Lights in the Deep Sea

Prof. Antje Boetius talks about the deep sea and our impact on the ocean.

There are fewer humans who have been diving in the deep sea than humans who have been to outer space. Antje Boetius is one of the deep sea explorers. We had the chance to get thrilling insider information about this uncharted area of our planet.

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I'm thriving for a deeper understanding. As a kid, I was so curious about how the earth and the oceans function, or how people function, and why things are the way they are. So to me, curiosity is the greatest force in my being and in my work. Inspiration is wanting to get a fuller picture, wanting to be close to the landscapes, the nature I love—which happens to be the deep sea and the oceans. Diving into a situation where most of my surroundings are unknown isn’t a threat, but inspiring. I'm taking a step into something that is not predictable to me, where there is an unknown and then step-by-step becoming a part of it.

Definitely the diving. We know that there are fewer humans who have been diving in the deep sea than humans who have been to outer space. And that's amazing to think, "Wow, I'm one of them". Those moments of diving and discovery just feel great. And then there are other moments in my career that were game-changing. I will never forget the moment I made a discovery about microorganisms that wasn’t understood, looking through the microscope discovering two types of microbes that interact to consume methane. It was such a special moment.

It begins with your entering the submersible, and then you and the submersible are put overboard. So when you go in you're very prepared, you know exactly what you’re there to do, what samples you have to collect, and so forth. At first, it’s very uncomfortable. It’s quite warm inside and sticky, and the waves are moving your around. So you’re happy when you start to sink. Then, at 50 meters all the technical checks begin happening, ensuring everything is watertight, and good with the gases. And then it's very calm, and you see the blue water, and the first fish swimming by. You look outside of the window, and then you see there is life around you.

When you sink down to the depths, you are basically sinking out of the sunlit zone. And so you're sinking through blue color after blue color, any sort of blue you can imagine, eventually to black. It becomes perfectly black. And when the photons are no longer present, then you encounter all of the fantastic deep-sea life with its own light - bioluminescence. And that's my favorite moment, because when you turn the lights off, you can see life shimmering all around you. Then you sink further. And when you are at two, three kilometers deep, then the water is entirely cleared out—almost no particles. And you encounter large squids and very weird deep-sea fish. And then as you come close to the sea floor, there is a lot of life again.

When you then turn on the lights and you see the sea floor, you see all the traces of life and you, you think okay now you're here, the sampling starts. And you count the time that you have—such dives are usually no longer than six to eight hours. And it’s never enough. You have two, three hours at the sea floor before you start rising again. And this time goes by far too fast because all you want is to look out the window. But you have to solve tasks. You have to describe and sample and give checkups back to the ship and those kinds of things. So it always goes far too fast. And then the dive is over, and you go up again.

Very early on when I was a student, I was invited to participate in a deep sea mission that really changed my life and my career because once I was out there at sea, and once I was able to see the sea floor with my own eyes—kilometers deep into the ocean and discover the strangeness of life and the different deep sea landscapes—I became absolutely convinced that this would be my profession. To understand this part of us that as humans we normally do not connect with. But early on I found out that our work as Marine researchers is much more than just describing and exploring. I started out as a student 30 years ago. And we saw traces of humankind everywhere. Be it the littering, be it the effects of climate change, be it the first experiments harvesting metals from the deep sea, remnants of fisheries, and other disturbances on the sea floor. There are so many changes that we humans have inflicted on the oceans, that I knew my profession would not only be exploring and admiring, but being an eyewitness to the changes we humans have caused, and then providing solutions that would inform our policies and relationship with the ocean.

I started my career with the whole question of carbon cycles and fluxes on earth. Back then, we were taught about this ever-increasing CO₂ concentration in the atmosphere and the threat that it meant for global warming. And to know that my entire lifetime scientists have been warning governments about this fact, and yet today, that it's increasing more than ever is disheartening.

However, with the recent pandemic, and with our suppressed energy consumption because of travel restrictions, we’ve seen the biggest impact humanity has ever made in changing the CO₂ path for the better. We can only hope that we learn from this and that we have a better solution for dealing with energy in the future, including switching to regenerative energies.

I will never forget my first expedition to the Arctic. My thinking had only been framed around the deep sea. And then I got to know sea ice as a habitat. That was in ‘92.

And then I was able to come back with the same ship and new technologies in 2012, which happened to be the period of largest ice melt since the onset of observations.

It was in the exact same region as during my PhD thesis. It was really shocking that during my lifetime this whole region had changed amazingly fast. It was so much warmer than the global average. The sea ice was much thinner. It breaks easier and melts really fast in the summertime. It's much warmer in the winter time in the Arctic than it ever has been.

To see how this affects every little bit of the Arctic from the atmosphere to the deep sea is really heartbreaking, because it means that from our energy usage alone, we are truly changing every place on earth, even places as remote as the North Pole.

Most people when you ask them would say I love the sea. I love being at the coast. I love the oceans. I want the waves to be protected. I want the penguins and the polar bears to be protected. And very often it’s disconcerting to them to realize that everyone is impacting the ocean already, and at a global scale. CO₂ we've already mentioned, but there are other parts that are more hidden.

For example, our everyday use of disposable plastics that leaves a big impact on the oceans because the oceans take in materials that are transported by the winds. They take in nanoplastics from the precipitation. And so the way we use plastics means that the ocean gets a tremendous amount of all of that.

Another hidden factor of our impact is agriculture. Agriculture happens on land, but the nutrients that we put into the fields, the fertilizers, they eventually make it into the ocean through rain and rivers. So the seas are getting far too many nutrients, and we have impacted the nitrogen cycle—more than even the carbon cycle. And that changes the health of the seas and coasts, and can cause toxic algae and other degradation of the environments.

Then of course there is the food. What few people know is that we rely more on aquaculture than on wild fish for seafood. And that comes with consequences. Aquaculture, if it's not done in a very sustainable way, destructs, for example, the mangroves or sea grasses or fjords or places where high density of fish are kept together. Antibiotics are dumped into the sea. We get anoxic areas.

So the list of how we all, in our everyday life, impact the oceans is unfortunately quite long. And it seems like we don't have a choice. It feels like no one can directly influence change with their own behavior. The fate of the oceans then relies on a political solution. We need other rules, other ways of getting to our nutrition, other ways of using materials, other ways of using energy.

Well, it's not so clear. Most people will describe perfectly how much they love oceans, but it's just not enough. We have a global economic and political system that doesn't favor the protection of nature. It favors its destruction. So we need first to fix those behaviors and frameworks that punish the good deeds and favor the bad.

Honestly, first there are the worries. The predictions that we have for 2100 is we’ll have lost 99% of our coral reefs due to bleaching, due to a warmed ocean. We’ll have a summer, ice-free Arctic. The climate change threats or the destruction of species and habitats may have become so large that our own health will be at risk.

And so, the hope for me is that what we are already experiencing now—the combination of knowledge, technical and social solutions, and the feeling of the crisis that is already here—that this mobilizes our energies, and brings us together as humanity and lets us act for a better future. That's the hope that I have.