WIND and tide cooperated on Monday to keep Australia's worst oil spill off the beaches and coral of Cervantes, Western Australia, about 100 miles north of Perth."It does not appear to be a major environmental problem at the moment," says Hayden Smith, an official with the Western Australia Department of Marine and Harbors. Officials cautioned that the spill, estimated to be as much as 160,000 barrels of crude, was still a threat to coastal regions, including crayfisheries and a colony of sea lions and sea birds. The spill took place Sunday morning when the Greek tanker Kirki reported a fire. The front of the tanker had broken off and three oil storage tanks had ruptured spilling light crude oil into the sea. The ship was en route from Abu Dhabi to British Petroleum's Kwinana refinery south of Perth. The stricken tanker is under tow 60 miles off the coast and heading west. Once the ship is 100 miles offshore, officials will tow it north to calmer waters to try transfer the remaining oil.