Atlantic cod Gadus morhua L. is host to more than 120 parasite species. Background abundance of these parasite species on adjacent wild hosts determines the infection pressure on cod farmed in open pens. In 2006, 2007 and 2008, 343 cod were collected from 4 locations along the coast of Norway: Øksfjord, Kvarøy, Brønnøysund and Ålesund. Freshly killed wild local cod, wild migratory cod, hatchery-reared ...