Emeritus Professor Butterworth heads the Marine Resource Assessment and Management (MARAM) Research Group. He has acted as a consultant on fisheries management issues to 11 other national governments, and also to fishing industries in 10 countries. He has served as a national representative or invitee in his personal capacity on the scientific committees of 11 international fisheries organisations.

His research covers many marine species, including anchovy, hake, krill, lobster, orange roughy, sardine, seals, tuna and whales. He has received a number of prestigious awards, including the South African President's National Orders award of the Order of Mapungubwe (silver) for contribution to the betterment of the environment and sustainability of fisheries.