MARAM_IWS_2018_Sardine_P2.pdf (188.92 kB)

Recruitment variability estimated by the sardine assessment model

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posted on 19.05.2021, 08:50 by Carryn de MoorCarryn de Moor
When the Hockey-stick stock recruitment relationship was estimated during the conditioning of the Operating Model for South African sardine (de Moor 2016a, de Moor 2018), the estimated πœŽπœŽπ‘…π‘…π‘†π‘† was close to the lower bound of the prior distribution for the west component, where (πœŽπœŽπ‘…π‘…π‘†π‘†)2~π‘ˆπ‘ˆ(0.16,10). Mixing of the MCMC chain for πœŽπœŽπ‘…π‘…π‘†π‘† has been slow and thus πœŽπœŽπ‘…π‘…π‘†π‘† has been fixed at a constant during MCMC simulations, and therefore also in projections of the population dynamics during the development of multiple OMPs. However, when the Operating Model was conditioned without any stock recruitment relationship and the Hockey-stick stock recruitment relationship subsequently estimated after conditioning (de Moor 2016b), the estimated πœŽπœŽπ‘…π‘…π‘†π‘† was much higher for both the south and west components.

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Department of Mathematics and Applied Mathematics, University of Cape Town