schaefer worked as a biologist at the washington state fisheries department and from 1937-1942 as a scientist for the international pacific salmon fisheries commission in new westminster, british columbia, canada. in 1946 he joined the united states fish and wildlife service and held various posts at the fishery biology headquarters at stanford university. later, he worked at the pacific oceanic fisheries investigations laboratory in honolulu, hawaii and completed a doctorate in fisheries from the university of washington in 1950. in 1951 schaefer became director of investigations at the inter-american tropical tuna commission (iattc). iattc established its first headquarters at the scripps institution of oceanography.