ANTARCTICA

Forest and Bird, Volume 18, Issue 4, 1 November 1987, Unnumbered Page

ANTARCTICA

by

Paul Broady

Terrestrial life on the desert continent

F most people, the mention of Antarctica conjures up images of huge expanses of ice and of penguins, seals and other life which abounds in the Southern Ocean. However, there is another quite different side to the region, that of the ice-free land and the animal and plant life that exists there. During the summer, penguins and seals leave the sea for the rocky ice-free areas around the coast in order to breed and moult. Flying birds can travel a considerable distance inland to mountain ranges to rear their young on windblown rock ledges. However, all these animals depend on the oceans for their food and spend most of their lives at sea. They are all part of what is termed the ‘‘marine ecosystem’. In contrast, the ‘‘terrestrial ecosystem’’ contains those plants and animals which never leave the land. This life is much less abundant than that found in the oceans because it is existing in a desert. The largest animal is only a few millimetres long and the largest plant is a grass which grows as a

few scattered clumps covering areas of only a few square metres in some of the most hospitable regions of an inhospitable continent. What a difference from the teeming life in the Southern Ocean!. The ‘‘terrestrial life’ exists on a mere 2.4 percent of the continent. This is the area which is free from a permanent cover of ice and snow. The total area is slightly greater than that of New Zealand. Most of this icefree land is found around the coast, the vast majority of the centre of the continent being covered by a massive ice-cap up to four kms thick. Despite its stark, desert-like nature the landscape in these ice-free areas is often magnificent. There are high rugged mountains and wide sweeping valleys. In some regions the valleys contain sparkling, sap-phire-blue lakes or the lake waters might be hidden below a permanent cover of floating ice. Glaciers tumble down from the mountains and terminate abruptly with high, vertical ice-cliffs which are sculptured by wind, sun and meltwater.

Different World Let us go for a wander through one of these areas and see what evidence of life we can find. Leaving our campsite we walk across an area of dry, sandy gravel and weave our way between rocks and boulders. We are not yet attuned to this new world which is so different to the one we are used to, nota sign of life can be seen, at first. Then, a few stain-like marks on the surface of a boulder catch our eye. Bending down for a closer look we see that we have found a lichen, forming a circular crust over the rock. This plant is a combination of a fungus and an alga helping one another to survive in these extremely dry conditions. One of our companions is interested in collecting a few rocks and he strikes a boulder with a hammer to break off a fragment. To our surprise this reveals the presence of a green layer just below the rock surface. We have found millions of microscopic plants living in the minute spaces between the rock crystals. In fact these algae could be the most widespread plant life on the whole continent; hidden away until the sur-

face rock is removed. A gleaming white quartz stone lying on the dark surface of the sandy ground attracts our attention. Picking it up, we uncover more of the hidden life of this remarkable place. The stone is acting like a miniature greenhouse! Light can penetrate through this type of rock and underneath the stone a little water is conserved — perfect conditions for the growth of more algae!. Peering at the green crusts with a magnifying glass, a sharp-eyed person notices some movement — animals with legs! One beast has red legs and a purple body. It is a mite less than a millimetre long browsing on the algae. A second beast is slightly longer and thinner and all of a sudden it disappears as it leaps through the air — a "‘springtail" or "‘collembolan’’ has just escaped!. An Antarctic Jungle Further down our valley there are a few small snowdrifts remaining from winter. We walk over to one of these hoping to find

some larger plants where meltwater percolates over the ground. We are not disappointed as we have discovered what in Antarctic terms is a veritable jungle. But no machete is needed here as the tallest plant is a mere centimetre high. The tiny, leafy stems of mosses are packed closely together to form a few cushion-like growths. Also, on the surrounding boulders are more lichens but some of these have a bushy appearance whilst others resemble small crumpled pieces of dark paper loosely attached to the rock. Where the ground is soaked with melt there are dark, jelly-like lumps and orange leathery sheets covering the sand. We have to use a hand-held microscope to see what is in these. Magnifying our samples by four hundred times reveals hair-like filaments. These are "‘blue-green algae’, very primitive plants which look similar to fossils of the first plants to evolve on our planet some three thousand million years ago. And yes, there are animals living here too. A wormlike ‘‘nematode"’ is thrashing from side to side and a most unusual eight-legged beast

with the unlikely name "‘tardigrade" is crawling through the filaments using the hooked claws at the end of each leg. The gleaming white cliffs of a glacier at the head of the valley entice us to continue our walk. When we reach this wall of ice we decide to put on our crampons and with the help of our ice-axes we climb up onto the glacier surface. We are surprised to find numerous pools of cold water, all of them with a thin layer of sand over the bottom. Here we encounter more of the jelly-like algae, actually growing on a glacier! Out with the microscope again and a quick look at a tiny specimen shows us that there are animals that can live happily even in these

constantly chilly conditions. The smallest of these consist of just a single cell. They are ‘‘protozoa’’, which move rapidly in between the algae by thrashing their whip-like appendages. Larger, but still invisible to the unaided eye are the "‘rotifers’’, which use similar appendages attached to their heads in order to move through the water. Because the sun is shining brightly there are streams of meltwater cascading over the terminal ice-cliffs. On the ground below, these merge to form quite substantial flows

of water in which are the lushest growths of plants that we have yet seen. Orange sheets of algae coat stones and gravel in the bed of the stream and bright green filaments wave in the turbulent flow. We follow the stream for at least two hundred metres and there are similar growths all the way along. The waters enter a large lake in the bottom of the valley. This is at least a kilometre long and is typical of the thousands of lakes in other ice-free areas around the continent. Only the water around the edge of the lake is free from ice, elsewhere there is a sheet of ice at least a couple of metres thick floating on the surface. Peering into the crystal clear water from the bank we can see an

abundance of algae similar to those in the stream. Where some of these have washed ashore we can see that the sheets are at least ten centimetres thick, possibly the result of hundreds of years of growth! In a droplet from the lake our microscope reveals other algae swimming through the water. We return to our camp convinced that there is far more to Antarctica than at first meets the eye. The awe-inspiring beauty of the landscape is all the more fascinating

when we realise the nature of the amazing life that lives within it. A Fragile Continent These small forms of life are under increasing threat as human presence on the Continent continues to expand. Although extremely hardy in the way that they grow, and sometimes thrive, under the rigorous Antarctic conditions, in another sense they are extremely delicate due to the ease with which they are catastrophically disturbed by our activities. Damage to the fauna and flora is easily caused by building and other construction works, by vehicles, trampling of feet and even by the accumulated effects of scientific studies by successive field parties in remote regions. The growth rates of these organisms are slow, so once damaged or removed from an area recovery would be imperceptible if it occurred at all. A major reason for concern is that this life exists on a mere 2.4 percent of the Continent and then mostly in a small percentage of this area close to the coast. It is this fraction of ice-free land which suffers the greatest human impact. During the last decade, international interest in Antarctica has been increasing rapidly and shows no sign of diminishing. Eighteen nations now have stations which they occupy all the year round. Others are strongly interested in establishing a presence in the region or are in the process of constructing facilities. Most nations are rebuilding and expanding their bases and some are constructing new stations in icefree areas which have previously lacked buildings of any kind. France has commenced construction of a rock-based aircraft landing strip and Australia is strongly interested in constructing another. It has been proposed that the latter could also service an hotel for tourists. Of special concern is the probability that early next year a convention will be agreed and signed by Antarctic Treaty nations which will open up the region for mineral exploration, including oil. Exploitation could be the next stage if deposits of suitable size and quality are discovered. At present the environmental movement, led by the Antarctic and Southern Ocean Coalition, (of which Forest and Bird is a member) is lobbying vigorously for the strongest possible environmental safeguards to be written into the ‘‘Minerals Convention’’. However, they realize that this is very much a second best. A stronger guarantee of Antarctica being maintained as a wilderness area of global importance would be for the international acceptance of a ‘‘Conservation Regime’"’. Under this the region would be managed for its natural values and mining activities would be excluded. Increased public support for this policy is essential now. Details of how you can help will gladly be provided if you write to ASOCNZ, P O Box 11-057, Wellington. The next year could be a critical turning point for the future of Antarctica. gf Dr Paul Broady is a scientist at The Department of Plant and Microbial Sciences, Canterbury University. He has been active in Australia on Antarctic conservation issues, and continues that interest in New Zealand.