The global marine ecosystem is being deeply altered by human activity. On the one hand, rising concentrations of atmospheric greenhouse gases are changing the physical and chemical state of the ocean, exerting pressure from the bottom up. Meanwhile, the global fishery has provided large economic benefits, but in so doing has restructured ecosystems by removing most of the large animal biomass, a major top-down change. Understanding the full range of interactions between humans and the marine ecosystem requires a framework that includes all relevant components.
The recent, rapid developments in Earth System modelling provide a computational infrastructure upon which to build this work – virtual oceans, that circulate according to equations describing the fundamental physics. These ocean models predict water temperature and light availability, allowing the growth of phytoplankton to be calculated as a function of the environment, and coupled to the cycling of dissolved nutrients and gases, using coupled biogeochemical models.
The recently-developed BiOeconomic mArine Trophic Size-structured (BOATS) model, a key proof-of-concept for the BIGSEA project, is designed to be embedded within a virtual ocean environment. BOATS is the first grid-based bioeconomic model of the global fishery that represents economic activity as an endogenous, free-running process, explicitly coupled to the ecosystem.
The BIGSEA project will build on the BOATS foundation, linking it with the BLING biogeochemical model using existing observations to develop quantitative relationships and new theory for critical missing processes. At the same time, the human dimensions of the model will be greatly expanded, in collaboration with economists and social scientists in Barcelona and abroad. By bringing together a diversity of traditionally-disparate domains within a single group, the BIGSEA project will open up new avenues of inquiry.