The Ocean System Pathways (OSPs): a new scenario framework to investigate the future of marine ecosystems and fisheries

Following the example of the Climate Model Intercomparison Project (CMIP), the Fisheries and Marine Ecosystems Model Intercomparison Project (FishMIP, https://fishmip.org/) has dedicated a decade to unravelling the potential impacts of climate change on marine animal biomass at the global and regional scales. Considering that the future of global fisheries and marine ecosystems will not only be shaped by climate change but also by long-term socio-economic shifts, FishMIP is now preparing a new simulation protocol to assess their combined impacts on the world marine fisheries and ecosystems. These projections will be based on the Ocean System Pathways (OSPs), a new set of socio-economic scenarios derived from the Shared Socioeconomic Pathways (SSPs) widely used by the Intergovernmental Panel on Climate Change (IPCC). The OSPs extend the SSPs to the economic, governance, management and socio-cultural contexts of large pelagic, small pelagic, benthic-demersal and emerging fisheries, as well as mariculture. Comprising qualitative storylines, quantitative model driver pathways and a “plug-in-model” framework, the OSPs are designed to enable a heterogeneous suite of ecosystem models to simulate fisheries temporally and spatially, in a standardised way. We present this OSP framework and the simulation protocol that FishMIP will implement to explore future ocean social-ecological systems holistically, with a focus on critical issues such as climate justice, global food security, equitable fisheries, aquaculture development, fisheries management and biodiversity conservation. Ultimately, this framework is tailored to contribute to the synthesis work of the IPCC in the perspective of the UN Framework Convention on Climate Change (UNFCCC), to inform ongoing policy processes within the United Nations Food and Agriculture Organisation (FAO) and to contribute to the synthesis work of IPBES, with a focus on the implementation of the Kunming-Montreal Global Biodiversity Framework (GBF) of the United Nations Convention on Biological Diversity (CBD).