That matters because theory suggests that the maximum sustainable yield that can be cropped from a fishery comes when the biomass of a target species is about 50% of its original levels.

• 因为理论,所以那有关系当目标种的生物量是有关50%25的它最初的水平事时候,可能从一个渔场被收割的最大足可支撑的生产量来。