A New Process-Based System-Wide Model for Policy Exploration and Optimization

Fisheries are complex coupled social-economic-ecological systems, rendering resource management difficult for scientists and policy-makers.  Therefore managers are typically unable to perform systematic empirical experiments to test different policy interventions.  As a result, a new mechanistic modeling platform is being developed which more explicitly incorporates fisher behavior dynamics into the system:  POSEIDON - Process-based Ocean-system Simulator for Evolving Integrated Domains and Operational Needs.  POSEIDON is a spatially explicit model capable of coupling to a variety of ecological sub-models.  The model contains a sophisticated agent-based fishing fleet, market dynamics, policy incentives and constraints, and an iterative optimization routine to help identify policies.  Theoretical results, together with those from an application to the US west coast ground fish fishery, suggest that highly realistic macro-patterns of behavior emerge under a wide range of simulated policy combinations.  For example, simulated vessels ‘fish the line’ to benefit from marine protected area spillover and avoid bycatch, and respond to individual transferable quotas and total allowable catch (TAC) limits.  The model is being developed to help managers understand the ecological and socioeconomic benefits and tradeoffs associated with an array of policy choices under a variety of conditions across different fishery architypes, and ultimately help reduce management uncertainty.