The Year of the Oceans
by Marc E. Norman

Men have swung golf clubs on the moon. Supersonic transports whisk passengers from New York to Paris in a few hours. Adventurers have climbed to the top of Mt. Everest more than 1,000 times. Yet as we approach the close of the 20th century, no human has visited the farthest depths of the ocean floor.

Even so, research over the past decades has made a steady stream of new - often revolutionary - discoveries about the workings of the deep sea. The deep ocean, it turns out, is far more varied and complex, far more important to the global ecosystem and far more threatened by humanity than most scientists ever dared imagine.

Fittingly, the United Nations has designated 1998 as the Year of the Ocean. The need for public understanding of the deep seas has never been greater.

The Earth's biosphere can be divided into three parts: terrestrial life, existing on land and within the narrow strip of habitable atmosphere around the globe; pelagic (upper sea) life, living within a few hundred meters of the surface of the oceans and relying on the sun for its energy; and, finally, the benthic (deep-sea) life, creatures living at depths below which no sunlight penetrates.

The land supports only one-twentieth of one percent of the volume of the biosphere and the upper sea 21 percent. The deep seas, by contrast, support 78.5 percent. When combined, the seas make up fully 99.5 percent of the global biosphere.

It is not only the size of the oceanic biosphere that so dominates the planet, but also its variety. As recently as ten years ago it was thought that the abyssal sea was largely lifeless. Instead, it turns out that the sea is inhabited from top to bottom.

The biological diversity of the unseen deeps is far more complex than that of the richest tropical rainforests. Compared to the roughly one million species known to exist on land, scientists now estimate that the deep seas teem with as many as ten million - the vast majority still undiscovered.

Megalithic chimneys of crystallized rock, extruded from the seabed by superhot volcanic vents, sometimes rise to the height of a fifteen-story building, These volcanic vents and chimneys, where temperatures often exceed 700 F, bristle with sizable deposits of copper, zinc, silver and gold while supporting vast arrays of lifeforms including microbes, tube worms, sponges, shrimp, anemones, mussels, crabs, and fish.

At its deepest point - the Marianas Trench in the western Pacific - the ocean's bed descends almost seven miles below the surface of the sea - more than a mile deeper than Mt. Everest is high. The world's largest mountain chains are all underwater, dwarfing the Alps and Himalayas. Rifts in the sea floor far outsize the Grand Canyon.

As meteorological techniques improve, and more research is devoted to understanding greenhouse warming, the magnitude of the oceans' climatic impact is beginning to be understood. Changes in the Pacific Ocean's El Niņo are being blamed for droughts and floods as far away as Africa. The amount of carbon in the oceans far surpasses that in the atmosphere. We still do not know how the deep oceans act to regulate global climate or understand what effects rising temperatures might have on ocean ecosystems.

Thousands of square miles of the sea floor, particularly in the Pacific, are covered by fields of walnut-sized manganese nodules containing considerable deposits of iron, copper, nickel and cobalt. Manganese is important in the manufacture of super-hard steel.

Deep sea mining has remained economically prohibitive because these nodules are found at depths greater than three miles. However, with the end of the Cold War, previously classified military technologies have become available for civilian use. Submersible robots now allow scientists to survey previously uncharted parts of the deep sea. These new technologies may also improve the economic viability of deep-sea mining. As terrestrial resources become increasingly depleted, pressure for undersea mining will only increase.

Once thought to be a barren, inexhaustible sink, the deep seas have served over the years as a repository for large quantities of human waste. Until medical and other wastes began washing up on our beaches, dumping sewage off the edge of the continental shelf was common practice in the US. Even now, large amounts of coastal urban and agricultural runoff eventually makes its way to the deep ocean.

Between 1946 and 1970, during the height of the Cold War, the US dumped more than 47,000 barrels of nuclear waste into the Pacific Ocean, 30 miles west of San Francisco. While this was the largest depository, the US dumped radioactive waste at about 50 different sites in the Atlantic and Pacific. The amount of radioactive waste disposed at sea by the former Soviet Union is now estimated to be 25 times greater than the US contribution. Other nations have also littered the ocean floor with chemical and radioactive wastes.

The War on Sea Life

As if the threats of undersea pollution were not enough, the creatures of the deep are also being attacked more directly. As traditional catches like haddock and cod are being harvested to near commercial extinction, fishermen are increasingly looking to exploit the biological riches of the deep.

One of the prime targets has been orange roughy. Found predominantly in the ocean depths near New Zealand, this fish has become prized for its mild white flesh. But unlike many coastal fish whose spawning cycles might occur over three or four years, orange roughy can live more than 100 years, and may not spawn until the age of 30.

This expanded life-cycle, apparently typical of deep sea creatures, makes it much harder for the roughy to recover from over-fishing. The effects of that depleting the roughy's population might have on the undersea food chain remain unknown.

Perhaps the most important feature of the deep sea, however, is the degree to which it still remains a mystery. Deep sea explorers have visited only a minute portion of the abyssal realm. Scientists have identified but a tiny fraction of the creatures below, and know next to nothing about how they live.

What is becoming increasingly apparent is the sheer magnitude and importance of this dark, forbidding world. As with extinction in the rainforests, extinction of deep sea organisms could foreclose future opportunities to develop valuable medicines and technologies.

As the Year of the Ocean commences, humanity must realize that it is but one species living in a tiny fraction of the Earth's biosphere. We must seek to understand our true place on this globe and learn to act appropriately.

Mark E. Norman, an environmental writer based in Arlington, Virginia, holds a doctorate in Energy Management and Environmental Policy from the University of Pennsylvania.