Aerial shark patrols have begun in South Australia two weeks ahead of schedule, following an attack south of Adelaide last week. A woman was seriously injured when she was bitten on the head near the Port Noarlunga jetty. Planes will fly up and down the coast between North Haven and Rapid Bay, as well as from Victor Harbor to the Murray Mouth, until the end of March. The flights usually begin in December, but the State Government is taking extra precautions with increased beach activity. Pilots say shark sightings can be unpredictable