Ecosystem-Economic Interactions in the Norwegian Sea: Analysis and Management

The Norwegian Sea ecosystem is productive and dynamic, and harbors some of the world's largest pelagic stocks. In the larger region, important stocks like Northeast Arctic cod are present. The stocks overlap geographically and seasonally and interact through competition for food, in predator-prey relationships, and also through economic market forces. In addition, the primary food source for the Norwegian Sea pelagic stocks, the zooplanktion Calanus finmarchicus, impact the different stocks and their interactions. Much of the dynamics on high levels in the ecosystem is probably linked to dynamics in C. finmarchicus. Knowledge of the inherent ecological and economic tradeoffs related to exploitation of resources in the Norwegian Sea ecosystem are emerging in the scientific community. The EINSAM-project has contributed to this development on several fronts. The first main topic in EINSAM has been method contributions related to bioeconomic modelling and analysis. The main contribution regarding modelling has been the application of data assimilation methods to bioeconomic modelling of ecosystems or food webs. Regarding analysis, a number of bioeconomic food web models has been subjected to stochastic decision analysis, posing relevant approaches to ecosystem-based fisheries management that are alternative to currently implemented management practices. An effort to marry these contributions and establish a complete model and analysis tool for the Norwegian Sea fisheries remain ongoing. The second main topic in EINSAM has been management and policy analysis. In several contributions, game theoretic analyses of shared Norwegian Sea fisheries was carried out. Part of this work was developed in parallel with modelling work in EINSAM. Another contribution regarded a conceptual understanding of harvest control rules in modern fisheries management. The conceptual framework was contrasted with practical experiences from a number of fisheries around the world, including several in the Norwegian Sea. Several side-tracks and spin-off ideas has been pursued under the EINSAM-project. Two particularly productive spin-offs are (i) an analysis of fisheries technological development in a stochastic trend framework and (ii) an extension of the classical Bellman optimization approach to consider problems involving periodic features.

The project focuses on an important subset of the biotic ocean resources, the main commercial fisheries in the Norwegian Sea, and strengthens the links between zooplankton dynamics, fisheries science, and fisheries management. The ecosystem in the Norwegi an Sea is highly volatile and productive and harbors some of the world's largest pelagic stocks like the Norwegian Spring Spawning Herring, blue whiting, and mackerel. Present in the larger region are Barents Sea capelin, Northeast Arctic cod, haddock, sa ithe, and a range of other species. Many of the stocks overlap geographically and temporally and interact in competition for food or in predator-prey relationships. In addition, the key zooplankton Calanus finmarchicus is the primary food source for the p elagic species in the Norwegian Sea as well as for cod larvae. Observed changes in distributions, population, and migrations of the pelagic stocks are probably closely linked to C. finmarchicus dynamics. While the biological and ecological understanding o f C. finmarchicus has developed for years, economists have yet to explicitly incorporate it in their bioeconomic analysis. Thus, not only is the project relevant for the development of ecosystem based management plans for the Norwegian Sea, it is also nov el in its extent and approach to bioeconomic modeling and analysis. The project covers topics of both theoretical and applied interest, and responds to the urgent need for applied and multidisciplinary research regarding exploitation of marine ecosystems with emphasis on modeling of decisions under uncertainty. The project focuses on strategies for optimal and simultaneous harvest decisions, for the main pelagic fisheries in the Norwegian Sea and for individual fleets from Norway, the European Union, the Faroe Islands, Iceland, and Russia, accounting for strategic behavior between fleets.