an exploration of the global blue economy
FishMIP's Ocean System Pathways: Aligning Fisheries Science with Global Policy
Towards coordinated governance of climate, food security, and biodiversity through climate scenario modeling
Over the past decade, the Fisheries and Marine Ecosystems Model Intercomparison Project (FishMIP) has emerged as a central pillar of global ocean science. Its early contributions brought clarity to how climate change alters marine mammal biomass through warming waters, shifting productivity, and large-scale ecosystem reorganization. These advances significantly refined understanding of the physical and biological constraints governing ocean systems. As this body of knowledge matured, however, a more consequential insight became unavoidable: climate change sets the context for ocean futures, but it does not determine them alone. Economic incentives, governance capacity, and policy decisions play an equally decisive role in shaping marine outcomes.
This recognition has guided FishMIP into a new and notably successful phase of development. The creation of the Ocean System Pathways (OSPs), marks a decisive evolution in how the future of fisheries and marine ecosystems is assessed. The OSPs are designed to capture the combined influence of climate change and socio-economic development, explicitly recognizing fisheries as complex social-ecological systems rather than purely biophysical ones. Built directly on the Shared Socioeconomic Pathways (SSPs) used by the Intergovernmental Panel on Climate Change (IPCC), the OSPs extend these global narratives into the institutional, economic, and cultural realities that govern marine capture fisheries and mariculture.
Where the SSPs describe broad trajectories of growth, inequality, and technological change, they remain largely silent on the mechanisms that determine fishing outcomes. They do not specify how fishing pressure evolves, how management capacity differs across regions, or how governance systems respond to ecological stress. The OSPs address this gap by translating high-development logics into operational assumptions that directly shape fisheries dynamics– harvest intensity, access regimes, compliance behavior, and adaptive responses. In doing so, they bridge a long-standing divide between climate scenario analysis and the practical demands of fisheries policy, providing a standardized and policy-relevant foundation for evaluating future ocean outcomes from regional to global scales.
The policy strength of the OSP framework lies in its deliberate design for application. Each pathway combines qualitative storylines with quantitative drivers and a flexible “plug-in-model” architecture that enables a wide range of marine ecosystem models to simulate fisheries dynamics in a consistent manner. This harmonization supports robust multi-model comparisons, which are essential for credible synthesis products used by international institutions. FishMIP has thus moved beyond exploratory modeling toward a framework explicitly constructed to inform governance, risk assessment, and long-term strategic planning.
The relevance of this achievement is already evident across major science-policy interfaces. For the IPCC, OSP-based simulations enhance assessments of climate impacts on marine ecosystems, fisheries productivity, and seafood availability, while enabling systematic analysis of how benefits and costs are distributed across countries. This distributional perspective is particularly critical for fisheries-dependent regions and directly supports work under the UN Framework Convention on Climate Change, including emerging considerations of climate-related losses and damages.
The OSPs also deliver tangible value for the United Nations Food and Agriculture Organization. By embedding alternative fisheries management strategies within a realistic “conventional trends” socio-economic context, FishMIP provides a credible platform for evaluating policy effectiveness. Comparing weak, current, and fully compliant management regimes under climate change generates actionable evidence on how governance quality influences food security, livelihoods, and economic stability, strengthening the capacity to support member states in designing resilient and adaptive fisheries policies.
Biodiversity governance represents a third pillar of impact. Through alignment with the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystems Services Nature Futures Framework, the OSPs translate sustainability objectives into operational scenarios that can be rigorously tested. This enables systematic evaluation of conservation strategies, including marine protected areas and alternative management regimes, in direct support of the Kunming-Montreal Global Biodiversity Framework and related international commitments.
Technically, the OSP simulation protocol reflects a mature and credible advance. Its integration with established methodologies, rigorous historical evaluation, and consistent treatment of climate and socio-economic drivers ensure projections that are both scientifically robust and policy-ready. By explicitly separating and recombining climate and human influences, FishMIP delivers transparent insight into which policy levers matter most, and under what circumstances.
Taken together, the Ocean System Pathways mark a clear success for FishMIP and a meaningful step forward for ocean governance. They demonstrate that coordinated, policy-oriented modeling can produce practical tools for managing climate risk, strengthening fisheries governance, enhancing food security, and conserving marine biodiversity simultaneously. More importantly, they affirm an empowering message for policymakers: the future of the ocean is not fixed by climate change alone, but can be actively shaped through informed, deliberate, and well-governed choices.