Comparative marine ecosystem analysis: Applications, opportunities, and lessons learned

The papers in this special issue seek to evaluate how ecosystem structure and function interact to support fisheries production. We particularly elucidate which processes amplify or dampen spatial and temporal variation in that production within and between ecosystems. This paper attempts to assess the contribution of marine comparative ecosystem analysis to knowledge of the factors that affect the structure and function of marine ecosystems. We introduce the reader to the special volume, briefly highlighting the manuscripts in this special issue as organized by various thematic emphases. Papers in this volume are reviewed and briefly summarized with respect to current approaches, applications, opportunities, and lessons learned. Several approaches, applied to ecosystems over different spatial and temporal periods as well as the application of innovative statistical methods, facilitated comparisons and revealed basic underlying patterns that would not have been observable if only one ecosystem had been examined. Results imply that deeper eastern ocean boundary systems are more strongly influenced by bottom-up forcing; that shallower western ocean boundary systems, mainly continental shelves, are more strongly influenced by top-down forcing; and that synchronous events have taken place around the world's oceans. In many examples, it appears as if fisheries landings have shifted in emphasis from groundfish to invertebrates and that fish communities have shifted from a demersal to pelagic dominated groups. The benthos is an important, but understudied component of most ecosystems. We advocate database standardization at the onset of comparative studies as a mechanism to facilitate effective comparisons in future studies. Effective marine ecosystem comparisons require large, multi-national collaborations. Published by Elsevier Ltd.