At the Annual Meeting of the Scientific Council of NAFO in September 1980, it was agreed that a review of environmental conditions in the northwest Atlantic during the 1970-79 decade was desirable. Consequently, a symposium was held at the Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada, on 15-16 September 1981, during which 15 contributions were discussed (NAFO Scientific Council Reports for 1981). Several of the papers were solicited by the convener to ensure that the major aspects of environmental conditions were covered. Twelve of the contributions are included in this volume.