A bad year for recruitment in a fished-down stock means losing both the new cohort and most of the spawners, because the latter are caught before they can spawn again. By contrast, a stock with lower mortality for large individuals at least maintains an adequate reserve of large individuals available as spawners next year.
这一政策之所以令人怀疑还因为产卵的成活率每年都大不相同。鱼类储备补充匮乏的年份意味着渔场会失去新的鱼群和大部分产卵鱼，因为产卵鱼在得以再次产卵之前就已被捕捞。与此相反，大鱼个体死亡率较低的鱼群至少可以保存足够数量的大鱼，为来年产卵作好准备。