Exploring the depths of the ocean used to be the stuff of science fiction novels. But now more than ever, tools and technologies are providing oceanographers with increasing opportunities to go sleuthing for new scientific breakthroughs on the seafloor – though there is still much to be discovered.
The deep ocean – or deep sea – stretches from 200 meters under the surface to the bottom of the Mariana trench, almost 11 kilometres below sea level. Although it covers two thirds of the Earth, less than one per cent of the seafloor has been monitored by scientists. The deep sea has also gone unnoticed in current international oceans treaties – partly because of the lack of available data on the seafloor, which make conservation efforts difficult.
Why ocean exploration matters. From new species to carbon sequestration, deep ocean ecosystems have a lot to offer, says Lisa Levin, professor of oceanography at the University of California, San Diego, speaking ahead of a cross-sector policy event on the topic of biodiversity and ocean conservation and organised by UNESCO’s Geneva Liaison Office, Microsoft Corporation’s United Nations Affairs team and The Graduate Institute.
“Most of the planet is ocean, and most of that is deep sea. It’s the biggest habitable area on the planet, and as a result, it’s a huge moderator of our climate: it takes up excess heat and carbon out of the atmosphere and controls the temperature that we experience on land.”
Oceans naturally act as carbon sinks: upon meeting the surface, carbon dioxide dissolves into the sea, and then sinks to deeper waters – thereby absorbing most of the excess heat generated by human activity. Around a third of global CO2 human emissions since the Industrial Revolution have been stored in the seas through this process.
Deep ocean ecosystems also play host to a variety of species, with new medical applications now emerging thanks to organisms living deep under the surface.
A derivative from a fluorescent protein found among amphioxus, a marine invertebrate living up to several dozen meters under sea level, was for instance used in the development of the Pfizer/BioNTech vaccine against Covid-19. Other studies have shown deep sea bacteria having promising anticancer effects.
And the best is yet to come, according to Levin: “There are other industrial solutions provided by deep sea genetic diversity, different enzymes that can do everything – they can break down lipids in cold water, sequester carbon, provide bio-inspiration templates for everything from artificial human blood to bone grafts. … And I think, really the deep ocean has the solution to problems that we don’t even know we have yet.”
A crucial role for technology. These discoveries were made possible thanks to major technological improvements in the last 20 years. When exploring the bottom of the oceans, today’s oceanographers use unmanned underwater vehicles called ocean gliders. Equipped with acoustics receivers which record the sounds emanating from schools of fish, these can be used to locate fish populations.
The real game-changer came with telemetry, which allows data and images to be sent directly from the exploratory devices: “That sort of changed the way we do science: rather than having the three people on the submarine at the bottom of the ocean, or maybe the fifteen people on the ship, we can have a hundred experts looking at an image, in real time, and telling us what it is, what we should collect and how to interpret it”, Levin explains.
But one major obstacle remains: “even though we’ve learned a lot in the last half century, we’ve still not seen most of the deep ocean, and our data are very sparse”, Levin says.
The Ocean Biodiversity Information System, an information platform that offers the most comprehensive open-source data on the deep ocean, is a perfect illustration of this lack of data: under 500 metres below sea level, most of the ocean is still missing on the world map.
And it is precisely the lack of data which has made conservation efforts as well as tracing the impact of climate change difficult in the deep ocean, as explained by Levin, speaking at the UNESCO event: “Climate change is going to interact with human disturbance in the deep sea, and data are needed for both of these, to manage the oceans and to promote deep ocean sustainability.”
New regulation – and the need for more. A new treaty is currently being discussed at the UN to bridge the gaps left by the 1982 UN Convention on the Law of the Sea. Establishing guidelines to manage the world’s oceans, the Law of the Sea put the International Seabed Authority in charge of the sea floor, while fisheries were left to the Food and Agriculture Organisation – but everything else was left unregulated, according to Levin.
Focusing on biodiversity conservation in international waters, a new Biodiversity Beyond National Jurisdictions treaty, which will amend the Law of the Sea, is set to be adopted this summer. Postponed because of the pandemic, the fourth and final stage of the negotiations will take place from 17 to 21 August.
Read also: Charting a new path to protect the high seas
Though the amendment will help in regulating marine ecosystems – safeguarding potential future biochemical applications of deep sea organisms – it falls short on another subject, according to Levin: climate change. “The UNFCCC, which is the big climate instrument in the Paris Agreement, really focuses on what states control. And the states mainly control activities within their Exclusive Economic Zones (EEE) and on land. But mainly, anything related to climate and climate impacts and the oceanic emissions in the international ocean isn’t covered under any treaty. And it’s not going to be covered under the biodiversity treaty either.”
The UN also launched the Decade of Ocean Science for Sustainable Development, this year. And Levin has her own idea of what it could lead to: “If you could just have anything, wouldn’t it be nice to have an international fleet that any country could use, without having to pay to maintain the really high technology all by itself? Most countries can’t afford to have deep sea vessels that go out – you know, it’s expensive. So it’d be wonderful to have a United Nations fleet that services, especially, the international waters, where nobody is really responsible for them.”