The Ocean System Pathways (OSPs): A New Scenario and Simulation Framework to Investigate the Future of the World Fisheries

The Fisheries and Marine Ecosystems Model Intercomparison Project (FishMIP) has dedicated a decade to unraveling the future impacts of climate change on marine animal biomass. FishMIP is now preparing a new simulation protocol to assess the combined effects of both climate and socio-economic changes on marine fisheries and ecosystems. This protocol 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 will enable a heterogeneous suite of ecosystem models to simulate fisheries dynamics in a standardised way. This paper introduces 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, the OSP framework is tailored to contribute to the synthesis work of the IPCC. It also aims to inform ongoing policy processes within the United Nations Food and Agriculture Organization (FAO). Finally, it seeks to support the synthesis work of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), with a particular focus on studying pathways relevant for the United Nations Convention on Biological Diversity. Key Points We present new scenarios and models for simulating fisheries and marine ecosystems, accounting for climate and socio-economic changes Our scenario framework extends the SSPs. It can be utilized by any marine ecosystem model and in particular those contributing to FishMIP We propose a simulation strategy addressing major research gaps and including policy-targeted simulation experiments Plain Language Summary The Fisheries and Marine Ecosystems Model Intercomparison Project (FishMIP) has spent 10 years studying how climate change might affect marine life. FishMIP is now getting ready for simulating how climate and socio-economic changes will affect marine fisheries worldwide. For this purpose, FishMIP develops the Ocean System Pathways (OSPs), a new set of scenarios that extend the scenarios used by the Intergovernmental Panel on Climate Change (IPCC) by considering the socio-economic factors related to different types of fishing and mariculture. The OSPs detail what might happen in the future and provide tools that will allow the ecosystem models involved in FishMIP to simulate fisheries in a consistent way. This paper presents the OSP framework and the simulation strategy adopted to explore how ecosystems and fisheries might change in the future, focusing on key issues such as climate justice, food security, equitable fisheries management, and biodiversity conservation. Ultimately, this work will contribute to the IPCC and to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) in understanding how to manage the impacts of climate change. It will also support the Food and Agriculture Organization of the United Nations (FAO) in assessing fisheries policies in the context of global change.