Stock synthesis (SS3) model runs conducted for north Atlantic shortfin mako shark

Stock Synthesis model runs were conducted for the North Atlantic shortfin mako shark based on the available catch, CPUE, length composition, and life history data compiled by the Shark Working Group. A sex-specific model was implemented in order to allow for observed differences in growth between sexes. Beverton-Holt stock-recruitment was assumed. The steepness of the stock recruitment relationship and natural mortality at age were fixed at independently estimated values. A two-stage data weighting approach was implemented. Ending year (2015) stock status relative to maximum sustainable yield (MSY) reference points obtained from the final SS3 model run following the two stage data weighting approach indicated that the fishing mortality rate in 2015 was above the fishing mortality rate at maximum sustainable yield (F_2015/F_MSY = 3.5) and that F_2015/F_MSY first exceeded 1.0 in 1985. The final SS3 model run indicated that spawning stock size in 2015, calculated here as spawning stock fecundity (SSF, 1,000s), was above the spawning stock size at MSY (SSF_2015/SSF_MSY = 1.217).