This publication comprises the proceedings of an international workshop convened in St. John's, Nfld, Nov. 26-29, 1979. The purpose of the workshop was to discuss the results of recent multispecies research, its applications to management, and to consider future directions for research in this field. A total of 26 papers were presented, including a combination of experience papers, state-of-the-art review, and new scientific findings. Sequential sessions were held on fisheries systems research by the Department of Fisheries and Oceans, multispecies considerations in fisheries research and management advice in the ICES area, species interactions in the Northeast Pacific and Northwest Atlantic, fisheries interactions, and applications to fisheries management. The workshop concluded with a substantial discussion of implications of present knowledge for advice to fisheries managers and implications for research program planning. The Workshop Report comprises the Chairman's opening remarks, a report on main elements of discussion in the sessions, and a summarization of workshop conclusions.