Nils Peter Emil Christiansen family

I am searching for decendents of my great grandfather Nils family. He was born 21 Oct 1854 in Fredrickstad and emigrated to Australia on ship Herschel leaving in Sept 1876 and arriving in Adelaide Jan 1877. He had sisters Helmine b 1852, Augusta b 1870 and brothers Ole Sovrin b 1857, Karl Julius b 1859 and Maurentsius b 1862. Any information appreciated