Regime shifts in harvested marine ecosystems around the world have been documented in empirical research, using concepts such as resilience, abrupt collapse, tipping points, and hysteresis, and considering levels of complexity from single species to entire communities. Ecological and economic studies approach the topic typically from different angles: While ecologists analyze empirical data to identify evidence and early warning signals, economists follow a theoretical, model-based approach with a focus on management. Although the linkages between the ecological and economic sub-systems of social-ecological systems are widely acknowledged, only very few studies investigate resource collapse and recovery in harvested marine ecosystems from an integrated ecological–economic perspective.
We review the development of concepts related to regime shifts and present the state of the art of the research field from ecological and economic perspectives. We develop an integrative ecological-economic view on regime shifts using Atlantic cod stocks as examples. We specifically address aspects of mutually reinforcing ecological, economic, and ecological-economic feedbacks leading to collapses of resource populations, and processes limiting or promoting recovery of ecosystems. We show that spatio-temporal cross-scale effects can play an important role in collapse and recovery of harvested fish populations. We conclude on the importance of regime shift concepts for ecosystem-based management and develop a positive perspective of shifting marine ecological-economic systems towards regimes of sustainability.
Christian Möllmann is a Professor for Fisheries Science at Hamburg University since 2008. He received a PhD in Fisheries Biology from Kiel University, Germany, in 2002 and was a postdoctoral researcher at the National Institute of Aquatic Resources in Charlottenlund, Denmark. His main research interest is in changes in ecosystem structure and function due to the cumulative effects of fisheries and climate change. He is furthermore interested in developing ecosystem-based fisheries management strategies.
Martin Quaas is Professor of Economics at Kiel University since 2007. He did his PhD in Economics at the University of Heidelberg in 2004, followed by Postdocs at the Department of Ecological Modelling, UFZ-Helmholtz Centre for Environmental Research Leipzig, and Tilburg University, The Netherlands. His research focuses on sustainability in human-nature relationships, especially sustainable fisheries and climate economics.