Guardian: Australian authorities remain on alert for a potential oil spill in waters around the Great Barrier Reef despite finding little sign of a reported kilometre-long slick off the north Queensland coast. Maritime safety authorities in Queensland confirmed that small patches of oily water were seen in waters south of Townsville where a fisherman had earlier reported seeing a slick close to 1km long. Aircraft from the Australian Maritime Safety Authority will renew the search for evidence of the oil...