MSY (Maximum Sustainable Yield)

Maximum sustainable yield is the largest catch a stock can sustain indefinitely under constant conditions, derived from a surplus production model where growth peaks at roughly half the unfished biomass. UNCLOS Articles 61 and 119 require coastal and high-seas states to maintain or restore stocks at levels that can produce MSY, qualified by environmental and economic factors. Modern management treats MSY as a limit rather than a target, pairing it with reference points like B-MSY and F-MSY to avoid overfishing the spawning stock.