Arni Thomson was born in Prince Rupert B.C. He graduated from Western Washington University in 1965 and began halibut fishing in 1966. He earned a Master's degree from Central Washington University in 1975, writing a thesis on the Pacific Halibut Fishery while working as a deckhand. Arni also had a distinguished 25-year career as the founding Executive Director of the Alaska Crab Coalition from 1985 to 2010.