Lost Woods (9 page)

But man, unhappily, has written one of his blackest records as a destroyer on the oceanic islands. He has seldom set foot on an island that he has not brought about disastrous changes. He has destroyed environments by cutting, clearing, and burning; he has brought with him as a chance associate the nefarious rat; and almost invariably he has turned loose upon the islands a whole Noah’s Ark of goats, hogs, cattle, dogs, cats, and other non-native animals and plants. Upon species after species of island life, the night of extinction has fallen.

In the world of living things, it is doubtful whether there is a more delicately balanced relationship than that of island life to its environment. In the midst of a great ocean, ruled by currents and winds that rarely shift their course, climate changes little. There are few natural enemies, perhaps none. The harsh struggle for existence that is the normal lot of continental life is softened on the islands. When this gentle pattern of life is abruptly changed, the island creatures have little ability to make the adjustments necessary to survival.

Ernst Mayr tells of a steamer wrecked off Lord Howe Island east of Australia in 1918. Its rats swam ashore. In two years they had so nearly exterminated the native birds that an islander wrote: “This paradise of birds has become a wilderness, and the quietness of death reigns where all was melody.”

On Tristan da Cunha, all of the unique land birds that had been evolved there in the course of the ages were exterminated by the hogs and the rats. The native fauna of Tahiti and thousands of other Pacific islands is losing ground against the horde of alien species that man has introduced.

Most of man’s habitual tampering with Nature’s balance by introducing exotic species has been done in ignorance of the fatal chain of events that would follow. But in modern times, at least, we might profit by history. About the year 1513, the Portuguese introduced goats onto the recently discovered island of St. Helena, which had developed a magnificent forest of gumwood, ebony, and brazilwood. By 1560 or thereabouts, the goats had so multiplied that they wandered over the island by the thousand, in flocks a mile long. They trampled the young trees and ate the seedlings. By this time the colonists had begun to cut and burn the forests, so that it is hard to say whether men or goats were the more responsible for their destruction. But of the result there was no doubt. Even as early as the year 1880 the naturalist Alfred Wallace had to describe this once beautiful, forest-clad volcanic island as a “rocky desert,” in which the fugitive remains of the original flora persisted only in the most inaccessible peaks and craters.

When the astronomer Halley visited the islands of the Atlantic about 1700, he put a few goats ashore on South Trinidad. This time without the further aid of man, the work of destruction proceeded so rapidly as to be nearly completed within the century. Today Trinidad’s slopes are the place of a ghost forest, strewn with the fallen and decaying trunks of long-dead trees; its soft volcanic soils, no longer held by the interlacing roots, are sliding away into the sea.

The Hawaiian Islands, which have lost their native plants and animals faster than almost any other area in the world, are a classic example of the results of interfering with natural balances. Certain relationships of animal to plant, and of plant to soil, had grown up through the centuries. When man came in and rudely disturbed this balance, he set off a whole series of chain reactions.

Vancouver brought cattle and goats to the Hawaiian Islands, and the resulting damage to forests and other vegetation was enormous. Many plant introductions were as bad. A plant known as the pamakani was brought in many years ago, according to report, by a Captain Makee for his beautiful gardens on the island of Maui. The pamakani, which has light, wind-borne seeds, quickly escaped from the Captain’s gardens, ruined the pasture lands on Maui, and proceeded to hop from island to island. The CCC boys once were put to work to clear it out of the Honouliuli Forest Reserve, but as fast as they destroyed it, the seeds of new plants arrived on the wind. Lantana was another plant brought in as an ornamental species. Now it covers thousands of acres with a thorny, scrambling growth – despite large sums of money spent to import parasitic insects to control it.

There was once a society in Hawaii for the special purpose of introducing exotic birds. Today when you go to the islands, you see, instead of the exquisite native birds that greeted Captain Cook, mynahs from India, cardinals from the United States or Brazil, skylarks from Europe, and titmice from Japan. Most of the original bird life has been wiped out, and to find its fugitive remnants you would have to search assiduously in the most remote hills.

One of the most interesting of the Pacific islands was Laysan, one of the far outriders of the Hawaiian chain, a tiny scrap of volcanic soil. It once supported a forest of sandalwood and fan-leaf palms, and had five land birds, all peculiar to Laysan alone. One of them was the Laysan Rail, a charming, gnome-like creature no more than six inches high, with wings that seemed too small (and were never used as wings) and feet that seemed too large, and a voice like tinkling bells. About 1887, the captain of a visiting ship moved some of the Rails to Midway, establishing a second colony. This seemed a fortunate move, for soon thereafter rabbits were introduced on Laysan. Within a quarter of a century the rabbits had killed off the vegetation of the tiny island, reduced it to a sandy desert, and all but exterminated themselves. As for the Rails, the devastation of their island was fatal, and the last Rail on Laysan died about 1924.

Perhaps the Laysan colony could later have been restored from the Midway group had not tragedy struck there also. During the war in the Pacific, rats went ashore from ships and landing craft on island after island. They invaded Midway in 1943. The adult Rails were slaughtered. The eggs were eaten, and the young birds killed. The world’s last Laysan Rail was seen in 1944.

The disruptive forces that had been operating for centuries throughout the Pacific were greatly accelerated by war. Some of the destruction was the direct result of bombing and artillery fire, but much of it was indirect. Ulithi Atoll in the Carolines was the home of a small rail, found nowhere else. The rail survived the early period of invasion, but perished when the taro swamps in which it lived were filled to make way for quonset huts. Large birds like albatrosses, shearwaters, and petrels often fell into abandoned foxholes and other steep-sided pits from which they could not escape, and starved. Planes killed thousands of birds, especially kinds that are active at night, like the Sooty Terns.

Out of the Pacific war, however, grew the first recognition of the conservation problem of the islands, and the first small beginnings of a constructive movement to salvage what remains. In 1946, the Pacific War Memorial was established. One of its purposes is the commemoration of lives lost in the Pacific by preserving, as living memorials, examples of original island life. Late in 1948 the Pacific War Memorial established a laboratory on the island of Koror, in the Palau Archipelago, to begin a study of conservation problems. The conservation crisis in the Pacific islands has also been the subject of several conferences sponsored by the National Research Council’s Pacific Science Board. The advice of leading specialists on Pacific conservation problems has been sought by the Navy in connection with the Trust Territory of Micronesia.

There is still a chance to preserve some of the unique island life of the Pacific by establishing sanctuary areas comparable to our own National Parks and Wildlife Refuges. The first actual start on such a program has just been made. Late in 1948, the Navy turned over to the Pacific War Memorial two areas on Saipan as conservation reserves to commemorate the men who died in the fighting on this island. Between them, the two areas – Lake Susupe and Mt. Tapotchau – contain almost the only remaining vestiges of the original wildlife and forests of the island.

Lake Susupe, with its surrounding swamp, is the last stronghold in the world of one of Micronesia’s most interesting birds, the Marianas Mallard. This bird has always been rare, and museums anywhere in the world that had a specimen counted themselves lucky. It was first described by scientists less than a century ago, from a single specimen in the Paris museum. It was found only on Guam, Tinian, and Saipan, and even there flocks of more than fifty or sixty birds were an unusual sight. It now seems to have disappeared from both Tinian and Guam, and probably not more than a score remain on Saipan. Under protection on Lake Susupe, conservationists hope that this remnant may build up enough to save the species from extinction.
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Mt. Tapotchau is in the high interior. Its jungled ravines and high ridges shelter most of what remains of the original forest of Saipan. Japanese farmers, clearing the island for sugar cane plantations, cut down much of the old forest elsewhere on the island, and war bombardments leveled the rest. Now the surviving native species on Mt. Tapotchau are threatened by the enemies of all island forests: burning, cutting, displacement by introduced plants, attack by insects and disease.

What can conservation areas accomplish? The species that are gone cannot be restored by any amount or kind of conservation work. As for those that remain, the example of the island of Lanai in the Hawaiian chain gives reason to hope that even badly damaged Pacific forests, and their associated life, could be brought back.

By about 1910, most of the forests and other vegetation of Lanai had been devoured by the cattle, sheep, goats, pigs, and deer which had been brought to the island over the years and allowed to run wild. Erosion on the north end had become so serious that the island was literally blowing away. About that time George C. Munro was sent to the island to manage the Lanai Ranch. Munro, a conservationist by instinct, had the practical common sense to realize that a ranch could not be a paying proposition unless the cattle had something to graze on. He took drastic action. He had the wild cattle driven into corrals to augment the depleted ranch herds. Then he and his men declared a relentless shooting war on the wild pigs, goats, sheep, and deer. They built miles of fences and kept even the ranch cattle away from the mountain forests.

A quarter of a century later the botanist F. R. Fosberg went to Lanai to collect, as he expected, the few dying remnants of a once magnificent flora. Instead, he found that a miracle of restoration had taken place. Once more, the ridges and valleys of Lanai were covered with extensive forests of native trees. The erosion on the north end of the island had been halted. Preserved on Lanai, as in a museum, were several Hawaiian endemics now to be seen nowhere else in the world, among them an exquisitely fragrant gardenia, and a small mint restricted to a tract less than an acre, now its only habitat on earth.

Whether the efforts of the Pacific War Memorial, the Pacific Science Board, and other conservation groups now at work in the Pacific have come in time, and have sufficient momentum, to achieve their aims, only the future will tell. As always in conservation problems, public ignorance and public apathy are the greatest obstacles to success. The degree of understanding and the amount of material support which are given these programs may well give the final answer to the challenge of the islands within our generation.

10

[1951]

New York Herald-Tribune
Book and Author Luncheon Speech

RACHEL CARSON
was somewhat uncomfortable with the public role she assumed when
The Sea Around Us
made her a literary celebrity. Unaccustomed to public speaking, she reluctantly agreed to appear at the
New York Herald-Tribune
Book and Author Luncheon after Irita Van Dorn, the irrepressible book review editor, invited her less than a month after
The Sea Around Us
had been published.

Carson prepared a brief speech on the mystery and fascination of the sea, and to fill time, armed herself with hydrophone recordings of sounds made by shrimp, whales, and other fish in the sea’s middle region that she had borrowed from the Woods Hole Oceanographic Institution. Her talk on the ancient evolution of the world’s ocean and its life was a great success and ironically left her much in demand as a speaker, although she spoke so softly some had to strain to hear her.

Carson once remarked that she was always more interested in what she was going to write about next than in what she had written. Her remarks here indicate that she was already involved in research for her next book on the transition of life from sea to land.

PEOPLE OFTEN SEEM TO BE SURPRISED
that a woman should have written a book about the sea. This is especially true, I find, of men. Perhaps they have been accustomed to thinking of the more exciting fields of scientific knowledge as exclusively masculine domains. In fact, one of my correspondents not long ago addressed me as “Dear Sir” – explaining that although he knew perfectly well that I was a woman, he simply could not bring himself to acknowledge the fact.

Then even if they accept my sex, some people are further surprised to find that I am not a tall, oversize, Amazon-type female. I can offer no defense for not being what people expect, but perhaps I might say a few words about why a woman, and only an average-size one at that, should have become a biographer of the sea.

I seem to have been born with a fascination for the ocean. For years before I had ever seen it, I thought about it and dreamed about it and tried to picture what it would be like. I loved Swinburne and Masefield and all the other great poets of the sea. The stories I wrote for my classes in English composition often had a marine background. After I became interested in biology as a college student, I very naturally came to specialize in marine biology. At the Marine Biological Laboratory at Woods Hole I had my first prolonged contact with the sea. There I never tired of watching the tidal currents pouring through the Hole, and the waves breaking on Nobska Point after a storm. It was there, too, that I first discovered the rich scientific literature of the sea. But it is fair to say that my first impressions of the sea were sensory and emotional, and that the intellectual response came later.

Recently I have discovered that a great many other people feel just as I do about the ocean. A really overwhelming number of them have written to tell me so. During this past summer I have been traveling along the New England coast, gathering material for a new book. And I have been looking at people as well as at sea animals. I have been deeply impressed by what I saw. Everywhere there were people who simply sat – or stood – and gazed out over the sea, without saying a word. Whatever they consciously thought, the spell that was cast over them was clearly written on their faces. I have been trying to analyze some of the reasons for this fascination.

The sea is a place where one gets a sense of the great antiquity of the earth. It seems changeless; but it is always changing. It links the dim beginnings of time with the present. The same sort of waves that we watch today must have rolled in from Paleozoic seas. I suppose that the surface waters of the ocean look much as they did half a billion or a billion years ago, when the first primitive forms of life stirred in it. And even some of our shores must look about as they did in that period, some 300 million years ago, when the first animals were coming out on land to take up a strange new life.

I was reminded of that last summer when I stood on one especially beautiful point on the rocky coast of Maine. We had come down to the point through an evergreen forest that had its own sort of enchantment. All its trees, the living and the dead, were hung with the silvery grey of mosses and lichens. But it was a foggy morning, and when we reached the rocks above the surf the mists lay between us and the forest, and all we could see were those massive, primeval rocks and the sea. Except for our own presence, the scene might have been one of the closing periods of the Paleozoic Era. Some of the animals clinging to the walls of the tide pools might almost have been those early pioneers from the sea, that first came out on land back in Silurian time.

Now here is the particular magic of the sea. Exciting things are happening there today, just as they did millions of years ago. Evolution and the adaptation of creatures to new surroundings did not stop back in prehistoric time; they are still going on. That very day, only a few weeks ago, we saw hundreds of small, inconspicuous sea animals in the midst of a great experiment – the transition from a sea life to a land life.

These animals were small snails known as periwinkles. I am sure all of you have seen them on rocky coasts, between the tide lines. In some places you can hardly step without treading on the dingy grey shells of the common periwinkle. The periwinkles are now in the process of leaving the sea and turning into land snails. One by one, they are cutting the ties that bind them to the sea. Some of them have made more progress in this direction than others.

Here on our northern Atlantic coast there are three species of periwinkles. One of them is still almost completely marine. It lives down among the rockweeds where it is always wet or at least very damp. It lays its eggs on the weeds, and the young hatch out there and develop. Another species, called the common periwinkle, comes far up on the shore – as far as the waters of the high tide. It can stand a good deal of exposure to the air. In fact, it has developed a very simple sort of lung for breathing out of water. But it is still dependent on the sea, for it sheds its eggs into the water, and all the baby common periwinkles must spend the first period of their existence swimming about in the waters of the ocean.

The third species, called the rough periwinkle, is almost a land animal. Some of them live in crevices in the rocks where they are wet only by the spray of breaking storm waves. They can live without any contact with sea water for a week or more. Even in their method of reproduction they have cut their ties with the sea. The young of this species undergoes complete development within the body of the mother. They emerge as little snails exactly like their parents, ready for adult life. And so the three species of periwinkles give us a beautiful demonstration of the pattern of evolution, as it has been working out in the sea over the ages.

That is part of the fascination of the ocean. But most of all, the sea is a place of mystery. One by one, the mysteries of yesterday have been solved. But the solution seems always to bring with it another, perhaps a deeper mystery. I doubt that the last, final mysteries of the sea will ever be resolved. In fact, I cherish a very unscientific hope that they will not be.

A century is a very short time. Yet only a century ago men thought nothing could live in the deep waters of the ocean. They believed that, at most, there could be only a “few sparks” of life in the black waters of the oceanic abyss. Now, of course, we know better. In the year 1860 a surveying vessel was looking for the best route for the trans-Atlantic cable. When the sounding line was brought up from a depth of about a mile and a half, there were starfish clinging to the line. The same year a cable was brought up for repairs from the bottom of the Mediterranean. It was heavily encrusted with corals and other animals that evidently had been living on it for months or years. Such discoveries gave our grandfathers and our great-grandfathers their first proof that the floor of the deep sea is inhabited by living creatures.

Now, in our own time, another mystery of the sea is engaging the attention of scientists. This is the nature of the life of those strange, middle regions – far below the surface, but also far above the bottom.
*

We had always assumed that these mid-depths were a barren, almost lifeless, Sahara of the sea. They lie beyond reach of even the strongest rays of the sun. And where there is no sunlight, no plants can live. So we assumed that food would be too scarce to support a very abundant animal population there.

Then about ten years ago came the discovery of immense concentrations of some living creatures, spread like a cloud over much of the ocean at a depth of a quarter of a mile or more. No one is sure just what these creatures are. As yet they have been “seen” only with the impersonal eye of echo sounding instruments. These instruments automatically record the depth of water under a moving vessel. They trace the contour of the ocean floor as a continuous line on a strip of paper. They also record, as traces or smudges on the paper, any solid objects, like schools of fish, that lie between the surface and the bottom. Hundreds of vessels have now found this layer of living creatures over the deeper parts of all oceans of the world. It has sometimes been called the “phantom bottom” of the sea, because people at first mistook it for shoals or sunken islands, and reported submerged land where none existed. Everyone agrees now that the layer is composed of living creatures. At night – in darkness – it moves up to the surface of the sea. But just before daybreak it descends again into deep water where light cannot follow it. Many small shrimplike creatures are known to do this. Also, some of the weird fishes of the deep sea come to the surface at night, like those Mr. Heyerdahl described so vividly in
Kon-Tiki.

Scientists have tried to sample the layer with nets. You can never be sure, though, that your nets are catching everything. Perhaps the very creatures that are the key to the mystery are too swift to be caught. So the results are not very satisfying. Some people think the mystery creatures are shrimps – billions and billions of them. Others think they are fish or squid. If they should turn out to be something edible, the layer would represent an enormous food supply because of its almost ocean-wide dimensions. The answer to this enigma may come very soon, for a great many people are working on it.

One very common misconception about the sea was corrected by studies made during the Second World War. We always used to think of the deep sea as a place of silence. The idea that there could be sound under water had not entered most people’s minds. Nor had the idea that fish or shrimp or whales had voices. When Navy technicians began listening for submarines during the war, they heard a most extraordinary uproar. In fact, the tumult of undersea voices was so great that whole fleets of submarines could have passed by undetected. Later, of course, means were developed for filtering out and separating the various sounds.