THE RECORD OF THE eels’ journey to their spawning place is hidden in the deep sea. No one can trace the path of the eels that left the salt marsh at the mouth of the bay on that November night when wind and tide brought them the feeling of warm ocean water—how they passed from the bay to the deep Atlantic basin that lies south of Bermuda and east of Florida half a thousand miles. Nor is there a clearer record of the journey of those other eel hordes that in autumn passed to the sea from almost every river and stream of the whole Atlantic Coast from Greenland to Central America.
No one knows how the eels traveled to their common destination. Probably they shunned the pale-green surface waters, chilled by wintry winds and bright as the hill streams they had feared to descend by day. Perhaps they traveled instead at mid-depths or followed the contours of the gently sloping continental shelf, descending the drowned valleys of their native rivers that had cut channels across the coastal plain in sunshine millions of years ago. But somehow they came to the continent’s edge, where the muddy slopes of the sea’s wall fell away steeply, and so they passed to the deepest abyss of the Atlantic. There the young were to be born of the darkness of the deep sea and the old eels were to die and become sea again.
In early February billions of specks of protoplasm floated in darkness, suspended far below the surface of the sea. They were the newly hatched larvae—the only testament that remained of the parent eels. The young eels first knew life in the transition zone between the surface sea and the abyss. A thousand feet of water lay above them, straining out the rays of the sun. Only the longest and strongest of the rays filtered down to the level where the eels drifted in the sea—a cold and sterile residue of blue and ultraviolet, shorn of all its warmth of reds and yellows and greens. For a twentieth part of the day the blackness was displaced by a strange light of a vivid and unearthly blue that came stealing down from above. But only the straight, long rays of the sun when it passed the zenith had power to dispel the blackness, and the deep sea’s hour of dawn light was merged in its hour of twilight. Quickly the blue light faded away, and the eels lived again in the long night that was only less black than the abyss, where the night had no end.
At first the young eels knew little of the strange world into which they had come, but lived passively in its waters. They sought no food, sustaining their flattened, leaf-shaped bodies on the residue of embryonic tissue, and so they were the foes of none of their neighbors. They drifted without effort, buoyed by their leafy form and by the balance between the density of their own tissues and that of the sea water. Their small bodies were colorless as crystal. Even the blood that ran in its channels, pumped by hearts of infinitesimal size, was unpigmented; only the eyes, small as black pinpricks, showed color. By their transparency the young eels were better fitted to live in this twilight zone of the sea, where safety from hungry foragers was to be found only in blending with the surroundings.
Billions of young eels—billions of pairs of black, pinprick eyes peering into the strange sea world that overlay the abyss. Before the eyes of the eels, clouds of copepods vibrated in their ceaseless dance of life, their crystal bodies catching the light like dust motes when the blue gleam came down from above. Clear bells pulsated in the water, fragile jellyfish adjusted to life where five hundred pounds of water pressed on every square inch of surface. Fleeing before the descending light, shoals of pteropods, or winged snails, swept down from above before the eyes of the watching eels, their forms glistening with reflected light like a rain of strangely shaped hailstones—daggers and spirals and cones of glassy clearness. Shrimps loomed up—pale ghosts in the dim light. Sometimes the shrimps were pursued by pale fishes, round of mouth and flabby of flesh, with rows of light organs set like jewels on their gray flanks. Then the shrimps often expelled jets of luminous fluid that turned to a fiery cloud to blind and confuse their enemies. Most of the fishes seen by the eels wore silver armor, for silver is the prevailing color or badge of those waters that lie at the end of the sun’s rays. Such were the small dragonfish, long and slender of form, with fangs glistening in their opened mouths as they roamed through the water in an endless pursuit of prey. Strangest of all were the fishes, half as long as a man’s finger and clothed in a leathery skin, that shone with turquoise and amethyst lights and gleamed like quicksilver over their flanks. Their bodies were thin from side to side and tapered to sharp edges. When enemies looked down from above, they saw nothing, for the backs of the hatchetfish were a bluish black that was invisible in the black sea. When sea hunters looked up from below, they were confused and could not distinguish their prey with certainty, for the mirror-like flanks of the hatchetfish reflected the blueness of the water and their outlines were lost in a shimmer of light.
The young eels lived in one layer or tier of a whole series of horizontal communities that lay one below the other, from the nereid worms that spun their strands of silk from frond to frond of the brown sargassum weed floating on the surface to the sea spiders and prawns that crawled precariously over the deep and yielding oozes of the floor of the abyss.
Above the eels was the sunlight world where plants grew, and small fishes shone green and azure in the sun, and blue and crystal jellyfish moved at the surface.
Then came the twilight zone where fishes were opalescent or silver, and red prawns shed eggs of a bright orange color, and round-mouthed fishes were pale, and the first light organs twinkled in the gloom.
Then came the first black layer, where none wore silvery sheen or opalescent luster, but all were as drab as the water in which they lived, wearing monotones of reds and browns and blacks whereby they might fade into the surrounding obscurity and defer the moment of death in the jaws of an enemy. Here the red prawns shed deep-red eggs, and the round-mouthed fishes were black, and many creatures wore luminous torches or a multitude of small lights arranged in rows or patterns that they might recognize friend or enemy.
Below them lay the abyss, the primeval bed of the sea, the deepest of all the Atlantic. The abyss is a place where change comes slow, where the passing of the years has no meaning, nor the swift succession of the seasons. The sun has no power in those depths, and so their blackness is a blackness without end, or beginning, or degree. No beating of tropical sun on the surface miles above can lessen the bleak iciness of those abyssal waters that varies little through summer or winter, through the years that melt into centuries, and the centuries into ages of geologic time. Along the floor of the ocean basins, the currents are a slow creep of frigid water, deliberate and inexorable as the flow of time itself.
Down beneath mile after mile of water—more than four miles in all—lay the sea bottom, covered with a soft, deep ooze that had been accumulating there through eons upon eons of time. These greatest depths of the Atlantic are carpeted with red clay, a pumicelike deposit hurled out of the earth from time to time by submarine volcanoes. Mingled with the pumice are spherules of iron and nickel that had their origin on some far-off sun and once rushed millions of miles through interstellar space, to perish in the earth’s atmosphere and find their grave in the deep sea. Far up on the sides of the great bowl of the Atlantic the bottom oozes are thick with the skeletal remains of minute sea creatures of the surface waters—the shells of starry Foraminifera and the limy remains of algae and corals, the flintlike skeletons of Radiolaria and the frustules of diatoms. But long before such delicate structures reach this deepest bed of the abyss, they are dissolved and made one with the sea. Almost the only organic remains that have not passed into solution before they reach these cold and silent deeps are the ear bones of whales and the teeth of sharks. Here in the red clay, in the darkness and stillness, lies all that remains of ancient races of sharks that lived, perhaps, before there were whales in the sea; before the giant ferns flourished on the earth or ever the coal measures were laid down. All of the living flesh of these sharks was returned to the sea millions of years before, to be used over and over again in the fashioning of other creatures, but here and there a tooth still lies in the red-clay ooze of the deep sea, coated with a deposit of iron from a distant sun.
The abyss south of Bermuda is a meeting place for the eels of the western and eastern Atlantic. There are other great deeps in the ocean between Europe and America—chasms sunk between the mountain ranges of the sea’s floor—but only this one is both deep enough and warm enough to provide the conditions which the eels need for the act of spawning. So once a year the mature eels of Europe set out across the ocean on a journey of three to four thousand miles, and once a year the mature eels of eastern America go out as though to meet them. In the westernmost part of the drifting sea of sargassum weed some of them meet and intermingle—those that travel farthest west from Europe and farthest east from America. So in the central part of the vast spawning grounds of the eels, the eggs and young of two species float side by side in the water. They are so alike in appearance that only by counting with infinite care the vertebrae that make up their backbones and the plates of muscle that flank their spines can they be distinguished. Yet some, toward the end of their period of larval life, seek the coast of America and others the coast of Europe, and none ever stray to the wrong continent.
As the months of the year passed, one by one, the young eels grew, lengthening and broadening. As they grew and the tissues of their bodies changed in density, they drifted into light. Upward passage through space in the sea was like passage through time in the Arctic world in spring, with the hours of sunlight increasing day by day. Little by little the blue haze of midday lengthened and the long nights grew shorter. Soon the eels came to the level where the first green rays, filtering down from above, warmed the blue light. So they passed into the zone of vegetation and found their first food.
The plants that received enough energy for their life processes from the sea-strained residue of sunlight were microscopic, floating spheres. On the cells of ancient brown algae the young eels first nourished their glass-clear bodies—plants of a race that had lived for untold millions of years before the first eel, or the first backboned animal of any kind, moved in the earth’s seas. Through all the intervening eons of time, while group after group of living things had risen up and died away, these lime-bearing algae had continued to live in the sea, forming their small protective shields of lime that were unchanged in shape and form from those of their earliest ancestors.
Not only the eels browsed on the algae. In this blue-green zone, the sea was clouded with copepods and other plankton foraging on the drifting plants, and dotted with the swarms of shrimplike animals that fed on the copepods, and lit by the twinkling silver flashes of small fishes that pursued the shrimps. The young eels themselves were preyed upon by hungry crustaceans, squids, jellyfish, and biting worms, and by many fishes who roved openmouthed through the water, straining food through mouth and gill raker.
By midsummer the young eels were an inch long. They were the shape of willow leaves—a perfect shape for drifters in the currents. Now they had risen to the surface layers of the sea, where the black dots of their eyes could be seen by enemies in the bright-green water. They felt the lift and roll of waves; they knew the dazzling brightness of the midday sun in the pure waters of the open ocean. Sometimes they moved in the midst of floating forests of sargassum weed, perhaps taking shelter beneath the nests of flying fishes or, in the open spaces, hiding in the shadow of the blue sail or float of a Portuguese man-of-war.
In these surface waters were moving currents, and where the currents flowed the young eels were carried. All alike were swept into the moving vortex of the north Atlantic drift—the young of the eels from Europe and the young of the eels from America. Their caravans flowed through the sea like a great river, fed from the waters south of Bermuda and composed of young eels in numbers beyond enumeration. In at least a part of this living river, the two kinds or species of eels traveled side by side, but now they could be distinguished with ease, for the young of the American eels were nearly twice as large as their companions.
The ocean currents swept in their great circle, moving from south through west and north. Summer drew to its end. All the sea’s crops had been sown and harvested, one by one—the spring crop of diatoms, the swarms of plankton animals that grew and multiplied on the abundant plants, the young of myriad fishes that fed on the plankton herds. Now the lull of autumn was upon the sea.
The young eels were far from their first home. Gradually the caravan began to diverge into two columns, one swinging to the west, one to the east. Before this time there must have been some subtle change in the responses of the faster-growing group of eels— something that led them more and more to the west of the broad river of moving surface water. As the time approached for them to lose the leaflike form of the larva and become rounded and sinuous like their parents, the impulse to seek fresher, shallowing waters grew. Now they found the latent power of unused muscles, and against the urging of wind and current they moved shoreward. Under the blind but powerful drive of instinct, every activity of their small and glassy bodies was directed unconsciously toward the attainment of a goal unknown in their own experience— something stamped so deeply upon the memory of their race that each of them turned without hesitation toward the coast from which their parents had come.
A few eastern-Atlantic eels still drifted in the midst of the western-Atlantic larvae, but none among them felt the impulse to leave the deep sea. All their body processes of growth and development were geared to a slower rate. Not for two more years would they be ready for the change to the eel-like form and the transition to fresh water. So they drifted passively in the currents.
To the east, midway across the Atlantic, was another little band of leaflike travelers—eels spawned a year before. Farther to the east, in the latitude of the coastal banks of Europe, was still another host of drifting eel larvae, these yet a year older and grown to their full length. And that very season a fourth group of young eels had reached the end of their stupendous journey and was entering the bays and inlets and ascending the rivers of Europe.
For the American eels the journey was shorter. By midwinter their hordes were moving in across the continental shelf, approaching the coast. Although the sea was chilled by the icy winds that moved over it, and by the remoteness of the sun, the migrating eels remained in the surface waters, no longer needing the tropical warmth of the sea in which they had been born.
As the young moved shoreward, there passed beneath them another host of eels, another generation come to maturity and clothed in the black and silver splendor of eels returning to their first home. They must have passed without recognition—these two generations of eels—one on the threshold of a new life; the other about to lose itself in the darkness of the deep sea.
The water grew shallower beneath them as they neared the shore. The young eels took on their new form, in which they would ascend the rivers. Their leafy bodies became more compact by a shrinkage in length as well as in depth, so that the flattened leaf became a thickened cylinder. The large teeth of larval life were shed, and the heads became more rounded. A scattering of small pigment-carrying cells appeared along the backbone, but for the most part the young eels were still as transparent as glass. In this stage they were called “glass eels,” or elvers.
Now they waited in the gray March sea, creatures of the deep sea, ready to invade the land. They waited off the sloughs and bayous and the wild-rice fields of the Gulf Coast, off the South Atlantic inlets, ready to run into the sounds and the green marshes that edged the river estuaries. They waited off the ice-choked northern rivers that came down with a surge and a rush of spring floods and thrust long arms of fresh water into the sea, so that the eels tasted the strange water taste and moved in excitement toward it. By the hundreds of thousands they waited off the mouth of the bay from which, little more than a year before, Anguilla and her companions had set out for the deep sea, blindly obeying a racial purpose which was now fulfilled in the return of the young.
The eels were nearing a point of land marked by the slim white shaft of a lighthouse. The sea ducks could see it—the piebald old-squaw ducks—when they circled high above the sea on their return every afternoon from inshore feeding grounds, coming down at dusk to the dark water with a great rush and a roar of wings. The whistling swans saw it, too, painted by the sunrise on the green sea beneath them as their flocks swept northward in the spring migration. The leader swans blew a triple note at the sight, for the point of land marked the nearness of the first stop on the swans’ long flight from the Carolina Sounds to the great barrens of the Arctic.
The tides were running high with the fullness of the moon. On the ebb tides the taste of fresh water came strongly to the fish that lay at sea, off the mouth of the bay, for all the rivers were in flood.
In the moon’s light the young eels saw the water fill with many fish, large and full-bellied and silvery of scale. The fish were shad returned from their feeding grounds in the sea, waiting for the ice to come out of the bay that they might ascend its rivers to spawn. Schools of croakers lay on the bottom, and the roll of their drums vibrated in the water. The croakers, with sea trout and spots, had moved in from their offshore wintering place, seeking the feeding grounds of the bay. Other fish came up into the tide flow and lay with heads to the currents, waiting to snap up the small sea animals that the swiftly moving water had dislodged, but these were bass who were of the sea and would not ascend the rivers.
As the moon waned and the surge of the tides grew less, the elvers pressed forward toward the mouth of the bay. Soon a night would come, after most of the snow had melted and run as water to the sea, when the moon’s light and the tide’s press would be feeble and a warm rain would fall, mist-laden and bittersweet with the scent of opening buds. Then the elvers would pour into the bay and, traveling up its shores, would find its rivers.
Some would linger in the river estuaries, brackish with the taste of the sea. These were the young male eels, who were repelled by the strangeness of fresh water. But the females would press on, swimming up against the currents of the rivers. They would move swiftly and by night as their mothers had come down the rivers. Their columns, miles in length, would wind up along the shallows of river and stream, each elver pressing close to the tail of the next before it, the whole like a serpent of monstrous length. No hardship and no obstacle would deter them. They would be preyed upon by hungry fishes—trout, bass, pickerel, and even by older eels; by rats hunting the edge of the water; and by gulls, herons, kingfishers, crows, grebes, and loons. They would swarm up waterfalls and clamber over moss-grown rocks, wet with spray; they would squirm up the spillways of dams. Some would go on for hundreds of miles—creatures of the deep sea spreading over all the land where the sea itself had lain many times before.
And as the eels lay offshore in the March sea, waiting for the time when they should enter the waters of the land, the sea, too, lay restless, awaiting the time when once more it should encroach upon the coastal plain, and creep up the sides of the foothills, and lap at the bases of the mountain ranges. As the waiting of the eels off the mouth of the bay was only an interlude in a long life filled with constant change, so the relation of sea and coast and mountain ranges was that of a moment in geologic time. For once more the mountains would be worn away by the endless erosion of water and carried in silt to the sea, and once more all the coast would be water again, and the places of its cities and towns would belong to the sea.