Resilient Sea

By BARRY HILLENBRAND LONDON

FOR SIX RELENTLESS DAYS, HUGE waves and strong winds mercilessly pounded the oil tanker Braer, grounded on the rocks of Fitful Head in the unspoiled Shetland Islands. Bit by bit, the cargo of 26 million gal. of Norwegian light crude leaked into the sea, turning it chocolate brown. On the seventh day, the pounding caused spouts of oil to gush spasmodically from deck hatches, making the tanker look like some pitiful beached whale blowing black blood in the throes of death. The following day the ship did die, splitting into at least three pieces and releasing all its remaining oil into the turbulent sea.

An important environmental battle seemed to be lost, a catastrophe imminent. "We were terribly disappointed that the ship broke apart before we could salvage the oil," says Sian Pullen, a marine-conservatio n officer with the World Wide Fund for Nature. "This is a horrible disaster: a toxic cloud of chemicals is spreading through the water." At first the area around Fitful Head was fouled by the oil. Birds such as the shag and the great northern diver became coated with crude and died. Whipped up by the 90-m.p.h. winds, an oily mist spread over the southern end of the Shetlands' main island, coating crops and flocks of sheep as well as people. Fish and other sea life were found dead on the beaches.

Yet, amazingly, less than two weeks after the ship ran aground on a trip from Norway to Canada, much of the visible evidence of the spill had disappeared. The water in the immediate area around the wreck still had patches of oil churning below the surface. But farther out, the sea had returned to its azure state, and there was no spreading slick. While some beaches were stained by puddles of ooze characteristic of spills, the damage to the coast was far from catastrophic.

The Shetlands accident and its aftermath demonstrate the remarkable ability of nature to repair itself -- even when confronted by an oil spill, one of humanity's more dangerous assaults on Mother Earth. The incident also shows that oil spills are not all the same; alarmist forecasts of ecological devastation, which invariably come after a big spill, are often off the mark.

In this case, the tempestuous weather was the culprit -- and then the savior. High winds and 30-ft. waves sent the ship onto the shore and prevented salvage crews from removing the oil. But "the weather had its good sides too," says Madeleine McDonagh, head of the marine-environment group at Britain's Warren Spring Laboratory. "The winds and waves helped induce a natural dispersion of the oil."

Spills are usually almost two-dimensional in their initial stage: the oil remains in a layer on the surface in one location. It spreads out slowly and sinks only gradually. But in the churning sea off the Shetlands, the spill quickly became three-dimensional and spread rapidly over a wide area -- at which point, some scientists argue, the concentration of oil is no longer dangerously high. The sea contains bacteria and other microbes that will naturally break down the oil droplets until they are eventually reduced to little more than carbon dioxide and water.

Since the concentrations of oil off the Shetlands are now low, seabirds are less likely to take on a fatal coat of crude than their counterparts in other spills. That is small comfort for the more than 700 birds that died in the early stages of the spill, or to the thousands more that may become sick from ingesting oil while preening or feeding on contaminated food. But the spill seems to have affected fewer birds than expected.

The vigorous wave action worked as a high-energy cleanser of rocks and beaches. Thus the Shetlands are likely to be spared the costly and environmentally disruptive cleanup that followed the spilling of nearly 11 million gal. of crude (less than half the amount lost by the Braer) into Prince William Sound in Alaska. Says Robert Spies, chief scientist for the Exxon Valdez Oil Spill Trustee Council: "There is ample evidence that overzealous cleanup can be harmful." The chemical detergents, high-pressure sprays and brushes used to clean beaches and rocks after a spill destroy microorganisms that are an important part of the seaside's ecology. The surfaces of rocks are attractively cleaned but left biologically dead. In the Shetlands, nature will take care of most of the cleanup. "The sea is doing a tremendous job of getting rid of the stuff already," says David Hammond, who runs a salmon smokehouse 25 miles north of the wreck site. "I'm optimistic that we will not have much to do."

There are other reasons why the Shetlands may avoid the ecological holocaust that hit Prince William Sound, where an estimated 435,000 birds died. January is the off-season for birds in the Shetlands. Had the accident taken place in the spring, when bird migration is in full swing -- as it was in Alaska just after the Exxon Valdez accident -- thousands of guillemots and razorbills, which nest and breed off nearby Sumburgh Head, would have been at risk.

The Shetlands also had a lucky break in the kind of oil carried by the Braer: a light variety called Gullfaks, which, unlike other crudes, resists taking up water and forming a stable emulsion. The viscosity of most crudes causes them to form hard, tight masses that are difficult to break up. The tar balls and gooey globs that plagued Alaska have not appeared in the Shetlands because of the peculiar nature of Gullfaks. Says Dan Lawn, an environmental engineer who works in Prince William Sound: "When I flew over the site in the Shetlands, I was astounded to see that the oil was not sticking to the beaches. It would roll up on the beach and then roll back down, leaving only a slight sheen. This oil acts very differently from ((Alaska's)) Prudhoe Bay crude."

Does all this mean that the scientists, conservationists and cleanup crews can pack their bags and go home? Hardly. Conservation groups such as Greenpeace and the World Wildlife Fund have been using the spill in the Shetlands as a bully pulpit to raise public awareness of the very real danger of the world's overreliance on oil. And, of course, a dramatic event in which animals are threatened makes fund raising easier. Greenpeace ads featuring oil-coated birds and soliciting donations appeared in British papers four days after the accident.

Though the spill was not so awful as had been feared, it did create a costly scare. Nearly 400 sq. mi. of fishing grounds, including 11 of the Shetlands' 61 salmon farms, have been closed until both the water and the fish can be tested for oil contamination. "We think things look good now," says Alistair Goodlad, co-owner of Bressay Salmon Co. "But we can't take a chance. We will voluntarily stay closed until we know things are safe." Experts are also testing sheep to discover the effect of their grazing on oil-tainted pastures. "And don't forget the people," says Jeremy Leggett, scientific director of Greenpeace in Britain. "They have been breathing in oil, which is a carcinogen."

While most concern focuses on birds and mammals, the oil may have harmed less visible -- and less photogenic -- creatures such as the sand eel, which has already suffered in recent years from overharvesting. The eels are an important food for arctic terns and other birds that breed on the Shetlands during the summer. "The birds had been weakened in previous seasons here," says Tim Thomas, a wildlife officer for Britain's Royal Society for the Prevention of Cruelty to Animals. "If the sand eel does not reproduce well this year because of the oil, the birds could be devastated."

But it would be a mistake to underestimate the resilience of nature. Studies of other spills reveal remarkable recoveries -- even from shocks like the estimated 250 million to 350 million gal. of crude that was deliberately pumped into the Persian Gulf in 1991 by Saddam Hussein's army. Though the majestic coral reefs in the gulf still show the effects of their trauma, they are slowly rebuilding. Says Sylvia Earle, a former chief scientist of the U.S.'s National Oceanic and Atmospheric Administration, who visited the gulf last year: "The reef was like a weedy lot, not a healthy wilderness, but it was green and growing. It was in a state of flux."

One of the ironies of the Persian Gulf spill, which some experts predicted would destroy the area's ecosystem, is that certain parts seem cleaner and healthier now than they were before the Iraqis dumped their crude. According to a study published last August in the journal Nature, the levels of petroleum hydrocarbons in sediments and some mollusks from Bahrain in June 1991 were lower than those recorded in prewar surveys. Scientists suspect that the reason for this startling finding is that during and after the war, tanker traffic in the gulf was cut back. "Normal" oil pollution, largely from tankers clearing their ballast, had been reduced.

Less than 10% of the oil dumped into the world's oceans each year is the result of large, well-publicized spills involving wrecked tankers or malicious Iraqi generals. Most of the fouling is caused by thousands of small, unrecorded spills from tankers and ships and by runoff from industrial plants. Oil's assault on the oceans is unceasing. Fortunately, as the Shetlands spill has shown, the seas have a greater ability to absorb punishment than humanity has any right to expect.

With reporting by Andrea Dorfman/New York