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1 An Ecosystem Model for Exploring the Ecological and Economic Role of Pacific Sardine in the California Current Large Marine Ecosystem By Rashid Sumaila and Andrés M. Cisneros-Montemayor University of British Columbia and Samuel F. Herrick Jr., NOAA Fisheries Southwest Fisheries Science Center
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The importance of the sardine resource in the California Current large marine ecosystem (CCLME) –Generated an ongoing effort to construct an ecosystem model that captures the environmental, ecological and economic dynamics within the CCLME. Objective: to evaluate different management strategies and quantify the effects of resulting environmental and ecological interactions on economic performance at various levels. –This includes landed values to fishermen, –downstream economic impacts, and –The value of ecosystem services provided by particular species, most notably small pelagic fishes. 2
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Begin with a conceptual sardine centric model linking: –Environment: climate change –Ecosystem: food web –Economy: total economic value 3
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Climate Change Low frequency Pacific sardine and northern anchovy fish-scale- deposition rates in sediments of the Santa Barbara Basin (Baumgartner et al.) –Shows nine major recoveries and subsequent collapses of the sardine population over 1700 years. –The average time for a recovery of the sardine is 30 years. –Current recovery is not unlike those of the past in its rate or magnitude. –Changes in the environment have been postulated as reasons for these cycles 4
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Of all CPS, sardine productivity is most strongly affected by environmental variation (Pacific Fishery Management Council, CPS FMP) –Periods of low abundance for sardine are probably inevitable, even in the absence of a fishery. Observed cycle during the 20 th century (Norton et al.) –Sardine abundance is related to accumulated SST anomalies –Accumulated anomaly curves change the sign of their slope, showing maxima (minima) when climate is favorable (unfavorable) to sardine productivity. 5
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–Implications for cooperative transboundary management: fishing game models under climate change, the case of pacific sardine. ( Gaku Ishimura at the 2009 Trinational) 6
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Climate Change High Frequency ENSO events and reproductive success –Sardine productivity also appears to be affected by interannual environmental variability as witnessed by relatively large 2003 and 2009 year classes following warm water episodes (NWS, Climate Prediction Center). –The environmental proxy derived from SIO pier temperature no longer predicts recruitment of Pacific sardine (McClatchie et al.) 7
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Ecology Ecological: food web, efficiency of converting sardine biomass to predator biomass Evaluation of food chains and energy transfer in CCLME (Field et al. 2006) –Which fish and animals prey on sardines –how much do they consume –how much of that is converted into fish or animal flesh that could either be caught or enjoyed in its natural surroundings. 8
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Economics Total economic value (Hannesson et al.) –How changes in the net per unit value of sardines, the net per unit value of sardine predators, and the transfer efficiency of predators affect the total net value of sardines –Taking the value of sardines as forage into account does not necessarily mean an either-or situation for the fishery –As long as there is some measure of net value from the fishery and net value from predation, both benefit society at large. 9
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Progress: Develop and combine these components into an integrated model, E 2 –Transboundary management model, Ishimura –An Ecopath with Ecosim model of the British Columbia Shelf, the northernmost distribution of the Pacific sardine population. –Provides useful information that can be used to evaluate management policies and advise stakeholders. 11
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Next we will hear from Andres Cisneros on the latest E 2 advances. 12
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References: Baumgartner, T. R., A. Soutar and V. Ferreira-Bartrina. 1992. Reconstruction of the history of Pacific sardine and northern anchovy populations over the past two millennia from sediments of the Santa Barbara Basin, California. Calif. Coop. Oceanic Fish. Invest. Rep. 33: 24-40. Norton, J. G. and J. E. Mason. 2005. Relationship of California sardine (Sardinops sagax) abundance to climate-scale ecological changes in the Calif. Coop. Oceanic Fish. Invest. Rep. 46: 83-92. Herrick, Jr. S. F., J. G. Norton, J. E. Mason and C. Bessey. 2007. Management application of an empirical model of sardine-climate regime shifts. Marine Policy 31:71-80. McClatchie, S., R. Goericke, G. Auad and K. Hill. 2010. Re-assessment of the stock– recruit and temperature–recruit relationships for Pacific sardine (Sardinops sagax) Can. J. Fish. Aquat. Sci. 67: 1782–1790. Field, J.C., R.C. Francis and K. Aydin. 2006. Top-down modeling and bottom-up dynamics: Linking a fisheries-based ecosystem model with climate hypotheses in the California Current. Progress in Oceanography 68:238-270. Hannesson, R., S. Herrick and J. Field. 2009. Ecological and economic considerations in the conservation and management of the Pacific sardine (Sardinops sagax). Ca. J. Fish. Aquat. Sci. 66: 859-868. Hannesson, R. and S.F. Herrick Jr. 2010. The value of Pacific sardine as forage fish. Marine Policy 34: 935–942. 13
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