biological sustainable level (fished within)

In fisheries organizations, biological sustainable levels are usually defined according to MSY, which is the Maximum Sustainable Yield (or catch) that can be continuously taken from a stock under existing environmental conditions without affecting its reproductive potential. Two key levels are considered: to assess the sustainability of fishing on a given stock: FMSY which is the fishing mortality that is consistent with achieving MSY and BMSY that is the biomass that results from fishing at FMSY for a long time.