It is too early to assess the environmental impact of this recent incident, but it will certainly be immensely serious. Local people will be looking back to some 10 years ago when a much smaller tanker, the Bridgeness, went aground in the same area, and they will remember that although only 167 tonnes of oil escaped, around 130 km of shore was affected and 5,000 seabirds died.
The Sea Empress was carrying 136,000 tonnes and the scale of the damage will be commensurately greater. Already seabirds have been killed off south-west Wales, fishing operations have been interrupted and shores have been contaminated. The final outcome will depend to some extent on the changing force and direction of the wind, but oil has reached the Isle of Skomer, one of Britain's two marine nature reserves.
The story is depressingly familiar. Nearly 30 years after the Torrey Canyon, have we learnt nothing from successive experiences of oil spills?
In fact, a great many lessons have been learnt - about the use of detergents and their replacement by relatively non-toxic dispersants; about the possibility of containing and picking up oil from the sea; about optional clean-up procedures ashore, and about when to act and when to leave things to nature. Also, in Britain, there are contingency plans for each part of the coast, and guidelines for the most environmentally sensitive areas.
Further, there are stocks of clean-up equipment stored at strategic points round the coast, and supplies of dispersants available for dedicated spraying aircraft.
All these measures, however, relate only to dealing with the immediate aftermath of a spill. After the Braer incident at Shetland in 1993, it was felt that as well as the usual detailed examination of the specific events, there should be a much broader review, so Lord Donaldson was asked to inquire into how the coast of the UK could be protected from pollution by merchant shipping.
His report was published in May 1994. As well as dealing with clean- up measures, it examined emergency procedure for ships in distress. In that context the report made, among other things, a 13-part recommendation for a system to ensure that tugs with adequate salvage capacity should be available at key points round the UK shores. It went on to suggest how these tugs might be staffed and administered. But the main thrust of the Donaldson report was its recognition that by far the best approach was to prevent accidents occurring in the first place. Thus, it looked at a whole spectrum of issues ranging from ship structure, design and maintenance, through navigation, routeing and tracking, to manning, handling and crew training.
The report was regarded as a blueprint for action, and indeed of its 103 recommendations the Government immediately accepted 86 and agreed to consider another 13. As a result, many substantial improvements have been made, others are in hand, while some are delayed by the need for international consultation and agreement.
It is against this background of vastly improved safety consciousness that we come back to the central question of this week's disaster: how was the Sea Empress accident able to occur? Must we conclude that such sporadic accidents will always be a feature of transporting oil?
It has been suggested that immediate steps should have been taken to transfer cargo from the Sea Empress to other vessels, that more tugs should have been on the spot at the beginning, so that the ship once pulled off the rocks could have been held clear, that even after the final grounding, powerful tugs could have hauled it free.
It is always easy to criticise a particular action or lack of action after the event, but only those on the scene can make the necessary carefully balanced judgements in the light of what seems best at the time. If stronger tugs had been able to pull the ship clear, this may have been done at the expense of damage to the hull and a release of more oil - a distinct possibility. To which the critics would have accused the salvors of overreacting, saying that brute force was not the answer.
On the information available, however, the official and obligatory inquiry will certainly want to know why the vessel, having first been pulled free, was not immediately towed well offshore.
It will also want to know why, at an earlier stage with a pilot aboard, the Sea Empress was out of the normal shipping channel, and what action was taken at that time. The tanker was a relatively new ship, built in 1993, and so far there has been no sign of mechanical failure. The possibility of human error will undoubtedly be raised.
These matters are for later. The immediate issue is too important to be turned into a tug-of-war between political parties. In my view, the salvors are pursuing the only course they can. The important thing is to ensure that they have access to the necessary facilities and expertise to avoid further serious spillages.
As to the environment, damage is already done. Even with the most effective clean-up operation and favourable weather conditions carrying the slick away from shore, the coastline of south-west Wales will be visibly affected for many months to come.
In the longer term, we have to face up to the problem of conflicting interests located in the same area. On one hand we want to be able to enjoy a pristine marine environment, with its wildlife, opportunities for recreation and its possibilities for fishing. On the other, there is society's need for oil, and the fact is that any laden tanker approaching a refinery or leaving an oil terminal must be a potential hazard. No matter how advanced our technology, human error can never be wholly eliminated.
The writer is professor of fisheries and oceanography at Aberdeen University, and a member of the Donaldson inquiry team.Reuse content