91av

You’ve spent months at a time on icebreakers in the Arctic. What’s life like up there?
It’s a fascinating landscape. You feel like this is an area where you don’t belong – but it’s beautiful. When sunlight hits the ice it glitters, and when the ship breaks the ice, the chunks flip and underneath there are sometimes fish or other animals. There are snow flowers that form on top of the ice. It almost feels like a different planet.

What are you looking for when you are there?
I’m interested in the deep sea. We have tried hard to produce high-quality images that show that the Arctic Ocean isn’t a dead ocean. There’s actually a lot of life on the sea floor.

I understand that there’s a decent amount of biomass but not a huge amount of diversity…
Yes, and that always intrigued me. This is an ocean covered by a lid of ice at the top of the world, where it receives little light: only two, three months in the year have enough sunlight for primary production [plant and algae growth], and the rest of the year it’s pitch dark. As a PhD student I took some of the first deep-sea samples of bacteria and was intrigued to find that there is quite some biomass. That told me there was an unknown source of energy for these waters.

Did you find that energy source?
I think it’s the ice algae. They form big accumulations that colour the ice green and brown. There can be 100 times or even 1000 times more algae in the ice than in seawater, though of course there’s less ice than there is water. But is most photosynthesis going on in the sea ice or in the water column? And when the ice is no longer there, will there be more productivity or less?

Are you talking about sea-ice loss as a result of climate change?
Yes. We were amazed by one type of algae, Melosira arctica. It grows in chains and forms what looks like an upside-down kelp forest, hanging from the ice. The filaments can reach 8 metres long. And because the ice drifts, they get lots of nutrients. These are the biggest accumulations of algae that we know of in the Arctic, besides kelp that grows on rocks at the shores. We have gone to great lengths to observe these algae with robots, cameras in the ice and by drilling holes. We were up there for the summer 2012 , which saw record ice loss. Because of that melt, all the ice algae fell to the sea floor. The entire Eurasian basin was littered with it.

The loss of all that algae sounds like a big deal.
Some scientists who have worked with ice algae say it will be the end when thick ice floes are gone because then the algae can no longer grow on the ice. I think we will lose these big forests, but there’ll be floating clumps.

Presumably life on the seabed benefits if more ice algae sink down, bringing more nutrients?
Well, one weird thing is very few animals are able to eat them, so they accumulate into big masses on the seabed. In the deep sea we found only two species that ate the algae – a sea cucumber and a brittle star. In other oceans you would find millions of organisms jumping into the green patches to feed. I think this seabed abundance is brand new for the Arctic, and deep-sea life has not yet adapted to it.

What counts as the “deep sea”, and are there any fish down there?
The deep sea is any part of the ocean where there is no sunlight at any point during the year: where it is forever night and very cold – below freezing. It is an enigmatic environment. Russian scientists suggested there were no fish in the Arctic deep sea. We thought this for a hundred years. But a fish was discovered down there for the first time last November.

Wow! How was the fish discovered?
We have hundreds of hours of film from the Arctic sea floor, and experiments with traps, and we had never seen a fish below 800 metres. Right now there are two Norwegians sitting on a hovercraft, overwintering in the Arctic (91av, 3 January 2015). They have a camera and occasionally they lower it to the bottom. In November, they documented a fish about 1400 metres down. It’s like an eel.

Is it possible that this fish is a new arrival, courtesy of warming waters?
That remains to be investigated. Most likely there are simply very few deep-sea fish. I tried to get my hands on all of the data and samples ever taken in the Arctic deep sea to count the animals, but we have very little data: most of it is from German and Russian expeditions. There are less than 100 samples, and very few zoologists can name the organisms retrieved. We basically rely on one Russian lab for that.

Does that make it difficult to understand the changes that are happening now?
The environment is changing faster than we can research it. It’s a shitty feeling for a scientist if you are trying to learn something from that change and you know you’re far too slow. People only started seeing that carbon dioxide in the atmosphere was increasing 30 years after it began. That is crazy. The change is happening right now and we can’t wait 30 years to conclude: “Oh, by now the entire typical life of the Arctic has been lost – wow, we have finally shown it.”

Is it hard to live with that feeling?
One year I do the climate change work and the next I like to do exploration work because it’s just too depressing otherwise. In 2016, I have a mission to explore a gigantic underwater mountain that starts in a hole at a depth of 4000 metres and climbs 3500 metres. I’ll go with robots and cameras to explore what life we find on these very steep walls. That’s not as sad as climate change research.

What drew you to the Arctic in the first place?
Adventure. I just love to be at sea and to see new things and work five steps ahead of everyone else. As a child I read all those adventure books, like Robert Louis Stevenson’s, and I imagined myself as an adventurer. I’m joyful that it came about.

Why didn’t you go to a tropical island instead?
I do that too. A tropical sunset with some flying fish is wonderful, but I am always drawn back to the ice.

Leader: “Chilling reminders of climate change in the Arctic“

This article appeared in print under the headline “I’m always drawn back to the ice”