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Tuesday, January 12, 1999 Published at 20:47 GMT


Sci/Tech

Assessing the oil spill impact

The Sea Empress lost 72,000 tonnes of light crude oil

It is nearly three years since the oil tanker, the Sea Empress ran aground in one of Britain's largest natural harbours. Tim Hirsch, Environment Correspondent for BBC News 24, assesses the environmental and natural consequences:

What happened?
Bird numbers down - but recovering
Fishing industry getting back to normal
Mixed news for shore-life
Tourism still vital

What happened?

Shortly after 8pm of 15 February 1996, the oil tanker Sea Empress grounded on the mid-channel rocks in the entrance to Milford Haven in Pembrokeshire - South Wales, one of Britain's largest and busiest natural harbours.

In the days that followed as salvage teams struggled to bring the vessel under control, some 72,000 tonnes of light crude oil and 480 tonnes of heavy fuel oil spilled into the sea, polluting about 200km of a coastline famed internationally for its wildlife and beauty.


[ image:  ]
For the people and natural environment of Pembrokeshire, the last three years have seen a process of remarkable recovery, and visitors to the area see no evidence today of the dismal predictions some were making at the time of the spill.

But before anyone starts claiming that the impact of oil spills has been exaggerated - or even, as some have bizarrely suggested, they may actually benefit the environment - it is as well to look at the conclusions of the large number of studies which have been carried out in south-west Wales since February 1996.

A common thread runs through all of them - things could have been a great deal worse. If the accident had happened a few weeks later, if the wind had been blowing from a different direction in the days following the spill, and if the oil had been of a heavier type, then the wildlife and economy of Pembrokeshire would be suffering to a much greater extent than they are.

Bird numbers down - but recovering

The most enduring image of any oil spill is probably the sight of blackened seabirds washed up dead or dying on polluted beaches.

Those images were not hard to come by in the days after the Sea Empress ran aground as thousands of oiled birds started to be recovered along the Pembrokeshire and Carmarthenshire coastline. The worst casualty was the Common Scoter duck (Melanitta nigra), whose feeding technique of diving just below the surface of Carmarthen Bay led it straight into the middle of some of the worst slicks.

Of a population of some 15,000 in the area, some 5,000 are estimated to have died, and recent studies show that while the species is recovering, numbers are still well down.


[ image: The Sea Empress in dry dock, three months after running aground]
The Sea Empress in dry dock, three months after running aground
Distressing as the pictures of dead and dying seabirds were, those familiar with the area knew the real risk of an environmental catastrophe lay in the fate of the island bird reserves of Skomer and Skokholm a short distance to the north-west of Milford Haven. This is where the luck came in - a small amount of oil did go ashore here, but a change of wind direction took most of it into Carmarthen Bay and up the Bristol Channel.

Equally important, the spill came just a few weeks before literally millions of seabirds were due to arrive on the islands to breed. Thanks to these two strokes of luck, the internationally-important colonies of Manx shearwaters, puffins, gannets and lesser black-backed gulls do not appear to have been affected. Other species such as guillemots and razor-bills were killed in considerable numbers, but these too appear to be recovering.

The RSPCA set up a bird-cleaning centre on an industrial estate outside Milford Haven, and with the help of volunteers, set up a major operation to rehabilitate and release as many birds as possible. It was painstaking and dirty work, with household detergent being used to clean the clogged-up feathers, and charcoal being forced down the birds' gullets to soak up toxic material.

A major study carried out by the British Trust for Ornithology questions the whole process of bird-cleaning. It looks at one species affected by the Sea Empress - the guillemot - and concludes that the average survival time for birds cleaned up after being oiled is just seven days.

This does not necessarily mean the bird-cleaning effort was a waste of time - the study only covered one species, and it could be argued that cleaning is worthwhile even if only a minority of the birds survive.

Fishing industry getting back to normal

One immediate impact of the Sea Empress oil spill was to turn the lives of local fishermen upside down as the government quickly imposed a complete ban on the catching of fin-fish and shellfish in the area. The industry employs about 700 people directly in south-west Wales, and is worth some £20m a year, so the implications were potentially devastating.

Although compensation was promised, the fishermen complained of delays and bureaucracy in processing their claims, and the months following the spill were traumatic for those whose livelihoods depended on the sea.

With the lifting of the bans, first on fin-fish and in stages on the different classes of shellfish, the industry has been getting back to normal, and there was relief that stocks did not appear to have been affected by the oil - in fact, there are even indications that a pause in the fishing of crab and lobster may have been beneficial, enabling their numbers to increase.


[ image:  ]
While the first complete season after the lifting of the ban was a good one, 1998 has been a very tough year for the shellfish industry in Pembrokeshire, but fishing authorities believe this was largely due to the poor weather

But it is clear that as with bird-life, luck played a large part in limiting the impact of the accident on the fishing industry. Most migrating fish were still well out to sea when the oil hit - had it come a few weeks later the story could have been very different.

The fact that the cargo was mainly light crude rather than heavier forms of oil also helped to limit the damage. Fears that shellfish from west Wales would be tainted in the minds of consumers have not, thankfully, been realised, and fishermen have been able to re-establish their markets since the lifting of the ban.

Mixed news for shore-life

It is a fact of life that if you report the death of five million limpets due to an oil spill, it will produce less reaction than the sight of a single puffin looking a bit unsteady on its feet. But some of the best-documented damage caused by the accident occurred to the less cuddly species lurking in the tidal pools along the Pembrokeshire coast.

A curious feature of the spill was that the patch of coastline which bore the brunt of the pollution in the early days following the grounding of the tanker happens to be one of the most intensively-studied intertidal habitats in the world.

West Angle Bay on the southern shore of Milford Haven faces directly out to the mid-channel rock where the Empress foundered, and has also been used for many years as a living laboratory by the nearby Orielton Field Studies Centre, which had recorded details of what creatures lived in virtually every square metre of the rock pools.

As a result, the marine biologist who runs the centre, Dr Robin Crump, was presented with a unique "before and after" study which is providing valuable information about the impact of oil on the life of the seashore. To the casual observer, the recovery of the bay seems complete, especially to those who recall the thick brown deposits of oil which coated the beach after the spill.


[ image: The RSPCA launched a massive operation with helpers to clean the birds]
The RSPCA launched a massive operation with helpers to clean the birds
But with the help of a guide like Dr Crump subtle changes in the balance of nature can be observed.

One of the most significant effects of the oil spill in scientific terms was felt by a tiny creature known as the brooding cushion-star, or Asterina phylactica to those in the know. This extremely rare species was first identified by Dr Crump himself at West Angle Bay - following the spill the local population of this starfish fell from around 200 to just five, leading to fears that the colony would be wiped out.

But in an example of the remarkable resilience of nature, the creature found a way of fertilising itself rather than relying on other starfish to breed, and recent observations have shown the cushion-star well on the road to recovery, with 50 individuals now lurking in the bay.

Dr Crump now admits that the oil spill provided him and other scientists with the most exciting research opportunity of their careers - and the general observation is of a quite astonishing recovery given the catastrophic damage caused to the shoreline in the short term.

Tourism still vital

With the closure of several defence establishments in Pembrokeshire and the scaling-down of the oil industry, tourism has become the lifeblood of the area, and one of the greatest fears at the time was that the Sea Empress spill would deter visitors from travelling to this picturesque area.

Local hoteliers were understandable infuriated when television pictures showing oiled beaches and birds continued to be broadcast long after most of the coastline had been cleaned.

But he important beaches at Tenby and Saundersfoot were looking impressively clean by the time of the Easter holiday, although there were still pockets of oil in the remote coves.

Research suggests that there probably was an impact on the number of visitors to Pembrokeshire in the 1996 season, but it is very difficult to measure the exact link with the Sea Empress and the images people saw on their television screens.

What seems clear is that any impact was short-lived, and the poor season in 1998 was shared by the whole of Wales, and seems to have been another consequence of the poor weather.





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