It is almost dusk. Soon purple and gold will swirl across the tropical sky, and the ocean will change. Sunset means feeding time and a changing of the marine guard. Sharks and other pelagic predators step up the hunt. Moray eels with needle-sharp teeth slither out of coral crevasses. Lobsters and crabs scuttle from their holes. Even some plankton-eating corals, dull brown by day, blossom into brilliant yellow starbursts at night. I wanted to see it.
I check my scuba gear and roll off a rubber dinghy into the Coral Sea. The water is warm and clear. At 75 feet, a single white-tip shark, big but harmless, swims silently by. The wreck of the Yongala, a passenger ship that sank in a typhoon in 1911, is just below, encrusted with coral from bow to stern. Two giant eagle rays glide gracefully past, just out of reach. With a flip of my fins, I push forward to touch the undulating wing. It feels like fine sandpaper sliding through my fingers. A flash of silver catches my eye. It is a school of barracuda, watching warily from a distance.
My dive mate, marine biologist Carolyn Williams, leads the way along the wreck, past lace-like fans, delicate feather stars and basket sponges. Two loggerhead turtles, their green shells dotted with white barnacles, chew noisily on hard coral at mid-deck. Using our flashlights, we part a gleaming curtain of jackfish and swim into a dark hole in the deck. Deep inside are old bottles, rusted fans and two large bones, presumably from one of the 121 people who perished aboard the Yongala. Back outside, poisonous banded sea snakes slither along the sandy sea floor. Orange and white damselfish play amid the swaying tentacles of flower-like pink anemones. Fat-lipped, dour-faced groupers, each the size of a small car, peer out under the stern.
This is Australia's Great Barrier Reef, or at least a tiny portion of it. I've dived on reefs across the Pacific, and I've never seen anything like it. There is nowhere like it.
The world's largest coral reef system is, in effect, the world's largest living structure. The intricate maze of 2,900 individual reefs and 900 islands and cays stretches for 1,400 miles along the continent's northeast coast, spread over an area bigger than Britain. The ocean teems with life: more than 1,500 species of fish and tens of thousands more of mollusks, crustaceans and other creatures. There are 22 types of whales alone, including huge humpback whales, the only ones to give birth here. And the coral is incomparable. More than 400 species thrive here; the entire Atlantic Ocean has only 65. Up close, the Great Barrier Reef is a fantasy world of surreal shapes and dazzling colors. From space, satellite pictures show it as a dappled white line, a jeweled necklace in the azure Pacific. So big and so little understood.
Scientists only learned in 1981, for example, that a majority of coral polyps, the tiny creatures that build the reef with their skeletal remains, spawn simultaneously on one or two nights a year here, usually just after sunset on a full moon in November. Responding to some unknown signal, countless polyps release thick clouds of pink and orange eggs and sperm, forming a slick that covers the ocean for hundreds of miles. The goal may be to overwhelm predators and ensure survival of the species. It is surely one of nature's greatest sex shows. "We call it the world's biggest orgasm from the world's biggest organism," one marine biologist says with a grin.
Australians embrace the reef as a national symbol, much as Americans treasure the Grand Canyon. Eighteen years ago, the Australian government, demonstrating the concern of its 17 million outdoors-minded citizens, made the reef a national park--the world's largest multi-use marine playground. Six years later it was designated a World Heritage site by UNESCO.
But despite the attention of these environmental bodies, the Great Barrier Reef is under growing threat today. Rampant tourism, wanton development, destructive fishing and illegal pollution are taking an accelerating toll on an exceedingly fragile environment. Runoff from farms and urban sewage are poisoning lagoons and nourishing algae that suffocate the coral. Hundreds of huge oil tankers, chemical carriers and other large vessels steam down a navigator's nightmare of sunken shoals and deadly reefs in a shallow shipping channel that has one of the world's highest accident rates.
"It's very likely there will be a major spill on the reef," warns Graeme Kelleher, chairman of the Great Barrier Reef Marine Park Authority, the government-chartered agency headquartered in Townsville, a bustling university town on the Queensland coast that is a world center of marine studies.
Nevertheless, the Great Barrier Reef is the best protected in the world. The marine park authority can overrule all state and federal laws except defense regulations for the "protection, wise use, understanding and enjoyment" of the reef. Zoning and other laws strictly limit how and where people may fish, dive, sail or build. But still the reef is inexorably changing. "The reef is in very different shape to what it was 10 or 15 years ago," says Craig Sambell, the marine park spokesman. "Man has impacted on the Great Barrier Reef. There's no two ways about it."
CORAL REEFS ARE LIKE RAIN FORESTS--BUT THEY HAVEN'T INSPIRED THE same worldwide passion. They are centers of biodiversity, vital to the spread of species and the health of the planet. Alive and ever-changing, a reef is the most highly evolved and most productive of aquatic ecosystems, an oasis in the desert-like ocean depths. Half the world's population depends on fish as a main food source, and a thriving reef is a virtual fish factory. It provides nursery, food and shelter for fish and other marine life. For man, reefs produce coral for jewelry and toiletries. They are a natural breakwater, guarding exposed coasts from battering waves and storms. They build beaches, atolls and islands. They provide food, jobs and building material to some of the world's poorest countries. Reefs may even provide clues to secrets of global warming and other environmental dangers. Still, scientists have barely begun to study them.
But the work is promising. "We're only talking about 20 years of proper research on the reef here," says Meryl J. Williams, director of the Australian Institute of Marine Science. "Now it's only a matter of 10 years until we have a steady stream of chemicals for clinical testing for possible use in anti-cancer, anti-AIDS and analgesic drugs." The Australian institute has shipped 3,000 coral samples to the National Cancer Institute in Bethesda, Md., and has filed patents to copy chemicals that corals use to block the sun's cancer-causing ultraviolet rays. It has also recently signed a $5-million contract with an Australian pharmaceuticals company to look for chemicals in coral that can be used in basic drugs.
Besides these possible benefits for the future, the reef holds an important record of the past. Williams says that marine institute scientists last year deciphered the "the Rosetta Stone of coral banding" so that they can "read" coral in much the same way their counterparts can read tree rings in temperate climates and icecap cores at the poles. The size, density and chemical composition of slices taken from 25-foot-long cores drilled from 1,000-year-old corals offer evidence of the environment, from rainfall to pollution. It's more than an academic exercise. Engineers building one of Australia's biggest dams, the Burdekin Dam south of Townsville, needed to know the worst-case rainfall probability to build for possible floods. Written records only go back 75 years, but the cores showed massive flooding in the early 1800s. "The cores give us climate-history records we've never had before," Williams says. "It opens up science for the tropics."
But coral reefs, like the rain forests, are disappearing at an alarming rate. The reasons are poverty, greed and ignorance. Clive Wilkinson, principal research scientist at the marine institute, estimates that 10% of the world's reefs have been destroyed, 30% are in critical condition and close to collapse, 30% more are threatened; only 30% are stable. Among those on Wilkinson's critical list is America's only continental reef, the 200-mile-long Florida Keys. Algae now smother most corals in John Pennekamp Marine Park off Key Largo, for example. Biologists blame yacht owners flushing toilets into a creek that flows onto the reef, and the erosion of fertilizer-rich soil from four nearby golf courses. But there is hope. In 1990, Congress created a national marine sanctuary in the Florida Keys.
That response is costly and therefore unlikely among poor coastal countries. Overfishing is ruining reefs in the Caribbean and East Africa. Pollution is poisoning parts of the Red Sea. In the Philippines, fishermen who increase their catch by stunning or killing fish with cyanide and dynamite have badly damaged the world's second largest reef area. In Indonesia, where the forestry department runs marine sanctuaries, runoff from indiscriminate logging has smothered them with silt. Elsewhere in Southeast Asia and the western Pacific, some reefs are already dead. Collectors plunder reefs in Thailand for home-aquarium fish and ornamental coral. Quick-profit builders mine them for lime for cement in Japan and Sri Lanka.
There are no easy solutions, especially in the Third World. Corruption is rife, and laws are ignored. There are few controls on dumping waste from mines, logging or factories. Poor fishermen compete for a shrinking catch, even if it means blasting the reef. "Fishermen know if you don't fish for a few years, the fishing gets better and easier, and the fish are bigger," says Charles Birkeland, professor of marine biology at the University of Guam. "But it's very difficult to tell them not to eat this year, wait until next year. How do they feed their kids?"
Scientists aren't sure how many coral reefs can be destroyed before the marine ecological system collapses. "No one really knows the long-term global implications," worries Michael Molina, former head of marine resources in the Federated States of Micronesia in the north Pacific. Once damaged, a reef may take decades to recover. And as with rain forests, no one knows how many potentially useful species of plants and animals are being lost forever. But reef expert Meriweather Wilson, interviewed at the East-West Center in Honolulu, concedes that destruction of reefs is hardly a burning public issue. "Sting isn't singing about reefs yet," she says with a sigh.
CAIRNS IS THE MAJOR JUMPING-OFF POINT FOR THE GREAT BARRIER REEF. Once a sleepy tropical town, it has become one of Australia's fastest-growing cities. Some 29,000 people arrived at the Cairns airport in 1975; last year nearly 1 million came from overseas alone. Jumbo jets fly in nonstop from Singapore, Bali, Honolulu and Tokyo. Japanese honeymooners, some fresh from prepackaged wedding ceremonies at Hamilton Island and other resorts, flock to nearby beaches.
Last year, 1.2 million people came to the reef, spending more than $1 billion. The boom is growing at 10% a year, and the impact is as clear as the waters. Accommodations range from roadside sprawls of cheap motels and backpacker hostels to $1,500-a-night private island getaways. Thousands crowd onto Hamilton, Australia's largest island resort. The mini-city has a 20-story hotel and high-rise apartment blocks, its own international airport, and a 400-boat marina. Hills were leveled, harbors dredged and artificial beaches created when the resort was built in the mid-1980s.
"I've heard about this delicate 'balance of nature' for years," the owner told a Melbourne newspaper at the time. "I don't know of anything that can take a better bashing than nature."
Not long ago, only a few fishermen, devoted divers and scientists saw the wonders of the Great Barrier Reef. And there are still vast parts of it where people rarely go. Many visitors, it seems, mostly see a great deal of each other. Fleets of high-speed catamarans, dive boats, seaplanes and other craft take thousands of people daily to a handful of islands and reefs. In Port Douglas, a laid-back town an hour north of Cairns, for example, Quicksilver Connections' two cats speed up to 550 tourists a day to Agincourt Reef. It is a 39-mile run to the reef's outer edge, an area considered inaccessible a decade ago. The open ocean and steep submarine cliffs of the Continental Shelf lie just beyond Agincourt.
The Wavepiercer, as the cat is called, looks like something out of the old Flash Gordon serials. It's built entirely of anodized aluminum, with twin needle-nosed hulls that crash through whitecaps at a sizzling 28 knots the day I am aboard. After 90 minutes, we tie up at a large moored platform, and several hundred passengers rush down the gangplank. Beginners rummage through bins on the platform for masks, fins and snorkels. Then, as crew members watch carefully, they jump off the edge to churn and paddle inside a small roped-off area. Experienced snorkelers are taken on a guided reef tour. And the few of us who opt to scuba board a small boat to dive farther down the reef.
More than half the crowd never gets wet. After a lavish buffet, they peer out plexiglass portholes or cruise in two "semi-submersibles," a modern version of a glass-bottom boat. A few folks even pay $55 extra for a 10-minute ride in a helicopter that clatters noisily overhead. "We've taken over half a million passengers to Agincourt," Max Shepherd, local operations director for the Hong Kong-based company, tells me later. This year, he says, he expects to carry 190,000 passengers to Agincourt and another dive site.
Business is booming ever more closer to Cairns. Green Island, a 32-acre coral cay just offshore, is besieged. Boats dump crowds of tourists onto a narrow beach beside a once-rich reef. "When you have 1,000 people on one reef, it's not exactly a wilderness experience," says Jon Brodie, the park's senior scientific officer. Peter Millios, a 27-year-old dive master, shakes his head when he talks of Green Island. "It's hopeless. It's too many people in one area. The visibility is worse now. They knock over coral. It's just like a factory, a numbers game."
People mean pollution, and coral grows best in clean water. Vast quantities of fertilizer, pesticides and herbicides wash off sugar-cane plantations and farms into the reef waters. Traces of lindane and PCBs, nickel, lead and cadmium have been found in coral. Sediment runoff is a more insidious threat. The silt blocks life-giving sunlight and hinders photosynthesis on the reef. And nutrients from the soil, sewage and agricultural runoff, especially nitrogen and phosphorus, encourage algae and phytoplankton that can kill or weaken the coral.
"What you end up with is an algae reef, not a coral reef," says Peter Bell, a Queensland University environmental engineer. "A number of the reefs have suffered to a certain extent. I don't think it's reached the outer reef, but it's just a matter of time."
The marine park authority is so alarmed that it has ordered the park's 25 island resorts to install tertiary sewage treatment by 1995, an expensive process that reduces waste almost to water. Coastal runoff is much harder to control. The state government of Queensland, which borders the reef, has urged local cattle and sugar-cane farmers to use less fertilizer and to cut erosion by planting trees along riverbanks and leaving tillage on fields.
Then there's fishing. Thousands of commercial trawlers, big-game fishermen and weekend sportsmen also take their toll. "Imagine thousands of anchors and chains going down every Sunday, smashing coral. It adds up," marine park spokesman Sambell says. Although the number of recreational fishermen is going up, their catch--an estimated 4,500 tons a year--isn't. Some surveys suggest it has even declined. Bruce Mapstone, the park's fishing chief, says limits may be put on the number of anglers. "Ultimately there has to be a cutoff. That's clear. You can't increase indefinitely." Under a new Queensland-wide rule, no one may possess more than 30 fish at a time, or more than 10 of a species, "even in your home freezer," Mapstone says. Certain activities are banned altogether from parts of the reef, and equipment and operations are closely regulated.
Commercial boats cause other problems. About 900 trawlers dredge for scallops or drag for prawns on the shallow seabed inside the reef. Most of what's scooped up is simply dumped back overboard. "Dragging a prawn net over the bottom of the ocean is like dragging a chain through a forest," Mapstone says. "It cuts everything in its wake." New technology, especially satellites that feed precise coordinates to captains, lets boats go deeper into the reef. "They're fishing areas they never could before," he adds. "Pristine, untouched areas of the Great Barrier Reef are increasingly hard to find."
Most worrisome of all, each year more than 2,000 large ships, including 200 oil tankers, sail the narrow channel that runs inside the reef. At least 43 large ships have collided or run aground since 1979. It's not only the worst collision rate per shipping unit in Australia; it's worse than England's Dover Strait, the world's busiest shipping channel, according to a risk analysis study prepared for the marine park. Although oil shipments are increasing yearly, the reef has been lucky. All the spills have been small.
But Steve Raaymakers, the park's oil expert, isn't optimistic. "If we have a big spill, we won't be able to handle it." Chemical dispersants, booms and other clean-up gear are stockpiled along the coast in a national "Reefplan" designed to deal with a 10,000-ton spill. Raaymakers just shakes his head. "There's only one thing certain about a 10,000-ton spill. You can't clean up a 10,000-ton spill." In any case, he added, 100,000-ton tankers now transit the reef.
And spills are not the only worry; some ships purposely pollute. At least 33 oil slicks, some up to 15 miles long, have been reported since 1990. Raaymakers says the oil was discharged from the bilges of passing freighters and other large ships. The slicks have oiled sea birds, fouled fishing grounds, killed mangroves and tarred beaches. Nine foreign-flagged vessels, dubbed "ships of shame" in the local press, have been prosecuted. But most miscreants are long gone by the time the oil is seen.
The focus now is on prevention. Navigation aids and channel markers are being upgraded. And major ships have been required since 1991 to hire locally licensed pilots to transit the reef's northern half, the most treacherous portion. The program, the first on any international waterway, hasn't entirely succeeded. Six ships have collided since 1991. "All had pilots on board," Raaymakers says.
New surveys are needed. The Pacific and Indian oceans meet in a maelstrom of complex currents and tides in the Torres Strait, at the northern end of the reef. Ships drawing 12 meters regularly sail through, although the water is only 10 meters at low tide. In 1970, the tanker Oceanic Grandeur hit an uncharted rock in the strait and spilled up to 4,100 tons of crude oil. Many charts are unreliable farther south as well. "A lot of navigation charts, a scary number of them, are based on soundings from the 1800s," Raaymakers says. "Some reefs are off by two kilometers."
It's one reason Greenpeace, the international environmental organization, wants to ban all oil tankers from the reef's inner passage. Rick Humphries, the group's oil campaigner, showed up at my hotel late one night to argue the point. "We're still getting foreign owned and operated vessels of dubious quality," he says heatedly. "It's an accident waiting to happen. They're playing Russian roulette with the greatest reef system in the world."
Raaymakers isn't convinced that sending oil tankers outside the reef is the solution. "To direct ships outside the reef puts them in the Coral Sea. It isn't called the Coral Sea for nothing. It's open ocean, with uncharted reefs. And if oil spills, prevailing wind and currents will wash it onto the Great Barrier Reef anyway."
GIVEN THE REEF'S VAST SIZE, shipping is mostly monitored by air. So I arrange to join a surveillance flight, driving five hours north from Townsville to Palm Cove one afternoon. The road winds past deserted beaches, rustling cane fields, misty mountains and lush jungle. My car startles a kangaroo by a fence at one point; I clock him at 35 m.p.h. as he hops madly away. Huge black fruit bats swarm across the sky at dusk. I bypass Cairns' sprawl of used car lots and shopping malls for a beachside hotel; at dinner I am the only non-Japanese customer. Early the next morning, James Haig, a ranger in the Queensland Department of Environment and Marine Parks, picks me up.
Haig's office is responsible for policing more than 600 miles of open water and coastline. They only fly three times a week, so it's spotty coverage at best. In three hours, we get 75 miles north in a twin-engine Aero Commander. Each time Haig spies a ship, pilot Phil Wiseman swoops over for a look. Nine trawlers are anchored in the lee of Low Isles, booms extended like wings over the water. Six more heave to at Snapper Island, bobbing gently in the waves. The crews sleep by day and fish at night.
Flying east over the water again, Haig points out Endeavour Reef. It was here, just off Weary Bay and north of Cape Tribulation, where England's greatest explorer nearly met disaster. In 1770, Capt. James Cook was making his first epic trip to then-unknown Australia when his ship, the Endeavour, ran aground. It took his crew three months of suffering and hardship to finally sail out of the Great Barrier Reef. He later described the maze of reefs as "memorials to distress."
From 500 feet up, however, it is a mosaic of color. The water is jade green in the shallows, turquoise over coral and royal blue in deeper channels. Haig points and speaks into the crackling headphones: "Turtles down there." Sure enough, I can see half a dozen olive ovals with flippers in the translucent sea. Six of the world's seven species of sea turtles breed on the reef. More than 11,000 lay eggs in a single night on Raine Island. If a hatchling is male, it never comes ashore again. If female, it may not return for 50 years.
Heading south, we zigzag along reef flats and circle over a small boat. "I recognize the boat," Haig says, peering through binoculars. "They're collecting aquarium fish. It's strictly licensed." Soon we are over Norman Reef, 32 miles from Cairns. Six shiny steel catamarans are moored by multistory floating platforms. Swimmers crowd the water and tiny rubber boats zip about, cutting white wakes. Haig shrugs. "There's a lot of people, but there's a lot of reef out here. Once you get beyond a day's destination, there's an awful lot of space between boats."
A sailboat and several small motorboats are anchored by Michaelmas Cay, a bird sanctuary laced with low scrub and grass. In the distance, a huge cargo carrier steams slowly south down the main shipping lane. Haig seems apologetic as we land back at Cairns. "We don't detect infringements on every flight," he says. "But that's not the whole purpose. We also need to know how many people are legitimately using the reef. That way we get patterns of use for future zoning."
Planning is difficult given the mysteries of the reef, but scientists do know the basics. As polyps grow, they secrete lime. When they die, their limestone skeletons provide a platform for more coral. It is a slow process: It can take five years or more to create an inch. Yet the barrier reef has come and gone over the eons. An international drilling project of reef sediments in 1990 found that the reef complex seems to have died and revived at least a dozen times as oceans rose and fell by hundreds of feet. The current reef is about 8,000 years old, emerging at the end of the last Ice Age when melting icecaps replenished the seas. But it is built on far older reefs, some up to 18 million years old.
With that time frame, scientists can only guess what happens naturally and where man has interfered. "We don't have really good, adequate monitoring of what's going on in the reef," says Jamie Oliver, head of the park's reef-monitoring program.
An ambitious project begun here last year will survey 216 reefs for fish, coral and water quality. Although divers still must count fish visually along the reefs, computers will help by analyzing underwater videotapes of the coral. And soon, low-flying planes will shoot color and infrared film to help identify corals and algae exposed at low tide. "We're trying to figure out what's normal," he says.
A current controversy, for example, focuses on coral "bleaching." Corals get their color from microscopic algae, which live in a symbiotic relationship with the animal polyps. When the corals are stressed, especially from a sudden change in water temperature, the algae are expelled. What's left is the bone-white, bleached-out skeleton. Some scientists blame global warming, citing an upsurge in bleaching around the world. Others blame the El Nino effect, a naturally occurring periodic warming of the oceans. And some simply blame other scientists. "Reports of bleaching may have increased because we're all looking for bleaching now," Oliver says.
Or take what's been called "the starfish wars," the battle over the crown-of-thorns starfish. Big and bristling with poisonous spines, the crown-of-thorns devours coral and spreads like wildfire. Reefs are literally eaten alive. Two recent plagues, first in the early 1960s and again in the late 1970s, ravaged up to a third of the Great Barrier Reef and then disappeared. Scientists fear another infestation may be developing near Cairns. Coral cores show the crown-of-thorns isn't new on the reef, but scientists argue fiercely whether man is to blame for the recent devastation. Evidence suggests, for example, that increased nutrients from coastal runoff may nourish the starfish larvae.
But just as natural forest fires clear dead wood and allow regeneration, the crown-of-thorns may be nature's way of regulating reefs. Partly for that reason, park policy is not to interfere with the starfish. Adds Brian Lassig, head of the park's crown-of-thorns research project: "The other reason is we don't have any way to control it."
THIS DOES NOT LOOK OR feel like an endangered habitat--and it isn't, not really, not yet. Public education will be key for the future. Boat owners should anchor in sand, not coral. Tourists should forgo curio shops selling coral and shells. Game fishermen should tag and release their catch, not take it home. And careful eco-tourism is needed to develop a "look but don't touch" ethos. Major tour operators on the Great Barrier Reef insist they are doing their part. "Protecting the reef is critical to our success," says Mike Ball, whose Townsville-based Dive Expeditions takes 3,000 divers a year to the wreck of the Yongala and other unusual dive sites on the reef.
Another hope is modern aquariums, many of which let people experience a reef without going out and trampling on it. At the Townsville aquarium, for example, a moving sidewalk takes awe-struck crowds down a glass-lined tube inside an enormous tank. On both sides and overhead are sharks, rays and 200 other species of fish, as well as living coral. "The more you get people to see the beauty of the reef, the more support there is to conserve it," says Oliver.
The beauty is difficult to describe. I make two dives at Agincourt, on the outer reef. The first is to a coral pinnacle, a sculpted palace for thousands of fish. Yellow butterfly fish, blue-spotted coral cod and delicate damselfish dart down twisting corridors and hide in dark crannies. Crimson nudibranchs called Spanish dancers swirl their skirts in the current. Steely-eyed barracuda hover nearby. In the afternoon, I dive by a sunken fishing boat. Reef sharks patrol over the shining white sand, past giant clams with rainbow-colored mantles. There are boulder-sized brain corals and an enchanted for est of staghorn coral. Blue-green chromis hover among the branches, scooting inside as I approach.
As the giant catamaran roars back to Port Douglas, Gareth Johnstone, one of 10 marine biologists who work with the Quicksilver tour company, sits beside me. I tell him I am impressed. Except for dead coral directly under the pontoons and a few sheets of tissue paper floating nearby, I can't see any obvious impact, underwater anyway, of Agincourt's 500,000 visitors.
He doesn't agree. "You can't bring all these people out here and have no impact," the British-born biologist says angrily. "The reef is stressed by large-scale tourism. Look at the sheer numbers. What about all the sunscreen washing off? What about all those people urinating in the water? I don't think we realize how delicate that system is. I don't think we really know what we're doing." He pauses and looks out the spray-splattered window. "There's got to be a limit to all this," he says finally. "We're loving the reef to death."