An updated production model fitting for redfish (Sebastes fasciatus and Sebastes mentella) in Units 1 and 2 / Murdoch McAllister and Daniel E. Duplisea.: Fs70-5/2016-084E-PDF

"A state-space Bayesian surplus production model (BSP) was fitted separately to Unit 1&2 Sebastes fasciatus and Sebastes mentella. This fitting used the same assumption and inputs as previous fittings in 2011 and 2012 but catch and survey data were updated until 2015. Additionally, it was possible to extend one survey data series back to 1984 which before only went back to 1990. Fits are very similar to previous fits with similar Bmsy and MSY estimates and both stocks are shown to be heavily depleted. Currently, S. mentella is estimated to be at about 32 kt and 14% of its limit reference point (40% Bmsy). S. fasciatus is estimated to be at about 43 kt and 28% of its limit reference point. BSP considers only adult/recruited biomass and therefore the present fitting cannot incorporate the abundance of the very strong cohorts of 2011 and 2012 as they have not yet recruited to adult biomass. For this reason, we have not tried to project this model. The utility of the present approach is primarily to show the level of decline experienced by these two stocks in relation to stock biomass limit reference points that are production based"--Abstract, p. iii.

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