Initial exploration of oscillations in the projections of exploitable biomass

Abstract

The Reference Case model RS02 (Ricker stock-recruitment relationship with central year of catch shift at 1958) is projected forwards 100 years under the rules of OMP2014 (TAC cap of 150 00t with no change in b) for 100 simulations and sine curves are fit to the resulting trajectories. For 70% of the simulations, a sine curve could readily be fit and the median period of the oscillations was found to be 21 with a 90% probability interval of (18, 30).