fish production and the elemental cycle. It is an integral part of the culture and well-being of local communities and the seabed is part of the global commons, which belongs to everyone on the planet and to everyone to come.
The more we marine scientists learn about the complexity and importance of life in the deep ocean, the more we realize the great peril it faces. Deep-sea ecosystems are subject to a number of human stressors, including climate change, destructive bottom trawling and pollution. And new threats are on the horizon.
Deep sea mining, a new industry that could be given the green light to start operating as soon as 2023, will add to these constraints. This could lead to loss of deep-sea biodiversity and disruption of ecosystem functioning and services that could last for millennia, or even be permanent.
The risks of deep sea mining are not fully understood
Compounding these concerns about the risks of deep-sea mining, a recent study has revealed how little experts know about the parts of the planet already leased for mineral exploration and how they could be affected by mining activities. . In fact, 57.8% of the scientific categories assessed for regions with mineral exploration areas were shown to have no or almost no scientific knowledge for evidence-based management. Only 1.1% had had enough. Without information on the environment, biodiversity and ecology, the potential risks of deep-sea mining to biodiversity, deep-sea ecosystems and functioning, as well as human well-being, cannot be fully understood.
The United Nations Decade of Ocean Science for Sustainable Development, launched last year, provides an opportune time to gather more information on species and ecosystems that could be affected by deep sea mining – before and not after the start of this industry. As scientists, we deeply value evidence-based decision-making, especially in such important cases as a global decision to open up a whole new ocean frontier to large-scale industrial resource exploitation. .
The very importance of the ocean to our planet and its inhabitants, and the risk of permanent and large-scale loss of biodiversity, ecosystems and their functioning, necessitate a pause from all efforts to begin mining of deep seabed. Unlike Pliny the Elder, we must recognize that we are far from having all the answers about things hidden in the depths, and instead take intelligent precautions and accelerate independent research, in order to better understand what is really in Game.
Douglas McCauley, professor, University of California at Santa Barbara; Member of Friends of Ocean Action; Director, Benioff Ocean Initiative
Diva Amon, Science Advisor, Benioff Ocean Initiative, University of California, Santa Barbara