Input values to SPR models Estimated from Stock assessment models Fixed parameters Assumptions. Estimated in stock assessment models. Fishery selectivity curves for retained and discarded crab by sex and shell condition Trawl bycatch selectivity and F Growth transition matrix by sex
Spawning biomass per recruit model results for snow crab. Mating ratio = 1.7(sex ratio at F=0). Total effective spawning biomass is female effective spawning biomass plus effective male spawning biomass (no mating ratio).
Figure 3. Mating ratio = 3.0. Primiparous and mulitparous separate. Total effective spawning biomass is female effective spawning biomass plus old shell male spawning biomass(no Mating ratio).
Red King Crab mating ratio 1:2(sex ratio at F=0), discard mortality 50%, all females together in effective spawning biomass calculation, nonmolting males
Red King Crab mating ratio 1:3, discard mortality 50%, MR applied separately to primiparous and multiparous in effective spawning biomass calculation, nonmolting males(each male can potentially mate with 6 females)
Red King crab Mating ratio 1:3, 50% discard mortality,prim and mult separate, all males (2005 F for red king crab = 0.31, max target F=0.76)