On ice: part two

My tiny part in protecting Antarctica’s Dry Valleys (10 minute read)

After weeks of hauling a sledge through Victoria Land, in East Antarctica, Robert Falcon Scott concluded that “there can be no place on earth that is less attractive”. After ascending a glacier, he’d discovered an unbroken plain of ice which he called “fearsomely monotonous”. The only variations in the landscape were sastrugi – wind-carved formations on the snow surface which made hauling a sledge difficult – and crevasses.

It was December 1903, and Scott had been in Antarctica for nearly two years, leading his first expedition to the ice. On this particular journey, he was accompanied by Edgar Evans and William Lashly, two strong, hard-working naval men who would also join Scott on his second expedition. It’s a wonder that they weren’t put off by their journey through Victoria Land, because along with facing the usual dire conditions, they lost their navigation tables in a gale and consequently got lost, and Evans and Scott were lucky to survive falling into a crevasse.

Scott’s account of his first expedition is less well-known than his second, but to someone with an Antarctic obsession, it’s just as fascinating. Of all the events in that book, something which happened just a couple of days after the fall into the crevasse has stayed with me. In searching for a route down from the featureless Polar Plateau, Scott, Evans and Lashly found themselves walking down a wide valley like none they’d ever seen before. It was completely free from ice, just bare gravel and sand crisscrossed with flowing streams and shallow lakes. The men were captivated by the valley, running their fingers through the sand, listening to the gurgling of the streams and discussing the prospect of growing potatoes.

I love reading Scott’s account, because he gives the first description of the Taylor Valley, one of the Dry Valleys of Victoria Land¹. I’ve never been there, and I probably never will, but I love those valleys. I have a vivid memory of watching a David Attenborough doumentary when I was a child, and seeing the valleys for the first time. I’m drawn to desert landscapes and these are the most extreme deserts of all. And, my work has played a very small part in helping to protect them.

As far as I can tell, the Dry Valleys are somewhere in behind these hills, seen from Crater Hill, Ross Island (image credit: Melanie Newfield)

But, before I get to that part of the story, back to Scott. To me, his most memorable comment about the valley was that he saw no living thing, “not even a moss or lichen”. All he found was a seal skeleton, and he was inspired to add “it is certainly a valley of the dead”.

Scott’s comment about finding no life is memorable because it’s a reminder that we may not always recognise the signs of life when we see them. There is life in the Dry Valleys, in fact, rather a lot by Antarctic standards. But it’s not obvious. Scott, who was no biologist, can be forgiven for failing to see it. But look closely, and a fascinating diversity is revealed.

By the time I visited Antarctica, in 2009, scientists had described delicate algal crusts on the gravel near water, layers of slime in the lakes and algae growing inside rocks. They’d described lichens growing on rocks and mosses in the cracks between. They’d found tiny animals, such as springtails, roundworms and the fascinating tardigrades (I’ve linked to some information about these remarkable creatures here). Microbes, such as bacteria, had been found in the sand and gravel.

When I was working with Antarctica New Zealand to understand the risks of introducing new species to Antarctica, these native species were part of what we were trying to protect. They aren’t charismatic like penguins, but they are interesting and unusual in their ability to survive extreme conditions. They are of great interest to scientists, because they can teach us about the ways that life survives in extreme environments. There are fewer species overall in Antarctic environments, so the interactions between them are sometimes easier to study than in more diverse places. The enzymes some species contain are being investigated for use in biotechnology. Studying the species of Antarctica can even help us understand how we might be able to detect alien life.

Antarctica’s unique species therefore have a value to humans and their protection may serve our interests. But there’s another reason to protect them too – one which is important to some people but not everyone. This is their intrinsic value, the value that they have just because they exist. Personally, I consider it important that, as much as possible, our planet’s living things be allowed to exist, even if they have no known value to us. If kākāpō became extinct, I believe it would be a great loss. They are such fascinating birds and, having had the privilege of seeing one, I have a sense of connection to them. But if we wiped out some of the tubeworms which live around hydrothermal vents deep in the ocean, I think that would be a loss too, even though I’m never going to see them. If we wipe out a tiny insect in the south-east Asian rainforest, I think that matters too. I understand, though, that not everyone will agree.

This is an important point when it comes to risk assessment. It’s often portrayed as a scientific process, but risks are always assessed in the context of a threat to something which is valued. It might be money, it might be a home, it might be New Zealand’s native birds, it might be a thousand-year-old lichen growing on rocks in Antarctica. Because we all value these things differently, we all look at risks differently.

When I was assessing the risk of accidentally bringing new species to Antarctica, I spent some time discussing with Antarctica New Zealand staff what they were trying to protect. They concluded that part of their role was protecting Antarctica’s unique species for their intrinsic value, as well as protecting them for their value to science and their potential commercial use. They were also trying to protect the operation of their bases and other human activities in Antarctica. For example, ants or pantry moths would be a problem because of the large amounts of food stored in the bases, and could prove difficult to eradicated if established.

So, we knew what we were trying to protect, but what were we protecting it from? To help us understand what might be hitching a ride to Scott Base, Jana, my collaegue from Antarctica New Zealand, and I spent a great deal of our time inspecting everything at Scott Base, from the fridges, where we found fresh vegetables with soil attached, to the alcohol store, where beer-soaked cardboard had been the source of the recent fly outbreak. We inspected inbound cargo, which arrived by air three times a week during the summer and by ship once a year. We also inspected goods which had been in Antarctica for a while: tents, sleeping bags, shovels, bamboo poles for flags used to mark roads on the ice, all sorts of things. This was partly to understand what might arrive, but also how species might move around.

McMurdo Station as seen from Crater Hill. If you look closely, you can see the supply ship. Also, in the distance, you can see one of the giant glaciers which flow down from the Polar Plateau (image credit: Melanie Newfield)

It was among the field supplies where we made what was perhaps our most important discovery. In the ferocious Antarctic wind, it’s essential that tents are well-secured to the ground. Depending on the type of ground – ice or ice-free – there are different types of tent pegs needed. One type, used in the barren soils of the Dry Valleys, was in the shape of a hollow cylinder. And in some of those cylinders were small plugs of soil.

Was this a problem? The tent pegs weren’t coming from New Zealand with soil attached – they would have been brand new when sent down to the ice. This was Antarctic soil. But there are several different valleys which make up the Dry Valleys, and the tent pegs could be moved between them. The fact that we had found some with soil suggested that soil could be moving from valley to valley.

At the time we were doing our work, we knew that there were microbes and small bugs in the Dry Valley soils. But the generally accepted wisdom said it was mostly the same limited range of species across all the different valleys. The tent pegs got us thinking, though. How unique were the different environments around the Ross Sea region, where New Zealand scientists were working? How much of a risk was there in moving equipment from site to site? There was great attention paid to ensuring equipment was clean before it was shipped to Antarctica. Our discovery of the tent pegs suggested that there wasn’t as much attention given to equipment moved around Antarctica.

This point struck us as important. The vast majority of new species arriving in Antarctica would find the environment too hostile to survive. Cold was the best protection Antarctica had against new species establishing. But what of species from Antarctica? It’s a big place – nearly twice the size of Australia if you count the ice shelves. Could species moving from one place in Antarctica to another be a problem?

At the time we were visiting Scott Base, Jana and I weren’t sure. It made sense that movement from one one side of Antarctica to the other was very likely to be a problem, but there was very little transport from somewhere like the Antarctic Peninsula to Scott Base. Movement around the Ross Sea region was more likely to happen, but we didn’t know how different the species were from place to place. Seals, penguins and skuas could travel considerable distances, and the savage Antarctic winds surely blew dust and other material a long way. Perhaps everything was moving around anyway.

Nonetheless, when we took everything into account, we concluded it was one of the highest risks. The frequency of human movement around the region, the chances of species from one area in Antarctica being able to survive in another, the very limited information available about what species could be found where – all of this added up to something which needed more attention. It wasn’t what we had expected when we set out to do the risk assessment, and not everyone was convinced. But it did lead to some changes in how Antarctica New Zealand managed its operations. For a start, they got rid of the hollow tent pegs.

There’s a sequel to this tale, and I think it’s one which shows the value of risk assessment. At the time we were working, there were two pieces of research underway which I wasn’t aware of. One was a large-scale project which divided Antarctica up into different regions based on the different environments and the species which lived in them. This research supported the idea that we should be concerned about the movement of species around Antarctica, because although many of the environments seemed superficially similar, there were important differences.

The other pieces of work was at an altogether different scale. It was led by a scientist from Waikato University, Craig Cary, who was using some new techniques to identify which microbes were living where in the Dry Valley soils. Until the 1970s, these soils has been considered sterile. Since then, some microbes had been detected, but they were thought to be largely the same few species, all of them widespread. But the new research found that there was a much greater diversity of soil microbes, and more differences from place to place, than had ever been suspected. We were right to get rid of the tent pegs.

1. I don’t have any photos to show you, since I’ve never been there, but there’s a great selection at the website I’ve linked to here.