Integrating human dimensions into a global model of the marine wild-capture fishery

Kim Scherrer, Autonomous University of Barcelona (UAB), Institute for Environmental Science and Technology (ICTA), Barcelona, Spain and Eric D Galbraith, McGill University, Montreal, QC, Canada; Autonomous University of Barcelona (UAB), Barcelona, Spain
The global oceans are increasingly impacted by human activity. Fishing is a major component of the coupled human-ocean system, since it may alter the resilience, size-structure and functioning of marine ecosystems. It also provides important human benefits. However, the future trajectory of global marine catches, which determines the sustained provision of nutrition and source of income for millions of people worldwide, depends on multiple interacting forces at play within human societies, including fisheries management and governance, techno-economic progress, and the capacity to mitigate climate change. Considering this complexity, there is an urgent need to better understand the dynamics of the global human-ocean system. We develop a unified modeling framework that simulates both the marine ecosystems and interactive fishing activity, in a way that is compatible with conducting multi-decadal simulations and projections in an Earth System modeling environment. When used to evaluate the importance of multiple drivers of change, the framework identifies management effectiveness and technologically-driven increase in catch efficiency as the main challenges for future sustainability. While climate change reduces the possible upper bound for global catches, its influence in the model is secondary to management, especially in the short-term. The results also suggest some problematic long-term mechanisms important to consider in natural resource management. When including coastal fishing undertaken by the local human population, the framework suggests hotspots for competition between coastal and long-range fisheries. This raises issues about regional differences in the potential for long-term sustainability and the distribution of benefits that humans can obtain from marine ecosystems.