Bioeconomic Multispecies Analysis of Marine Ecosystems

The project Bioeconomic Multispecies Approach to Marine Ecosystems (BMAME) has fulfilled its main objective: Establishing a generic instrument determining Consistent Harvest Control Rules (CHCR) for all species simultaneously i.e. the harvest control rule for each individual species depends directly on the state of affair of every species involved. In principle it can run on a website such that any stakeholder can get TACs resulting from their informed guess on stock compositions at any point in time (present or future). Participants may invest or disinvest and take their loss or gain accordingly. This transparency is needed in order to facilitate stability in markets and reduce volatility in prices. Implementing tools like CHCR and its implied transparency will incentivize the formation of forward prices/markets that are more ecosystem friendly and internalizing more of biological/environmental and economic uncertainties. It is expected that forward prices will dynamically restructure the industrial sector to adapt to future needs conditioned on maintaining healthy and productive marine eco-regions. The BMAME instrument optimizes value creation constrained by sustainability and represents a more holistic perspective than present day fisheries management. The present operating framework is mainly single species management with heuristic harvest control rules (HCR) and ad hoc stability rules and neither are value optimizing. The total allowable catches (TACs) implied by the BMAME harvest rules are multispecies adapted both in sea and on land. They are adapted to interaction in the ocean (biology) as well as potential economic interaction. Hence the ideas and results from the project represent a big step towards developing a transparent and practical framework meeting the international commitments to implement Ecosystem Approach to Fisheries (EAF). An important step towards Ecosystem Approach to Management (EAM) is breaking the chain of single species HCR or single species management in parallel, which is present day state-of-the-art fisheries management. The first version of the BMAME instrument works with three species simultaneously (tested on cod, capelin and herring in the Barents Sea). The generic ideas hold for any number of species although our computer implementation is limited to three. Increasing the number of species (complexity in the sea) and the overall complexity in the human-ecosystem interaction are practically limited by computational power. Even with a limited number of species involved the program addresses key questions of high relevance for progress on EAM recommended by the European Science Foundation: (i) Developing strategies and tools for partitioning natural variability and human-induced variability. (ii) Putting in place a framework for effectively dealing with reducible uncertainty and coping with irreducible uncertainty. (iii) Improve the scientific basis for cost-benefit analysis, across social, economic and ecological dimensions of sustainability, including non-monetary values. The harvest policy outcome from the BMAME framework is robust against dynamic uncertainty and has a high threshold against risks by maintaining stability and resistance against random shocks without suppressing natural cycles in fish stocks and their ability to adapt to a changing environment. EAM implies determining TACs of various species as interrelating parts of a system rather than individual stocks. TACs are macro quantities derived from top-down decisions framework, which induces aggregated decisions rules for the harvest implying that each TAC depends on all species and their inherent stochasticity. Our multispecies bioeconomic modeling is the key to ensure overall management objectives are economic sound and informational efficient and compatible over time and stock levels. Furthermore, ecosystem management means awareness of effects on different scales. This is why we use lower leveled (micro) biological-founded ecosystem simulators to validate a given policy to ensure micro details aggregated away in policy step do not produce unexpected and unacceptable negative effects. This two-stage process is a policy generation on the overall uncertainty and an associated micro risk assessment Applying the framework on the Barents Sea reveals new information and TAC policy. Strong interdependency in the biomasses of the species (capelin, cod and herring) implies that for certain combinations of stock sizes it might be better reducing the harvest of capelin as it becomes more of it. Somewhat counterintuitive. In economic context it makes sense. If cod is more valuable it may occur that it is better to let the cod eat more capelin ensuring higher density of cod and less costly harvesting. In general the multispecies approach results in a policy with lower TACs and higher value creation due to markets effects.

The project covers topics that are both of theoretical and applied interest and cover several subprograms within the purview of the program Havet og kysten. We believe there is an urgent need for applied research regarding utilization of marine ecosystems with emphasis on decision modeling of total allowable catches (TACs) in a broad multispecies context. This investigation will focus on strategies for optimal and simultaneous decisions concerning capelin, herring and cod in the Barents Sea, one of the m ost productive ocean areas in the world. The ecosystem is highly dynamic and volatile. The modeling of a top-down and multidimensional bioeconomic decision process may be used to produce economic sound and informational efficient management strategies ens uring long term sustainability. Due to the level of aggregation the resulting feedback policies should be validated by more detailed biological ecosystem models which, by themselves, lack the ability to determine optimal policies. The modeling and integra tion of such a two-stage process need multidisciplinary collaboration and will provide opportunities for novel research of cutting-edge academic quality beyond the Ph.D. level. A successful outcome of the proposed project will develop basic as well as app lied scientific results in the fields of bioeconomics and fishery research, numerical modeling of multidimensional stochastic bioprocesses, and operational research and management science.