Margalef, one of the most prominent scientists that Spain has produced, worked at the Institute of Applied Biology (1946–1951), and at the Fisheries Research Institute, which he directed during 1966-1967.
Margalef arbeitete am Institut für Angewandte Biologie (1946–1951) und am Institut für Fischereiforschung, das er von 1966 bis 1967 leitete.