It’s almost a year since the Sea Empress dumped 70,000 tonnes of oil on the beautiful beaches of Pembrokeshire. Anyone who knows this lovely coast watched in horror as television news crews showed rockpools coated with sludge and birds and seals surfacing in a sea of black oil. But for the people who live and work there, it was like seeing their home desecrated.

Julian Cremona, a former head of science at St Mary’s College, Southampton, had just started his new job at Dale Fort field studies centre. Normal services were suspended as Dale Fort became headquarters for animal rescue teams, science labs were converted to intensive care units for oiled sea birds, and Mr Cremona coped with a barrage of press inquiries from all over the world.

Dale Fort’s spectacular cliff-top position at the mouth of Milford Haven, where the Sea Empress went aground, provides a fine view of the oil refineries opposite and a reminder of the vulnerability of nature reserves with such potentially lethal neighbours. “For 10 days the oil kept coming in on every tide,” Mr Cremona says. “As fast as it was cleaned, it kept coming back in.” Twice during the crisis, when it was thought the tanker would explode, staff were evacuated to the local pub, on another occasion they provided sanctuary to lighthouse staff.

Anxiety for precious research sites was worsened by the frustration caused by mismanagement of the rescue operation. Last month, the draft report by government accident investigators, leaked to the BBC, revealed a catalogue of failures, penny-pinching, and confusion over who was in charge. As the various interest groups argued about what to do, the oil continued to leak from the tanker.

At one stage, Cremona wondered what the future for field studies at Dale would be. But the moment of doubt soon passed as it became clear that here was an opportunity to turn an environmental disaster to positive educational ends. As one of the first Field Studies Council centres for marine ecology and a focus of research into rocky shore habitats, Dale Fort is ideally placed to monitor the long-term effects of the oil. Within two weeks of the disaster, teaching resumed with pollution studies on the programme.

The Sea Empress provided a lesson that few students would forget, says deputy warden, John Archer-Thomson, who took groups of PGCE students on to the beaches when the stench of oil was overwhelming and a shiny film covered the rocks and seaweed. The death toll for birds may never be known, because thousands died at sea. Nearly 7,000 oiled birds of 28 species were recovered. Among the worst hit were the thousands of scoter ducks, rafting out at sea, and guillemots, down in number by 60 per cent. The effect on breeding seal populations will take years to establish.

Last October, there were few signs of oil on the beaches around Dale Fort. Windsurfers were scudding across the sparkling waters of Milford Haven, and there were seal pups on the beach opposite Skomer. A massive cleaning operation brought summer holiday-makers back, but used methods which, it was feared, could cause even more damage. The slick had gone, but so had more than half of the molluscs and 80 per cent of the barnacles on the beaches beneath the fort. A “green flush” of Enteromorpha spread over everything, showing how badly disrupted these finely balanced habitats had become.

Nevertheless, the area has recovered remarkably well, and in a way that graphically explains the principles of ecology to schools, says Mr Cremona. The Sea Empress Resource Pack, published this month, based on data collected by staff and students, is an account of the spill and its effect on groups of organisms as well as on the wider marine environment and human activity such as tourism. Supported by CD-Rom with video clips and spreadsheet data, it should prove an invaluable resource for students’ own investigations.

Meanwhile, Dale Fort’s pre-disaster attractions are as strong as ever. The centre is surrounded by superb habitats: sheltered rocky seashores beneath the fort; exposed beaches a short walk away across the headland; estuary saltmarshes; sand and mud shores; heath and acid grassland; offshore islands for seabird colonies. There are plans for saltwater aquaria at the centre, but study sites are so close there is little need for collection.

Brigid Tullie, head of biology at North Halifax grammar school, has been taking groups to Dale Fort for the past 14 years and says it gives her students the first-hand experience and understanding essential for A-level. Despite budget cuts, they expect to have about 40 in this year’s group.

Of all types of fieldwork, marine ecology is one of the most popular. The great variety of species with amazing adaptations and the sheer beauty and drama of rockpool life seem guaranteed to capture students’ interest. Courses are intensive - the day starts with lectures, followed by field trips, and ends with slide shows and writing up sessions.

Information technology is essential if you are training people to be scientists, says Cremona. He has acquired 15 more computers for the centre and plans to extend equipment for data logging in the field. A-level courses - “projects without tears” - offer help with equipment, methods and assessment. The library includes the latest journals, multimedia and an Internet connection.

In the centre’s 50th anniversary year, Mr Cremona also plans to develop geography fieldwork and courses for primary schools. He wants them to have an enjoyable and memorable environmental experience, so they have barbecues on the beach where they also make transects (studies along a given line), look for seals basking on Stack Rocks, and go badger-watching in the woods.

The fort’s history and location have a powerful appeal.

It was completed in 1856 as a major part of the Pembroke Dock fortification against the French. And there are plenty of conservation issues to be discovered at first hand. “You don’t have to go to the Amazon to learn about deforestation,” says Mr Cremona. A visit to Skomer, for example, reveals the succession of farming interests from prehistoric times to the 1950s when the island became a nature reserve.

Now that the Sea Empress has added further evidence of the threats to our coastline, there are new lessons to be learned from a visit to Dale Fort.

Dale Fort Field Centre, Haverfordwest, Dyfed SA62 3RD. Tel: 01646 636205.

Dale Fort Field Centre Sea Empress Resource Pack available from the warden, Pounds 6.95 (or Pounds 9.95 including disc plus Pounds 1 postage).

Further reading: A Guide for Rocky Shore Investigations by John Archer-Thomson, Field Studies Council, Pounds 5.

A Field Atlas of the Sea Shore by Julian Cremona, Cambridge University Press, Pounds 8.25