Tanker Grounded Off Shetlands Appears to Be Splitting : Oil spill: A fishing ban is imposed to ensure the quality of the catch, which earns islanders $120 million a year.

The wrecked oil tanker Braer apparently was breaking up on the rocks of this island late Friday, even as Scottish authorities banned all fishing in the area because of pollution risks.

About half of the crude oil, which has contaminated the coast and adjacent fields, is probably still aboard the 700-foot tanker, said Capt. Geert Koffeman of the Dutch salvage company Smit Tak, which will try to pump out the remaining cargo.

Capt. George Sutherland, Shetlands marine operations chief, said the ship was “showing signs of breakup in the aft area,” adding, “the engine room is separating from the cargo tank area.”

If the ship’s stern does snap off, it may be easier for crews to salvage the remaining crude on the Braer because the section of the vessel with the tanks in it might become more stable, Koffeman said. He said crews hope to reach the tanker’s cargo holds to pump the oil there through floating hoses into a huge, nearby offshore barge.

But heavy seas and high winds continued to frustrate cleanup efforts Friday. Authorities for a second day grounded DC-3 Dakota planes that were to spray chemicals to disperse the slick from the Braer; they said that the continuing stiff winds blew cleanup chemicals aimed at the oil-soaked water onto land.

For Shetlanders, some of whom labored Friday to install concrete dams and booms between their salmon farms and the encroaching slick, the oily mist from the huge spill and wind-churned ocean continued to be a major irritant and health concern.

As for the fishing ban, the government said it was imposed to ensure the quality of the catch from the Shetlands area and to save a local industry that earns $120 million a year and employs almost one-third of the working population here. Local fishermen supported the move, because, as spokesman Alistair Goodlad explained, “We’re absolutely of one mind--no product will go out of Shetland which is not of the best quality.”

Marks & Spencer, the British chain merchandising giant, announced on Friday it would stop buying salmon from Shetland fish farms as “a temporary precaution measure” to ensure no contaminated seafood reached its stores.

As Prince Charles and his father, Prince Philip, announced plans to visit the Shetlands in the next few days to investigate the spill-related damage, there was some speculation Friday that the tanker’s owners might get more cash from their insurance than if they had sold their vessel before it ran aground.

B & H Ship Management of New York, Reuters news service reported, took out a policy in mid-January, 1992, that values the ship at $12.7 million. The policy includes an extra $6.3 million against loss of earnings from any wreck.

Norwegian ship brokers Fearnleys said that, intact, the 17-year-old Braer would have fetched $4.5 million to $5 million on the secondhand market. But a Fearnleys official said it was unfair to say the Braer’s owners would profit from the disaster, as they had paid $15 million or $16 million for the vessel in 1989. Also, the policy reflected the value of the ship a year ago, Reuters said.

“The idea of the owners escaping loss will be little comfort to inhabitants of the Shetlands, facing years of pollution left by the disaster,” one shipping expert told Reuters. “But to imply that the owners will be laughing all the way to the bank is ridiculous. They’ve lost a lot since buying the ship and may be stuck with big debts.”

Projections that insurance payouts would more than cover the cost of replacing the vessel also assume that claims for cleaning up pollution damage do not exceed an insured value of $700 million, Reuters said. If they do, the owners’ assets could be seized. Also, if the owners could be shown to be grossly negligent, then they might have to pay. But the vessel has been generally praised as well maintained for its age.