Arthur C. Clarke laments the degradation of a submarine paradise.
" Full fathom five, thy father lies; Of his bones are coral made; Those are pearls that were his eyes; Nothing of him that doth fade, But doth suffer a sea-change Into something rich and strange "
The Tempest, act 1, scene 2
Coral is a mysterious substance, that has fascinated mankind since the earliest times. For proof of that, one need only glance in the Oxford Dictionary where there are more than60 words associated with it. My favourite is "corallidomous" - which I hereby present to organisers of spelling bees.
There are few more evocative phrases than "Coral Island", which instantly brings up images of palm trees, golden sands and buried pirate treasure. The tiny coral polyps are the builders of the mightiest structures on this planet: Australia's Great Barrier Reef is the most famous, but all the world's tropical oceans contain smaller versions. For thousands of years these have been a danger to ships, so great efforts have been made to map their locations. It is only recently, with the help of satellites, that this task has been completed.
The World Atlas of Coral Reefs , prepared at the UNEP World Conservation Monitoring Centre in Cambridge, is a magnificent tribute to the mariners and scientists who have devoted, and often sacrificed, their lives to the study of one of nature's greatest wonders. As this atlas covers all the world's oceans in detail, one would like to think it is the last word on the subject. Unfortunately, that may not be the case because the coral reefs are now threatened by global warming, pollution and, ironically, tourism.
Just half a century ago, the invention of the aqualung opened up the world's shallow seas to exploration by anyone who could afford the equipment - which now means tens of millions. In many ways this was a good thing, especially for the economies of small tropical islands with no resources except sand, sea and sun.
Coral is an excellent source of good-quality lime, easily harvested (at least in shallow waters). In some countries, for example the Maldives, the reef provides the only building material and the islanders are faced with a major dilemma. In creating their shelter, they are destroying the source of their food.
Moreover, the inhabitants of the reef are collected not only for food, but for ornamentation. Swift airfreight has created a huge trade in tropical fish for aquariums all over the world. Unfortunately, the techniques used to collect fish are often not only wasteful - only a few per cent of the transported fish survive - but destructive to the environment. Perhaps worst is the use of cyanide squirted into the reefs: some fish survive this treatment, but a greater number are killed. Fortunately, attempts are being made to put a stop to this practice.
An even worse form of destruction is the use of dynamite for fishing. I can recall seeing a bay off the south coast of Ceylon covered with dead fish, which were being collected by the dynamiters. This again is a completely illegal practice, though unfortunately it still continues.
As a defence against their numerous enemies, corals have devised an astonishing range of chemical weapons - organic compounds of great complexity - and it has now been discovered that many of these have extremely valuable medicinal properties. For example, to quote the atlas, "pseudopterosins derived from Caribbean sea-whip corals are being investigated for skincare and anti-inflammatory properties". The marine creatures found in the reefs are equally promising future sources of pharmaceuticals. We have barely begun the examination of the coral-reef pharmacopia and many treasures must still remain to be discovered.
It is also a curious and somewhat ironic thought that corals have concealed a substantial portion of the world's total wealth. When a ship is wrecked on a reef, it is quickly torn to pieces by wave action, and its heavier contents, especially gold, become lodged in the crevasses. It then takes the coral only a few decades to hide them from sight. However, with modern metal detectors, much of this age-old wealth is now being discovered.
The three pages of the atlas devoted to the reefs around Sri Lanka, which I first visited in 1955, were of particular interest to me. It was sobering to read that the mere one square kilometre of the protected reef around the tourist resort of Hikkaduwa, 100km south of Colombo, received more than 10,000 visitors in 1994. No wonder that on my last visit I met scarcely any fish - and the fearless giant groupers we once fed by hand have long since vanished.
It was while diving off the east coast of Sri Lanka in the 1960s with Commander Don Walsh (who holds one of the few records that will never be beaten: seven miles down in the Marianas Trench) that I encountered another major threat to the coral reefs. Extensively discussed in this atlas, the crown-of-thorns starfish is a spiny multi-armed creature, that can move over a reef like a vacuum cleaner, sucking out its life and leaving only the white skeleton, a veritable coral cemetery.
In 1955, with my late diving partner, Mike Wilson, we were guests of the Great Barrier Reef Committee in its newly constructed marine biology research station on Heron Island. When we arrived, the research station was nothing more than a large wooden hut, completely devoid of fittings - but its floor was soon covered with our aqualungs, cameras and so on. Now, almost half a century later, Heron Island is a major tourist attraction, and I wonder how the reef is surviving.
Though I sometimes revisit it in my dreams, I now know that I shall never return. My last memories of the reef combine the magic of both sea and sky. On a brilliant moonlit night we waded out over the barely exposed reef, using flashlights that we turned off from time to time to study the bioluminescent organisms flashing their own signals in search of prey or mates.
The problem of choosing a path through the difficult territory ahead of us had so engaged my mind that, for once, I scarcely noticed the glory of the tropical sky. Then somebody pointed to the west and said: "What's that light over there?" I looked up into the stars. The sun had set long before, and no trace of the brief evening's afterglow remained. Yet straddling the western sky, and stretching halfway to the zenith, was a faint cone of light, tilted somewhat toward the south. At first glance, it might have been taken for the Milky Way - but the densely packed star-clouds of the galaxy arched across a different portion of the heavens.
It was, I knew, the zodiacal light: that pale and mysterious apparition that stretches outward from the sun like a millionfold-greater enlargement of the corona. I was seeing it for the first time in my life and was surprised at its extent and the ease with which it could be observed.
But, alas, no longer - the steadily increasing pollution of the atmosphere and the sheer waste of millions of kilowatts of electric lighting have eliminated all but the brightest stars from the night sky. The blue planet so beautifully shown in the Apollo photographs has become the grey planet.
Looking at the strange creatures whose photographs appear in this book - pages 38-40 provide fine examples - one cannot help wondering if there could be more bizarre denizens in outer space. It was in fact my interest in space exploration that brought me to the sea, because I realised that there I could experience something akin to the weightlessness that is so characteristic of space travel.
In the 1950s, I infected many of my friends with my enthusiasm and wrote several books (both fiction and non-fiction) to support my new lifestyle. I would like to end with this quote from the introduction one distinguished convert wrote to The Challenge of the Sea - shortly before he persuaded President Kennedy to go to the moon.
"You may think it strange that I, of all people, should be writing an introduction to a book on the challenge of the sea. But, in a way, I owe it to my friend Arthur Clarke. For it was he who introduced me to the sport that has rapidly become my favourite - skin-diving. There is a close relationship between the sea and space. From a poetical, but not too far-fetched, viewpoint, we on Earth can consider the bottom of our sea as man's point of departure on his extremely long trip to outer space. Life began in the depths of the sea, and through eons moved upward to the land. Today, after a brief pause, he has the means for continuing his journey from the land upward through the atmospheric sea to the reaches beyond the sun and its satellites." - Wernher von Braun.
Sir Arthur C. Clarke, fellow of King's College, London, was a pioneer diver in the Indian Ocean around Sri Lanka and has crusaded for more than 30 years to save Sri Lanka's coral reefs from illicit mining and fishing.