Emmigration from Norway to Australia

I am trying to trace the family of my great grandfather from Bergen Norway to Australia. Halsten Johnsten(Johannsen) born 11th October 1846. Occupation Seaman. His Australian marriage certificate states his parents as Andrew and Martha(Nilsen) Johnsten. I also have a copy of his brother Andrews death certificate. I believe he was a crewman aboard a Norweigen ship, before possibly jumping ship in Australia, where he married Elizabeth Jones, who bore him ten children. Can anyone help me?