Tracing the fate of escaped farmed cod (Gadus morhua L.) in a Norwegian fjord system

Summary of thesis: The aim of this thesis was to investigate the fate of escaped farmed cod and detect any introgression in the local stock. Phenotypic discrimination of wild and farmed cod, and genetic baseline values for wild and farmed characteristics were established. The thesis also included a simulated escape (tag and recapture experiment), to study dispersal and presence of escapees in the Trondheimsfjord estuarine system, and an investigation of pen-spawned pelagic cod eggs and larvae in the neighbourhood of the cod farm. The potential impact escape by spawning on local cod populations was assessed. Two large escape events and extensive pen spawning has been reported for the farm in the Trondheimsfjord, still the genetic evidence did not show a robust sign of introgression of farmed cod into the wild stock. The results also indicate a limited presence of escaped farmed cod, suggesting a low ability to adapt to a life in the wild