Phase 1 activities:  Preliminary evaluation of the climate change effects on the four main tuna species of importance in the SPC region

• Revise/complete the parameter optimization for Pacific skipjack, bigeye, yellowfin and South Pacific albacore tuna populations using the forcing fields of the ORCA-PISCES coupled model forced by the atmospheric NCEP reanalysis (previous skipjack and bigeye optimizations were undertaken with the ESSIC reanalysis). This revision to the earlier optimizations is required for consistency with the Earth system modelling framework now generally used for climate change simulations.
• Produce preliminary estimates of the climate change impacts through the 21^st century on Pacific skipjack, bigeye, yellowfin and South Pacific albacore tuna populations under the IPCC A2 and B1 (reduced emissions) scenarios. Reporting of model outputs will cover the 21^st century, with particular focus on 2035 and 2100 to be consistent with IPCC reporting protocols and the 5^th IPCC Assessment Report in particular.
• Document the methodology and results of the research for peer-reviewed scientific publication.
• Use the results of the modeling to inform the more general debate on climate change impacts on Pacific fisheries and aquaculture, including vulnerability assessments, implications of impacts and possible adaptation strategies.

The expectation from phase 1 is that modelling results should be available by 31 July 2011, with a preliminary paper presented to the Western and Central Pacific Fisheries Commission (WCPFC) Scientific Committee in August. We also expect to present these results at the Pacific Climate Change conference in Rarotonga, Cook Islands in October 2011.

Phase 2:     Enhanced estimates of climate change impacts on Pacific tuna, including estimates of uncertainty

• Further develop the SEAPODYM model to more realistically model the impacts of climate change related variables, e.g. ocean acidification, on Pacific tuna populations.
• Assemble a plausible ensemble of IPCC-class climate change simulations to characterize a scientifically defensible range of uncertainty in climate change predictions. The IPCC A2 and B1 scenarios will be key elements of the ensemble.
• Generate population simulations for the four tuna species for each of the climate change simulations in the plausible ensemble and summarize the results in appropriate forms to articulate both the predicted overall spatial and temporal trends in tuna stocks and the uncertainty in those trends. The uncertainty envelope would be conditioned on the plausible ensemble of climate change simulations as well as structural and parameter uncertainty of the SEAPODYM model. As for Phase 1, reporting of model outputs will cover the 21^st century, but with particular focus on 2035, extending to 2100, to be consistent with IPCC reporting protocols, and the 5^th IPCC Assessment Report in particular.
• Document the methodology and results of the research for peer-reviewed scientific publication.
• Use the results of the modeling to inform the more general debate on climate change impacts on Pacific fisheries and aquaculture, including vulnerability assessments, implications of impacts and possible adaptation strategies. Model outputs will also be summarized at the national level where appropriate, to provide scientific advice to support national policy development.

Phase 2, should funding support be identified, would undertake over 3 years a more comprehensive suite of analyses of the four species to characterize the uncertainty in the predictions in relation to alternative population dynamics model structures, parameter uncertainty and plausible climate change scenarios