Oceans despair

Oceans despair ABOUT two-thirds of the world's population lives within 60 km of some coast or the other, a proportion that matches the Earth's surface covered by water. That 1998 is the International Year of the Ocean only adds to the importance to the watery part of the planet. Many nations depend on the sea for survival, whether through fishing, maritime trade or tourism. Oceans and the atmosphere combine to drive global climate and to absorb the shocks of change, both natural and human-made. Much news from the deep, let alone the shallows, is not good. Over-fishing is rampant, dumping of toxic wastes is widespread and coral reefs are threatened. But there are benefits too.

Japanese scientists have isolated 3,000 pharmaceutically active sub-stances from marine animals and plants. Some may prove to be the foundation of anti-viral or anti-cancer drugs. Ocean explorers have discovered new marine life forms, some of which thrive on hydrogen sulphide and turn it into nutrients. Understanding how they do it may lead to lots of applications in industries, for example waste-processing.

However, possible benefits from the seas are outweighed by the dangers to them. Pollution is perhaps the greatest threat. There is as much water on the Earth as ever there will be. That is why it is essential to keep it pure. The seas have about 97 per cent of all the water on the Earth. About 85 per cent of air vapour comes from them.

The second most significant threat is from the effects of global warming. It has brought some small island states to predict their own extinction due to the fear of rising sea levels. But some human activities can cause sea levels to rise regardless of global warming. One-third of sea-level rises might result from activities such as chopping down forests and pumping groundwater from sub-surface aquifers. Pulling water from the ground contributes to the problem because some water brought to the surface eventually makes its way to the oceans. Deforestation can increase sea levels as much of the water locked up in trees escapes into the atmosphere when they decompose or are burned.

And of course, there is El Nino. This unpredictable current has already caused global havoc this year. The phenomenon is characterised by a pronounced warming in the central and eastern Pacific Ocean, which recurs every four to seven years.

Under normal circumstances, cold, nutrient-rich currents well up on South America's west coast. These are influenced by surface winds that pile up warm water in the south-west Pacific. The resultant warm air rises, producing heavy rain. In an El Nino year, however, air movements are reversed. El Nino produces a miniature sea of hot water trapped further east of its usual location in the larger Pacific. The hot water rises because broad waves travel eastwards and then reflect off the coast of North and South America, reducing the usual cold currents. Surface winds there are weaker. Rising air over the Americas causes storms and flooding. The over-all effect is eventually to alter weather in many places. That significantly affects many natural phenomena.

All of which goes to show that the oceans are too easily taken for granted. The critical importance of rational ocean management is promoted by several international bodies. One of them, the Independent World Commission on the Oceans, will present its recommendations in Lisbon in September. They are likely to include reinforced measures for combating pollution.

The International Year of the Ocean is a reminder that the seas are neither inexhaustible nor indestructible. If that message gets through to those who abuse them, mandating a year of the ocean will not, after all, be a waste of time.

Related Content