CLIOTOP WG4 ↔ WG5 Integrating biophysical and socio- economic models to address the Challenge(s) of Change

WG4 (Synthesis & Modeling) What is the relative importance of fishing and the environment in structuring PEs? What mechanism(s) explain observed variation across species, regions, etc. and have good predictive power? What alternative states might occur in PEs; how are they caused; what are their consequences; are they reversible? Does knowledge about environmental forcing and the nature of fisheries suggest an optimal allocation of fishing activities? Important and necessary but arguably academic Applied but possibly a poor question (blame me)

Assertions The Challenges of Change are more strategic (e.g., allocations among fleets) than tactical (e.g., how much yellowfin to catch) Identifying optimal strategies is probably a poor concept – flexibility and robustness seem best suited for dealing with Change

A Useful Framework Performance measures Implementation Complex model of ecological system that includes fishing, physical forcing, etc. Data collection Simpler model that provides an assessment of conditions in the ecological system Rules that determine what actions are taken in response to the assessment Current emphasis of work in WG4 Lots of available models Developed from objectives

WG4 – Current Work Two “complex models” with different assumptions and structural equations Both use ocean circulation and biogeochemical models to provide bottom-up forcing and fishing to provide top-down forcing Both predict the biomasses of “tuna forage” Maury et al. – APECOSMLehodey et al. – SEAPODYM

WG4 – Current Work Both models being “validated” from comparisons with observed spatial and temporal data Aim is for both models to provide global coverage with ability to forecast the impacts from future climate change and fishing Maury et al. – APECOSMLehodey et al. – SEAPODYM

Performance measures Implementation Complex model of ecological system that includes fishing, physical forcing, etc. Data collection Simpler model that provides an assessment of conditions in the ecological system Rules that determine what actions are taken in response to the assessments Model that provides an assessment of conditions in the socio-economic system Complex model of socio-economic system that includes important “external factors” Data collection Implementation Straw Man

Give & Take global, spatially-explicit predictions about things that matter to Industry, Governments, and NGOs a richer (more realistic?) set of rules, actions, and objectives WG4 → WG5 WG4 ← WG5 Synergism an integrated modeling effort that can help identify management strategies and actions which are flexible and robust to Change WG4 ↔ WG5