AS the anniversary approaches of the Braer tanker disaster, the seas remain at risk of pollution with two decades after the Shetland oil spill, according to conservationists.

January 5 marks the day 20 years ago that the Liberian-registered vessel ran aground with 85,000 tonnes of crude oil on board – twice as much as was on the Exxon Valdez, whose grounding four years earlier off Alaska had devastated wildlife.

Thanks to some of the worst weather ever seen on Shetland, coastlines were spared the worst, with the oil dispersed by weeks of storms.

Lang Banks, of conservation group WWF, claimed the UK Government's "foolhardy decision" to press ahead with the removal of one of two emergency tugs covering the Scottish islands has left the marine environment without adequate protection.

He said: "One only needs to look at the recent accidents on Total's Elgin and Shell's Gannet Alpha platforms, or the almost one thousand other oil and chemical spills that take place around our coast annually, to know that we're never far away from the next major pollution incident.

"Despite the passage of some 20 years, the sad fact is that much of Scotland's marine environment remains just as much at risk from oil and other pollution."

Jonathan Wills, a Shetland councillor who wrote a book about the disaster, has uncovered evidence he says throws doubt on the tanker's seaworthiness.

He also believes questions prompted by the grounding remain unanswered.

He asks: "Why didn't the Crown bring charges under the Control of Pollution Act, at the very least? Why don't insurers insist on better inspections of the ships they cover?

"And why does the British Government still allow tankers to sail through our fishing grounds and environmentally sensitive coastal waters without all-risks insurance?

"The law needs changing, to make sure that polluters really are fully covered and really do pay up."

Martin Heubeck, employed by Aberdeen University to monitor seabird populations around Shetland, watched the Braer go on the rocks and was part of the wildlife rescue that followed.

He said: "Just round the corner from the Braer was Sumburgh Head, where there is an RSPB reserve and, between 1992 and 1993, the breeding numbers of shag halved, and black guillemots fell by a third – but the mortality will probably have been greater."

Billy Fox, the Shetland South councillor with the Braer site in his ward, helped rescue oiled birds in the aftermath. He said: "The scene was pretty grim. Mother nature intervened with the horrendous weather, which persisted for the next two to three weeks, dispersing the oil.

"Within a couple of years, unless you lifted up a stone on the shore and found some oil residue, you wouldn't have known it happened. It is a bad dream that we managed to get over surprisingly quickly."